KR20000029277A - Liquid crystal device, its preparation and examination method - Google Patents

Abstract

PURPOSE: A methods for manufacturing and evaluating LCD is provided to prevent an after image and remaining due to optical hysteresis, and to improve the display quality such as respondency, contrast by decreasing the optical hysteresis with controlling an increase of driving voltage. CONSTITUTION: A liquid-high molecular complex layer(1006) including a liquid and a high molecular, is formed between a pair of substrates(1001). A dispersion condition of the liquid-high molecular complex layer(1006) is changed and displayed by applying a field to the liquid-high molecular complex layer(1006). The liquid-high molecular complex layer(1006) is formed with a plurality of regions having a different applied voltage-light transmissivity in a first pixel.

Description

Liquid crystal display device, manufacturing method thereof and evaluation method {LIQUID CRYSTAL DEVICE, ITS PREPARATION AND EXAMINATION METHOD}

The present invention relates to a liquid crystal display device in a light scattering mode using a liquid crystal-polymer composite system, a manufacturing method thereof, and an evaluation method thereof.

LCD display devices are thin, compact, low voltage drive and low power consumption, and are widely used in displays such as wristwatches and electronic calculators, navigation systems, notebook PCs, LCD monitors, data projectors, and projection LCD TVs. It is becoming. TN (Twisted Nematic) type liquid crystal display devices have been widely used in the past among the display modes of such liquid crystal display devices. This TN type liquid crystal display device has a structure in which a liquid crystal layer having a structure in which the arrangement of liquid crystal molecules is twisted 90 degrees up and down between two opposed substrates is provided, and two polarizing plates are provided on the outside of both substrates. In addition, STN (Super Twisted Nematic) type liquid crystal display elements having improved time division driving characteristics in TN type liquid crystal display elements are also used in Japanese word processors and the like. Moreover, recently, information devices using ferroelectric liquid crystals which change the arrangement state of liquid crystal molecules by spontaneous polarization of liquid crystal molecules and use the electro-optic effect according to the change of the arrangement state for display have been put to practical use. However, since these liquid crystal display elements require at least one polarizing plate, there is a problem that the display is dark, the alignment process is required, and the cell thickness control is not easy.

On the other hand, the liquid crystal display element of the light-scattering mode using the liquid crystal-polymer composite system is proposed with respect to the above various display systems. The liquid crystal display device does not require a polarizing plate and controls the arrangement of liquid crystal molecules by an electric field to produce a cloudy or transparent state. In this method, a composite layer composed of a liquid crystal and a transparent polymer is sandwiched between a pair of substrates, and when the liquid crystal molecules have positive dielectric anisotropy, the refractive index of the polymer and the ordinary refractive index of the liquid crystal molecules are set to match. When no electric field is applied to the composite layer having such a configuration, each liquid crystal molecule is arranged so that the long axis of the liquid crystal molecules is parallel to the electric field direction. As a result, the phase refractive index of the liquid crystal molecules and the refractive index of the transparent polymer coincide with each other, so that light scattering is eliminated at the interface (liquid crystal / polymer interface), resulting in a transparent state. On the other hand, when no electric field is applied, the liquid crystal molecules are oriented in various directions, and thus the refractive index does not coincide at the interface with the transparent polymer, so that light scattering occurs, resulting in a cloudy and opaque state. As described above, the liquid crystal display device displayed by changing the light scattering state of the composite layer by applying an electric field to the composite layer has been actively researched and developed in recent years for reasons such as simple device structure and high light utilization efficiency. have.

Examples of the liquid crystal display device of the display method include microencapsulated nematic liquid crystals, such as NCAP (Nematic Curvilinear Aligned Phase), with polyvinyl alcohol or the like (powder and industry, VOL. 22, NO. 8 (1990)). . In addition, some liquid crystals, called PDLCs (Polymer Dispersed Liquid Crystals), are dispersed in a matrix of polymer (flat panel display '91, Nikkei BP Co., p.219). In addition, in addition to these, there is a structure in which a polymer called PNLC (Polymer Network Liquid Crystal) has a structure in which a three-dimensional mesh is developed in a continuous phase of liquid crystals (Korea Institute of Electrical and Information Technology Research, EID89-89, p.1). ). The composite layer which consists of these liquid crystals and a transparent polymer is collectively called a polymer dispersion type liquid crystal.

In addition, the composite layer which consists of these liquid crystals and a polymer is formed by the manufacturing method mentioned below. That is, a mixed composition obtained by dissolving an uncured resin monomer such as an acrylic or epoxy ultraviolet curable resin and a liquid crystal material is injected between two substrates to irradiate the mixed composition with ultraviolet rays. As a result, the uncured resin monomer polymerizes, and the liquid crystal material and the polymer phase separate. As a result, a structure in which a liquid crystal is dispersed in a polymer matrix formed of a polymer or a structure in which a polymer is developed into a mesh shape in a liquid crystal is obtained (flat panel display '91, Nikkei BP Co., p. 219, Telecommunications Information and Communication). Korean Institute of Technology Research Report, EID89-89, p.1.

Hereinafter, as disclosed in Japanese Laid-Open Patent Publication No. 60-252687 and the like, the PDLC type liquid crystal display device will be specifically described as an example. This PDLC is a display device whose main component is a composite layer composed of liquid crystals dispersed in a polymer having the same refractive index as a nematic liquid crystal. Contrast is achieved by switching the light transmittance of the composite layer to light and dark by applying an electric field. Is the way to get.

The liquid crystal display of the PDLC type will be described in detail as follows. 1 is a schematic cross-sectional view for explaining the principle of display of this display system. As shown in the figure, the liquid crystal display device has a structure in which a composite layer 1006, which is a main component, is enclosed between a pair of substrates 1001 ... having a transparent electrode 1002 .... The composite layer 1006 is composed of a polymer matrix phase 1005 and a liquid crystal droplet 1004 made of a polymer, and the liquid crystal droplet 1004 becomes micro droplets around several micrometers in diameter and dispersed in the polymer matrix phase 1005. Maintained. The polymer matrix phase 1005 is made of a polymer that gives an index of refraction almost equal to the normal refractive index (refractive index in the major axis direction) of the liquid crystal droplet 1004.

In such a polymer dispersed liquid crystal display device, when a voltage is applied to a pair of transparent electrodes 1002.. (FIG. 1A), the long axis (molecular axis) of the liquid crystal molecules is random in each liquid crystal region 1004. Heading in the direction. Therefore, the refractive index of the liquid crystal droplet 1004 with respect to the incident light 1010 and the refractive index of the polymer matrix phase 1005 surrounding the liquid crystal droplet 1004 are different, and the incident light 1010 incident on the device is the polymer matrix phase 1005. Is scattered at the interface between the liquid crystal droplet 1004 and becomes scattered light 1011. As a result, a scattering state is obtained and becomes dark display.

On the other hand, when a voltage greater than or equal to the threshold is applied to the pair of transparent electrodes 1002..., The long axis of the liquid crystal molecules in the liquid crystal droplet 1004 is oriented in the electric field direction, and as a result, the long axis of the liquid crystal molecules in the liquid crystal droplets 1004. It is parallel to this incident light 1010 (FIG. 1B). Accordingly, the refractive index of the liquid crystal droplets 1004 and the refractive index of the polymer matrix phase 1005 become substantially the same, and the incident light 1010 is transmitted without being scattered at the interface between the polymer matrix phase 1005 and the liquid crystal droplets 1004. 1012). As a result, in a voltage application state, a transmission state is obtained, resulting in bright display.

In the polymer dispersed liquid crystal display device operating according to the above-described display principle, since light transmission can be easily controlled by voltage ON / OFF, a polarizing plate for obtaining linearly polarized light is required as in the conventional TN liquid crystal display device. Do not Therefore, the device structure is simplified and at the same time there is no light loss due to the polarizing plate, so that bright display is possible and the viewing angle is also expanded. On the other hand, the polymer dispersed liquid crystal display device is a device having a high driving voltage. Therefore, under the request of reducing the driving voltage, the? Value is usually set to 2 or less in the conventional PDLC (see 1990 SID international Symposium Digest of Technical Papers p. 227 to 230). Here, the value of γ is defined as V ₉₀ / V ₁₀ when the driving voltage at which the maximum transmittance is 90% is set to V ₉₀ and the driving voltage at which the maximum transmittance is 10% is set to V ₁₀ . will be.

By the way, in the light-scattering mode liquid crystal display device using the liquid crystal-polymer composite system represented by PDLC, hysteresis exists inherently due to its structure. In fact, when a liquid crystal display device of the PDLC type is manufactured and its electro-optical characteristics (change in light transmittance with respect to an applied voltage) are measured, hysteresis occurs as shown in FIG. The figure is a graph showing the applied voltage-light transmittance characteristics in the liquid crystal display using PDLC. As can be understood from this figure, the applied voltage-transmittance characteristic is the same in the case of increasing the applied voltage (raising voltage process, scattering state → transmission state) and decreasing (high voltage process, transmitting state → scattering state). Not shown, hysteresis (optical hysteresis and voltage hysteresis) is shown in the applied voltage-transmittance curve (Liquid Crystal Discussion Lecture Preliminary Proceedings, p.312 (1991), SID'93 Digest, p.575 (1992), etc.). This hysteresis shows the characteristic that the applied voltage gradually increases and becomes the largest in the region where the applied voltage is relatively small. Therefore, the size of the optical hysteresis is, for example, about 2, 3% to + several%. Due to changing).

The expression of hysteresis is believed to be due to the reasons mentioned below. That is, in the liquid crystal display device of this display mode, its electro-optical characteristics greatly affect the interaction between the liquid crystal and the polymer. This interaction is generally smaller than the interaction between the alignment film and the liquid crystal in a conventional TN type liquid crystal display device. For this reason, hysteresis occurs in the liquid crystal display of the display mode.

The mechanism of expression of hysteresis is roughly as described above, but it is considered to be as follows from the viewpoint of molecular dynamics, paying attention to the behavior of liquid crystal molecules and their molecular groups. 3 is a graph showing an example of optical hysteresis characteristics of the PDLC type liquid crystal display device. It is considered that the optical hysteresis characteristics in the polymer dispersed liquid crystal display device are related to a regulating force (hereinafter referred to simply as an interfacial regulating force) acting at the liquid crystal / polymer matrix (comprising polymer) interface. This interfacial regulating force acts as a force for transferring the liquid crystal molecules arranged in the electric field direction to the random arrangement state in the initial alignment state when the electric field is OFF. However, when this force is weak, the transition of liquid crystal molecules, particularly near the liquid crystal / polymer matrix phase interface, is unlikely to occur (difficult to be transferred). Therefore, a state where the transmittance of the liquid crystal display element is large is maintained. As a result, the applied voltage-light transmittance characteristic is large in optical hysteresis as shown in the characteristic curve VTb of FIG.

On the other hand, when the interfacial regulating force is strong, the transition of liquid crystal molecules occurs easily near the interface, the change in transmittance is smooth in the liquid crystal display device, and as shown in the characteristic curve VTa of FIG. -Optical hysteresis is small in light transmittance characteristics. Therefore, according to the above mechanism, it is understood that in order to reduce the optical hysteresis, the interfacial control force may be strengthened. In addition to optical hysteresis, it has been pointed out that the above-described interfacial regulating force also affects the response speed. However, the current situation is that there is no suitable means for controlling the interfacial control force. In addition, since the interfacial regulating force also relates to the response speed, the control is also involved in improving the response speed. For this reason, conventionally, a liquid crystal display device in which an interface control force is controlled to reduce optical hysteresis is desired.

On the other hand, voltage hysteresis and optical hysteresis are respectively defined as follows (see Fig. 4). First, the magnitude of voltage hysteresis is defined as the ratio of the voltage difference between the step-up process and the step-down process (referred to as voltage hysteresis width DELTA V) at a predetermined transmittance to the voltage of the step-down process. That is, the magnitude H _v (T) [%] of the voltage hysteresis is expressed as a function of the transmittance T, and is defined by the following equation (1).

H _v (T) [%] = {(V _up (T)-V _down (T)) / V _down (T)} x 100... (l)

Here, V _up (T) in the formula represents a voltage at the time of the voltage rise at the transmittance T, and V _down (T) represents the voltage at the voltage drop at the transmittance T. In the light scattering mode using the conventional liquid crystal-polymer composite system, this voltage hysteresis exhibited almost the same voltage hysteresis width even when the slope (stiffness) of the applied voltage-light transmittance curve was changed. In addition, the value when the voltage hysteresis value H _v (T) as an objective measure (ie, representative value) of a particular liquid crystal display element is maximized is selected.

Next, the magnitude of the optical hysteresis is defined as the ratio of the maximum luminance of the white level of the transmittance difference (referred to as optical hysteresis width DELTA T) between the step-up process and the step-down process at the same applied voltage. That is, the magnitude H _t (V) [%] of the optical hysteresis is expressed as a function of the applied voltage V and is defined by the following equation (2).

H _t (V) [%] = {(T _down (V) -T _up (V)) / (T _max -T0)} x 100... (2)

Here, T _up (V) in the formula represents the transmittance when the voltage rises at the applied voltage V, T _down (V) represents the transmittance when the voltage falls at the applied voltage V, T _max represents the maximum transmittance, T0 represents the transmittance without application. Unlike the voltage hysteresis, the optical hysteresis H _t (V) is a concept introduced to handle hysteresis based on the transmittance of the liquid crystal display device. The value at which the optical hysteresis value H _t (V) as the representative value of the liquid crystal display element is maximized is selected.

In summary, since the liquid crystal display device in the light scattering mode using the conventional liquid crystal-polymer composite system exhibits an optical hysteresis phenomenon, the display quality due to deterioration of an afterimage or gradation display due to the optical hysteresis, generation of display stains, etc. There is a problem that causes a significant decrease. For this reason, the liquid crystal display element of the said light-scattering mode excellent in display performance is promising.

FIG. 1 is a schematic cross-sectional view for explaining the driving principle of a liquid crystal display device using a conventional polymer dispersed liquid crystal. FIG. 1A shows a case where a composite layer is scattered in the liquid crystal display device, and FIG. 1B shows the liquid crystal display. The case where a composite layer is a permeable state in an element is shown.

2 is a graph showing applied voltage-light transmittance characteristics in the liquid crystal display device.

3 is a graph showing the hysteresis characteristics of each of the present invention and the conventional example.

4 is a graph for explaining optical hysteresis and voltage hysteresis.

FIG. 5 is an explanatory view for explaining the principle of display of the liquid crystal display device according to the first invention group, FIG. 5A is a perspective view showing a liquid crystal and polymer composite layer in the liquid crystal display device, and FIG. 5B is a cross section showing a display state. It is a schematic diagram.

FIG. 6 is a graph for explaining applied voltage and light transmittance characteristics in the liquid crystal display, and FIG. 6A is a graph showing applied voltage and light transmittance characteristics of the first region A, the second region B, and the entire display element. 6B is a graph comparing optical hysteresis when the steepness of applied voltage and light transmittance characteristics is different.

Fig. 7 is a simplified cross-sectional view of a liquid crystal display device according to Embodiment A-1 of Group A of the present invention.

Fig. 8 is an enlarged view showing the shape of the liquid crystal droplets in the vicinity of the insulating film and the shape of the liquid crystal droplets in the central portion of the polymer dispersed liquid crystal layer.

9 is a graph showing the correlation between optical hysteresis and applied voltage-light transmittance characteristics.

Fig. 10 is a conceptual diagram showing the relationship between γ values and optical hysteresis, Fig. 10A shows the applied voltage-light transmittance characteristics when the particle size is large, and Fig. 10B shows the applied voltage-light transmittance characteristics when the particle size is small, Fig. 10C shows the characteristics when the applied voltage-light transmittance characteristics shown in Figs. 10A and 10B are overlapped.

Fig. 11 is a graph showing the relationship between γ _10-90 and optical hysteresis.

FIG. 12 is a simplified cross-sectional view of a liquid crystal display device according to Embodiment A-2 of Group A of the present invention. FIG.

FIG. 13 is a simplified cross-sectional view of another liquid crystal display device according to Embodiment A-2.

14 is a graph showing the correlation between γ _10-90 and γ _10-50 .

15 is a graph showing the relationship between γ _10-50 and optical hysteresis.

16 is a schematic sectional view showing an outline of a liquid crystal display device according to Embodiment B of Group B of the present invention.

Fig. 17 is a schematic cross-sectional view schematically showing the main part of the liquid crystal display element, Fig. 17A shows the shape of the liquid crystal droplets in the vicinity of the insulating film, and Fig. 17B shows the shape of the liquid crystal droplets present in the central portion of the liquid crystal / polymer composite layer.

18 is a flowchart for explaining a manufacturing process of the liquid crystal display device.

19 is a graph showing the relationship between optical hysteresis and (γ _LC -γ _p ) in the liquid crystal display device.

20 is a graph showing a relationship between a response speed and (γ _LC -γ _p ) in the liquid crystal display device.

21 is a cross-sectional view showing the configuration of a liquid crystal display device according to Embodiment C of the present invention group C. FIG.

Fig. 22 is a graph showing the hysteresis characteristics of each of the present invention and the conventional example.

FIG. 23 is a cross-sectional schematic diagram showing an alignment state of liquid crystal molecules in the liquid crystal droplet 313. FIG. 23A shows a state in which liquid crystal molecules are oriented almost parallel to the substrate surface, and FIG. 23B shows a liquid crystal molecule substrate surface. The state orientated in the substantially vertical direction with respect to is shown.

24 is an explanatory diagram for explaining a display principle of a liquid crystal display device according to the second invention group, FIG. 24A is a perspective view showing a liquid crystal and polymer composite layer in the liquid crystal display device, and FIG. 24B is a cross section showing a display state. It is a schematic diagram.

FIG. 25 is a graph for explaining applied voltage and light transmittance characteristics of the liquid crystal display, and FIG. 25A is a graph showing applied voltage and light transmittance characteristics of the first region A, the second region B, and the entire display element. 25B is a graph comparing optical hysteresis when steepness of applied voltage and light transmittance characteristics is different.

FIG. 26 is a cross-sectional view showing the configuration of a liquid crystal display device according to Embodiment D-1 of the group D of the present invention. FIG.

27 is a cross sectional view showing a configuration of a liquid crystal display device according to Embodiment D-2 of the present invention group D. FIG.

FIG. 28 is a cross-sectional view for illustrating a manufacturing step of the liquid crystal display device according to Example D-1 of the group D of the present invention. FIG.

29 is a flowchart for explaining a method for manufacturing the liquid crystal display device.

30 is a graph showing applied voltage-light transmittance characteristics in the liquid crystal display device.

31 is a graph showing the applied voltage-light transmittance characteristics of the liquid crystal display device according to Comparative Example D. FIG.

Fig. 32 is a graph showing the relationship between the average particle diameter or average mesh size R of the liquid crystal droplets and the threshold voltage.

Fig. 33 is a graph showing the relationship between the average particle diameter or average mesh size R of the liquid crystal droplets and the scattering gain.

34 is a cross-sectional view for illustrating a manufacturing step of the liquid crystal display device according to Example D-2 of the group D of the present invention.

35 is a schematic sectional view of one pixel of the liquid crystal display device according to Embodiment E of the present invention group E. FIG.

36 is a schematic diagram showing the manufacturing method of the liquid crystal display device according to Example E-1 of the group E of the present invention.

37 is a flowchart for explaining a method for manufacturing the liquid crystal display device.

38 is a flowchart for explaining a step of forming an ultraviolet transmittance adjustment layer.

Fig. 39 is a graph showing applied voltage and light transmittance characteristics of the liquid crystal display device according to Example E-1.

40 is a cross-sectional view of one pixel of the polymer dispersed liquid crystal display device according to Comparative Example E. FIG.

Fig. 41 is a graph showing applied voltage-light transmittance characteristics of the polymer dispersed liquid crystal display device.

FIG. 42 is a view showing a principle of reducing optical hysteresis of the liquid crystal display device according to Example E-1. FIG.

Fig. 43 is a graph showing the relationship between the average particle diameter of liquid crystal droplets and the threshold voltage.

Fig. 44 is a graph showing the relationship between the average particle diameter of the liquid crystal field and the scattering gain G;

45 is a graph showing the relationship between the value of γ and optical hysteresis.

Fig. 46 is a graph showing the relationship between the applied voltage and the transmittance, Fig. 46A shows the case of Vb ₉₀ / Va ₉₀ = 0.4, and Fig. 46B shows the case of Vb ₉₀ / Va ₉₀ = 0.7.

Fig. 47 is a schematic sectional view showing an outline of a liquid crystal display device according to Embodiment F of the present invention group F. Figs.

48 is a schematic sectional view showing a main portion of the liquid crystal display element.

Fig. 49 is a graph showing the apparent applied voltage-light transmittance characteristics in the liquid crystal display device.

50 is a flowchart for explaining a manufacturing step of the liquid crystal display device.

51 is a plan view showing a pattern shape of a light shielding portion in an optical mask,

FIG. 51A shows a case where the light shield is a stripe shape, and FIG. 51B shows a case where the light shield is a lattice shape.

Fig. 52 is a schematic sectional view showing a main portion of a liquid crystal display device according to the embodiment F;

Fig. 53 is a flowchart for explaining the manufacturing steps of the other liquid crystal display device.

54 is a graph showing the relationship between the ratio of the distance between electrodes between the counter electrode and the pixel electrode and the optical hysteresis.

Fig. 55 is a graph showing the relationship between the ratio of driving voltages and optical hysteresis.

Fig. 56 is a graph showing the relationship between the ratio of the distance between electrodes between the counter electrode and the pixel electrode and the optical hysteresis.

Fig. 57 is a graph showing the relationship between the ratio of driving voltages and optical hysteresis.

Fig. 58 is a simplified perspective view of a liquid crystal display device according to Embodiment G of the group G of the present invention.

59 is a simplified cross-sectional view of the liquid crystal display device.

60 is an enlarged view of the driving electrode and the counter electrode.

Fig. 61 shows the alignment of the liquid crystalline polymer with the liquid crystal.

FIG. 62 is a perspective view for explaining the operation of the liquid crystal display device, FIG. 62A shows a case where a voltage is not applied, and FIG. 62B shows a case where a voltage is applied.

FIG. 63 is a plan view showing a modification of the drive electrode and the counter electrode, FIG. 63A shows a case where the distance between electrodes differs, and FIG. 63B shows a case with a bent portion.

Summary of the Invention

According to the present invention of group 1, an optical hysteresis is suppressed while suppressing an increase in driving voltage, thereby preventing afterimages and seizure caused by the optical hysteresis, and having excellent display quality such as responsiveness and contrast, and the like. It is an object to provide a manufacturing method and an evaluation method thereof.

In order to solve the above problems, in the liquid crystal display device of the present invention, a liquid crystal / polymer composite layer including a liquid crystal and a polymer is provided between a pair of substrates, and a liquid crystal / polymer composite is applied by applying an electric field to the liquid crystal / polymer composite layer. A liquid crystal display device for changing and displaying a light scattering state of a layer, wherein the liquid crystal / polymer composite layer is composed of a plurality of regions having different applied voltage and light transmittance characteristics in one pixel.

According to the above structure, the steepness of the voltage region with large hysteresis in the applied voltage-transmittance curve is selectively lowered by forming a plurality of regions having different electro-optical characteristics (applied voltage-transmittance characteristic) in one pixel. Appearance hysteresis can be reduced. As a result, afterimage and seizure due to optical hysteresis are prevented. Here, in the following, it shall refer to the 1st invention group and the 2nd invention group roughly for every closely related invention. The first invention group is characterized in that different regions of the applied voltage-light transmittance characteristic have a plurality formed in a vertical direction. The second invention group is characterized by having a configuration in which a plurality of regions having different applied voltage-light transmittance characteristics are arranged in the in-plane direction. Further, the first invention group is classified into invention groups A to C, and the second invention group is classified into invention groups D to G. In the following, the contents of each invention group will be described in turn.

[1st invention group]

In the liquid crystal display device of the first invention group, a liquid crystal / polymer composite layer containing a liquid crystal and a polymer is provided between a pair of substrates, and an electric field is applied to the liquid crystal / polymer composite layer to change the light scattering state of the liquid crystal / polymer composite layer. A liquid crystal display device, wherein the liquid crystal-polymer composite layer is composed of a plurality of regions having different applied voltage and light transmittance characteristics within one pixel, and the plurality of regions having different applied voltage and light transmittance characteristics It is characterized by being arranged in the vertical direction with respect to.

As a result, the individual regions are different in characteristics, but since the respective regions are stacked vertically with respect to the plane, these characteristics are superimposed on the characteristics of the entire display element. That is, as the applied voltage-light transmittance characteristics of the entire display element, the steepness of the voltage region where hysteresis is maximized is selectively lowered, so that smooth steepness can be compared with the applied voltage-light transmittance characteristics in the conventional polymer dispersed liquid crystal panel. We can do with characteristic equipped. Therefore, it is possible to provide a liquid crystal display device having excellent display quality, such that optical hysteresis can be reduced, and generation of afterimages and sticking caused by the optical hysteresis can be prevented. Moreover, the value of the applied voltage when maximizing the light transmittance does not exceed the value of the applied voltage when the light transmittance becomes maximum in the applied voltage-light transmittance characteristics of each region. Therefore, it becomes possible to suppress power consumption.

The liquid crystal / polymer composite layer has liquid crystals dispersed in a polymer matrix containing polymers, and thus the liquid crystal droplets may have different average particle diameters corresponding to a plurality of regions having different applied voltage and light transmittance characteristics. The liquid crystal-polymer composite layer is formed by dispersing liquid crystal in a mesh of a three-dimensional mesh-like matrix in which a polymer is impregnated, and corresponding to a plurality of regions having different applied voltage-transmittance characteristics of the three-dimensional mesh-like matrix. The average mesh size can be made different. With each of the above configurations, it is possible to form a plurality of regions having different applied voltage and light transmittance characteristics in the thickness direction (perpendicular to the substrate surface) of the element in one pixel. Therefore, apparent hysteresis (optical hysteresis) can be reduced, so that display quality can be improved.

The liquid crystal-polymer composite layer may have a configuration in which the alignment states of liquid crystal molecules in the vicinity of the above substrates are different from each other in correspondence with a plurality of regions having different applied voltage-light transmittance characteristics. As a result, the applied voltage-transmittance characteristic in the vicinity of both substrates and the applied voltage-transmittance characteristic in the central portion of the liquid crystal-polymer composite layer may be different from each other. Therefore, apparent hysteresis (optical hysteresis) can be reduced, and display quality can be improved.

Furthermore, it is preferable that the liquid crystal molecules in the vicinity of the one substrate are oriented in the vertical direction with respect to the substrate, and the liquid crystal molecules in the vicinity of the other substrate are aligned in the parallel direction with respect to the substrate. In this way, when the liquid crystal molecules near one substrate are vertically aligned and the liquid crystal molecules near the other substrate are aligned in parallel, the steepness of the applied voltage and light transmittance characteristics can be made smoothest. The occurrence can be minimized.

Invention Group A

As a result of earnestly researching to solve the above problems, the present inventors have found that the value of γ is closely related to the optical hysteresis, so that the large value of γ lowers the optical hysteresis. On the other hand, when the value of γ becomes large, the driving voltage increases, which causes trouble in actual driving. Therefore, in order to achieve both the reduction of the optical hysteresis and the driving voltage, there is an optimum range in the gamma value, and the present invention group A has been completed by realizing a liquid crystal display device having the gamma value set in such a range. Specifically, it is as follows.

In order to solve the above problems, in the liquid crystal display device of the present invention, a liquid crystal and a polymer composite layer including a liquid crystal and a polymer are provided between a pair of substrates each having an electrode, and an electric field is applied to the liquid crystal and polymer composite layer. A liquid crystal display device for changing and displaying a light scattering state of a liquid crystal / polymer composite layer, and when the driving voltage at which the maximum transmittance is 90% is V ₉₀ and the driving voltage at 10% is V ₁₀ , the ratio V ₉₀ / V ₁₀ It is characterized by two or more and 3.1 or less.

If the liquid crystal / polymer composite layer is not composed of a region having a single applied voltage-transmittance characteristic, but is composed of a plurality of regions having different applied voltage-transmittance characteristics, the optical hysteresis of each region is overlapped and the display element The overall optical hysteresis is reduced. Here, the ratio V ₉₀ / V In regard to _l0, different plurality of the applied voltage-ratio V ₉₀ / V _l0 when superimposed the light transmission characteristics becomes large. Therefore, when the ratio V ₉₀ / V ₁₀ is increased, the optical hysteresis can be reduced. However, if too large, an increase in the driving voltage will interfere with the actual driving. Therefore, in order to reduce both the optical hysteresis and the driving voltage, there is an optimum range in the ratio V ₉₀ / V ₁₀ . According to experimental results of the present inventors, optical hysteresis can be reduced when the ratio V ₉₀ / V ₁₀ is 2 or more (see FIG. 11). On the other hand, when the ratio V ₉₀ / V ₁₀ exceeds 3.1, driving becomes difficult.

Therefore, both the optical hysteresis and the driving voltage can be reduced by setting the ratio V ₉₀ / V ₁₀ to 2 or more and 3.1 or less.

On the other hand, in the conventional polymer dispersed liquid crystal display device, the γ value is usually 2 or less (see 1990 SID international Symposium Digest of Technical Papers p. 227 to 230). However, a polymer dispersed liquid crystal display device having a gamma value of 1.95 or more and 2.25 or less has been proposed (see Japanese Patent Application Laid-Open No. 11-14974). It aims at the improvement and does not aim at the reduction of optical hysteresis.

In order to solve the above problems, the liquid crystal display device of the present invention is provided with a liquid crystal and a polymer composite layer containing a liquid crystal and a polymer between a pair of substrates each having an electrode, and an electric field is applied to the liquid crystal and polymer composite layer. A liquid crystal display device for changing and displaying a light scattering state of a liquid crystal / polymer composite layer, and when a driving voltage of 50% of the maximum transmittance is V ₅₀ and a driving voltage of 10% is V ₁₀ , the ratio V ₅₀ / V _10. It is characterized by being 1.1 or more and 1.8 or less.

γ value is, in general, it is also possible to evaluate a ratio V ₅₀ / V ₁₀ in place of the ratio V ₉₀ / V ₁₀ to define the γ value in a non-V ₅₀ / V _10, but to be defined by the ratio V ₉₀ / V ₁₀ . In particular, in the case of the ratio V ₅₀ / V ₁₀ , the correlation with the optical hysteresis is stronger than the ratio V ₉₀ / V ₁₀ (see FIG. 14). Therefore, when the ratio V ₅₀ / V ₁₀ is used as the γ value, more accurate optical hysteresis can be controlled than when the ratio V ₉₀ / V ₁₀ is used. On the other hand, the optimum range of gamma values for both reduction of optical hysteresis and driving voltage is in the range of 1.1 or more and 1.8 or less when the ratio V ₅₀ / V ₁₀ is evaluated (see FIG. 15).

In addition, the liquid crystal / polymer composite layer has a structure in which liquid crystal molecules are dispersed and maintained in a polymer matrix composed of a polymer between the pair of substrates provided with an insulating film, and the liquid crystal / polymer composite layer is almost a spherical shape present therein. A liquid crystal of a dome-shaped liquid crystal and a dome-shaped liquid crystal present on each of the insulating films and expanding toward the inside of the liquid crystal-polymer composite layer, wherein the average particle diameter in the panel gap direction is smaller than that of the spherical liquid crystal. It has a kind, and when the drive voltage at which the maximum transmittance is 90% is set at V ₉₀ and the drive voltage at which 10% is set at V ₁₀ , the ratio V ₉₀ / V ₁₀ may be 2.0 or more and 3.1 or less. By the above configuration, the applied voltage-light transmittance characteristics in the almost spherical liquid crystal region and the applied voltage-light transmittance characteristics in the dome-shaped liquid crystal region are different. The applied voltage and light transmittance characteristics of the entire display element overlap the two applied voltage and light transmittance characteristics. Therefore, the hysteresis can be reduced by forming the liquid crystal area in the liquid crystal-polymer composite layer into two types of liquid crystals, which are almost spherical liquid crystals and dome-shaped liquid crystals as in the above-described configuration. On the other hand, the ratio V ₉₀ / V ₁₀ for reducing the optical hysteresis and the driving voltage may be set in the range of 2 or more and 3.1 or less as described above.

In addition, the liquid crystal and polymer composite layer has a structure in which a liquid crystal is dispersed and maintained in a polymer matrix composed of a polymer between the pair of substrates provided with an insulating film, and the liquid crystal and polymer composite layer is almost a spherical shape present therein. A liquid crystal of a dome-shaped liquid crystal and a dome-shaped liquid crystal present on each of the insulating films and expanding toward the inside of the liquid crystal-polymer composite layer, wherein the average particle diameter in the panel gap direction is smaller than that of the spherical liquid crystal. and it has less type of liquid crystal, when the driving voltage is the maximum transmittance is 50% of the driving voltage is ₅₀ V, 10 V% to _l0, ratio V ₅₀ / V ₁₀ may be 1.1 or more and 1.8 or less configuration. As described above, the hysteresis can be reduced by forming the liquid crystal area in the liquid crystal-polymer composite layer into two types of liquid crystals, almost a liquid crystal of a spherical shape and a liquid crystal of a dome shape. On the other hand, as the γ value was evaluated as a ratio V ₅₀ / V _10.

In addition, the liquid crystal-polymer composite layer has a structure in which a plurality of polymer dispersed liquid crystal layers in which liquid crystals are dispersed and maintained in a polymer matrix including polymers, and a polymer dispersed liquid crystal layer having different applied voltage and light transmittance characteristics are laminated. It is possible to have a configuration in which the ratio V ₉₀ / V ₁₀ is 2 or more and 3.1 or less when the drive voltage which is 90% of the maximum transmittance is set to V ₉₀ and the drive voltage which is 10% of the maximum transmittance is set to V ₁₀ . . With this arrangement, the applied voltage-light transmittance characteristics of the entire display element are averaged of the applied voltage-light transmittance characteristics of each layer. Therefore, the optical hysteresis is superimposed and the optical hysteresis is reduced. On the other hand, as the γ value was evaluated as a ratio V ₉₀ / V _10.

Further, the average particle diameter of the liquid crystal droplets may be different for each of the plurality of polymer dispersed liquid crystal layers. As described above, by configuring the liquid crystal droplets to have different particle diameters for each of the plurality of polymer dispersed liquid crystal layers, the applied voltage and light transmittance characteristics of the plurality of polymer dispersed liquid crystal layers are different.

The combination of the layer thicknesses of the plurality of polymer dispersed liquid crystal layers and the average particle diameter of the liquid crystal droplets may be different for each polymer dispersed liquid crystal layer. As described above, even if the combination of the layer thickness of the plurality of polymer dispersed liquid crystal layers and the particle size of the liquid crystal droplets is different for each liquid crystal layer, the applied voltage-light transmittance characteristics can be different for each liquid crystal layer. On the other hand, in the present invention according to the combination of the layer thickness and the particle size of the liquid crystal droplets, it becomes possible to produce a difference in the applied voltage-light transmittance characteristics that are more delicate and dense as compared with the case where only the particle diameter of the liquid crystal droplets is changed.

In addition, it may have even more than the ₉₀ V 15V. The reason why V ₉₀ is regulated as described above is that, when V ₉₀ / V ₁₀ exceeds 3.1, V ₉₀ becomes 15 V or more and actual driving becomes difficult according to the experimental results of the present inventors and the like.

The active element may be formed on one of the pair of substrates. This configuration can realize an active drive type polymer dispersed liquid crystal display device capable of reducing both optical hysteresis and driving voltage.

The liquid crystal-polymer composite layer is a polymer dispersed liquid crystal layer in which liquid crystals are dispersed and maintained in a polymer matrix including polymers, and has a structure in which polymer dispersed liquid crystal layers having different applied voltage and light transmittance characteristics are stacked. It is possible to have a configuration in which the ratio V ₅₀ / V ₁₀ is 1.1 or more and 1.8 or less when the driving voltage at 50% of the maximum transmittance is V ₅₀ and the driving voltage at 10% of the maximum transmittance is V ₁₀ .

With this arrangement, the applied voltage-light transmittance characteristics of the entire display element are averaged of the applied voltage-light transmittance characteristics of each layer. Therefore, the optical hysteresis can be reduced. On the other hand, as the γ value was evaluated as a ratio V ₅₀ / V _10.

(Invention Group B)

MEANS TO SOLVE THE PROBLEM The present inventor earnestly examined about the liquid crystal display element and its manufacturing method so that the said conventional problem may be solved. As a result, by providing an insulating film on the substrate surface and controlling the critical surface tension of the insulating film, it was found that a liquid crystal display device having good optical hysteresis and responsiveness was obtained, thereby completing Group B of the present invention.

That is, in order to solve the above problems, in the liquid crystal display device of Group B of the present invention, a liquid crystal / polymer composite layer containing a liquid crystal and a polymer is provided between a pair of substrates, and the liquid crystal / polymer composite layer is applied within one pixel. -A liquid crystal display device composed of a plurality of regions having different light transmittance characteristics,

The liquid crystal and polymer composite layer is formed by providing a mixed composition containing a liquid crystal and a polymer material between the pair of substrates, and phase-separating the liquid crystal and the polymer material by polymerizing the polymer material.

The interfacial tension at the interface between the liquid crystal and the polymer material is constant, and the interfacial tension γ _ip (dyne / cm) between the insulating film and the polymer material provided inside the substrate is determined between the liquid crystal and the polymer material. _Has a relationship between the interfacial tension γ _LCp (dyne / cm) and the following formula (1),

The insulating film is made of at least two kinds of materials having different interfacial tension with the liquid crystal.

γ _LCp -γ _iP <0. (One)

According to the above configuration, the insulating film is made of at least two materials having mutually different interface tensions at the interface with the liquid crystal. Therefore, by appropriately changing the compounding ratio of these materials, it is possible to control the interfacial tension at the interface between the insulating film and the polymer material. As a result, it can control so that the relationship of said Formula (1) may hold regardless of the kind of liquid crystal. Therefore, it is possible to provide a liquid crystal display device having improved optical hysteresis using any liquid crystal.

The reason why the optical hysteresis can be reduced is based on the reason mentioned below. That is, when the polymer material is polymerized to form a polymer resin (polymer), the polymer material and the liquid crystal are phase separated. In the phase separation process, when γ _ip and γ _LCp have a relationship of the above formula (1), the liquid crystal adheres to the surface of the insulating film and wets it. Therefore, the liquid crystal area on the surface of the insulating film is formed in a dome shape. Under this environment, the liquid crystal inside the liquid crystal liquid is subject to strong alignment control force at the insulating film interface. In particular, the alignment control force by the insulating film also affects the liquid crystal present in the vicinity of the polymer resin. Therefore, when the electric field is turned from the ON state to the OFF state, the alignment control force of the insulating film serves to assist the interface control force at the liquid crystal / polymer resin interface. As a result, the transition of the liquid crystal molecules in the liquid crystal stack near the liquid crystal / polymer matrix interface occurs smoothly. Therefore, it is thought that optical hysteresis becomes small.

In addition, in this invention, the conditions mentioned below are presupposed. That is, it is assumed that the interfacial tension between the polymer material and the liquid crystal is constant in the phase separation process. Therefore, in the present invention, the liquid crystal and the polymer material are fixed in order to make this interfacial tension constant. Or both materials of a liquid crystal and a polymeric material are changed suitably so that interface tension may become constant.

The liquid crystal and polymer composite layer is formed by mixing a liquid crystal and a polymer material between the pair of substrates, and is formed by phase-separating the liquid crystal and the polymer material by polymerizing the polymer material. The interfacial tension γ _ip (dyne / cm) between the insulating film and the polymer material provided on the inner side of the substrate is constant at the interface between the liquid crystal and the polymer material, and the interfacial tension γ _LCp ( dyne / cm) and the following formula (2), and the insulating film may be composed of at least two kinds of materials having different interfacial tension between the liquid crystals.

-1 <gamma _LCp -gamma _ip <1. (2)

According to the above arrangement, since the insulating film is composed of at least two materials having mutually different interface tensions at the interface with the liquid crystal, the relation of the formula (2) is used regardless of the kind of liquid crystal. Can be controlled. Therefore, it is possible to provide a liquid crystal display device having improved response, regardless of the material of the liquid crystal.

The improvement in the responsiveness is due to the reasons mentioned below. In other words, when (γ _LCp -γ _ip ) exceeds -1 dyne / cm and is within a range of less than 0, the influence of the alignment control force by the insulating film is also appropriately applied to the liquid crystal present in the vicinity of the polymer resin. For this reason, when the electric field is turned from the ON state to the OFF state, the orientation regulation force of the insulating film serves to assist the interfacial regulation force of the polymer resin. As a result, the response speed is improved by smoothly transitioning the liquid crystal in the liquid crystal stack including the vicinity of the polymer resin.

On the other hand, when (γ _LCp -γ _iP ) is within a range of 0 or more and smaller than 1, the liquid crystal does not get wet on the insulating film surface. For this reason, the influence of the alignment control force on the insulating film does not directly affect the liquid crystal. However, since it acts indirectly through the polymer resin, the transition of the liquid crystal occurs smoothly when an electric field is applied, and the rise of the liquid crystal is faster, resulting in an improvement in response speed. It is planned.

The liquid crystal and polymer composite layer is formed by mixing a liquid crystal and a polymer material between the pair of substrates, and is formed by phase-separating the liquid crystal and the polymer material by polymerizing the polymer material. The interfacial tension γ _ip (dyne / cm) between the insulating film and the polymer material provided on the inner side of the substrate is constant at the interface with the interfacial layer, and the interfacial tension γ _Lcp ( dyne / cm) and the following formula (3), and the insulating film may be composed of at least two kinds of materials having different interfacial tension between the liquid crystals.

-1 <gamma _LCp -gamma _ip <0. (3)

According to the above structure, since the insulating film is composed of at least two materials having mutually different interfacial tensions at the interface with the liquid crystal, the relation of the formula (3) is established regardless of what kind of liquid crystal is used. Can be controlled. Therefore, the liquid crystal display element which improved both optical hysteresis and responsiveness irrespective of the material of a liquid crystal can be provided.

In addition, an insulating film is provided inside the substrate, and the critical surface tension γ _i (dyne / cm) of the insulating film is expressed by the following equation (4) between the surface tension γ _LC (dyne / cm) of the liquid crystal. The insulating film may be made of at least two materials having different critical surface tensions.

γ _LC -γ _i <0. (4)

In the above configuration, in the phase separation process between the polymer material and the liquid crystal, when γ _i and γ _LC have a relationship of the above formula (4), the liquid crystal adheres to the surface of the insulating film to form a domed liquid crystal on the surface of the insulating film. do.

In this configuration, the interfacial tension between the insulating film and the polymer material is replaced by the critical surface tension γ _i of the insulating film, and the interfacial tension between the liquid crystal and the polymer material is replaced by the surface tension γ _LC of the liquid crystal. The reason is mentioned below.

In general, the wettability can be considered from the balance of the interfacial tension of the contacting liquid, solid, and the like. That is, when two kinds of liquids (liquid crystal and polymer material) can contact the solid surface (equivalent to the insulating film), the interface tension at the interface between the solid (insulation film) and the polymer material, and the interface between the liquid crystal and the solid It is believed that the phenomenon of wetness occurs due to the balance of the triad of the interfacial tension in the interface and the interfacial tension in the interface between the polymer material and the liquid crystal. On the other hand, when the liquid crystal and the polymer material are considered to be fixed, the interfacial tension between the liquid crystal and the polymer material can be made constant. In this case, the wettability is determined by the interfacial tension between the solid (insulating film) and the polymer material and the interfacial tension between the liquid crystal and the solid. This considers the polymer material as a gas and changes the interfacial tension between the liquid crystal and the polymer material to the surface tension of the liquid crystal, and also changes the interfacial tension between the solid (insulating film) and the polymer material to the critical surface tension of the insulating film. Even if it holds. As long as the interfacial tension between the liquid crystal and the polymer material is considered to be constant, the wettability is determined by the interfacial tension between the insulating film and the polymer material and the interfacial tension between the liquid crystal and the solid. This is because no special meaning is found in the value of the interfacial tension itself. Therefore, the wettability can also be evaluated by the magnitude relationship between the surface tension of the liquid crystal and the critical surface tension of the insulating film. Therefore, it is possible to provide a liquid crystal display device having improved optical hysteresis using any liquid crystal.

In addition, an insulating film is provided inside the substrate, and the critical surface tension γ _i (dyne / cm) of the insulating film is expressed by the following equation (5) between the surface tension γ _LC (dyne / cm) of the liquid crystal. The insulating film may be made of at least two kinds of materials having different critical surface tensions.

-1 <γ _LC -γ _i <1. (5)

Thereby, even if it uses what kind of material irrespective of the kind of liquid crystal, it can control so that the relationship of said formula (5) may hold. Therefore, it is possible to provide a liquid crystal display device having improved response, regardless of the material of the liquid crystal.

Further, an insulating film is provided inside the substrate, and the critical surface tension γ _i (dyne / cm) of the insulating film is expressed by the following equation (6) between the surface tension γ _LC (dyne / cm) of the liquid crystal. The insulating film may be made of at least two kinds of materials having different critical surface tensions.

-1 <gamma _LC -gamma _i <0. (6)

Thereby, even if it uses what kind of material irrespective of the kind of liquid crystal, it can control so that the relationship of said formula (6) may hold. Therefore, the liquid crystal display element which improved both optical hysteresis and responsiveness irrespective of the material of a liquid crystal can be provided.

Furthermore, at least two kinds of materials constituting the insulating film include a first insulating film material having a critical surface tension smaller than the surface tension of the liquid crystal and a second insulating film material having a critical surface tension greater than the surface tension of the liquid crystal. good. Thereby, when the compounding ratio of the first insulating film material and the second insulating film material is changed, an insulating film corresponding to various liquid crystals can be easily formed.

Further, the first insulating film material may be a fluorine-based surfactant, and the second insulating film material may be a polyimide compound. Since the critical surface tension of the fluorine-based surfactant is extremely small, the addition of an extremely small amount can reduce the magnitude of the critical surface tension of the insulating film. On the other hand, for example, in the case where an insulating film is contained in the insulating film which is not fixed, the material starts to melt in the liquid crystal / polymer composite layer, resulting in a decrease in the voltage holding ratio of the liquid crystal / polymer composite layer. In this case, it is also contemplated that the fluorine-based surfactant starts to melt together depending on the above materials. However, since the amount of the fluorine-based surfactant added is inherently a small amount as described above, the amount of the fluorine-based surfactant that starts to melt in the liquid crystal-polymer composite layer is also extremely small. Therefore, even in the case where the fluorine-based surfactant starts to melt, adverse effects on the liquid crystal display element, such as a decrease in the voltage holding ratio, can be minimized.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of the liquid crystal display element of this invention is a manufacturing method of the liquid crystal display element in which the liquid crystal and the polymer composite layer containing a liquid crystal and a polymer were provided between a pair of board | substrates which have electrodes, respectively,

An insulating film forming step of forming an insulating film on an inner surface of the electrode, and providing a mixed composition including the liquid crystal and the polymer material between the pair of substrates;

A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material,

The insulating film forming step is an insulating film made of at least two kinds of materials having different interfacial tension between the liquid crystal, and has a relationship that the interfacial tension is constant at the interface between the liquid crystal and the polymer material. The interfacial tension γ _ip (dyne / cm) between the insulating film and the polymer material provided on the inner side of the surface is determined by the relationship between the interfacial tension γ _LCp (dyne / cm) between the liquid crystal and the polymer material. A satisfactory insulating film is formed.

γ _LCp -γ _ip <0. (One)

According to the above method, in the liquid crystal-polymer composite layer forming step, by polymerizing the polymer material, microparticles of the polymer material and the liquid crystal phase-separate to form a liquid crystal. This microscopically aggregates with other microscopically in the vicinity and gradually grows large with the liquid crystal of spherical shape. Here, the interfacial tension γ _ip between the insulating film and the polymer resin satisfies the relationship between the interfacial tension γ _LCp between the liquid crystal and the polymer resin and the formula (1). When the spherical liquid crystal liquid comes into contact with the insulating film, a wet phenomenon occurs, thereby forming a domed liquid crystal liquid. As a result, a liquid crystal display device having reduced optical hysteresis can be produced regardless of the type of liquid crystal.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of the liquid crystal display element of this invention is a manufacturing method of the liquid crystal display element in which the liquid crystal and the polymer composite layer containing a liquid crystal and a polymer were provided between a pair of board | substrates which have electrodes, respectively,

An insulating film forming step of forming an insulating film on an inner surface of the electrode;

Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates;

A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material,

The insulating film forming step is an insulating film made of at least two kinds of materials having different interfacial tension between the liquid crystal, and has a relationship that the interfacial tension is constant at the interface between the liquid crystal and the polymer material. The interfacial tension γ _ip (dyne / cm) between the insulating film and the polymer material provided on the inner side satisfies the relationship between the interfacial tension γ _LCp (dyne / cm) between the liquid crystal and the polymer material and the following formula (2). An insulating film is formed.

-1 <gamma _LCp -gamma _ip <1. (2)

According to the said method, the liquid crystal display element which improved responsiveness can be manufactured regardless of the kind of liquid crystal.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of a liquid crystal display element is a manufacturing method of the liquid crystal display element in which the liquid crystal and the polymer composite layer containing a liquid crystal and a polymer were provided between a pair of board | substrates which have electrodes, respectively,

An insulating film forming step of forming an insulating film on an inner surface of the electrode;

Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates;

A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material,

The insulating film forming step is an insulating film made of at least two kinds of materials having different interfacial tension between the liquid crystal, and has a relationship that the interfacial tension is constant at the interface between the liquid crystal and the polymer material. The interfacial tension γ _ip (dyne / cm) between the insulating film and the polymer material provided on the inner side satisfies the relationship between the interfacial tension γ _Lcp (dyne / cm) and the following formula (3) between the liquid crystal and the polymer material. An insulating film is formed.

-1 <gamma _LCp -gamma _ip <0. (3)

According to the above method, it is possible to manufacture a liquid crystal display device having improved both optical hysteresis and responsiveness.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of the liquid crystal display element of this invention is a manufacturing method of the liquid crystal display element in which the liquid crystal and the polymer composite layer containing a liquid crystal and a polymer were provided between a pair of board | substrates which respectively have an electrode,

An insulating film forming step of forming an insulating film on an inner surface of the electrode;

Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates;

A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material,

The insulating film forming step is an insulating film made of at least two materials having different critical surface tensions and has a relationship that the interface tension is constant at the interface between the liquid crystal and the polymer, and the insulating film provided on the inner surface of the electrode. The critical surface tension γ _i (dyne / cm) is characterized by forming an insulating film which satisfies the relationship between the surface tension γ _LC (dyne / cm) of the liquid crystal and the following formula (4).

γ _LC -γ _i <0. (4)

In the above method, when the interfacial tension between the liquid crystal and the polymer material is made constant, the wettability is determined by the interfacial tension between the insulating film and the polymer material and the interfacial tension between the liquid crystal and the solid. do. Therefore, even if the wettability is replaced by the magnitude relation between the surface tension of the liquid crystal and the critical surface tension of the insulating film, the liquid crystal wets with respect to the insulating film. Therefore, since a dome-shaped liquid crystal region is formed on the surface of the insulating film, a liquid crystal display device having reduced optical hysteresis can be manufactured regardless of the kind of liquid crystal.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of the liquid crystal display element of this invention is a manufacturing method of the liquid crystal display element in which the liquid crystal and the polymer composite layer containing a liquid crystal and a polymer were provided between a pair of board | substrates which respectively have an electrode,

An insulating film forming step of forming an insulating film on an inner surface of the electrode;

Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates;

A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material,

The insulating film forming step is an insulating film made of at least two materials having different critical surface tensions and has a relationship that the interface tension is constant at the interface between the liquid crystal and the polymer, and the insulating film provided on the inner surface of the electrode. The critical surface tension γ _i (dyne / cm) is characterized by forming an insulating film which satisfies the relationship between the surface tension γ _LC (dyne / cm) of the liquid crystal and the following formula (5).

-1 <γ _LC -γ _i <1. (5)

According to the said method, the liquid crystal display element which improved responsiveness can be manufactured regardless of the kind of liquid crystal.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of the liquid crystal display element of this invention is a manufacturing method of the liquid crystal display element in which the liquid crystal and the polymer composite layer containing a liquid crystal and a polymer were provided between a pair of board | substrates which respectively have an electrode,

An insulating film forming step of forming an insulating film on an inner surface of the electrode;

Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates;

A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material,

The insulating film forming step is an insulating film made of at least two materials having different critical surface tensions and has a relationship that the interface tension is constant at the interface between the liquid crystal and the polymer, and the insulating film provided on the inner surface of the electrode. The critical surface tension γ _i (dyne / cm) is characterized by forming an insulating film satisfying the relationship between the surface tension γ _LC (dyne / cm) of the liquid crystal and the following formula (6).

-1 <gamma _LC -gamma _i <0. (6)

According to the above method, it is possible to manufacture a liquid crystal display device having improved both optical hysteresis and responsiveness.

Furthermore, at least two kinds of materials constituting the insulating film may include a first insulating film material having a critical surface tension smaller than the surface tension of the liquid crystal and a second insulating film material having a critical surface tension greater than the surface tension of the liquid crystal. .

The first insulating film material may be a fluorine-based surfactant, and the second insulating film material may be a polyimide compound.

Invention Group C

In the liquid crystal display device of the invention group C, a liquid crystal-polymer composite layer containing a liquid crystal and a polymer is provided between a pair of substrates, and the liquid crystal-polymer composite layer is divided into a plurality of regions having different applied voltage-transmittance characteristics in one pixel. As a configured liquid crystal display device,

An insulating film is provided inside the substrate. When the critical surface tension of the insulating film is γ _i and the critical surface tension of the polymer is γ _p , γ _i and γ _p satisfy the relationship of the following equation (7). It features.

γ _i ≧ γ _p . (7)

By the above configuration, the polymer resin is easily wetted on the insulating film. As a result, a hemispherical liquid crystal liquid (see Fig. 21) is formed on the insulating film. Under such circumstances, the liquid crystal molecules are subjected to strong alignment control force at the substrate interface, and this regulating force acts to assist the interface control force at the liquid crystal / polymer resin interface, and as a result, the liquid crystal hit including the liquid crystal / polymer resin interface vicinity. Transition occurs smoothly, and optical hysteresis becomes small.

Further, when the surface tension of the liquid crystal is γ _LC , γ _i and γ _LC may satisfy the relationship of the following formula (8).

γ _i > γ _LC ... (8)

In order to make a liquid crystal wet easily by the said structure, the liquid crystal molecule in the hemispherical liquid crystal droplet contacting on an insulating film is orientated substantially parallel to a board | substrate (refer FIG. 23 (a)). This improves the scattering performance in addition to the reduction of optical hysteresis.

Further, when the surface tension of the liquid crystal is γ _LC , γ _i and γ _LC may satisfy the relationship of the following formula (9).

γ i <γ _LC ... (9)

Because of this configuration, the liquid crystals are less likely to get wet, so that the liquid crystal molecules in the hemispherical liquid crystal region (see Fig. 21) in contact with the insulating film are almost perpendicular to the substrate (see Fig. 23 (b)). This improves the electric field response in addition to the reduction of the optical hysteresis.

[2nd invention group]

In the liquid crystal display device of the second invention group, a liquid crystal / polymer composite layer containing a liquid crystal and a polymer is provided between a pair of substrates, and an electric field is applied to the liquid crystal / polymer composite layer to change the light scattering state of the liquid crystal / polymer composite layer. As a liquid crystal display device to display by

The liquid crystal-polymer composite layer is composed of a plurality of regions having different applied voltage and light transmittance characteristics in one pixel, and the plurality of regions having different applied voltage and light transmittance characteristics are arranged in parallel with respect to the pixel plane. It features.

When the display screen of the liquid crystal cell provided with the liquid crystal and polymer composite layer is observed, the display light reaching the observer is recognized as the sum of the light transmitted through each region. That is, the applied voltage-transmittance characteristics of the entire display element are averaged in the characteristics of each region, and the observer selectively reduces steepness in the voltage region where the hysteresis is maximized, and is applied in the conventional polymer dispersed liquid crystal panel. It is recognized as a display element having a characteristic with smooth steepness compared with the voltage-light transmittance characteristic. As a result, it is possible to prevent the occurrence of afterimages and seizure caused by optical hysteresis and to provide a liquid crystal display device having excellent display quality.

(Invention Group D)

In order to solve the above problems, in the liquid crystal display device of the invention group D, a liquid crystal / polymer composite layer containing a liquid crystal and a polymer is provided between a pair of substrates, and the liquid crystal / polymer composite layer is applied voltage-light in one pixel. A liquid crystal display device composed of a plurality of regions having different transmittance characteristics,

The plurality of regions having different applied voltage-light transmittance characteristics are arranged in parallel to the pixel plane,

The liquid crystal-polymer composite layer is characterized in that the liquid crystal groups are dispersed and maintained in a polymer matrix including polymers, and the average particle diameter of the liquid crystal droplets is different from each other in response to a plurality of regions having different applied voltage-transmittance characteristics. . The liquid crystal-polymer composite layer is formed by dispersing and maintaining liquid crystals in a mesh of a three-dimensional mesh matrix including polymers, and corresponding to a plurality of regions having different applied voltage and light transmittance characteristics. The matrix may have different average mesh sizes.

When a plurality of regions having different scattering characteristics, that is, regions having different electro-optical characteristics (applied voltage-transmittance characteristics) are formed in one pixel, each of these characteristics is averaged and recognized by the observer. In other words, although the characteristics of the individual regions are different from each other, the characteristics of the display elements as a whole are averaged. In this case, the applied voltage-transmittance characteristic of the entire display element is a characteristic of selectively lowering the steepness of the voltage region where the hysteresis is maximum in the applied voltage-transmittance curve, thereby reducing the apparent hysteresis (optical hysteresis). . Therefore, according to the above structure, afterimage or seizure due to hysteresis can be prevented and the display quality can be improved.

Moreover, it is preferable that the average particle diameter R (micrometer) of the said liquid crystal volume exists in the range of 0.6 <R <1.6. Moreover, it is preferable that the average mesh size R (micrometer) of the said three-dimensional mesh matrix is in the range of 0.6 <R <1.6. By setting the average particle diameter of the liquid crystal droplets or the average mesh size of the three-dimensional mesh matrix to fall within the numerical range, for example, a practical driving voltage (about 6 to 12 V) is considered in an active matrix liquid crystal display element using TFT. If so, good scattering properties can be achieved. Thereby, the liquid crystal display element which can display a high contrast can be provided.

One of the pair of substrates may be an active matrix substrate provided with a plurality of pixel electrodes and active elements for controlling voltages applied to the pixel electrodes. Thereby, optical hysteresis can be reduced, and the light-scattering mode liquid crystal display element which drives by active matrix drive with favorable display quality is obtained.

The liquid crystal-polymer composite layer may correspond to a plurality of regions having different applied voltage and light transmittance characteristics, and may have different configurations of liquid crystal molecules in the vicinity of the substrate. According to the above arrangement, by changing the alignment state of the liquid crystal molecules, it is possible to form regions having different electro-optic characteristics (applied voltage-transmittance characteristics) in the direction parallel to the substrate surface in one pixel. As a result, apparent hysteresis (optical hysteresis) can be reduced, and display quality can be improved.

Further, the liquid crystal molecules near the substrate are oriented in the vertical direction with respect to the substrate in one of the plurality of regions having different applied voltage-light transmittance characteristics, and the liquid crystal molecules near the substrate in the other region. It is preferable to orientate in parallel with respect to the said board | substrate. In this way, when the liquid crystal molecules near the two substrates are vertically aligned in one region and the liquid crystal molecules near the two substrates in parallel in the other region, the steepness of the applied voltage and light transmittance characteristics is the smoothest. As a result, the occurrence of apparent hysteresis (optical hysteresis) can be suppressed to a minimum.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, in the manufacturing method of the liquid crystal display element of this invention, the liquid crystal and the polymer composite layer of the structure which the liquid crystal liquid was disperse | maintained is arrange | positioned in the polymer matrix comprised by the polymer contained between a pair of board | substrates, A method of manufacturing a liquid crystal display device having a plurality of regions having different applied voltage and light transmittance characteristics, comprising: an electrode forming step of forming an electrode layer on an inner side surface of the pair of substrates, and the electrode layers facing the pair of substrates; UV light through a bonding step of bonding to form an empty cell, a step of providing a liquid crystal and a polymer precursor solution inside the empty cell, and a filter having a plurality of regions having different UV transmittances in the liquid crystal and the polymer precursor solution. Phases of the liquid crystal and the polymer precursor phase solution were investigated, and the average of the liquid crystal drops in the direction parallel to the substrate in one pixel. Characterized in that wonder align the liquid crystal, the polymer composite layer formation step of forming a liquid crystal-polymer composite layer having a plurality of different areas.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of the liquid crystal display element of this invention arrange | positions the liquid crystal and the polymer composite layer of the structure which the liquid crystal was disperse | distributed and maintained in the mesh of the three-dimensional mesh-like matrix comprised by including a polymer between a pair of board | substrates. And a method of manufacturing a liquid crystal display device having a plurality of regions having different applied voltage and light transmittance characteristics in one pixel.

An electrode forming step of forming an electrode layer on inner surfaces of the pair of substrates;

Bonding the pair of substrates so that the electrode layers face each other to form an empty cell; providing a liquid crystal / polymer precursor solution inside the empty cell; and a UV transmittance between the liquid crystal and the polymer precursor solution. Phase-separation of the liquid crystal and polymer precursor solution by irradiating ultraviolet rays through a filter having a plurality of different regions to have a plurality of regions having different average mesh sizes of three-dimensional mesh matrix in a direction parallel to the substrate in one pixel. A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer is provided.

According to each of the above methods, it is possible to form a liquid crystal-polymer composite layer having a plurality of regions in which the average particle size of the liquid crystal droplets or the average mesh size of the three-dimensional mesh matrix are parallel to the substrate in one pixel. As a result, a plurality of regions having different applied voltage and light transmittance characteristics can be formed in one pixel, and a liquid crystal display device having reduced optical hysteresis can be manufactured.

Invention Group E

The present invention provides a liquid crystal display device comprising a liquid crystal and a polymer composite layer including a liquid crystal and a polymer between a pair of substrates, wherein the liquid crystal and polymer composite layer comprise a plurality of regions having different applied voltage and light transmittance characteristics in one pixel. The increase in the driving voltage is suppressed by arranging a plurality of regions having different average particle sizes of liquid crystal droplets or average mesh sizes of three-dimensional mesh matrix in a direction parallel to the pixel plane in one pixel, thereby suppressing an increase in driving voltage. In this case, only the steepness of the voltage region with the largest hysteresis is selectively lowered, and the optical hysteresis is reduced.

Furthermore, in order to realize the above liquid crystal display device, a manufacturing method capable of easily forming a plurality of regions having different particle diameters or the like of liquid crystal droplets in one pixel without using a special ultraviolet light source (parallel ultraviolet rays) is provided.

In the above configuration, in the liquid crystal display device of the invention group E, one of the pair of substrates has a plurality of regions having different ultraviolet transmittances within one pixel region,

The liquid crystal-polymer composite layer has a structure in which a liquid crystal group is dispersed and maintained in a polymer matrix including a polymer, and is irradiated with ultraviolet rays through one of the substrates in each region where the ultraviolet transmittances differ in one pixel. Corresponding liquid crystal and polymer composite layers in which a plurality of regions having different average particle diameters are formed.

Furthermore, a plurality of regions having different average particle diameters of the liquid crystal droplets also correspond to a plurality of regions having different applied voltage-light transmittance characteristics.

In addition, one of the pair of substrates has a plurality of regions having different ultraviolet transmittances in one pixel region, and the liquid crystal and polymer composite layer has a liquid crystal in a mesh of a three-dimensional mesh matrix composed of a polymer. It is formed in a dispersed structure and a plurality of regions having different average mesh sizes of the three-dimensional mesh matrix corresponding to each region where the ultraviolet transmittance differs in one pixel by irradiating ultraviolet rays through the one substrate. The formed liquid crystal-polymer composite layer, and the plurality of regions having different average mesh sizes of the three-dimensional mesh matrix may also correspond to a plurality of regions having different applied voltage and light transmittance characteristics.

In general, when the irradiation intensity of ultraviolet rays is changed, it is possible to control the average particle size of the liquid crystal droplets or the average mesh size of the three-dimensional mesh-like matrix (hereinafter referred to as "particle diameter of liquid crystal"). Herein, by irradiating ultraviolet rays through a substrate having a plurality of regions having different ultraviolet transmittances as described above, ultraviolet rays having a high irradiation intensity can be irradiated in some regions, while ultraviolet rays having a weak irradiation intensity are irradiated in other regions. You can investigate. Thus, for example, in the case of PDLC, the polymerization rate of the polymer-cured polymer is increased in the region to which the ultraviolet ray with strong irradiation intensity is irradiated to form a liquid crystal with a small particle diameter. On the contrary, in the region to which ultraviolet irradiation with low irradiation intensity is irradiated, the polymerization rate of the polymer is slowed to form a liquid crystal with a large particle diameter. Therefore, it is possible to form a liquid crystal-polymer composite layer having a plurality of regions having different particle diameters of liquid crystal in one pixel. In other words, a plurality of regions having different applied voltage and light transmittance characteristics can be formed in one pixel, and the characteristics of each region are averaged to reduce the optical hysteresis of the entire display element. As a result, afterimage and seizure resulting from optical hysteresis can be reduced, and display quality can be improved.

Moreover, according to the above structure, since the substrate itself has a function of adjusting the transmittance of ultraviolet rays, the ultraviolet rays with the adjusted irradiation intensity can be directly irradiated directly to the liquid crystal or the polymer material to be irradiated. Therefore, even if a mask with extremely high pattern accuracy or a special light source capable of irradiating parallel ultraviolet rays is not used, a plurality of minute regions having different particle diameters of liquid crystal can be formed in one pixel. As a result, even if the pixel size of an active matrix type light valve using a high-definition TFT (Thin Film Transistor) is about several tens of micrometers, the area can be divided and a liquid crystal display device having reduced optical hysteresis can be provided.

On the other hand, the particle diameter of the liquid crystal means the average mesh size (net nose spacing) in PNLC (Polymer Network Liquid Crysta1) having a structure in which the polymer is expanded in a three-dimensional network shape in the middle of the continuous phase of the liquid crystal. In addition, in PDLC (Polymer Dispersed Liquid Crystal) in which spherical or spheroidal liquid crystals are dispersed independently of each other in the polymer matrix, the average particle diameter of liquid crystals is meant. However, when using as an average particle diameter of a liquid crystal drop, the said liquid crystal area is not limited to what completely disperse | distributed completely, It means using as an average particle diameter of the liquid crystal drop even when some liquid crystal drops are connected.

Furthermore, an ultraviolet transmittance adjusting layer for forming a plurality of regions having different applied voltage and light transmittance characteristics in one pixel may be provided on the inner surface of one of the pair of substrates. According to this structure, when irradiating an ultraviolet-ray through the board | substrate with which the ultraviolet-light transmittance adjustment layer was provided, a part of ultraviolet-ray absorbs in an ultraviolet transmittance adjustment layer. For this reason, in the area | region corresponding to the said ultraviolet transmittance adjustment layer, ultraviolet-ray with a small irradiation intensity is irradiated compared with another area | region, and this raises the particle size of a liquid crystal in the said area | region. Therefore, the liquid crystal and polymer composite layer which has several area | regions from which the particle diameter of a liquid crystal differs can be formed. On the other hand, it is most preferable to provide an ultraviolet-ray transmittance adjustment layer adjacent to the liquid-crystal and polymer precursor solution which is an irradiated body in order to form the liquid-crystal / polymer composite layer provided with the some area | region with a different particle diameter of a liquid crystal.

A transparent electrode layer may be provided between the ultraviolet light transmittance adjusting layer and the liquid crystal-polymer composite layer and inside the other substrate on one substrate side of the pair of substrates. The UV transmittance adjusting layer may be formed on the transparent electrode layer (ie, between the transparent electrode layer and the liquid crystal and polymer composite layer), but in this case, the UV transmittance adjusting layer and the transparent layer above and below the liquid crystal and polymer composite layer. The electrode layers are adjacent to each other, and layers having different kinds or film thicknesses exist in up-and-down asymmetry, and are likely to cause sticking. Therefore, when the transparent electrode layer is provided between the UV transmittance adjusting layer and the liquid crystal and polymer composite layer, the transparent electrode layers are adjacent to each other on the upper and lower sides of the liquid crystal and polymer composite layer, thereby becoming vertically symmetric and no sticking phenomenon occurs.

In addition, insulating films may be provided on the inner surfaces of the pair of transparent electrode layers, respectively. By providing the insulating film, the alignment control force (anchoring) applied to the liquid crystal molecules in contact with the insulating film can be controlled, and it becomes easy to adjust the γ value (V ₉₀ / V ₁₀ ) which reduces optical hysteresis. In addition, the insulating film prevents impurity ions in the liquid crystal from moving to the transparent electrode layer, thereby improving the voltage holding ratio, thereby improving display quality and reliability. In addition, (gamma) value is mentioned later.

The ultraviolet transmittance adjusting layer may be a photoresist layer. As the ultraviolet transmittance adjusting layer, the same effect can be obtained as long as it is made of a material which partially absorbs ultraviolet rays. Particularly, since the photoresist can be formed using a very general technique in a semiconductor process such as coating, exposure, development, and curing, it is easy to process and ensures ease of manufacture. In addition, many photoresists have a characteristic of partially absorbing ultraviolet rays, so that the selection of materials may be appropriate according to various conditions, and thus the degree of freedom of selection is high.

The plurality of regions having different ultraviolet transmittances may have a structure in which visible light transmittances are substantially the same. When a region almost absorbing visible light exists in the substrate, a desired phase separation structure is hardly obtained in the portion of the liquid crystal-polymer composite layer corresponding to the region. As a result, a good transmittance is not obtained in the portion corresponding to the above region, and this causes a decrease in display quality. Therefore, even if the UV transmittances are different from each other, the lower the display quality can be suppressed in the case where the substrate is provided with a region that transmits the visible light at substantially the same transmittance. For example, many photoresists exhibit semi-absorbency only to ultraviolet rays and transmittance to visible rays, and thus photoresists are suitable as ultraviolet transmittance adjusting layers.

Further, when the total number of a plurality of regions having different applied voltage-light transmittance characteristics is n and the total area of one pixel is S, the area s of each region may almost satisfy the following formula (10).

s = S / n... 10

The technical significance of satisfying the relationship of the above formula (10) lies in making the area s of the plurality of regions almost equal (for example, the area ratio when the area division is divided into two). This makes it possible to substantially maximize the difference between the applied voltage and the light transmittance characteristics in each region, thereby minimizing the optical hysteresis.

Incidentally, the ratio V ₉₀ / V ₁₀ when the drive voltage is a driving voltage to 90% of the maximum transmittance to the V _90, V ₁₀ to 10% may be two or more. Conventional polymer dispersion liquid crystals have optical hysteresis as high as 2% or more, but in the same manner as in the present invention, the transmittance of individual regions is synthesized by forming a liquid crystal-polymer composite layer having a plurality of regions having different particle diameters. The gamma value (ratio V ₉₀ / V ₁₀ ) of one whole pixel can be 2 or more and the optical hysteresis can be 1% or less, so that the optical hysteresis can be reduced. On the other hand, the size of the optical hysteresis depends on the conditions such as the evaluation method, the size of the liquid crystal material, the size of the liquid crystal droplets, and the like, the liquid crystal fraction.

Moreover, an active element may be formed in the other board | substrate among the said pair of board | substrates. On the substrate (array substrate) on which the active element is formed, various wirings, such as gate lines and source lines, which are impermeable to light, are formed. Therefore, when the ultraviolet rays are irradiated from the array substrate side, some of the ultraviolet rays are shielded by these various wirings, and there is a portion where the phase separation of the liquid crystal and the polymer precursor phase solution is not sufficiently completed. Because of this, a problem arises in device characteristics and reliability, so that the active element is preferably formed on a substrate having no plurality of regions having different ultraviolet transmittances.

Among the pair of substrates, one substrate has a plurality of regions having different ultraviolet transmittances in one pixel region, and liquid crystal molecules are dispersed in a polymer matrix composed of a polymer by irradiating ultraviolet rays through the one substrate. The liquid crystal-polymer composite layer formed in the retained structure has a plurality of regions in which the average particle diameter of the liquid crystal droplets are different from each other in the parallel direction with respect to the substrate, and the maximum transmittance of the maximum and minimum regions of the average particle diameter of the liquid crystal droplets is 90. When the driving voltages to be% are set to Vb ₉₀ and Va ₉₀ , the configuration may be such that the ratio Vb ₉₀ / Va ₉₀ is 0.6 or more and 0.9 or less.

In addition, one of the substrates has a plurality of regions having different ultraviolet transmittances within one pixel region, and liquid crystal is contained in the mesh of the three-dimensional mesh matrix formed by containing a polymer by irradiating ultraviolet rays through the one substrate. The liquid crystal-polymer composite layer formed by this dispersed structure has a plurality of regions in which the average mesh size of the three-dimensional mesh matrix is different in parallel to the substrate in one pixel, and the average of the three-dimensional mesh matrix is different. When the driving voltages that make 90% of the maximum transmittance of the maximum area and the minimum area of the mesh size are Vb ₉₀ and Va ₉₀ , the configuration may be such that the ratio Vb ₉₀ / Va ₉₀ is 0.6 or more and 0.9 or less.

If a plurality of regions having different particle diameters of liquid crystal are formed in one pixel, a plurality of regions having different driving voltages can be formed, and if the driving voltage ratio (ratio Vb ₉₀ / Va ₉₀ ) of the maximum region and the minimum region of the driving voltage is reduced, The value of γ becomes large and optical hysteresis can be reduced. However, as shown in Fig. 46A, when the driving voltage ratio is smaller than 0.6, an inflection point may occur in the transmittance-applied voltage curve, so it is preferably 0.6 or more. If the driving voltage ratio is greater than 0.9, the change in the γ value is smooth, and the optical hysteresis reduction effect may be reduced. Therefore, the ratio Vb ₉₀ / Va ₉₀ is more preferably not more than 0.6, 0.9 or less. On the other hand, the above-mentioned numerical range is an optimum implementation requirement for achieving the best effect, and it is also possible to adopt a value of the driving voltage ratio such that an inflection point appears if a slight deterioration of the transmittance is allowed.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, in the manufacturing method of the liquid crystal display element of this invention, the liquid crystal and the polymer composite layer of the structure which the liquid crystal liquid was disperse | maintained is arrange | positioned in the polymer matrix comprised by the polymer contained between a pair of board | substrates, A manufacturing method of a liquid crystal display device having a plurality of regions having different applied voltage and light transmittance characteristics in

A UV transmittance adjusting layer forming step of forming an ultraviolet transmittance adjusting layer by applying photoresist to an inner surface of one of the pair of substrates and irradiating ultraviolet rays through a mask patterned to a predetermined shape on the photoresist. and,

Forming a transparent electrode layer on an inner surface of the pair of substrates;

Bonding the pair of substrates together so that the transparent electrode layers face each other to form empty cells;

Providing a liquid crystal / polymer precursor solution within the empty cell;

The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through a substrate on which the UV transmittance adjusting layer is provided to perform phase separation of the liquid crystal and the polymer precursor solution, and a plurality of liquid crystal drops having different average particle diameters in parallel to the substrate in one pixel. A liquid crystal and polymer composite layer forming step of forming a liquid crystal and polymer composite layer having a region is provided.

In order to solve the above problems, in the method of manufacturing a liquid crystal display device of the present invention, a liquid crystal / polymer composite layer having a structure in which a liquid crystal is dispersed and maintained in a mesh of a three-dimensional mesh-like matrix in which a polymer is impregnated between a pair of substrates, A method of manufacturing a liquid crystal display device having a plurality of regions having different applied voltage and light transmittance characteristics in one pixel, wherein the inner surface of one substrate and the inner surface of the other substrate have a plurality of regions having different ultraviolet transmittances. Forming a transparent electrode layer on the transparent electrode layer,

Bonding the pair of substrates together to face the transparent electrode layer to form an empty cell;

Providing a liquid crystal / polymer precursor solution within the empty cell;

The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through a substrate having a plurality of regions having different UV transmittances, and phase separation of the liquid crystal and the polymer precursor solution is performed. A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer having a plurality of regions having different average mesh sizes of the shape matrix is provided.

In order to form a plurality of regions having different particle sizes (average particle diameter of liquid crystal or average mesh size of a three-dimensional mesh matrix) of liquid crystals in one pixel, it is necessary to change the intensity of ultraviolet rays in each region. For example, in a region irradiated with ultraviolet rays having strong irradiation intensity, a liquid crystal group having a small particle size is formed, and in a region having a low irradiation intensity, a liquid crystal field having a large particle size is formed.

In the above configuration, the ultraviolet transmittance adjusting layer has a function of adjusting the amount of ultraviolet rays transmitted for each region, and the intensity of ultraviolet rays can be changed for each region by one ultraviolet irradiation. Thus, by irradiating ultraviolet light to the liquid crystal-polymer precursor solution in proximity to the substrate through a substrate having a UV transmittance adjusting function as in the above method, a liquid crystal-polymer composite layer having a plurality of regions having different particle diameters is formed. It can be formed. As a result, it becomes possible to manufacture the liquid crystal display element which reduced optical hysteresis and improved the display quality, such as an afterimage and seizure.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, in the manufacturing method of the liquid crystal display element of this invention, the liquid crystal and the polymer composite layer of the structure which the liquid crystal liquid was disperse | maintained is arrange | positioned in the polymer matrix comprised by the polymer contained between a pair of board | substrates, A manufacturing method of a liquid crystal display device having a plurality of regions having different applied voltage and light transmittance characteristics in

A UV transmittance adjusting layer forming step of forming an ultraviolet transmittance adjusting layer by applying a photoresist to an inner surface of one of the pair of substrates and irradiating ultraviolet rays through a mask patterned to a predetermined shape on the photoresist; ,

Forming a transparent electrode layer on an inner surface of the pair of substrates;

Bonding the pair of substrates together to face the transparent electrode layer to form an empty cell;

Providing a liquid crystal / polymer precursor solution within the empty cell;

The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through a substrate on which the UV transmittance adjusting layer is provided to perform phase separation of the liquid crystal and the polymer precursor solution, and a plurality of liquid crystal drops having different average particle diameters in parallel to the substrate in one pixel. A liquid crystal and polymer composite layer forming step of forming a liquid crystal and polymer composite layer having a region is provided.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of the liquid crystal display element of this invention arrange | positions the liquid crystal and the polymer composite layer of the structure which the liquid crystal was disperse | distributed and maintained in the mesh of the three-dimensional mesh-like matrix comprised by including a polymer between a pair of board | substrates. And a method of manufacturing a liquid crystal display device having a plurality of regions having different applied voltage and light transmittance characteristics in one pixel.

A UV transmittance adjusting layer forming step of forming an ultraviolet transmittance adjusting layer by applying a photoresist to an inner surface of one of the pair of substrates and irradiating ultraviolet rays through a mask patterned to a predetermined shape on the photoresist; ,

Forming a transparent electrode layer on an inner surface of the pair of substrates;

Bonding the pair of substrates together to face the transparent electrode layer to form an empty cell;

Providing a liquid crystal / polymer precursor solution within the empty cell;

Irradiating ultraviolet light to the liquid crystal and polymer precursor solution through the substrate provided with the UV transmittance adjusting layer, performing phase separation of the liquid crystal and polymer precursor solution, and performing an average mesh of the three-dimensional mesh matrix in a direction parallel to the substrate in one pixel. A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer having a plurality of regions having different sizes is provided.

According to the said method, ultraviolet-ray is irradiated to a liquid-crystal-polymer precursor solution through the said ultraviolet transmittance adjustment layer. Therefore, the liquid crystal and the polymer composite layer formed by irradiation of ultraviolet rays can form a plurality of regions having different particle diameters of the liquid crystal in one pixel. As a result, a plurality of regions having different applied voltage and light transmittance characteristics can be formed, and a liquid crystal display device having reduced optical hysteresis can be manufactured.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, in the manufacturing method of the liquid crystal display element of this invention, the liquid crystal and the polymer composite layer of the structure which the liquid crystal liquid was disperse | maintained is arrange | positioned in the polymer matrix comprised by the polymer contained between a pair of board | substrates, A manufacturing method of a liquid crystal display device having a plurality of regions having different applied voltage and light transmittance characteristics in

A UV transmittance adjusting layer forming step of forming a UV transmittance adjusting layer by applying photoresist to an inner surface of one of the pair of substrates and irradiating ultraviolet rays through a mask patterned to a predetermined shape on the photoresist. and,

Forming a transparent electrode layer on the pair of substrates;

An insulating film forming step of providing an insulating film on the transparent electrode layer;

A joining process of joining the pair of substrates to face the insulating film to form an empty cell;

Providing a liquid crystal / polymer precursor solution within the empty cell;

The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through the substrate on which the UV transmittance adjusting layer is provided, and the liquid crystal and polymer precursor solution are subjected to phase separation. A liquid crystal and polymer composite layer forming step of forming a liquid crystal and polymer composite layer having a region is provided.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of the liquid crystal display element of this invention arrange | positions the liquid crystal and the polymer composite layer of the structure which the liquid crystal was disperse | distributed and maintained in the mesh of the three-dimensional mesh-like matrix comprised by including a polymer between a pair of board | substrates. And a method of manufacturing a liquid crystal display device having a plurality of regions having different applied voltage and light transmittance characteristics in one pixel.

A UV transmittance adjusting layer forming step of forming an ultraviolet transmittance adjusting layer by applying a photoresist to an inner surface of one of the pair of substrates and irradiating ultraviolet rays through a mask patterned to a predetermined shape on the photoresist. and,

Forming a transparent electrode layer on the pair of substrates;

An insulating film forming step of providing an insulating film on the transparent electrode layer;

A joining process of joining the pair of substrates to face the insulating film to form an empty cell;

Providing a liquid crystal / polymer precursor solution within the empty cell;

Irradiating ultraviolet light to the liquid crystal and polymer precursor solution through the substrate provided with the UV transmittance adjusting layer, and performing phase separation of the liquid crystal and polymer precursor solution to obtain an average mesh of a three-dimensional mesh matrix in a direction parallel to the substrate in one pixel. A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer having a plurality of regions having different sizes is provided.

According to the above method, by forming the insulating film, it is possible to control the alignment control force acting on the liquid crystal molecules in the vicinity to a desired condition. As a result, the adjustment of the gamma value becomes easy, and if the orientation control force is controlled to increase the gamma value, the optical hysteresis can be reduced. In addition, it is possible to prevent impurity ions in the liquid crystal from moving to the transparent electrode layer. As a result, the voltage holding ratio can be improved, and the display quality and reliability can be improved.

(Invention Group F)

The present invention provides a liquid crystal display comprising a liquid crystal and a polymer composite layer including a liquid crystal and a polymer resin between a pair of substrates, and changing the light scattering state of the liquid crystal and the polymer composite layer by applying an electric field to the liquid crystal and the polymer composite layer. As an element, the apparent applied voltage and light transmittance characteristics are configured to have smooth steepness within a predetermined applied voltage range. Thereby, optical hysteresis can be reduced and the afterimage and seizure resulting from the optical hysteresis are prevented.

That is, in order to solve the above problem, the liquid crystal display device of the invention group F is provided with a liquid crystal and a polymer composite layer containing a liquid crystal and a polymer between a pair of substrates, and the liquid crystal and polymer composite layer is applied within one pixel. A liquid crystal display device composed of a plurality of regions having different light transmittance characteristics,

The plurality of regions having different applied voltage-light transmittance characteristics are arranged in parallel to the pixel plane,

Electrodes are provided inside the pair of substrates, and the plurality of regions are provided such that the distance between the electrodes between the pair of electrodes is different from each other.

If the cell gap, more precisely the distance between electrodes, changes, the transmittance of the liquid crystal / polymer composite layer will be different even if the same applied voltage is applied correspondingly. Therefore, as in the above configuration, it is possible to vary the applied voltage and light transmittance characteristics for each of the regions by making the distance between electrodes different for each region.

Further, when the inter-electrode distance is d _l in one region arbitrarily selected among the plurality of regions and the inter-electrode distance in d other region is d _n , the d _l and d _n are represented by the following equation ( It may be a configuration that satisfies the relationship of 11).

d _n / d _l ≦ 0.85... (11)

In the above configuration, when the difference between d ₁ and d _n is not too different, for example, d _n / d _l ≒ 1, the applied voltage-light transmittance characteristic and the electrode in the region of d _l In the region _where the distance is d _n, the applied voltage and light transmittance characteristics are the same. Even if both characteristics are averaged, the apparent applied voltage-transmittance characteristic is such that the rising voltage process (scattering state → transmission state) is close to the strong voltage process (transmission state → scattering state), and the steepness is slow. no. Therefore, the reduction of optical hysteresis is not enough to prevent deterioration of the display quality. However, when d _l and d _n are set to satisfy the relationship of Equation (1), the apparent applied voltage-transmittance characteristic may be a characteristic in which the steepness close to the boost and strong voltage processes becomes smooth. . Therefore, optical hysteresis can be reduced to such an extent that deterioration of display quality, such as sticking, can be prevented.

Furthermore, the relationship between the driving voltage in the region of one side by V _A, and when the driving voltage in the region of the other side to V _B, wherein V _A and V _B is the following formula (12) of the plurality of regions It may be a satisfactory configuration.

V _A / V _B ? 0.85... (12)

(In the formulas, V _A and V _B each represent a drive voltage when the maximum transmittance of the liquid crystal display element becomes 90%.)

If the difference between V _A and V _B is not too non-difference in the configuration, for example V _A / V _B the case such that a ≒ 1, the applied voltage in the region of V _A - area of the light transmission properties and, V _B In this case, the applied voltage and light transmittance characteristics are the same. Therefore, even if both characteristics are averaged, the apparent applied voltage-transmittance characteristic cannot be sufficiently reduced in optical hysteresis. However, if V _A and V _B are set to satisfy the relationship of the formula (12) as described above, the optical hysteresis can be reduced to such an extent that deterioration of display quality such as seizure can be prevented.

Furthermore, a stepped film whose surface is covered by an electrode layer on one of the pair of electrodes may be provided, and the electrode and the electrode layer may be in a conductive state. According to the above configuration, by providing a stepped film, it is possible to vary the distance between electrodes in each region.

Moreover, the surface of any one of the said pair of board | substrates may be provided with the level | step difference in an uneven | corrugated shape. As described above, by forming a step in a concave-convex shape on the surface of one of the substrates, it becomes possible to vary the distance between electrodes for each region.

The refractive index of the stepped film may be substantially the same as the refractive index of the polymer constituting the liquid crystal and polymer composite layer. According to this configuration, when light transmits through the liquid crystal-polymer composite layer by making the refractive index of the polymer resin almost the same in the stepped film and the liquid crystal-polymer composite layer, the light is separated at the step-film-liquid-polymer composite layer interface. It becomes possible to prevent refraction. Thereby, the reduction of contrast and transmittance can be suppressed, and the liquid crystal display element which has the outstanding display performance can be provided.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, in the manufacturing method of the liquid crystal display element of this invention, the liquid crystal and the polymer composite layer containing a liquid crystal and a polymer are provided between a pair of board | substrates with an electrode, respectively, and the electric field is formed in the said liquid crystal and a polymer composite layer. A method of manufacturing a liquid crystal display device for changing a light scattering state of a liquid crystal / polymer composite layer by applying a photoresist, comprising: a photoresist film forming step of forming a photoresist film on an electrode in any one of the pair of substrates; A stepped film forming step of forming a stepped film made of the photoresist film on the electrode by irradiating light through a mask having a light shielding portion having a predetermined shape on the resist film, and developing the photoresist film; And an electrode layer forming step of forming the electrode layer so as to cover it.

According to the above method, it is possible to form a stepped film on any one of a pair of substrates, and a plurality of regions having different distances between electrodes can be formed. Here, when the distance between electrodes is different, the value of transmittance with respect to the value of an arbitrary applied voltage changes for each area. Therefore, as described above, by forming a plurality of regions having different distances between electrodes, the applied voltage and light transmittance characteristics can be changed for each region. In view of the above, when the display screen is visually recognized, the applied voltage and light transmittance characteristics are averaged, which makes it possible to obtain a characteristic with smooth steepness compared with the applied voltage and light transmittance characteristics in a conventional polymer dispersed liquid crystal display device. . As a result, optical hysteresis can be reduced, suppression of sticking or afterimage on the display screen, and production of a liquid crystal display device having good display characteristics can be achieved.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, in the manufacturing method of the liquid crystal display element of this invention, the liquid crystal and a polymer composite layer containing a liquid crystal and a polymer are provided between a pair of board | substrates with an electrode, respectively, and an electric field is applied to the said liquid crystal and a polymer composite layer. A manufacturing method of a liquid crystal display device which is applied to change a light scattering state of a liquid crystal and a polymer composite layer to display it.

An etching step of forming a mask having a predetermined shape on the substrate, chemically etching an area not protected by the mask with an etching solution, and forming the concave-convex surface of the substrate;

And an electrode layer forming step of forming an electrode layer on the substrate having the uneven surface.

Further, in the mask, the pattern shape may be a stripe shape.

In the mask, the pattern may be a lattice.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, in the evaluation method of the liquid crystal display element of this invention, the liquid crystal and a polymer composite layer containing a liquid crystal and a polymer are provided between a pair of board | substrates with an electrode, respectively, and an electric field is formed in the said liquid crystal and a polymer composite layer. Is a method for evaluating a liquid crystal display device in which a light scattering state of a liquid crystal / polymer composite layer is changed and applied to the liquid crystal display, wherein the optical hysteresis H _t (%) in the applied voltage-transmittance characteristic of the whole liquid crystal / polymer composite layer is It evaluates by (13), It is characterized by the above-mentioned.

_{H t (%) = (T} down (V 10~30) -T up (V 10 ~ 30)) / (T max -T o) × 100 ... (13)

(V _10-30 represents the applied voltage when the transmittance is 10% to 30% in the step- _up process, and T _up (V _10-30 ) represents the transmittance at V _10-30 in the step- _up process. shows, the transmittance indicates the transmittance in the V _l0~30, T _max represents the value at the time the transmittance is to be maximum, T ₀ is in the voltage is applied in the steel voltage process T _down (V _{10 ~ 30)} In the conventional method for evaluating applied voltage and light transmittance characteristics, an optical hysteresis is calculated in the case where the transmittance in the step-up voltage becomes 50%, for example. However, the greatest optical hysteresis is in the case of the region where the voltage level of the applied voltage is low, and is about 10% to 30% in terms of transmittance during the boosting process. Therefore, as in the method described above, the optical hysteresis when the transmittance becomes 10% to 30% in the step-up process is calculated by the evaluation formula represented by Equation (13), thereby making it possible to reliably correct the defect of the applied voltage-light transmittance characteristics. It becomes possible to evaluate.

Invention Group G

In order to solve the above problems, in the liquid crystal display device of the invention group F, a liquid crystal and a polymer composite layer including a liquid crystal and a polymer are provided between a pair of substrates, and the liquid crystal and polymer composite layer are applied voltage-light in one pixel. A liquid crystal display device composed of a plurality of regions having different transmittance characteristics,

The plurality of regions having different applied voltage-light transmittance characteristics are arranged in parallel to the pixel plane,

In the liquid crystal-polymer composite layer, the liquid crystal and the polymer are aligned with each other.

On one of the pair of substrates, comb-shaped electrodes for driving in the transverse electric field mode are formed to face each other in the substrate surface, and a driving voltage of 90% of a maximum transmittance of V ₉₀ and a driving voltage of 10% is set to V _10. The ratio V ₉₀ / V ₁₀ is 2 or more and 3.1 or less.

By the above structure, both the optical hysteresis and the driving voltage can be reduced even in the polymer dispersed liquid crystal display device in the transverse electric field mode. On the other hand, as the γ value was evaluated as V ₉₀ / V _10.

Furthermore, the electrode spacing of the comb-shaped electrodes may be different in plane. As described above, the electrode spacing of the comb-shaped electrodes is different, so that the magnitude of the electric field is different between the electrodes in the substrate surface. This means that the applied voltage and the light transmittance characteristic are different for each of the divided regions between the electrodes. Therefore, in the case of the display device as a whole, there are regions in which the plurality of applied voltage and light transmittance characteristics are different, and the applied voltage and light transmittance characteristics of the entire display element are obtained by averaging the applied voltage and light transmittance characteristics of the respective regions. It becomes. This reduces the optical hysteresis. On the other hand, the value of γ can be controlled by adjusting the electrode spacing of the comb-shaped electrode.

Further, it is the V ₉₀ may be less than 15V. The reason why V ₉₀ is regulated as described above is that, when V ₉₀ / V ₁₀ exceeds 3.1, V ₉₀ becomes 15 V or more, and actual driving becomes difficult according to the experimental results of the present inventors and the like.

The active element may be formed on one of the pair of substrates.

In the liquid crystal-polymer composite layer, liquid crystals and polymers are aligned with each other, and on one of the pair of substrates, comb-shaped electrodes for driving in the transverse electric field mode are formed to face each other in the substrate surface, and have a maximum transmittance. When the driving voltage at ₅₀ % of V is set to V ₁₀ and the driving voltage at 10% is set to V ₁₀ , the configuration may be such that the ratio V ₅₀ / V ₁₀ is 1.1 or more and 1.9 or less.

By the above structure, both the optical hysteresis and the driving voltage can be reduced even in the polymer dispersed liquid crystal display device in the transverse electric field mode. On the other hand, as the γ value was evaluated as a ratio V ₅₀ / V _l0.

Other objects, features and advantages of the present invention will be fully understood by the following description. Further advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.

The technical idea of the present invention is to provide a liquid crystal / polymer composite layer including a liquid crystal and a polymer between a pair of substrates, and to change the light scattering state of the liquid crystal / polymer composite layer by applying an electric field to the liquid crystal / polymer composite layer. In a liquid crystal display device for displaying an image or the like, the liquid crystal-polymer composite layer has a plurality of regions having different applied voltage and light transmittance characteristics within one pixel, thereby reducing hysteresis while suppressing increase in driving voltage. will be.

In the above liquid crystal-polymer composite layer, the technical significance of forming a plurality of regions having different applied voltage and light transmittance characteristics in one pixel is as mentioned below.

In the liquid crystal display device represented by the conventional PDLC, a hysteresis loop appears in the relationship between the applied voltage and the light transmittance, and hysteresis exists inherently. This hysteresis is not solved even if the particle size of the liquid crystal phase is changed, for example. For example, focusing on the transmittance, only the driving voltage value necessary for obtaining the same transmittance is changing. In short, the applied voltage-light transmittance characteristic only shifts to the low applied voltage side or to the high applied voltage side, and does not fundamentally eliminate hysteresis.

However, in the case of a configuration in which a plurality of regions having different applied voltage and light transmittance characteristics are provided in one pixel as in the present invention, the characteristics of the display elements as a whole are combined or averaged, resulting in an applied voltage-light transmittance characteristic with a moderate steepness. . In short, the hysteresis path of the display element as a whole changes smoothly in comparison with the applied voltage-light transmittance characteristics in the individual regions. This makes it possible to reduce the transmittance difference at any applied voltage value in the rising voltage process (when the applied voltage rises) and the falling voltage process (when the applied voltage falls). This means that the optical hysteresis is being reduced, whereby the afterimage and the sticking caused by the optical hysteresis can be reduced. Moreover, the characteristic as the whole display element does not exceed the maximum applied voltage of the applied voltage-light transmittance characteristic on the side of the applied voltage region as high as possible in order to combine or average a plurality of regions having different characteristics. Therefore, it is also possible to suppress the increase of the driving voltage.

From these, according to the liquid crystal display device of the present invention, it is possible to reduce optical hysteresis while suppressing an increase in power consumption.

[1st invention group]

In the first invention group, the liquid crystal-polymer composite layer has a configuration in which a plurality of regions having different applied voltage and light transmittance characteristics are arranged in a direction perpendicular to the substrate surface in one pixel. With such a configuration, the hysteresis selectively lowers the steepness of the voltage region in which the hysteresis is large in the applied voltage-transmittance curve (hereinafter, also referred to simply as a curve). The difference in transmittance (i.e., optical hysteresis) at the same voltage in the case of reduction is reduced. As a result, a liquid crystal display device having excellent display quality can be provided by preventing the occurrence of afterimage or seizure due to optical hysteresis.

Hereinafter, the technical meaning of a 1st invention group is explained based on FIG. 5 and FIG. 5 is an explanatory diagram for explaining a display principle of the liquid crystal display device according to the first invention group. 6 is a graph showing an applied voltage-light transmittance curve in the liquid crystal display device.

First, as shown in FIG. 5A, in the liquid crystal-polymer composite layer 100, a first region A and a second region B having different applied voltage and light transmittance characteristics are stacked in a direction perpendicular to the plane. . In the figure, a part corresponding to one pixel is shown.

The first region A is formed so as to have an applied voltage-light transmittance characteristic indicated by an applied voltage-light transmittance curve VTa shown in FIG. 6A. On the other hand, the second region B is shifted to the lower voltage side than the curve VTa, and is formed to have the applied voltage-light transmittance characteristic indicated by the applied voltage-light transmittance curve VTb shown in FIG.

When the display screen of the liquid crystal cell with the liquid crystal and polymer composite layer 100 is observed, the irradiated light irradiated from the rear of the liquid crystal cell passes through the first region A and the second region B in turn, and finally, as the display light. Reach the observer (see FIG. 5B). Here, the individual regions are different in characteristics, but since the respective regions are stacked vertically with respect to the plane, these characteristics overlap as the characteristics of the entire display element. That is, it becomes the applied voltage-light transmittance characteristic shown by the curve VTc shown in FIG. 6A.

The applied voltage-light transmittance characteristic indicated by this curve VTc is also described in detail. As is apparent from Fig. 6A, the curve VTc is located between the curve VTa and the curve VTb, and in the region where the applied voltage is relatively low, the trace V follows the curve VTb, while in the region where the applied voltage is relatively high, It is a trajectory that follows. Therefore, the curve VTc is a curve having a gentle slope compared to the curves VTa and VTb.

Here, the relationship between the magnitude of the physical hysteresis (voltage hysteresis) and the magnitude of the apparent hysteresis (optical hysteresis) that causes afterimages or sticking will be considered. As shown in Fig. 6B, the physical hysteresis is a difference between the voltage of the applied voltage passing through the specific transmittance and the voltage of the falling voltage in the transmittance-applied voltage curve, and can be described quantitatively as hysteresis width ΔV. . In addition, this hysteresis width DELTA V shows a dependence on the transmittance | permeability prescribed | regulated, for example, in the liquid-crystal display element of the light-scattering mode using a liquid crystal-polymer composite system, it is normal that it becomes the maximum in the low applied voltage area | region of 10 to 30% of transmittance normally. The inventors have found out.

In the case where the applied voltage-light transmittance characteristic is represented by the curve VTc shown in Fig. 6A, it is possible to reduce the optical hysteresis due to the reasons described below.

The applied voltages between the applied voltage-light transmittance curves VTa to VTc and the transmittance T ₁ (values in the range of 10 to 30% of the maximum transmittance for the maximum hysteresis width) are set to Va, Vb, and Vc, respectively. In this case, at each of the applied voltages Va to Vc, the optical hysteresis is ΔTa, ΔTb or ΔTc, respectively. As is apparent from Fig. 6A, the curved slope VTc has a smaller optical hysteresis than the curves VTa and VTb. This is evident from the relationship between the curves VTd and VTe shown in Fig. 6B. In other words, when the curve VTd and the curve VTe having different gradients are compared even when having the same hysteresis width DELTA V, the optical hysteresis at Vd is smaller in the curve VTe having a gentle gradient. In short, ΔTd> ΔTe. From this, the curve VTc can be discussed in the same way, that is, since the curve VTc has a gentler slope than the curves VTa and VTb, the optical hysteresis can be reduced.

The problem that optical hysteresis is a problem in display quality is that the transmittance differs depending on the display history of pixels when the same voltage is applied. As a result, when an image is displayed on a liquid crystal display element, it is recognized by an observer in the form of an afterimage or a sticking phenomenon. However, by setting it as the said structure, reduction of optical hysteresis is aimed at, and as a result, the afterimage resulting from the said optical hysteresis and seizure can be reduced.

In the following, invention groups A to C in the first invention group will be described next in order.

Invention Group A

The central technical idea of the group A of the present invention is that the liquid crystal-polymer composite layer has a configuration in which a plurality of regions having different applied voltage and light transmittance characteristics in one pixel are arranged in the direction perpendicular to the substrate surface and the gamma value is set to an optimum range. This aims to reduce both the optical hysteresis and the driving electrode. In more detail, in each embodiment mentioned below, it becomes clear.

(Embodiment A-1)

7 is a simplified cross-sectional view of the liquid crystal display device 101 according to Embodiment A-1 of the present invention. The liquid crystal display device 101 is a polymer dispersed liquid crystal disposed between an array substrate 102 and an array substrate 102 disposed between the array substrate 102 and the array substrate 102 and the array substrate 102. It has a layer 104 (liquid crystal, polymer composite layer). The array substrate 102 and the counter substrate 103 are, for example, transparent substrates made of glass. On the array substrate 102, a source line 105, a transparent pixel electrode 106, and a thin film transistor (TFT) 115 as a pixel switching element (active element) are formed. These source lines 105, the pixel electrodes 106, the TFTs 115, and the like are covered with the insulating film 107. A transparent counter electrode 109 is formed on the inner surface of the counter substrate 103, and the counter electrode 109 is covered by the insulating film 110.

In addition, the polymer dispersed liquid crystal layer 104 is composed of a polymer 111 and two kinds of liquid crystals 112 and 113. The liquid crystal in the liquid crystals 112 and 113 has a positive dielectric anisotropy. The liquid crystal droplet 112 is present in the polymer dispersed liquid crystal layer 104 and is formed in a substantially spherical shape like the liquid crystal droplet in a conventional polymer dispersed liquid crystal. On the other hand, the liquid crystal droplets 113 are formed on each of the insulating films 107 and 110, and are formed in a dome shape that swells into the polymer dispersed liquid crystal layer 104 inward. Specifically, the liquid crystal droplets 113 are formed in a hemispherical shape or a flat hemisphere shape in contact with a large circle on the insulating films 107 and 110. Therefore, as shown in FIG. 8, the particle diameter d ₁ of the liquid crystal droplet 112 is larger than the particle diameter d ₂ of the liquid crystal droplet 113. Here, the particle diameters d ₁ and d ₂ mean average particle diameters, and the term "liquid crystal grain size" means an average particle diameter. In addition, the particle size d ₂ of the liquid crystal droplet 113 means the maximum distance (particle diameter in the panel gap direction) between the surfaces bulged from the insulating films 107 and 110 and the insulating films 107 and 110. do.

On the other hand, although the liquid crystals 112 shown in FIG. 7 may be formed in the form which was partially connected, it is thought that in the case of such a shape broadly, two almost spherical liquid crystals exist. Therefore, the liquid crystal droplets in the polymer dispersed liquid crystal layer 104 are composed of two kinds of liquid crystal droplets 112 and 113 having different particle diameters.

In addition, the materials of the insulating films 107 and 110 are selected in advance so that the wettability of the insulating films 107 and 110 is greater than that of the polymer material. That is, when the surface tension γ _LC of the liquid crystal material for the insulating films 107 and 110 and the surface tension γ _p of the polymer material for the insulating films 107 and 110 are compared, γ _Lc &_lt; Insulating films 107 and 110 are used. As a result, the liquid crystal droplets 113 are formed. In addition, the size of the particle diameter d ₂ of the liquid crystal liquid 113 can be controlled by changing the materials of the insulating films 107 and 110.

In this way, the γ-value of the liquid crystal layer in the polymer dispersed liquid crystal layer 104 is composed of two kinds of liquid crystals 112 and 113 having different particle diameters. can do. Then, in the form A-1 of the present embodiment to adjust the size of the particle diameter d ₂ of the liquid crystal red (113), the γ value is set in the range of 2 or more, and 3.1 or less. As a result, both the optical hysteresis and the driving voltage can be reduced. In addition, the detailed reason regarding this is mentioned later.

Here, γ is a value when the drive voltage that the driving voltage is 90% of the maximum transmittance to the V _90, V ₁₀ to 10%, is defined as the ratio V ₉₀ / V _10. However, in the present invention, in addition to evaluating the value of γ as the ratio V ₉₀ / V ₁₀ as described later, the case may be evaluated at the ratio V ₅₀ / V ₁₀ . Therefore, in order to distinguish these two types of gamma values, it is assumed that the gamma value of the ratio V ₉₀ / V ₁₀ is _denoted by gamma _10-90 and the gamma value of the ratio V ₅₀ / V ₁₀ as gamma _10-50 .

Next, the reason why the optical hysteresis and the reduction of the driving voltage can be achieved by setting gamma _10-90 within the range of 2 or more and 3.1 or less as described above will be described in detail below.

Optical hysteresis is due to the fact that the arrangement of the liquid crystals inside the liquid crystal is different at the time of the voltage rise and fall.

However, in general, the transmitted light intensity of the liquid crystal panel is closely related to the alignment state of the liquid crystal molecules. In addition, it is considered that the optical hysteresis of the liquid crystal panel averages the magnitude of the optical hysteresis of the individual liquid crystals. Here, when the polymer dispersed liquid crystal layer in which the particle diameters of the liquid crystal droplets are almost the same has the applied voltage-light transmittance characteristic shown by the curve M1 of FIG. 9, the magnitude H of the optical hysteresis is shown by the curve M2 of FIG. That is, the size H of the optical hysteresis when the particle diameters of the liquid crystal drops are almost the same is large in the range of about 20% to 30% of panel transmittance, and is small at 30% or more. This is considered to be because the optical hysteresis becomes large even if averaged between the liquid crystals in order to obtain the maximum value of the optical liquid hysteresis of the plurality of liquid crystals at almost the same applied voltage. Therefore, if the applied voltage when the optical hysteresis takes the maximum value is different for each liquid crystal, it is considered that the optical hysteresis is averaged and the optical hysteresis of the entire liquid crystal panel is reduced.

As a result of intensive studies based on these ideas, the inventors have found that optical hysteresis becomes small when the liquid crystal droplets have different particle sizes in the liquid crystal panel. This is because the optical hysteresis is also averaged with each liquid crystal because the orientation upon application of voltage is different when the particle diameter is different. In general, when the liquid crystal group is small, the driving voltage increases, and when it is large, the driving voltage decreases. As described above, when the particle diameters are the same, the increase in optical hysteresis is in the range of 20% to 30%. Considering this point, when the particle diameters of the individual liquid crystal drops are different, as shown in FIG. 10, the peaks of the optical hysteresis are averaged by conceptually overlapping the applied voltage-light transmittance curves of the individual liquid crystal drops. Becomes small. Specifically, with reference to FIG. 10, assuming that two kinds of liquid crystals having different particle diameters exist, the applied voltage-transmittance characteristic when the particle diameter shown in FIG. 10A is large and the particle diameter shown in FIG. 10B are small It is considered that the applied voltage-light transmittance characteristic shown in Fig. 10 (c) including the applied voltage-light transmittance characteristic of is the applied voltage-light transmittance characteristic of the entire liquid crystal panel. As is apparent from Fig. 10 (c), the transmittance at which the optical hysteresis increases becomes a gentle curve in the range of 20% to 30%, which means that the peak of the optical hysteresis is averaged and the optical hysteresis becomes small. do. On the other hand, when the values of gamma in FIG. 10C and the values of gamma in FIGS. 10A and 10B are compared, the value of gamma in FIG. 10C is larger than the values of gamma in FIG. This means that when the liquid crystal group in the polymer dispersed liquid crystal layer is constituted by two kinds of liquid crystals having different particle diameters, the value of γ is increased as compared with the configuration having the same particle diameter. Therefore, it is understood that optical hysteresis is reduced by increasing the value of γ. Moreover, it is understood that the polymer dispersed liquid crystal layer may be composed of a plurality of regions having different applied voltage and light transmittance characteristics as a means for increasing the γ value from FIG. 10. And it is understood as one aspect of the means which enlarges (gamma) value, that liquid crystal phase in a high molecular weight type liquid crystal layer comprises liquid crystal with a different particle diameter.

However, if the value of γ is increased, the driving voltage also increases in response to this, and if the value of γ is too large, driving of the device becomes difficult in reality. For this reason, the upper limit of the gamma value is regulated. Therefore, in order to satisfy both the reduction of the optical hysteresis and the reduction of the driving voltage, an optimal range exists in the gamma value.

Fig. 11 shows experimental results of the inventors of the present invention regarding the relationship between optical hysteresis and gamma _10-90 . 11, it is recognized that γ _10-90 should be set to 2 or more in order for the optical hysteresis to be 2% or less. On the other hand, when γ _10-90 exceeds 3.1, V ₉₀ becomes 15 V or more, which makes driving difficult. Therefore, it is understood that the optimal range of gamma _10-90 is 2 or more and 3.1 or less.

In this manner, according to the above experimental results and the like, in the present embodiment A-1, the polymer dispersed liquid crystal layer is constituted by two kinds of liquid crystal droplets having different particle diameters, and the particle diameter d ₂ of the liquid crystal droplets 113 is adjusted, and The value is set to 2 or more and 3.1 or less. As a result, the optical hysteresis can be reduced and the driving voltage can be reduced.

As said example, as a (gamma) value, it evaluated by (gamma) _10-90 . However, as shown in Fig. 9, considering that the peak value of optical hysteresis exists between 20% and 30% of transmittance, it is also effective to evaluate using γ _10-50 . This is because, as the applied voltage-light transmittance curve in the range of 10% to 50% of the transmittance is gentler, the overlapping effect becomes larger and the optical hysteresis becomes smaller. According to the experimental results of the present inventors, in order to make optical hysteresis 2% or less, gamma _10-50 needed to be 1.1 or more and 1.8 or less (refer FIG. 15). In addition, this advantage is explained in full detail in Example A-1 mentioned later.

(Embodiment A-2)

12 is a simplified cross-sectional view of a liquid crystal display element 101B according to Embodiment A-2 of the present invention. In Embodiment A-2, a polymer dispersed liquid crystal layer having a two-layer structure having different particle diameters is used to form a plurality of regions having different applied voltage and light transmittance characteristics. Parts corresponding to the embodiment A-1 are denoted by the same reference numerals and detailed description thereof will be omitted. In Embodiment A-2, two polymer dispersion liquid crystal layers 120 and 121 are stacked as a polymer dispersion liquid crystal layer. The polymer dispersed liquid crystal layer 120 is composed of a polymer 122 and a liquid crystal droplet 123. The polymer dispersed liquid crystal layer 121 is composed of a polymer 124 and a liquid crystal droplet 125. The particle diameters of the liquid crystal droplets 123 and the liquid crystal droplets 125 are different. That is, the particle diameter of the liquid crystal droplets 123 is set smaller than the particle diameter of the liquid crystal droplets 125. As a result, the polymer dispersed liquid crystal layer is formed in two regions where the applied voltage and the light transmittance characteristics are different from the whole display element. Therefore, optical hysteresis can be reduced by the same action as in Embodiment A-1. In addition, also in this Embodiment A-2, (gamma) ₁₀₉₀ is 2 or more and 3.1 or less like Embodiment A-1. This makes it possible to achieve both optical hysteresis and reduction in driving voltage as in Embodiment A-1.

In addition, even if considered as good γ _10-50 as form A-1 of the embodiment, in this case, a balance between the reduction of reduced and the drive voltage of the optical hysteresis is set in the range of more than 1.8 or less _10-50 1.1 γ We can plan.

In the present embodiment A-2, the polymer dispersed liquid crystal layer 120 and the polymer dispersed liquid crystal layer 121 are brought into close contact with each other to form one structural unit as the polymer dispersed liquid crystal layer. Although the present invention group A is not limited to this at all. For example, as shown in FIG. 13, a film-like sheet having transparent electrode layers 131 and 132 on both sides is retrofitted between the polymer dispersed liquid crystal layer 120 and the polymer dispersed liquid crystal layer 121. You may let it. Even in such a configuration, optical hysteresis can be reduced by forming a polymer dispersed liquid crystal layer composed of two regions having different applied voltage and light transmittance characteristics in one pixel. Furthermore, even if the thicknesses of the polymer dispersed liquid crystal layer 120 and the polymer dispersed liquid crystal layer 121 are different, optical hysteresis can be reduced. In this case, the particle diameters of the liquid crystal droplets 123 and the liquid crystal droplets 125 may be the same.

(Example A)

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the drawings described above. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention to them only, unless specifically stated otherwise. Do.

Example A-1

It is an Example corresponding to Embodiment A-1, and the liquid crystal display element 101 was manufactured with the following method.

On an array substrate 102 having a pixel electrode 106, a source line 105, and a TFT 115, AL3046 (trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.) as an insulating film material was applied by spin coating. The thickness at the time of application | coating was 1000 kPa. Furthermore, it heated in the oven to predetermined | prescribed temperature, and hardened | cured so that the insulating film 107 was formed. On the other hand, the insulating film 110 was formed on the counter substrate 103 having the counter electrode 109 in the same manner as the insulating film 107. Then, the array substrate 102 and the counter substrate 103 were bonded to each other with a panel gap of 10 μm through a sealant to prepare an empty panel.

Subsequently, 89% by weight of 2-ethylhexyl acrylate as the polymerizable monomer, 9% by weight of Biscot 828 (trade name, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and 1% by weight of the polymerization initiator were mixed as an oligomer. 80 wt% of liquid crystal material TL205 (trade name, manufactured by Melk Co., Ltd.) was mixed with 20 wt% of the polymer precursor mixture to prepare a liquid crystal and polymer precursor solution.

Subsequently, a liquid crystal-polymer precursor solution was injected between the panels, and the polymer dispersed liquid crystal layer 104 was produced by irradiating ultraviolet rays. At this time, polymerization temperature was 20 degreeC and ultraviolet intensity was 100 mW / cm <^2> .

Finally, the injection port was sealed with a sealing agent to produce a polymer dispersed liquid crystal display device 101.

The electro-optical properties of the produced polymer dispersed liquid crystal display device 101 were measured at 30 ° C. Γ _{10 -90} was 2.5 and the maximum value of optical hysteresis was 0.8%. In addition, even when the display was performed, no layer distortion occurred, and good display was obtained. In addition, the surface tensions of the polymer precursor and the liquid crystal material with respect to the insulating film were measured separately, and the surface tension of the liquid crystal material with the polymer precursor of 28 dyne / cm was smaller than that of the polymer precursor with respect to 27 dyne / cm for the liquid crystal material. . In addition, the liquid crystal panel after UV polymerization was cut and the cross-section of the polymer dispersed liquid crystal layer 104 was observed under a microscope. As a result, the liquid crystal region 112 in the layer was almost spherical, and liquid crystal ( 113 has a hemispherical shape in contact with the insulating films 107 and 110, and it is confirmed that the particle diameter of the liquid crystal droplets is different in the liquid crystal panel.

Subsequently, the type of the insulating film and the temperature at the time of curing the insulating film material were changed, and the γ value and the optical hysteresis were measured. The result is shown in FIG. From the figure, there is a strong correlation between the value of gamma and optical hysteresis, and it is recognized that gamma _10-90 should be 2 or more in order to make optical hysteresis 2% or less. Moreover, as γ _10-90 increases, V ₉₀ also increases, and when γ _10-90 exceeds 3.1, V ₉₀ becomes 15 V or more, which makes driving difficult. For this purpose, there is an optimum range for the value of γ, and γ _10-90 is set to 2 or more and 3.1 or less, so that both optical hysteresis and reduction of driving voltage are compatible.

In the above example, the range in which the optical hysteresis becomes 2% or less is shown, but this can be changed in the range of the gamma value in accordance with an appropriate need. For example, when optical hysteresis 1% or less is required in a moving image display requiring multi-layer tone display or the like, γ _10-90 needs to be 2.25 or more and 3.1 or less in FIG. 11.

As shown in Fig. 14, the present inventors found that there is a convex correlation upward between gamma _l0-90 and gamma _l-50 . V ₉₀ in the case where γ _{10 -90} is large is determined by the particle size of the liquid crystal region of the substrate interface. For this reason, when γ _{10 -90} is large, the applied voltage-light transmittance characteristic is larger in inclination between V ₅₀ and V ₉₀ than inclination between V ₁₀ and V ₅₀ . Thus, there is a convex upward correlation between γ _l0-90 and γ _10-50 .

Moreover, the relationship between gamma _10-50 and optical hysteresis is shown in FIG. At this time, there was a strong correlation between γ _10-50 and optical hysteresis. When optical hysteresis is defined as gamma _10-50 , gamma _10-50 needs to be 1.1 or more and 1.8 or less in order to make optical hysteresis 2% or less. Moreover, in order to make optical hysteresis 1% or less, it is necessary to make gamma _10-50 1.3 or more and 1.8 or less.

The value of γ may be basically any of γ _10-90 and γ _10-50 . When γ _10-50 is used, there is an effect that the correlation with optical hysteresis is stronger, and higher accuracy of optical hysteresis can be evaluated. In addition, using γ _10-90 has the effect of analyzing both the driving voltage width and the magnitude of the optical hysteresis.

In addition, the insulating film may be formed in a hemispherical shape on the substrate without using the above example. The insulating film may be changed into an upper and lower substrate. If the insulating film differs from the upper and lower substrates, the particle diameter of the liquid crystal droplet 113 in contact with the array substrate 102 and the liquid crystal droplet 113 in contact with the opposing substrate 103 can be different, whereby the? Value is further arbitrarily selected. Can change.

In this embodiment, the device was fabricated by phase-separating the liquid crystal and the polymer by ultraviolet polymerization, but this may be thermal phase separation. In addition, the material and polymerization conditions of the liquid crystal and the polymer are not limited to the above examples. As the above example, the liquid crystal panel is a transmissive liquid crystal panel using a glass substrate, but this may be a reflective liquid crystal panel using an opaque substrate on one side. Moreover, you may provide a color filter layer in one side of a board | substrate like a transmission type and a reflection type.

Example A-2

It is an Example corresponding to Embodiment A-2, and the liquid crystal display element 101B was produced with the following method.

After the array substrate 102 and the glass substrate coated with the release agent were bonded to each other with a gap of 4 μm, a liquid crystal / polymer precursor solution having a liquid crystal fraction of 77% in the same composition as in Example A-1 was injected. Subsequently, the panel was kept at 20 ° C. and irradiated with ultraviolet rays having a strength of 100 mW / cm ² to polymerize the liquid crystal and the polymer precursor. Subsequently, the glass substrate coated with the release agent was peeled off, thereby forming a polymer dispersed liquid crystal layer 120 having a thickness of 4 μm. Next, the array substrate 102 with the polymer dispersed liquid crystal layer 120 and the counter substrate 103 are bonded to each other so that the space between the polymer dispersed liquid crystal layer 120 and the counter substrate 103 becomes 7 μm. Thereafter, a liquid crystal-polymer precursor solution having a liquid crystal fraction of 80% was injected. Next, the panel was kept at 20 ° C. to irradiate ultraviolet rays of 100 mW / cm ² of irradiation intensity to polymerize the liquid crystal / polymer precursor to produce a polymer dispersed liquid crystal display device 101B. At this time, the particle diameter of the liquid crystal droplet 123 of the polymer dispersed liquid crystal layer 120 manufactured with the liquid crystal fraction 77% was 0.9 μm, and the liquid crystal droplet (125) of the polymer dispersed liquid crystal layer 121 produced with the liquid crystal fraction 80%. ) Was 1.4 µm.

As a result of measuring the electro-optic characteristics of the panel, the average voltage and transmittance characteristics of the two layers with different particle diameters resulted in γ _10-90 being 2.3 and optical hysteresis being reduced to 1%. Obtained. On the other hand, γ _10-50 was 1.3.

In this embodiment, the device was fabricated by laminating two layers of the polymer dispersed liquid crystal layer, but this may be two or more layers. By using the above method of peeling off the glass substrate after polymerization, the polymer dispersed liquid crystal layer can be easily and largely laminated.

The layer thickness and the particle size of the liquid crystal droplet of the polymer dispersed liquid crystal layer can be selected in consideration of scattering properties, γ values, and the like, regardless of the above values. At this time, in consideration of suppressing the increase of the driving voltage and securing scattering property, the polymer thickness of the polymer dispersed liquid crystal layer having the liquid crystal region having the small particle diameter is determined by the layer thickness of the polymer dispersed liquid crystal layer having the liquid crystal region having the large particle diameter. It is necessary to make it larger than the layer thickness of 120). This is because a layer having a particle size of about 1.4 μm has an effect of increasing scattering property, and a layer having a particle size of 1 μm or less has an effect of increasing V ₉₀ to increase γ value. Therefore, the layer having a small particle diameter has an effect of raising V ₉₀ even though it is relatively thin as about 1 to 3 liquid crystals, but the layer having a large particle size requires about 6 to 10 liquid crystal layers in order to produce scattering properties. .

In the above example, an insulating film is not provided on the substrate, but an insulating film may be provided, which is effective in improving the voltage holding ratio. In addition, as described in Example A-1, the insulating film has an effect of increasing γ value. To this end, by providing an insulating film and a plurality of polymer dispersed liquid crystal layers, the γ value can be more easily changed.

As described above, according to the present invention group A, by setting the gamma value (γ _10-90 or gamma _10-50 ) to an optimum range, it is possible to achieve both reduction of optical hysteresis and reduction of driving voltage. Get

(Invention Group B)

The central technical idea of this invention group B is as follows. It is considered that the expression of optical hysteresis in PDLC is related to the regulating force (hereinafter, simply referred to as interfacial regulation force) acting on the liquid crystal / polymer matrix interface. In addition, in order to reduce optical hysteresis, it is considered necessary to strengthen the interfacial control force. However, there has been no precise means to control this interfacial force until now.

Therefore, the inventors of the present invention have attempted to solve the optical hysteresis with the configuration mentioned below (Japanese Patent Laid-Open No. 11-14974). That is, in the polymer dispersed liquid crystal display device in which a liquid crystal-polymer composite layer was formed between a pair of substrates provided with electrodes, an insulating film was formed on the electrodes. Then, the inventors have found that the above problems can be solved by satisfying the relationship between the critical surface tension of the insulating film material and the surface tension of the liquid crystal represented by the following formula (B-1).

γ _LC -γ _p <0.. (B-1)

As a result, the optical hysteresis can be improved. However, since the liquid crystal and insulating film which satisfy | fill the said Formula (B-1) are limited, it was necessary to develop an insulating film so that the relationship of said Formula (B-1) may hold also for various various liquid crystals.

Group B of the present invention has obtained the idea of the above-described points, and by providing an insulating film capable of controlling the critical surface tension, an insulating film showing wettability with respect to various liquid crystals is formed and thereby applied in one pixel. The structure having a plurality of regions having different voltage-light transmittance characteristics in the direction perpendicular to the substrate surface is used to suppress the reduction of optical hysteresis and the deterioration of the response. In more detail, it becomes clear according to embodiment mentioned below.

(Embodiment B)

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described according to drawing.

Embodiment B of this invention is demonstrated according to FIG. 16 and FIG. 17 as follows. However, parts unnecessary for the description are omitted, and there are parts shown to be enlarged or reduced in order to facilitate explanation. The above is also the same with respect to the following drawings.

16 is a schematic sectional view showing an outline of a liquid crystal display device 201 according to the present invention. The liquid crystal display device 201 is a liquid crystal and a polymer disposed between the array substrate 202 and the array substrate 203 opposed to the array substrate 202 and the array substrate 202 and the array substrate 203. It has a composite layer 204. The array substrate 202 to the counter substrate 203 are, for example, transparent substrates made of glass. On this array substrate 202, a thin film transistor (TFT) as a pixel switching element, a metal wiring (scanning signal line, image signal line), a transparent pixel electrode 206, and the like are formed. These metal wires, the TFT, the pixel electrode 206 and the like are covered with the insulating film 207. In addition, in FIG. 16, metal wiring, TFT, etc. are abbreviate | omitted in order to make understanding of invention content easy.

A transparent counter electrode 209 is formed on the inner surface of the counter substrate 203, and the counter electrode 209 is covered with an insulating film 207. The pixel electrode 206 and the counter electrode 209 are made of, for example, indium tin oxide (ITO).

The liquid crystal-polymer composite layer 204 is basically a polymer dispersed liquid crystal (PDLC) layer having a structure in which liquid crystals are independently dispersed in a polymer matrix. However, in the present embodiment, the liquid crystal and polymer composite layer 204 is composed of a polymer resin 211 (polymer) and two kinds of liquid crystals 212 and 213, unlike a normal PDLC layer. The liquid crystal 210 in the liquid crystal droplets 212 and 213 has a positive dielectric anisotropy. The liquid crystal droplets 212 exist inside the liquid crystal and polymer composite layer 204, and are formed in a substantially spherical shape like the liquid crystal droplets in a normal polymer dispersed liquid crystal. On the other hand, the liquid crystal droplets 213 are formed on each insulating film 207 and are formed in a dome shape which swells to the inner side of the liquid crystal and polymer composite layer 204. Specifically, the liquid crystal droplets 213 are formed in a hemispherical shape or a flat hemisphere shape in contact with a large circle on the insulating film 207. On the other hand, the liquid crystal-polymer composite layer 204 is not limited to the PDLC layer, but may be a polymer network liquid crystal layer in which a liquid crystal is held in a three-dimensional network polymer. In addition, the array substrate 202 and the counter substrate 203 are bonded to each other and sealed by the space-sealing resin 220.

The insulating film 207 is made of at least two kinds of materials having different critical surface tensions, and more specifically, the surface of the first insulating film material and the liquid crystal 210 having a critical surface tension smaller than the surface tension of the liquid crystal 210. And a second insulating film material having a critical surface tension greater than tension. With such a configuration, the interfacial tension can be controlled at the interface between the insulating film 207 and the polymer material by appropriately changing the mixing ratio of the first and second insulating film materials, or the threshold of the insulating film 207 can be controlled. Surface tension can be controlled. It does not specifically limit as said 1st insulating film material, For example, a fluorine-type surfactant etc. are mentioned. In addition, it does not specifically limit as a 2nd insulating film material, For example, polyimide resin etc. are mentioned.

Here, it is possible to characterize the present invention to have an insulating film 207 that can be appropriately responded to various liquid crystals so as to satisfy the relationship of the following formulas (B-1) to (B-3). By the insulating film 207, the optical hysteresis can be reduced and the response can be improved regardless of the type of liquid crystal.

γ _LCp -γ _ip <0.. (B-1)

-1 <gamma _LCp- gamma _ip <1... (B-2)

-1 <gamma _LCp -gamma _ip <0... (B-3)

(In the formula, γ _ip (dyne / cm) represents the interfacial tension between the insulating film and the polymer material, and γ _LCp (dyne / cm) represents the interfacial tension between the liquid crystal and the polymer material.)

This is described in detail below. 17 is a cross-sectional view schematically showing the existence of liquid crystal droplets in the vicinity of the insulating film 207. In the present invention, the following conditions are assumed. That is, it is assumed that the interfacial tension between the polymer material and the liquid crystal is constant in the phase separation process. Therefore, in this invention, in order to make this interface tension constant, the material of a liquid crystal and a polymeric material is being fixed. Alternatively, the materials of both the liquid crystal and the polymer material are appropriately changed so that the interfacial tension is constant.

First, the insulating film 207 is formed by changing the compounding ratio of the first and second insulating film materials so that the relationship of Formula (B-1) holds. As a result, the optical hysteresis can be reduced. In more detail, it is as follows. That is, in the phase separation process between the polymer material and the liquid crystal when the liquid crystal and polymer composite layer 204 is formed, a spherical liquid crystal group is first formed. The liquid crystal droplets in the vicinity of the liquid crystal stack insulating film 207 are wetted in contact with the insulating film 207, thereby forming a dome-shaped liquid crystal droplet 212 (see Fig. 17A). Under this environment, the liquid crystal 210 inside the liquid crystal droplets 212 is subjected to strong alignment control force from the insulating film 207. In particular, the alignment control force by the insulating film 207 also affects the liquid crystal 210 present in the vicinity of the polymer resin 211. Therefore, when the electric field is turned from the ON state to the OFF state, the alignment regulating force of the insulating film 207 serves to assist the interfacial regulating force of the polymer resin 211. As a result, the transition of the liquid crystal 210 in the liquid crystal droplet 212 including the polymer resin 211 in the vicinity occurs smoothly. This means that the applied voltage-transmittance characteristic is different in the vicinity of the insulating film 207 on which the dome-shaped liquid crystal droplets 212 are formed and in the central portion of the liquid crystal-polymer composite layer 204. In other words, the applied voltage-light transmittance characteristics in the vicinity of the insulating film 207 shows the characteristics shifted to the strong voltage side in comparison with the applied voltage-light transmittance characteristics in the center portion. The liquid crystal-polymer composite layer 204 has a structure in which two regions having different applied voltage and light transmittance characteristics in one pixel are provided in the direction perpendicular to the substrate surface. Therefore, although individual characteristics are different from each other, the steepness in which these characteristics overlap as a characteristic of the whole display element becomes moderate. As a result, optical hysteresis is considered to be small.

Next, by forming the insulating film 207 so as to satisfy the relationship of the formula (B-2), responsiveness can be improved. This will be described by dividing the liquid crystal 210 into a case where the liquid crystal 210 is wet with the insulating film 207 and a case where the liquid crystal 210 is not wet. First, when the liquid crystal 210 is wet with respect to the insulating film 207, (γ _LCp -γ _ip ) exceeds -1 dyne / cm and is within a range smaller than 0 (see FIG. 17A). Here, by changing the compounding ratio of the first and second insulating film materials, the height d is controlled so as not to be too small in the film thickness direction of the liquid crystal droplet 212 shown in FIG. 17A. Therefore, the liquid crystal 210 inside the liquid crystal droplets 212 receives an appropriately strong alignment control force from the insulating film 207. In particular, the alignment control force by the insulating film 207 also affects the liquid crystal 210 present in the vicinity of the polymer resin 211. Therefore, when the electric field is turned from the 0N state to the OFF state, the orientation regulating force of the insulating film 207 serves to assist the interfacial regulating force of the polymer resin 211. As a result, the transition of the liquid crystal 210 in the liquid crystal droplets 212 including the vicinity of the polymer resin 211 occurs smoothly, so that the liquid crystal descends quickly. As a result, it is considered that the responsiveness is improved as compared with the case where the liquid crystal group becomes wet with the insulating film and the height d becomes extremely small. When the height d becomes extremely small, the descending speed becomes faster, whereas the ascending speed becomes slower, and the response speed as the sum of the ascending speed and the descending speed eventually becomes slow. Therefore, the response can be improved in the state which receives appropriate strong orientation control force, ie, the state controlled so that height d will not become small too much.

On the other hand, when the liquid crystal 210 is not wet with the insulating film 207, (γ _LCp -γ _ip ) is within a range of 0 or more and smaller than 1 (see Fig. 17B). Here, the liquid crystal liquid 213 has a spherical shape or an ellipsoidal shape. The liquid crystal 210 inside the liquid crystal 213 is indirectly affected by the alignment control force of the insulating film 207. This is because the distance between the pair of insulating films 207 and 207 is very short, and the interaction between the insulating film 207 and the liquid crystal 213 or indirectly through the polymer resin 211, for example, van der Does it apply to the force of the liquid, the polar-polar interaction force, etc., and this interaction also affects the liquid crystal 213 inside the liquid crystal-polymer composite layer 204 far from the surface of the insulating film 207. And inferred. As a result, it is considered that the liquid crystal 210 smoothly descends due to the same reason as described above, so that the liquid crystal is lowered and the response is improved.

On the other hand, when (γ _LCp -γ _ip ) is outside the numerical range shown by said formula (B-2), it becomes as follows. That is, when (γ _LCp -γ _ip ) is -1 dyne / cm or less, the wettability is improved. Therefore, the contact area with respect to the insulating film 207 of the liquid crystal area 212 becomes large, and therefore the height d becomes small. Therefore, since the liquid crystal 210 inside the liquid crystal droplets 212 receives excessively strong alignment control force of the insulating film 207, the response that occurs when an electric field is applied is impaired. As a result, the response speed becomes slow. On the other hand, when (γ _LCp -γ _ip ) is 1 · dyne / cm or more, since the liquid crystal 210 is not influenced by the orientation control force of the insulating film 207 when it is turned from the ON state to the OFF state, the transition of orientation is It doesn't happen smoothly. Therefore, the descending response of the liquid crystal 210 is impaired, and the response speed is also slowed.

Subsequently, by forming the insulating film 207 so as to satisfy the relationship of the formula (B-3), both optical hysteresis and responsiveness can be improved. This is because (γ _LCp -γ _ip ) is preferably in a range where the above formulas (B-1) and (B-2) overlap in order to make both optical hysteresis and responsiveness appropriate.

In the formulas (B-1) to (B-3), the interfacial tension between the insulating film 207 and the polymer material is replaced with the critical surface tension γ _i (dyne / cm) of the insulating film 207, and the liquid crystal The interfacial tension between the polymer material and the polymer material may be substituted by the surface tension γ _LC (dyne / cm) of the liquid crystal, and may be represented as shown in the following formulas (B-4) to (B-6). The reason is mentioned below.

γ _LC -γ _i <0.. (B-4)

-1 <gamma _LC -gamma _i <1... (B-5)

-1 <gamma _LC -gamma _i <0... (B-6)

As mentioned earlier, the wettability can be considered from the balance of interfacial tension of the liquid, solid, etc. in contact. In other words, the interfacial tension at the interface between the insulating film 207 and the polymer material, the interfacial tension at the interface between the liquid crystal and the insulating film 207 (solid), and the three-way balance of the interfacial tension at the interface between the polymer material and the liquid crystal. It is thought that wet phenomenon occurs. On the other hand, when the liquid crystal and the polymer material are considered to be fixed, the interface tension can be made constant at both interfaces. In this case, the wettability is determined by the relationship between the interfacial tension between the insulating film 207 and the polymer material and the interfacial tension at the interface between the liquid crystal and the insulating film 207 (solid). This considers the polymer material as a gas, thereby changing the interfacial tension between the liquid crystal and the polymer material to the surface tension of the liquid crystal, and converting the interfacial tension between the insulating film 207 and the polymer material to the surface of the insulating film 207. This is true even if it is replaced with the critical surface tension. Therefore, the wettability can also be evaluated by the magnitude relationship between the surface tension of the liquid crystal and the critical surface tension of the insulating film 207. From the above, also in the case where the relationship shown in the formulas (B-4) to (B-6) is established, the same effects and effects as in the formulas (B-1) to (B-3) can be obtained.

The critical surface tension γ _i of the insulating film 207 is preferably larger than the critical surface tension γ _s of the array substrate 202 and the counter substrate 203 in order to form the insulating film 207 having a uniform film thickness. . When γ _i is smaller than γ _s , it is not preferable because the formation of the insulating film 207 having a uniform film thickness and critical surface tension becomes difficult. This is based on the reason mentioned below. In general, the thinner the film thickness, the larger the film thickness error tends to be. In addition, when the film thickness is thin, there is a possibility that the critical surface tension of the array substrate 202 or the counter substrate 203 is added. On the other hand, when the insulating film material gets wet with the array substrate 202 or the counter substrate 203, the insulating film material becomes thinner, so that an insulating film having a small film thickness is formed. Therefore, it becomes difficult to form the insulating film 207 having a uniform film thickness and critical surface tension. For the above reason, it is preferable that? _I >? _S to form an insulating film 207 having a small film thickness error and having a film thickness that is not affected by the array substrate 202 or the counter substrate 203.

Next, the manufacturing method of the liquid crystal display element which concerns on this invention is demonstrated below. 18 is a flowchart for explaining the manufacturing steps of the liquid crystal display element.

First, on the array substrate 202, a thin film transistor and a pixel electrode 206 are formed by a conventionally known method (S201).

In addition, an insulating film forming step of forming an insulating film 207 on the inner surface of the pixel electrode 206 is performed (S202). First, a solution for forming an insulating film in which the first insulating film material and the second insulating film material are dissolved in an organic solvent to a predetermined mixing ratio is prepared. This insulating film formation solution was applied onto the array substrate 202, and then fired at a predetermined temperature and time to evaporate the organic solvent. This forms an insulating film 207 on the pixel electrode 206. Here, the coating method of the solution for forming an insulating film is not particularly limited, and can be performed by a conventionally known method. Specifically, for example, the spinner method, the roll coat method, the dipping method, the spray method, the screen printing method, the brushing method and the like can be mentioned. On the other hand, on the counter substrate 203, after forming the counter electrode 209 by a conventionally well-known method (S203), the insulating film 207 is formed by performing the above process.

Subsequently, the spacer and the sealing resin 220 are applied on either of the array substrate 202 or the counter substrate 203 so that the coating shape becomes a residual pattern in which portions of the liquid crystal inlet are formed. Then, the array substrate 202 and the counter substrate 203 are bonded to each other so that the insulating films 207 and 207 face each other to form an empty cell (S205). A liquid crystal and a polymer mixture layer are injected into the empty cell to form a liquid crystal and a polymer material (S206).

Then, a liquid crystal-polymer composite layer forming step of forming a liquid crystal-polymer composite layer 204 by phase separation by polymerization of a polymer material is performed (S207). For example, when forming the liquid crystal-polymer composite layer 204 by the photopolymerization phase separation method, it is performed as follows. That is, ultraviolet-ray which uses high pressure mercury lamp as a light source is irradiated to the said liquid crystal polymer mixture layer. At this time, the commercially available polymer material and the liquid crystal are minutely separated by phase separation as the polymerization of the polymer material proceeds and microparticles are deposited. This minute droplets aggregate with other minute droplets in the vicinity and gradually grow large in liquid crystal form. Here, for example, when the insulating film 207 is formed so as to satisfy the relationship of the formula (B-1), when the liquid crystal group in the vicinity of the insulating film 207 is in contact with the surface of the insulating film 207, the dome-shaped liquid crystal 212 is formed. On the other hand, the phase-separated polymer material is also solidified to form the liquid crystal-polymer composite layer 204.

Furthermore, in the case of performing the photopolymerization phase separation method, it is preferable to add a polymerization initiator to the polymer material in order to facilitate the polymerization of the polymer material smoothly. As the polymerization initiator, for example, generally commercially available polymerization initiators such as Darocure 1173, Darocure 4265, or Irgacure 184 manufactured by Chiba Co., Ltd. can be used. You may use combining these polymerization initiators 2 or more types. Moreover, as irradiation conditions, it is preferable to make irradiation intensity of ultraviolet-ray 20-200mw / cm <^2> , irradiation time 10-60sec. Although ultraviolet light does not care about the kind of the source, it may cut ultraviolet light of short wavelength which cannot destroy the liquid crystal molecules, or may be irradiated through a predetermined filter when irradiated for a predetermined intensity. Further, the material and thickness of the array substrate 202 and the counter substrate 203 and the wavelength of the ultraviolet ray may be irradiated with the intensity considering the amount of ultraviolet rays absorbed by the substrate.

(Example B)

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention to them only, unless specifically stated otherwise. Do.

Example B-1

The liquid crystal display element concerning Example B-1 has the structure similar to the said embodiment, and it produced as follows.

First, a thin film transistor and a pixel electrode 206 were formed on the array substrate 202 in the same manner as in Embodiment B.

Next, an insulating film 207 was formed on the inner surface of the pixel electrode 206. That is, for insulating film formation in which 3 parts of AL1051 (trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.) containing 1% by weight of a fluorine-based surfactant (trade name: FC430, manufactured by 3M Corporation) are dissolved in 97 parts of γ-butyrolactone The solution was prepared. This insulating film forming solution was applied onto the array substrate 202 with a spinner, and then fired at 180 ° C. for 1 hour. Application | coating by the said spinner was performed for 30 second by the rotation speed of 3,000 rpm.

Here, the critical surface tension γ _i of the insulating film 207 at the temperature of 20 ° C. was obtained by the Jiesman plot method. That is, wettability test standard reagents (manufactured by Nakaray Tesque Co., Ltd.) having various surface tensions were attached to the surface of the insulating film 207 to measure the respective contact angles θ. Next, the surface tension of cosθ = 1 was plotted on the horizontal axis and the various wettability standard reagents on the vertical axis, and the surface tension was defined as the critical surface tension γ _i of the insulating film 207. As a result, γ _i was 32.6 dyne / cm. Further, the critical surface tension of the array substrate 202 with the pixel electrode 206 was found to be 27.9 dyne / cm (20 DEG C).

On the other hand, after the counter electrode 209 was formed on the counter substrate 203 by the same method as in the above-mentioned embodiment B, the insulating film 207 was formed by performing the above process. Next, on the counter substrate 203, an acid anhydride curable epoxy resin as a spacer and sealing resin 220 was formed so as to have an after-image pattern in which a coated shape formed a portion of the liquid crystal inlet. The acid anhydride cured epoxy resin is previously dispersed with a rod-like glass fiber having a diameter of 13 µm. The array substrate 202 and the opposing substrate 203 were joined while pressing the insulating films 207 to face each other. In addition, the spacer and real paper 220 was cured by heating at 150 ° C. for 2 hours to produce an empty cell.

Subsequently, as a material for forming the liquid crystal-polymer composite layer, 15 parts of 2-ethylhexyl acrylate (manufactured by Nakaray Tesque Co., Ltd.), 4 parts of HX620 (trade name, manufactured by Nippon Kayaku Co., Ltd.), and monovalent as a polymerization initiator A mixed composition consisting of 0.3 parts of Cure 651 (trade name, manufactured by Chiba-Geigi Co., Ltd.) and 80.7 parts of liquid crystal material (trade name: TL-213, manufactured by Melk Co., Ltd.) was prepared. Surface tension (gamma) _LC of the said liquid crystal was measured by the hit method, and it was 30.3 dyne / cm (20 degreeC).

The liquid crystal polymer mixture layer was formed by injecting the mixed composition into the liquid crystal inlet by vacuum injection and sealing the liquid crystal inlet. This liquid crystal polymer mixture layer was irradiated with ultraviolet rays using a high-pressure mercury lamp as a light source to form a liquid crystal-polymer composite layer 304. As irradiation conditions, the irradiation intensity was about 50 mW / cm ² at a wavelength of 365 nm, and the irradiation time was 60 seconds. In addition, irradiation of the ultraviolet-ray was performed through the optical cut filter (brand name: UV35, Toshiba-colored glass company make).

With respect to the liquid crystal display device according to Example B-1 obtained as described above, voltage hysteresis and response time were measured at 20 ° C. The results are shown in Table B-1 below.

TABLE B-1

Concentration of FC430 (wt%) Critical surface tension γ _i (dyne / cm) of insulating film * γ _LC -γ _i (dyne / cm) H _v (%) τ _r + τ _d (ms) Example B-1 One 32.6 -2.3 0.2 82.3 Example B-2 2 32.0 -1.7 0.3 70.1 Example B-3 3 31.3 -1.0 0.5 48.2 Example B-4 4 30.9 -0.6 0.6 39.2 Example B-5 5 30.3 0.0 0.7 34.1 Example B-6 6 29.7 +0.6 2.1 38.5 Example B-7 7 29.3 +1.0 4.2 45.6 Comparative Example B-1 0 33.3 -3.0 0.1 99.8 Comparative Example B-2 8 28.8 +1.5 6.3 65.2

* γ _LC = 30.3 dyne / cm

According to the result of Table B-1, the relationship between voltage hysteresis and (γ _LC -γ _i ) and the response time and (γ _LC -γ _i ) are shown in FIGS. 19 and 20, respectively.

On the other hand, voltage hysteresis H _v (%) was defined as shown in the following formula (B-7).

H _v (%) = (V _{50 ↑} -V _{50 ↓} ) / V _{50 ↑} × 100... (B-7)

Here, V50 _↑ (V) and V50 _↓ (V) in the formula were defined as follows. First, using the LCD5000 manufactured by Daesong Electronics Co., Ltd., the voltage-light transmittance characteristics when changing from the scattering state to the transmission state (when the voltage rises) and when changing from the transmission state to the scattering state (when voltage drop) The voltage-transmittance characteristics of) were measured, respectively. Moreover, the voltage at the time of 50% change of transmittance | permeability was calculated | required according to each voltage-transmission characteristic, respectively, and these were set as V50 _↑ or V50 _↓ . In H _v (%) defined as described above, the smaller the value, the smaller the voltage hysteresis.

In the present embodiment, the performance of the liquid crystal display device is evaluated by measuring voltage hysteresis, but this is based on the fact that the change in voltage hysteresis is related to the change in optical hysteresis. That is, when voltage hysteresis decreases, optical hysteresis can also be considered to be reduced, and it can be said that the display quality deterioration resulting from the optical hysteresis can be prevented.

In addition, evaluation of response speed was performed using the response time defined as follows. That is, daesong Electronic Industry Co., Ltd. If the response time τ _r and the transmittance in the case where using the LCD5000 transmittance of manufacture was changed from 10% to 90% (when the voltage rise) was changed from 90% to 10% (voltage drop The response time τ _d of h) was obtained, respectively. The sum of these response times (τ _r + τ _d ) was taken as the response time of the liquid crystal display element.

Example B-2

The liquid crystal display device according to Example B-2 shown in Table B-1 was fabricated in the same manner as in Example B-1 except that the concentration of FC430 as the insulating film material was changed to 2% by weight. As shown in Table B-1, voltage hysteresis and response time were measured at 20 ° C in the same manner as in Example B-1.

Example B-3

The liquid crystal display device according to Example B-3 shown in Table B-1 was fabricated in the same manner as in Example B-1 except that the concentration of FC430 as the insulating film material was changed to 3% by weight. As shown in Table B-1, voltage hysteresis and response time were measured at 20 ° C in the same manner as in Example B-1.

Example B-4

The liquid crystal display device according to Example B-4 shown in Table B-1 was produced in the same manner as in Example B-1 except that the concentration of FC430 as the insulating film material was changed to 4% by weight. As shown in Table B-1, voltage hysteresis and response time were measured at 20 ° C in the same manner as in Example B-1.

Example B-5

The liquid crystal display device according to Example B-5 shown in Table B-1 was fabricated in the same manner as in Example B-1 except that the concentration of FC430 as the insulating film material was changed to 5% by weight. As shown in Table B-1, voltage hysteresis and response time were measured at 20 ° C in the same manner as in Example B-1.

Example B-6

The liquid crystal display device according to Example B-6 shown in Table B-1 was fabricated in the same manner as in Example B-1 except that the concentration of FC430 as the insulating film material was changed to 6% by weight. As shown in Table B-1, voltage hysteresis and response time were measured at 20 ° C. in the same manner as in Example B-1.

Example B-7

The liquid crystal display device according to Example B-7 shown in Table B-1 was produced in the same manner as in Example B-1 except that the concentration of FC430 as the insulating film material was changed to 7% by weight. As shown in Table B-1, voltage hysteresis and response time were measured at 20 ° C in the same manner as in Example B-1.

Comparative Example B-1

The liquid crystal display device according to Comparative Example B-1 shown in Table B-1 was manufactured in the same manner as in Example B-1 except that the concentration of FC430 as the insulating film material was changed to 0% by weight. As shown in Table B-1, voltage hysteresis and response time were measured at 20 ° C in the same manner as in Example B-1.

On the other hand, Comparative Example B-1 shown above is for revealing the effect of improving the responsiveness of each of the above examples, and although the comparative example is changed for each of the examples, the applied voltage-light transmittance characteristics have different areas. Is included in the embodiment from the viewpoint of the configuration (corresponding to claim 2 relating to the first invention group).

Comparative Example B-2

The liquid crystal display device according to this Comparative Example B-2 shown in Table B-1 was manufactured in the same manner as in Example B-1 except that the concentration of FC430 as an insulating film material was changed to 8% by weight. As shown in Table B-1, voltage hysteresis and response time were measured at 20 ° C. in the same manner as in Example B-1.

[result]

The voltage hysteresis and response time of the liquid crystal display elements according to Examples B-1 to B-7 obtained as described above and the liquid crystal display elements according to Comparative Examples B-1 and B-2 were measured, respectively. We found the following.

That is, as apparent from FIG. 19, it was found that the smaller the value of (γ _i -γ _LC ), the smaller the voltage hysteresis H _v (%). Furthermore, as understood in the figure, in order for the voltage hysteresis H _v (%) to be 1% or less, it is preferable that (γ _i -γ _LC ) satisfies the relationship of the formula (B-1). On the other hand, as understood from FIG. 20, in order for a response time to be 40 ms or less, it is preferable that ((gamma) _i- (gamma) _LC ) satisfy | fills the relationship of said Formula (B-2). 19 and 20, in order for both voltage hysteresis and response speed to be good together, it is preferable to satisfy the relationship of the formula (B-3).

This invention group B is implemented by the form demonstrated above, and acquires the effect which it says below.

That is, according to the liquid crystal display element which concerns on group B of this invention, and its manufacturing method, the interface between a liquid crystal and an inner surface of a pair of electrodes so that the relationship shown by following formula (B-1)-(B-3) may be satisfied. An insulating film made of at least two kinds of materials having different tensions is provided.

γ _LCp -γ _ip <0.. (B-1)

-1 dyne / cm &lt; y _LCp -y _ip &lt; (B-2)

-1 dyne / cm &lt; γ _LCp -γ _ip <0. (B-3)

(Wherein, γ _ip represents the interfacial tension at the interface between the insulating film and the polymer material, and γ _LCp represents the interfacial tension between the liquid crystal and the polymer material.)

Thereby, the relationship of said Formula (B-1) can be satisfy | filled irrespective of a kind of liquid crystal, and in this case, the liquid crystal display element which improved optical hysteresis can be provided. Regardless of the type of liquid crystal, the relationship of the formula (B-2) can also be satisfied. In this case, a liquid crystal display device having good responsiveness can be provided. Moreover, regardless of the type of liquid crystal, the relationship of the formula (B-3) can also be satisfied, and in this case, an effect of providing a liquid crystal display device having improved optical hysteresis and responsiveness can be provided.

Moreover, according to the liquid crystal display element which concerns on this invention, and its manufacturing method, the interface tension between liquid crystals on the inner surface of a pair of electrodes so that the relationship shown by following formula (B-4)-(B-6) may be satisfied. An insulating film made of at least two different materials is provided.

γ _LC -γ _i <0. (B-4)

-1 dyne / cm &lt; γ _LC -γ _i &lt; (B-5)

-1 dyne / cm &lt; γ _LC -γ _i <0. (B-6)

(Wherein γ _i represents the critical surface tension of the insulating film and γ _LC represents the surface tension of the liquid crystal).

Thereby, the relationship of Formula (B-4) can be satisfied regardless of the type of liquid crystal, and in this case, it is possible to provide a liquid crystal display device having improved optical hysteresis. Regardless of the type of liquid crystal, the relationship of the formula (B-5) can also be satisfied. In this case, a liquid crystal display device having good responsiveness can be provided. Moreover, regardless of the type of liquid crystal, the relationship of the formula (B-6) can also be satisfied. In this case, an effect of providing a liquid crystal display device having improved optical hysteresis and responsiveness can be provided.

Invention Group C

The central technical idea of the present invention group C is that in the light-scattering mode liquid crystal display device using the liquid crystal-polymer composite system, the critical surface tension of the insulating film provided on the substrate surface and the critical surface tension of the polymer satisfy a predetermined relationship. It is intended to have a configuration in which a plurality of regions having different applied voltage-light transmittance characteristics are provided in the vertical direction, and further, to reduce optical hysteresis and driving voltage. In more detail, it turns out in embodiment mentioned below.

(Embodiment C)

21 is a simplified cross-sectional view of a liquid crystal display element 301 according to Embodiment C of the present invention. The liquid crystal display device 301 is a liquid crystal / polymer composite body disposed between the array substrate 302 and the counter substrate 303 disposed to face the array substrate 302 and the array substrate 302 and the counter substrate 303. Has a layer 304. The array substrate 302 and the counter substrate 303 are, for example, transparent substrates made of glass. On the array substrate 302, thin film transistors (TFTs), metal wirings (scanning signal lines, image signal lines), transparent pixel electrodes 306, and the like as pixel switching elements are formed. These metal wires, the TFT, the pixel electrode 306 and the like are covered with the insulating film 307. In addition, in FIG. 21, metal wiring, TFT, etc. are abbreviate | omitted in order to make understanding of invention content easy.

A transparent counter electrode 309 is formed on an inner side surface of the counter substrate 303, and the counter electrode 309 is covered with an insulating film 310. As shown in FIG. The pixel electrode 306 and the counter electrode 309 are made of, for example, ITO (Indium Tin Oxide).

The liquid crystal-polymer composite layer 304 is basically a polymer dispersed liquid crystal (PDLC) layer having a structure in which liquid crystal groups are independently dispersed in a polymer resin matrix. In the present embodiment, however, the liquid crystal-polymer composite layer 304 is different from a normal polymer dispersed liquid crystal layer, and is composed of a polymer resin 311 and two kinds of liquid crystals 312 and 313. The liquid crystal in the liquid crystal droplets 312 and 313 has a positive dielectric anisotropy. The liquid crystal droplets 312 exist inside the liquid crystal and polymer composite layer 304, and are formed in a substantially spherical shape like the liquid crystal droplets in a normal polymer dispersed liquid crystal layer. On the other hand, the liquid crystal droplets 313 are formed on each of the insulating films 307 and 310 and are formed in a dome shape which swells into the liquid crystal-polymer composite layer 304 inward. Specifically, the liquid crystal droplets 313 are formed in a hemispherical shape or a flat hemispherical shape in contact with a large circle on the insulating films 307 and 310. The liquid crystal-polymer composite layer 304 is not limited to a polymer dispersed liquid crystal (PDLC) layer, but may be a polymer network liquid crystal layer in which a liquid crystal is held in a three-dimensional network polymer.

On the other hand, the array substrate 302 and the counter substrate 303 formed by the spacer and the sealing resin 315 are bonded to each other to encapsulate the liquid crystal and polymer composite layer 304.

Herein, the insulating films 307 and 310 are selected as materials whose materials satisfy the relationship of the following formula (C-1).

γ _i ≧ γ _P ... (C-1)

In formula (C-1), γ _i represents the critical surface tension of the insulating films 307 and 310, and γ _P represents the critical surface tension of the polymer resin 311. It is a feature of the present invention that the insulating films 307 and 310 satisfying such conditions are used. As a result, the dome-shaped liquid crystal 313 can be formed. As a result, the optical hysteresis can be reduced. Can be. Below, the reason is explained in full detail.

The present inventors aimed at adjusting the interfacial regulation force, and in particular, the results of the experiment focusing on the balance of the surface energy in the vicinity of the array substrate 302 and the counter substrate 303 sandwiching the liquid crystal-polymer composite layer 304. It has been found that there is a certain correlation between the critical surface tension of the substrate and the critical surface tension of the polymer resin and the optical hysteresis. In short, it was found that hysteresis becomes extremely small when the critical surface tension of the substrate is greater than the critical surface tension of the polymer resin. On the other hand, as the critical surface tension of the substrate, specifically, various insulating films having different critical surface tensions were formed on the substrate to change the critical surface tension of the substrate. In other words, hysteresis becomes extremely small when the critical surface tension γ _i of the insulating films 307 and 310 is greater than the critical surface tension γ _P of the polymer resin 311. The occurrence of such a phenomenon is considered to be due to the following action.

That is, when γ _i ≧ γ _P is satisfied, the polymer resin 311 is easily wetted on the insulating films 307 and 310, and a domed liquid crystal 313 is formed. In explaining this reason, it is generally known that a liquid having a surface energy less than that of a solid is wet as a condition for the liquid to wet the solid surface. In this embodiment, the surface tension of the polymer material (liquid) is replaced with the critical surface tension of the polymer resin (solid). In this way, the surface tension of the polymer material (liquid) and the polymer resin (solid) may be changed even if the surface tension of the polymer material (liquid) and the surface tension of the polymer material (liquid) are replaced by the critical surface tension of the polymer resin. This is because there is little difference from the critical surface tension of and it is considered that it does not affect the presence or absence of wettability of the polymer material (liquid). Thus, when the critical surface tension γ of the critical surface tension γ _{P i} and the polymer resin of the insulating film satisfies γ _i ≥γ _P, the polymer material (a liquid) is easily wettable on the insulating film. When the polymer material (liquid) is easily wetted on the insulating film as described above, in the polymerization process of the polymer dispersed liquid crystal material including the polymer material and the liquid crystal material, the liquid crystal droplets deposited near the insulating film interface are transferred from the polymer covering the liquid crystal area to the insulating film. It is pressed in the direction which abuts, and the dome-shaped liquid crystal liquid 313 is formed.

In this way, when the dome-like liquid crystal 313 is formed, it is considered that optical hysteresis is reduced by the following mechanism. That is, by forming the dome-shaped liquid crystal droplets 313, the liquid crystal molecules in the liquid crystal droplets 313 are subjected to strong alignment control force at the substrate interface. This regulating force propagates not only in the liquid crystal 313 but also in the liquid crystal 312, and serves to assist the interfacial regulating force at the liquid crystal / polymer resin interface for all the liquid crystal 312 and 313. As a result, when the electric field is turned off from the electric field ON state, all liquid crystal molecules in the liquid crystal 312 and 313 including the vicinity of the liquid crystal / polymer resin interface transition smoothly to the original random arrangement. Therefore, optical hysteresis can be reduced.

Specifically, as shown by the curve VTa shown in Fig. 22, the applied voltage-light transmittance characteristic with reduced optical hysteresis is obtained. However, in the present invention, the driving voltage is larger than the conventional example shown in the curve VTb in FIG. Therefore, in the case where a liquid crystal display device in which the driving voltage is not too large even if the optical hysteresis is reduced is desired, the insulating film may be appropriately selected within a range that satisfies the relationship of the above formula (C-1).

Next, the relationship between the liquid crystal contained in the liquid crystal and the polymer composite layer 304 and the insulating film will be described. That is, since the liquid crystal-polymer composite layer 304 contains a liquid crystal in addition to the polymer resin, it is necessary to consider the relationship between the liquid crystal and the insulating film. According to the experimental results of the present inventors, when the relationship of the formula (C-1) is satisfied and the relationship of the following formula (C-2) is satisfied, as shown in FIG. 23A, the liquid crystal 313 The liquid crystal molecules were aligned almost parallel to the substrate.

γ _LC <γ _i . (C-2)

Here, γ _LC represents the surface tension of the liquid crystal. On the contrary, in the case where the relationship of the formula (C-1) is satisfied and the relationship of the following formula (C-3) is satisfied, as shown in FIG. 23B, the liquid crystal molecules in the liquid crystal 313 are almost in relation to the substrate. Oriented vertically.

γ _LC > γ _i . (C-3)

This is because when the relationship of γ _LC <γ _i is satisfied, the liquid crystal is easily wetted, so that the liquid crystal molecules in the liquid crystal droplet 313 are subjected to a large alignment control force from the insulating film, which is considered to align almost in parallel. . On the other hand, when the relationship of γ _LC > γ _i is satisfied, the liquid crystal becomes difficult to get wet, so that the alignment control force from the insulating film with respect to the liquid crystal molecules in the liquid crystal droplets 313 becomes small, and therefore, it is considered to align almost vertically. .

Comparing the state of FIG. 23A with the state of FIG. 23B, the scattering performance is good in the case of FIG. 23A, but the field response is poor. In contrast, in the case of Fig. 23A, the scattering performance is poor, but the electric field response is good. Therefore, a liquid crystal material satisfying γ _LC > γ _i or γ _LC <γ _i may be selected depending on which of scattering performance and electric field response is given in consideration of the use environment of the liquid crystal display element.

(Example C)

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention to them only, unless specifically stated otherwise. Do.

The liquid crystal display element according to Example C has the same configuration as in the above embodiment, and was produced as follows.

(1) the production of empty cells

A transparent electrode (corresponding to the pixel electrode 306 and the counter electrode 309) made of ITO, and two glass substrates (array substrate 302 and counter substrate) on which insulating films 307 and 310 are formed on the transparent electrode. (303)) and a sealing resin 315 serving as a spacer on the surface of the insulating film 307 of one of the glass substrates (e.g., the array substrate 302). The acid anhydride cured epoxy resin dispersed therein was printed on the other side with a width of 2 mm, leaving only 3 mm of the four sides of the array substrate 302 as an opening. Subsequently, the opposing substrates 303 are arranged on the array substrate 302 in a state where the electrode faces are opposed to each other, pressurized in this state, and heated at 150 ° C. for 2 hours to be hard-bonded to form an empty cell. On the other hand, the insulating films 307 and 310 are baked at 180 ° C. for 1 hour after spinner coating a solution of 3% by weight of a polyimide component. As the insulating films 307 and 310, a material having a relationship of the formula (C-1) was used. On the other hand, the critical surface tension γ _P of the polymer resin was previously measured by the following method.

That is, as a material for forming a polymer resin, 59 parts by weight of 2-ethylhexyl acrylate (manufactured by Nakaray Tesque Co., Ltd.), 14 parts by weight of lauryl acrylate (manufactured by Kogyo Holding Chemicals Co., Ltd.), 1,6- Mixed composition consisting of 25 parts by weight of hexanediol diacrylate (manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY CO., LTD., Trade name Biscot # 230), and 2 parts by weight of Ilgacua 651 (trade name, manufactured by Chiba-Geigi Co., Ltd.) Is prepared. This composition A was polymerized by ultraviolet irradiation at 25 degreeC by nitrogen atmosphere, and the polymer film was produced. High pressure mercury lamps were used for ultraviolet irradiation, and an optical cut filter was placed on the light irradiation surface for polymerization. As the optical cut filter, UV35 (trade name) manufactured by Oshiba Glass Co., Ltd. was used. On the other hand, the high-pressure mercury lamp was irradiated for 60 seconds using a UV wavelength of 50mW / cm ² at the dominant wavelength 365nm. The critical surface tension γ _P of the polymer film thus produced was determined by the Gsman plot method. That is, wettability test standard reagents (manufactured by Nakaray Tesque Co., Ltd.) having various surface tensions were attached to the polymer film surface, and each contact angle θ was measured. Next, the surface tensions of the various wettability standard reagents were plotted on the horizontal axis and the wettability test standard, and the surface tension of cosθ = 1 was obtained, and the surface tension was defined as the critical surface tension γ _p of the polymer film. As a result, (gamma) _p = 30.6 dyne / m in 20 degreeC.

(2) Preparation of polymer dispersed liquid crystal material

The composition A and the liquid crystal material were mixed at a ratio of composition A: liquid crystal = 20:80 to prepare a polymer dispersed liquid crystal material.

(3) polymerization treatment

The polymer dispersed liquid crystal material was injected into the opening of the empty cell produced by the above (1) by vacuum injection, and the opening was sealed after the injection. Subsequently, the high pressure mercury lamp was used as a light source, and superposition | polymerization was carried out at 25 degreeC. At this time, the optical cut filter was arrange | positioned at the light irradiation surface, and it superposed | polymerized. As the optical cutter filter, UV35 (trade name) manufactured by Oshiba Glass Co., Ltd. was used. On the other hand, the high-pressure mercury lamp was irradiated for 60 seconds using a UV intensity of 50mW / cm ² at the dominant wavelength 365nm. When the polymerization was completed, the liquid crystal display device shown in Fig. 21 was produced.

[Example C-1] to [Example C-4]

In Examples C-1 to C-4, four kinds of insulating film materials satisfying the relationship of the formula (C-1) as the materials of the insulating films 307 and 310 (brand names: AL1051, AL5417, JALS212 ( In the above, Japan Synthetic Rubber Co., Ltd. and SE7992 (made by Ilsan Chemical Co., Ltd.) were selected. and γ _LC = 29.5 dyne / cm) Various liquid crystal display devices were manufactured by the above production method using these various materials. The alignment state was oriented vertically with respect to the array substrate 302 as shown in Fig. 23A. With respect to these liquid crystal display elements, voltage hysteresis was measured under the following conditions. In addition, these liquid crystal display elements are called liquid crystal display element C1, C2, C3, C4 of this invention.

[Condition of experiment]

(1) The critical surface tension γ _i of each insulating film material was obtained by the Gessman plot method under the condition of 20 ° C using a wettability standard reagent (manufactured by Nakaray Tesque Co., Ltd.).

(2) The value of hysteresis was defined as follows. Measure the applied voltage-transmittance characteristic of the scattering state → transmission state and the applied voltage-transmittance characteristic of the transmission state → scattering state, respectively, and measure the voltage when the transmittance changes by 50% in each applied voltage-transmittance state. when the v ₅₀ and v _{50 ↑ ↓,} was a value H _v as defined by the following formula as an index of the hysteresis voltage.

H _v = (V _{50 ↑} -V _{50 ↓} ) / V _{50 ↓} × 100 [%]

On the other hand, in this experiment, the performance of the liquid crystal display device is evaluated by measuring voltage hysteresis, but this is based on the fact that the change in voltage hysteresis is related to the change in optical hysteresis. That is, when voltage hysteresis is reduced, it can be judged that optical hysteresis is also reduced, and deterioration of the display quality resulting from the said optical hysteresis can be aimed at.

(3) The critical surface tension γ _P of the polymer resin was 30.6 dyne / cm at 20 ° C. as in the embodiment.

Comparative Example C-1 to Comparative Example C-3

The liquid crystal display elements according to Comparative Examples C-1 to C-3 include three kinds of insulating film materials (trade name: JALS214, JALS246 (above, manufactured by Nippon Synthetic Rubber Co., Ltd.), SE1211 (trade name: Ilsan Chemical Co., Ltd.). It produced by the above-mentioned manufacturing method except having used the agent. The three kinds of insulating film materials are insulating film materials that do not satisfy the relationship of the formula (C-1). With respect to these liquid crystal display elements, voltage hysteresis was measured under the above conditions. The results are written together in Table C-1 below. In addition, these liquid crystal display elements are called comparative example liquid crystal display element X1, X2, X3.

Table C-1

Insulating film γ _i (dyne / cm) Voltage hysteresis H _v (%) Invention Liquid Crystal Display C1 AL1051 33.0 0.5 Invention Liquid Crystal Display C2 AL5417 31.0 0.9 Invention Liquid Crystal Display C3 JALS212 31.3 0.8 Invention Liquid Crystal Display C4 SE7992 31.2 0.8 Comparative Example Liquid Crystal Display X1 JALS214 30.1 3.9 Comparative Example Liquid Crystal Display X2 JALS246 29.6 5.8 Comparative Example Liquid Crystal Display X3 SE1211 28.1 3.7

γ _P = 30.6 dyne / cm

Example C-5

The liquid crystal display device according to Example C-5 was manufactured by the above-described manufacturing method except that BL002 (trade name) satisfying the relationship of Formula C-3 was used as the liquid crystal material. In the liquid crystal display device according to the present embodiment, the liquid crystal molecules in the liquid crystal droplets 313 are aligned in the vertical direction with respect to the array substrate 302 as shown in FIG. 23B. This liquid crystal display element is called liquid crystal display element C5 of the present invention.

In addition, the transmittance | permeability was measured about the liquid crystal display element C5 of this invention by the following method. That is, green (G) light is irradiated to the liquid crystal display element by arranging a green filter between the white light source and the liquid crystal display element using the LCD 500 (manufactured by Otsuka Electronics Co., Ltd.) as a measuring device. The transmittance | permeability was measured at the time of no application. Moreover, surface tension (gamma) _LC of the liquid crystal material (brand name: BL002) was measured by the hit method. The results are written together in Table C-2. On the other hand, in Table C-2, data relating to the liquid crystal display device C1 of the present invention is also described.

Table C-2

Insulation Material γ _i (dyne / cm) γ _LC (dyne / cm) Liquid crystal material TransmittanceT _o (%) The present invention liquid crystal display device C1 AL1051 33.0 29.5 TL205 1.3 The present invention liquid crystal display device C5 AL1051 33.0 33.9 BL002 1.6

[result]

As is apparent from Table C-1, hysteresis is considerably small in the liquid crystal display devices C1, C2, C3, and C4 of the present invention in which an insulating film having a critical surface tension γ _i greater than the critical surface tension γ _P of the polymer matrix is provided. On the other hand, hysteresis is large in Comparative Example liquid crystal display elements X1, X2, and X3 provided with an insulating film having a critical surface tension γ _i smaller than the critical surface tension γ _P of the polymer matrix. Therefore, it is recognized that hysteresis can be reduced by providing an insulating film that satisfies the relationship of γ _i > γ _P.

In addition, as apparent from Table C-2, the transmittance of the liquid crystal display device C1 of the present invention is lower than that of the liquid crystal display device C5 of the present invention. Therefore, although the scattering performance of the liquid crystal display device C5 of the present invention was slightly lower than that of the liquid crystal display device C1 of the present invention, the voltage hysteresis was 0.5%, and the hysteresis was reduced. The response speed was satisfactory at 37 ms.

As described above, according to the present invention group C, it has a critical surface tension γ _i that satisfies the relationship between the critical surface tension γ _P of the polymer resin and the following formula (C-1) on a pair of substrates sandwiching the liquid crystal polymer composite layer. By providing the insulating film, the effect that the liquid crystal display device with improved hysteresis characteristics is realized is obtained.

γ _i ≧ γ _P ... (C-1)

(Wherein, γ _P represents the critical surface tension of the polymer resin, γ _i represents the critical surface tension of the insulating film.)

[2nd invention group]

The second invention group is a light-scattering mode liquid crystal display device having a liquid crystal / polymer composite layer, wherein the liquid crystal / polymer composite layer has a region where the electro-optic characteristics (i.e., applied voltage-transmittance characteristics) are different in one pixel. It is a structure which has two in parallel direction. With such a configuration, the hysteresis selectively lowers the steepness of the large voltage region in the applied voltage-transmittance curve (hereafter, simply referred to as a curve). When the voltage is decreased, the difference in transmittance (hereinafter referred to as optical hysteresis) at the same voltage is reduced. Therefore, it is possible to prevent the occurrence of afterimages and seizure due to optical hysteresis, and to provide a liquid crystal display device having excellent display quality.

Hereinafter, the technical principle of a 2nd invention group is explained, referring FIGS. 24 and 25. FIG. 24 is an explanatory diagram for explaining a display principle of the liquid crystal display device of the present invention. Fig. 25 is a graph showing an applied voltage-light transmittance curve in the liquid crystal display device.

First, as shown in FIG. 24A, in the liquid crystal-polymer composite layer 400, the first region A and the second region B having different applied voltage and light transmittance characteristics are arranged in parallel with respect to the plane. . The liquid crystal / polymer composite layer 400 is a polymer dispersed liquid crystal (PDLC) layer having a liquid crystal but independently dispersed structure in a polymer. In the figure, a part corresponding to one pixel is shown.

The first region A is formed to have the applied voltage-light transmittance characteristic indicated by the applied voltage-light transmittance curve VTa shown in FIG. 25A. On the other hand, the second region B is shifted to the lower voltage side than the curve VTa, and is formed to have the applied voltage-light transmittance characteristic indicated by the applied voltage-light transmittance curve VTb shown in FIG. On the other hand, Fig. 24A shows a case where the liquid crystal droplets have different particle diameters as an example of a means for changing the applied voltage-light transmittance characteristics, but the present invention is not limited thereto. Details of this will be described in the embodiments and the like described below.

When the display screen of the liquid crystal cell with the liquid crystal and polymer composite layer 400 is observed, the display light Lc reaching the observer is the light La and the second light transmitted through the first region A, as shown in FIG. 25B. It is visually recognized as the sum with the light Lb which permeate | transmitted the area | region B. As a result, the liquid crystal cell is visually recognized as having the applied voltage-light transmittance characteristic indicated by the curve VTc shown in FIG. 25A. Because, as a result, a plurality of areas having different applied voltage and light transmittance characteristics coexist in one pixel, the observer has an apparent applied voltage and light transmittance characteristic in which the applied voltage and light transmittance characteristics are averaged in these areas and represented by the curve VTc. Because it becomes.

The curve VTc concerning this display light Lc is explained in full detail below. As is apparent from Fig. 25B, the curve VTc is located between the curve VTa and the curve VTb, and in the region of the applied voltage is relatively low, the trajectory is drawn according to the transmittance-applied voltage curve VTb, while the transmittance in the region of the applied voltage is relatively high. -The trace is as follows according to the applied voltage curve VTa. Therefore, the transmittance-applied voltage curve VTc is a curve having a gentle slope as compared with the transmittance-applied voltage curves VTa and VTb.

Here, the relationship between the magnitude of physical hysteresis (voltage hysteresis) and the magnitude of apparent hysteresis (optical hysteresis) such as afterimage or sticking phenomenon is considered. As shown in Fig. 25B, the physical hysteresis is the difference between the voltage of the applied voltage passing through the specific transmittance and the voltage of the falling voltage in the transmittance-applied voltage curve, and can be described quantitatively as hysteresis width ΔV. . In addition, this hysteresis width shows dependence on the transmittance | permeability prescribed | regulated, For example, as a liquid crystal display element of the light-scattering mode using a liquid crystal-polymer composite system, it is normal that the maximum becomes in the low applied voltage area | region of 10 to 30% of transmittance normally. And found.

In the case where the applied voltage-light transmittance characteristic is represented by the curve VTc shown in Fig. 25A, it is possible to reduce the optical hysteresis due to the reasons mentioned below.

The applied voltages of the applied voltage-light transmittance curves VTa to VTc and the transmittance T ₁ (values in the range of 10 to 30% of the maximum transmittance for the maximum hysteresis width) are set to Va, Vb, and Vc, respectively. In this case, the optical hysteresis becomes ΔTa, ΔTb or ΔTc at each of the applied voltages Va to Vc, respectively. As is apparent from Fig. 25A, when there are curves VTa to VTc having almost the same hysteresis width, the curved slope VTc has a smaller optical hysteresis than the curves VTa and VTb. This is evident from the relationship between the curves VTd and VTe shown in Fig. 25B. That is, when there are transmittance-applied voltage curves VTd and curves VTe having exactly the same hysteresis width DELTA V and different gradients, optical hysteresis at Vd is smaller in the curve VTe having a gentle gradient. In short, ΔTd> ΔTe. From this, the curve VTc can be discussed in the same way. Since the curve VTc has a gentler slope than the curves VTa and VTb, the optical hysteresis can be reduced.

Optical hysteresis becomes a problem in display quality because the transmittance is different depending on the display history of pixels when the same voltage is applied. As a result, when an image is displayed on the liquid crystal display, it is recognized by the observer in the form of an afterimage or a sticking phenomenon. However, by setting it as the said structure, reduction of optical hysteresis is aimed at, As a result, the afterimage resulting from the said optical hysteresis and seizure can be reduced.

Below, invention group D-G in 2nd invention group is demonstrated in order.

(Invention Group D)

The central technical idea of Group D of the present invention is that in the liquid crystal-polymer composite layer, in order to form regions with different applied voltage and light transmittance characteristics in the in-plane direction, particle diameters such as liquid crystals are different from each other in each region, or liquid crystals The orientation state of liquid crystal molecules such as red may be shifted to reduce the optical hysteresis and the driving voltage. More specifically, it reveals in each embodiment mentioned below.

(Embodiment D-1)

Embodiments of the present invention will be described below with reference to FIG. 26. However, parts unnecessary for the description are omitted, and some parts are enlarged or reduced for ease of explanation. The above is also the same with respect to the following drawings.

26 is a sectional view showing an outline of a liquid crystal display element according to the present embodiment. In the figure, a part corresponding to one pixel is shown. The liquid crystal display element has a top plate 411, a base plate 412 disposed to face the plate 411, and a liquid crystal-polymer composite layer 410 disposed between the plate 411 and the base plate 412. Configuration. On the lower substrate 412, a transparent electrode layer 413b, metal wiring (scanning signal line, image signal line), thin film transistor (TFT) 415, etc., arranged in a matrix form serving as a pixel electrode, are formed. These transparent electrode layers 413b, TFT 415, and the like are covered with an insulating film 414b. On the other hand, a transparent electrode layer 413a serving as a transparent counter electrode is formed on the lower surface (inner surface) side of the plate 411.

The upper plate 411 and the lower plate 412 are transparent substrates made of, for example, glass. The transparent electrode layer 413a and the transparent electrode layer 413b are made of, for example, indium tin oxide (ITO). The TFT 415 has a function as a pixel switching element (active element) for controlling the voltage applied to the transparent electrode layer 413b.

In the liquid crystal and polymer composite layer 410, the liquid crystal liquid 418 is independently dispersed and maintained in the first region 410 a and the polymer 416 in which the liquid crystal liquid 417 is independently dispersed and maintained in the polymer 416. The PDLC layer is formed of the second region 410b. The first region 410a and the second region 410b are formed such that their respective area areas are substantially the same in plan view. In the liquid crystal droplets 417, the particle diameter d ₁ and the liquid crystal droplets 418 are formed such that the particle diameter d ₂ has a relationship of d ₁ <d ₂ . In other words, the liquid crystal-polymer composite layer 410 is constituted of a plurality of regions having different average particle diameters of the liquid crystal droplets. On the other hand, among the forms in which the liquid crystal groups are dispersed and maintained in the polymer, an embodiment in which the liquid crystal groups are partially connected is also considered. And in such a case, since it is thought that two types of liquid crystal groups are disperse | distributed and hold | maintained broadly, this invention also includes the said aspect. In addition, the particle diameter d ₁ and a diameter d ₂ is assumed to mean a liquid crystal average particle size of the enemy.

As described above, the liquid crystal droplets in the liquid crystal and polymer composite layer 410 are composed of two kinds of liquid crystal droplets 417 and 418 having different particle diameters, compared with the case where only one type of liquid crystal droplets is formed. , the value of γ can be increased (stiffness). As a result, the reduction of optical hysteresis can be realized. Therefore, the display quality can be improved by reducing the afterimage, seizure, etc. resulting from the hysteresis phenomenon.

On the other hand, in this embodiment, as shown in Fig. 26, the liquid crystal phase is a structure in which the liquid crystal phase is dispersed as an independent phase (liquid crystal) in a polymer matrix (polymer phase) in which the liquid crystal and polymer composite layer 410 is made of a transparent polymer. The case of the polymer dispersed liquid crystal (PDLC) layer is mentioned. However, in this invention, it is not limited to this at all, The polymer network structure in which a liquid crystal phase and a polymer phase form a continuous phase may be sufficient. In this case, it can be formed by changing the liquid crystal material, polymerization conditions and the like, as disclosed in the Technical Research Report of the Telecommunications Technology Association (ElD 89-89, p. 1). In this case, the size of the mesh spacing in the network-like polymer is expressed by the average mesh size (average mesh spacing), and this is used in place of the average particle diameter of the liquid crystal. Also in the following description, the type mainly disperse | distributed in the polymer matrix as a liquid phase is mentioned.

(Embodiment D-2)

Embodiment D-2 of this invention is demonstrated according to FIG. 27, as follows. In addition, about the component which has the same function as the liquid crystal display element of Embodiment D-1, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

As shown in FIG. 27, the structure of the liquid crystal display element concerning Embodiment D-2 differs from the point mentioned below compared with the structure of the liquid crystal display element concerning Embodiment D-1 mentioned above. That is, the insulating film 430a is provided on the transparent electrode layer 413a, and the insulating film 430b is provided on the transparent electrode layer 413b. Further, dome-shaped liquid crystal droplets 422 and 423 are formed on the insulating layers 430a and 430b. In FIG. 27, spacers, sealing materials, and the like are omitted.

The liquid crystal and polymer composite layer 420 shown in FIG. 27 is basically a polymer dispersed liquid crystal (PDLC) layer having a structure in which liquid crystals are independently dispersed in a polymer matrix. In the present embodiment, however, the liquid crystal-polymer composite layer 420 is different from a normal PDLC layer, and is composed of a polymer 416 and three kinds of liquid crystals 421 to 423. As for the liquid crystal in liquid crystal 421-423, the positive dielectric anisotropy is used. The liquid crystal droplets 421 are present inside the liquid crystal and polymer composite layer 420, and are formed in a substantially spherical shape like the liquid crystal droplets in ordinary PDLC. On the other hand, the liquid crystal droplets 422 and 423 are formed on each of the insulating films 430a and 430b and are formed in a dome shape which swells to the inner side of the liquid crystal and polymer composite layer 420. Specifically, the liquid crystal liquids 422 and 423 are formed in a hemispherical shape or a flat hemisphere shape in contact with a large circle on the insulating films 430a and 430b.

However, each of the insulating films 430a and 430b has a plurality of regions having different critical surface tensions in the same plane. More specifically, in the region corresponding to the first region 420a, the critical surface tension of both insulating layers is greater than that in the region corresponding to the second region 420b. To this end, in the first region 420a, the liquid crystal molecules inside the dome-shaped liquid crystal droplets 422 are aligned in a substantially parallel direction with respect to the substrate surface. In the second region 420b, the liquid crystal molecules inside the dome-shaped liquid crystal droplets 423 are oriented substantially perpendicular to the substrate surface. The liquid crystal-polymer composite layer 420 is not limited to the PDLC layer, but may be a polymer network type liquid crystal layer in which a liquid crystal is held in a three-dimensional network polymer.

The insulating material used for the insulating films 430a and 430b is not particularly limited as long as the liquid crystal exhibits wettability with respect to the insulating films 430a and 430b. In order to show wettability, it is a condition that the critical surface tension of both the insulating films 430a and 430b is large compared with the surface tension of liquid crystal.

As described above, only one type of liquid crystal is formed by changing the alignment states of the liquid crystal molecules in the dome-shaped liquid crystal droplets 422 and 423 for each of the first region 410a or the second region 410b. The value of γ can be increased in comparison with the case where it is. This is based on the reason mentioned below.

The liquid crystal molecules in the liquid crystal droplets 422 and the liquid crystal molecules in the liquid crystal molecules 423 differ from each other more precisely because anchoring (orientation control force) for the liquid crystal molecules differs for each region. All. Specifically, when the anchoring acts strongly on the liquid crystal molecules, the liquid crystal molecules are oriented at a low pretilt angle, while when weakly acting, the liquid crystal molecules are oriented at a high pretilt angle.

When an electric field is applied to the liquid crystal-polymer composite layer 420, the liquid crystal molecules oriented at a high pretilt angle are oriented almost vertically even at a low applied voltage. On the other hand, since liquid crystal molecules oriented at a low pretilt angle are strongly influenced by anchoring, the response is slower (ie, a higher applied voltage is applied) than the liquid crystal molecules oriented at a high pretilt angle in the vertical direction. Orient.

When the electric field applied to the liquid crystal / polymer composite layer 420 is made unapplied from the applied state, the liquid crystal molecules oriented at a low pretilt angle in the initial alignment state are strongly influenced by the anchoring from the nearby substrate. As a result, the restoration to the initial orientation state occurs strongly. On the other hand, since liquid crystal molecules oriented at a high pretilt angle are not inherently strongly influenced by anchoring, restoration of the initial alignment state is relatively slow. That is, in the first region 420a, the applied voltage-light transmittance characteristic indicated by the curve VTa shown in FIG. 25 is shown. In the second region 420b, the applied voltage-light transmittance characteristic indicated by the curve VTb shown in the figure is shown. As a result, the applied voltage-light transmittance characteristic in the first region 420a and the applied voltage-light transmittance characteristic in the second region 420b are averaged, so that only the steepness is selectively selected in the low applied voltage region having the largest hysteresis. It is possible to reduce the applied voltage and light transmittance characteristics, thereby reducing the apparent hysteresis (optical hysteresis). As a result, it is possible to reduce the afterimage and seizure due to the optical hysteresis, and the display quality of the display element can be improved.

(Example D)

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention to them only, unless specifically stated otherwise. Do.

Example D-1

The liquid crystal display element concerning Example D-1 has the structure similar to the said Embodiment D-1, and was produced as follows. 28 is a schematic sectional view referred to for describing the manufacturing steps of the liquid crystal display device according to the present embodiment. 29 is a flowchart for explaining a method for manufacturing a liquid crystal display device.

First, a transparent electrode layer 413b made of an indium tin oxide film (ITO film) or the like was formed on a lower substrate 412 by a conventionally known method. Further, on the plate 411, a transparent electrode layer 413a made of an ITO film was formed (S401, electrode forming step).

Subsequently, after the thermosetting sealing material (struct: Mitsui Oatsu Chemical Co., Ltd.) was applied on either of the substrate 411 or the substrate 412, the coated image formed a part of the liquid crystal inlet. The coating was carried out to make a pattern. The upper plate 411 and the lower plate 412 were bonded to each other via a spacer made of plastic having a diameter of 12 µm (Micro Pearl: Integral Fine Co., Ltd.) so as to face the electrodes. After heat treatment at 150 ° C. for 2 hours, the sealing material was completely cured to prepare an empty cell (S402, bonding step). In FIG. 28, spacers, sealing materials, and the like are omitted.

Next, 8.50 g of TL-213 (trade name, manufactured by Melk Co., Ltd.) as a liquid crystal material, 0.80 g of 2-ethylhexyl acrylate (copper curing agent) as a polymerizable monomer, 0.60 g of polyurethane acrylate as an oligomer, and dalocure as a photoinitiator. 0.05 g of 1173 (brand name, Chiba-Geigi Co., Ltd.) was mixed, and it fully stirred in 25 degreeC environment, and prepared the uniform liquid-crystal-polymer precursor solution (S403, liquid crystal-polymer precursor solution preparation process).

The liquid crystal polymer precursor solution was vacuum-injected into the empty cell from a liquid crystal inlet (sealed part) under an environment of 25 ° C. Thereafter, the resultant was sealed with Loctia (trade name, manufactured by Loctia Nippon Co., Ltd.), which is an ultraviolet curing sealing resin, to form a liquid crystal-polymer precursor solution.

Next, as shown in FIG. 28, ultraviolet-ray was irradiated to the liquid-crystal-polymer precursor solution layer through the mask (filter) 440. As shown in FIG. At this time, the plate 411 and the mask 440 were brought into close contact with each other. As the mask 440, a metal chromium 442 serving as a light shielding portion was patterned on a transparent quartz substrate 441 in a predetermined shape.

In the liquid crystal-polymer precursor-like solution layer irradiated with ultraviolet rays, a polymerizable monomer initiated a polymerization reaction under the action of a photopolymerization initiator, and the liquid crystal and the polymer phase separated. In other words, the liquid crystal liquid 417 is formed in the first region 410a, and the liquid crystal liquid 418 is formed in the second region 410b, thereby forming the liquid crystal and polymer composite layer 410 (S405, liquid crystal and polymer). Composite layer forming process). On the other hand, as irradiation conditions, irradiation intensity was 100 mW / cm <^2> and irradiation time was 60 second in 125 degreeC environment. In addition, a high pressure mercury lamp was used as a light source. In the case of ultraviolet irradiation, in order to prevent the ultraviolet-ray which belongs to a short wavelength region of 350 nm or less decompose | disassemble a liquid crystal, it carried out through the ultraviolet cut filter UV-35 (Toshiba Glass Co., Ltd.).

In the mask 440, the metal chromium 442 blocks ultraviolet rays because the metal chromium 442 is a light shielding part. Therefore, in the liquid crystal-polymer precursor-phase solution layer, the polymerization reaction does not occur inherently in the region corresponding to the metal chromium 442, and no phase separation occurs. In practice, however, the liquid crystal 418 is formed, which is for the reasons mentioned below. In other words, the metal chromium 442 is formed at a very narrow interval in the mask 440. Moreover, a high pressure mercury lamp is used as a light source, and the ultraviolet-ray to irradiate is not parallel light. By setting the above conditions, ultraviolet rays are returned to the rear side of the metal chromium 442 to cause polymerization and phase separation even under the metal chromium 442. In addition, the ultraviolet light that has entered the metal chrome 442 and reaches the second region 410b has a lower irradiation intensity than that of the light source, which is larger than the liquid crystal 417 formed in the first region 410a. This is the main reason for forming the large liquid crystal 418.

As described above, the polymer dispersed liquid crystal cell according to the present Example D-1 was produced. Herein, the liquid crystal display device was disassembled by removing the plate 411, and the liquid crystal material was washed and removed with isopropyl alcohol, and the phase separation structure of the liquid crystal and polymer composite layer 410 was observed. An optical microscope was used for the observation. As a result of observation, the liquid crystal liquids 417 and 418 were not perfectly spherical but had a crooked shape. It was also confirmed that the liquid crystals were continuously connected to adjacent liquid crystals. And the average particle diameter R in the observation area was calculated | required from the observation result on an optical microscope. As a result, the average particle diameter of the liquid crystal droplets 417 was 1.0 µm, and the average particle diameter of the liquid crystal droplets 418 was 1.2 µm.

In addition, the applied voltage-light transmittance characteristics of the polymer dispersed liquid crystal cell according to this embodiment were examined. 30 is a graph showing the relationship between the applied voltage and the transmittance in the polymer dispersed liquid crystal cell. The measurement conditions were carried out by applying a square wave of 30 Hz as an applied voltage at a measurement temperature of 30 ° C. and a light receiving angle of 0.20.

The two curves in Fig. 30 respectively show applied voltage-transmittance characteristics (solid line) when the applied voltage is increased from 0V to 30V and applied voltage-transmittance characteristics (dotted line) when the applied voltage is decreased from 30V to 0V. Indicates. Both curves are not exactly the same, some hysteresis is observed. The maximum optical hysteresis (ΔTc) at which the optical hysteresis was greatest was ΔTc. The ΔTc of the polymer dispersed liquid crystal cell produced in this example was 1.0%.

Comparative Example D

The polymer dispersed liquid crystal cell according to this comparative example differs from the liquid crystal display device according to Example D-1 in that the average particle diameter of the liquid crystal droplets is almost uniform in the liquid crystal / polymer composite layer. In addition, the manufacturing method was produced in the same manner as in Example D-1, except that no mask having a metal chrome patterned into a predetermined shape was used.

In the polymer dispersed liquid crystal cell of the present comparative example, the change in transmittance with respect to the applied voltage was measured with a luminance meter as in Example D-1. As shown in FIG. 31, the maximum optical hysteresis ΔTc was 2.0%.

[result]

As is apparent from Example D-1 and Comparative Example, it was found that the optical hysteresis was the largest in the low voltage region in the applied voltage-light transmittance curve. As in the polymer dispersed liquid crystal cell of Example D-1, a plurality of regions having different average particle diameters of liquid crystal droplets are prepared in one pixel, so that the steepness of the applied voltage-light transmittance curve is smooth in the low voltage region. It was possible to reduce the optical hysteresis in comparison with the comparative example.

[Experiment]

Various experiments mentioned below were carried out to investigate appropriate specifications of the polymer dispersed liquid crystal cell according to Example D-1.

(1) Relation between average particle diameter R or average mesh size R of liquid crystal area and threshold voltage

First, a polymer dispersed liquid crystal cell was prepared in which the average particle diameter or average mesh size R (µm) of the liquid crystal droplets was different. All of these liquid crystal cells are liquid crystal display elements in which a normal PDLC layer is formed in place of the liquid crystal / polymer composite layer in which a plurality of regions having different particle sizes of liquid crystal droplets are formed. In addition, the average particle diameter or average mesh size R (micrometer) of a liquid crystal droplet can be controlled by changing the weight fraction of a liquid crystal material, the polymerization fraction ratio of an oligomer, and a monomer, or an ultraviolet intensity.

Each threshold voltage was measured by applying an applied voltage to the various liquid crystal display elements. The results are shown in FIG. 32. 32 is a graph showing the relationship between the average particle diameter or average mesh size R of the liquid crystal droplets and the threshold voltage when the cell thickness is 13 μm.

It can be seen that the threshold voltage has a greater dependence on the average particle diameter or the average mesh size R of the liquid crystal region than the above figure. The same can be said for the cell thickness. In addition, as shown in the drawing, in consideration of the practical driving voltage (about 6 to 12V) of the active matrix polymer dispersed liquid crystal using TFT, the R is preferably 0.4 µm or more. On the other hand, in view of the power consumption of the device, the upper limit of R is preferably such that the driving voltage is smaller than about 12V.

(2) Relation between average particle diameter or average mesh size R of liquid crystal area and scattering gain G

Scattering gain G was also examined about the various liquid crystal display elements used in said (1).

Scattering gain G is used as an index for quantifying the scattering characteristics of the polymer dispersed liquid crystal cell. When the illuminance on the light irradiated surface of the polymer dispersed liquid crystal cell is E and the luminance on the surface opposite to the light irradiated side of the polymer dispersed liquid crystal cell is represented by B and the circumferential ratio is represented by the following formula (D-1) Is defined to be.

G = πB / E... (D-1)

The measurement was performed as follows. That is, light is irradiated perpendicularly to the substrate surface of the polymer dispersed liquid crystal cell, and the illuminance E is measured with an illuminometer (T-1M manufactured by Minolta) disposed on the substrate surface of the polymer dispersed liquid crystal cell. In addition, the luminance B on the surface on the side opposite to the light irradiation side of the polymer dispersed liquid crystal cell is measured with a luminance meter (BM-8 made by TOPCON). Scattering gain G is computed by substituting these measurements into said formula (D-1). On the other hand, if the polymer dispersed liquid crystal cell is a complete scattering body, the scattering gain G is 0.5. In addition, the contrast of the polymer dispersed liquid crystal cell is proportional to the inverse of the scattering gain G. The scattering gain G is described in "Liquid Crystal Video Projector Technology" (Sasaki Jung, 1990, Oct. 29, p139).

For various liquid crystal display elements, scattering gain G was calculated by measuring illuminance and luminance by the above-described measuring method. The results are shown in FIG. 33.

Fig. 33 is a graph showing the relationship between the average particle diameter or average mesh size R of the liquid crystal droplets and the scattering gain G when the cell gap is 13 µm. As shown in the figure, it is understood that the scattering gain G also shows dependence on the average particle diameter (liquid crystal diameter) or the average mesh size (when polymer network structure) R of the liquid crystal drops. In addition, in order to realize a high contrast, the value of the scattering gain G may be small. Therefore, as can be seen from FIG. 33, when R is 0.6 µm <R <1.6 µm, a high contrast is obtained. Therefore, also in the liquid crystal display element concerning this Example, it is more preferable that R is in the said numerical range.

Example D-2

The liquid crystal display element concerning Example D-2 has the structure similar to the said Embodiment D-2, and it produced as follows. 34 is a schematic sectional view referred to for describing the manufacturing steps of the liquid crystal display device according to the present embodiment.

First, a transparent electrode layer 413b made of an indium tin oxide film (ITO film) or the like was formed on a lower substrate 412 by a conventionally known method. In addition, a transparent electrode layer 413a made of an ITO film was formed on the plate 411.

Subsequently, SE-7992 (trade name, manufactured by Ilsan Chemical Co., Ltd.) as an insulating film was applied onto the transparent electrode layer 413b by a spinner on the lower substrate 412. Then, the film was heat-treated at 180 ° C. for 30 minutes to be cured to form an insulating film 430b made of a polyimide film.

Next, ultraviolet rays were irradiated to the insulating film 430b through a mask 440 similar to that used in Example D-1. Irradiation conditions were made into irradiation intensity 100mW / cm <^2> and irradiation time 300 second in 25 degreeC environment. In addition, a high pressure mercury lamp was used for the light source.

Subsequently, the same process as described above with respect to the plate 411 was performed to form an insulating film 430a on the transparent electrode layer 413a.

And the said board 411 and the lower board 412 were bonded together through the spacer, and the empty cell was produced by performing the process similar to the said Example D-1. At this time, in the insulating film 430a and the insulating film 430b, the regions subjected to ultraviolet treatment were opposed to each other.

Next, in the same manner as in Example D-1, 8.50 g of TL-213 (trade name, manufactured by Melk Corporation), 0.80 g of 2-ethylhexyl acrylate (copperizing agent) as the polymerizable mono, and polyurethane as the oligomer were prepared. 0.60 g of acrylate and 0.05 g of Dalcure 1173 (trade name, Chiba-Geigi Co., Ltd.) were mixed as a photoinitiator, and the mixture was sufficiently stirred in a 25 ° C environment to prepare a uniform liquid crystal-polymer precursor solution.

This liquid crystal-polymer precursor solution was vacuum injected into the empty cell from the liquid crystal inlet (sealed part) in the same manner as in Example D-1. Furthermore, it sealed with Loch Tire (brand name, the Japan Loch Tire Co., Ltd. product) which is an ultraviolet curing sealing resin, and formed the liquid-crystal-polymer precursor liquid solution layer.

Ultraviolet rays were irradiated onto the liquid crystal polymer conjugate solution layer to initiate a polymerization reaction of the polymerizable monomer by the action of the photopolymerization initiator to phase-separate the liquid crystal and the polymer. In addition, irradiation conditions were made into the irradiation intensity 100mW / cm <^2> and irradiation time 60 second in 25 degreeC environment. In addition, a high pressure mercury lamp was used as a light source. In the case of ultraviolet irradiation, in order to prevent ultraviolet rays belonging to the short wavelength region of 350 nm or less from being decomposed into liquid crystal, UV cut filter UV-35 (Toshiba Glass Co., Ltd.) was performed.

As described above, the liquid crystal-polymer composite layer 420 having a structure in which the liquid crystal groups were independently dispersed in the polymer matrix was provided, and the liquid crystal display device according to the present embodiment was obtained.

Here, the liquid crystal display device was disassembled by removing the plate 411, and the phase separation structure of the liquid crystal and polymer composite layer 420 was observed. Observation used an optical microscope. As a result, the average particle diameter of the liquid crystal droplets 421 was 1.0 µm.

In the liquid crystal display device, when a voltage is applied to the transparent electrode layers 413a and 413b and visually observed, the threshold voltage is low in the portion corresponding to the region where the insulating films 430a and 430b are irradiated with ultraviolet rays, and the alignment layer is oriented. It was found that the liquid crystal molecules near the interface were oriented in the vertical direction with respect to the substrate surface. This is considered to be the result of the decrease of the critical surface tension in the region irradiated by irradiating ultraviolet rays to the insulating film.

Moreover, the liquid crystal display element which concerns on a present Example was examined. The measurement conditions were conducted by applying a rectangular wave of 30Hz as applied to the measurement temperature 30 ℃, acceptance angle of 0.2 ⁰ voltage. As a result, the applied voltage-light transmittance curve in the rising voltage process and the applied voltage-light transmittance curve in the strong voltage process are not exactly the same, and some hysteresis is observed, but the value when the optical hysteresis is maximized. Is 1.5% and is considerably improved compared with the liquid crystal display device according to the comparative example.

(Other matters)

On the other hand, in the above embodiment D-2, the liquid crystal molecules inside the dome-shaped liquid crystal droplets 422 in the first region 420a are oriented substantially in parallel with the substrate surface, and further, the second region 420b. The aspect in which the liquid crystal molecules inside the dome-shaped liquid crystal droplets 423 are oriented almost perpendicularly to the substrate surface is described. However, the present invention group D is not limited to this at all, and the liquid crystal molecules inside the liquid crystal droplets 422 are aligned at a low pretilt angle, and the liquid crystal molecules inside the liquid crystal droplets 423 are aligned at a high pretilt angle. You should do it. This is because by applying different pretilt angles in at least the first region 420a and the second region 420b, the applied voltage-light transmittance characteristics can be different in each region.

As described above, according to the present invention group D, in the liquid crystal-polymer composite layer, a plurality of regions in which the particle diameters such as liquid crystals differ from each other are formed for each pixel, or the alignment states of liquid crystal molecules inside the liquid crystals are different. By suppressing the increase in the driving voltage, the hysteresis is suppressed to be low, thereby achieving the effect of realizing a liquid crystal display device having excellent display quality with high contrast.

Invention Group E

The central technical idea of the inventive group E is as mentioned below. In order to make the polymer dispersed liquid crystal layer have a plurality of regions having different applied voltage and light transmittance characteristics in one pixel, ultraviolet rays are irradiated to the liquid crystal and the polymer precursor solution through a mask, and a plurality of liquid crystal drops having different average particle diameters are used. A method of forming a region is contemplated. However, for example, when the pixel size is about 10 [mu] m, such as an active matrix type light valve using a high-definition thin film transistor (TFT), the region must be further finely divided. Therefore, in the above method, it is necessary to use a special light source capable of irradiating parallel ultraviolet rays through a mask having extremely good pattern accuracy. However, with this method, it is difficult to form extremely precisely a plurality of regions having different average particle diameters of liquid crystals with sufficient ultraviolet intensity (for example, optical hysteresis increases rapidly if not more than 100 mW / cm ² ). The average particle diameter may be the same.

In consideration of the above points, the present invention group E enables formation of extremely fine regions by using a substrate having a plurality of regions having different ultraviolet transmittances within one pixel region. As a result, a structure in which a plurality of regions having different applied voltage and light transmittance characteristics in one pixel can be provided in parallel with the substrate surface enables optical hysteresis and reduction of driving voltage. In more detail, it discloses in embodiment mentioned below.

(Embodiment E)

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

35 is a cross-sectional view showing one pixel of the liquid crystal display device according to the embodiment of the present invention. The liquid crystal display element 501 includes a liquid crystal and polymer composite layer 510 disposed between the upper plate 511 and the lower substrate 512 disposed to face the upper plate 511 and the lower substrate 512. Has The upper plate 511 and the lower plate 512 are, for example, transparent substrates made of glass. On the lower substrate 512, a thin film transistor (TFT) 519 as a pixel switching element (active element), metal wiring (scanning signal line, image signal line) and a transparent pixel electrode 513b are formed. These metal wires, the TFT 519, the pixel electrode 513b, and the like are covered with the insulating film 514b. In addition, in FIG. 35, metal wiring etc. are abbreviate | omitted in order to make understanding of invention content easy.

On the other hand, an ultraviolet transmittance adjustment layer 515 having an area of about 1/2 of one pixel is formed on the lower surface (inner surface) side of the plate 511. Furthermore, a transparent counter electrode 513a is provided to cover the plate 511 and the UV transmittance adjusting layer 515. The counter electrode 513a is covered with an insulating film 514a.

The counter electrode 513a and the pixel electrode 513b are made of, for example, indium tin oxide (ITO). On the other hand, the UV transmittance adjusting layer 515 may be formed on the counter electrode 513a (between the counter electrode 513a and the insulating film 514a), or may be formed on the insulating film 514a. .

The liquid crystal and polymer composite layer 510 is a PDLC layer formed by irradiating ultraviolet rays through the UV transmittance adjusting layer 515, and a first region in which the liquid crystal 517 is independently dispersed and maintained in the polymer 516. Among the 510a and the polymer 516, the liquid crystal liquid 518 is formed by the second region 510b which is dispersed and maintained independently. The first region 510a and the second region 510b are formed such that their respective area areas are substantially the same in plan view. In the liquid crystal droplets 517, the particle diameter d _l and the liquid crystal droplets 518 are formed such that the particle diameter d ₂ has a relationship of d _l <d ₂ . In other words, the liquid crystal-polymer composite layer 510 has a structure composed of a plurality of regions having different average particle diameters of liquid crystal droplets. On the other hand, in the form in which the liquid crystal groups are dispersed and maintained in the polymer, the embodiment of the embodiment in which the liquid crystal groups are partially connected is also considered. And in such a case, since it is thought that two types of liquid crystal groups are disperse | distributed and hold | maintained broadly, this invention also includes the said aspect. In addition, said particle diameter d _l and particle diameter d ₂ shall mean the average particle diameter of a liquid crystal droplet.

The ultraviolet transmittance adjusting layer 515 is not particularly limited as long as it partially absorbs ultraviolet rays and does not exhibit absorbance with respect to visible light. Specifically, a polymer resist, an inorganic resist, etc. are mentioned, for example. Moreover, as said polymer resist, a positive type photoresist and a negative type photoresist are mentioned. Moreover, the photoresist which added the pigment | dye etc. can also be used for the dye which does not show absorbency with respect to visible light.

As described above, the liquid crystal droplets in the liquid crystal and polymer composite layer 510 are composed of two kinds of liquid crystal droplets 517 and 518 having different particle diameters, as compared with the case where only one type of liquid crystal droplets is formed. It is possible to increase the γ value (slow stiffness). In the present embodiment, the gamma value is set to two or more. As a result, the optical hysteresis can be reduced, and the residual image resulting from the hysteresis can be reduced, and the display quality can be improved in the display element. This reason will be described later.

In the present embodiment, as shown in Fig. 35, the liquid crystal phase is a structure in which the liquid crystal phase is dispersed as an independent phase (liquid crystal) in a polymer matrix (polymer phase) in which the liquid crystal and polymer composite layer 510 is made of a transparent polymer. The case of a polymer dispersed liquid crystal (PDLC) layer is mentioned. However, in this invention, it is not limited to this at all, The polymer network structure in which a liquid crystal phase and a polymer phase form a continuous phase may be sufficient. In this case, as disclosed in the Technical Research Report of the Telecommunications Technology Association (ElD 89-89, p. 1), it can be formed by changing the liquid crystal material, polymerization conditions, or the like. In the above-described case, the size of the mesh spacing in the network-like polymer is expressed by the average mesh size (average mesh spacing), and it is used to change this to the average particle diameter of the liquid crystal region. Also in the following description, the type mainly disperse | distributed in the polymer matrix as a liquid phase is mentioned.

(Example E)

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention to only those examples, unless specifically stated otherwise. Do.

Example E-1

This embodiment corresponds to the above embodiment E, and description of specific components of the liquid crystal display element is omitted. Hereinafter, the manufacturing method of the liquid crystal display element which concerns on a present Example is demonstrated. 36 is a schematic view for explaining a method for manufacturing a liquid crystal display device. 37 is a flowchart for explaining a method for manufacturing a liquid crystal display device. 38 is a flowchart for explaining a method for forming an ultraviolet ray transmittance adjusting layer.

First, an ultraviolet transmittance adjusting layer 525 was formed on the plate 521 made of glass or the like (S501). That is, the plate 521 was washed with an alkaline detergent, and then irradiated with ultraviolet light to decompose organic contaminants. Next, NN700 (trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.) as a negative photoresist was diluted with ethylene glycol ethyl methyl ether to prepare a photoresist liquid (S511). The photoresist solution was added dropwise to the plate 521 and coated with a spinner (coating conditions: 500 rpm-5 seconds, 1000 rpm-30 seconds) (S512), and prebaked for 120 seconds on a hot plate set at 90 ° C. (S513).

Next, an ultraviolet ray of 12.5 mW / cm ² was exposed to the photoresist for 20 seconds with an aligner through a stripe mask (quartz substrate) made of metal chrome having a line width of 25 μm and a spacer width of 25 μm (S514). . Subsequently, NMD-3 (trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.) was immersed in a developer diluted with distilled water for 60 seconds and developed. Thereafter, the plate 521 to which the patterned negative photoresist is attached was heat-treated in an oven to cure the negative photoresist (S515). As heat processing conditions, it was set as temperature 180 degreeC, and processing time for 1 hour. As a result, an ultraviolet transmittance adjusting layer 525 having a film thickness of about 5000 Angstroms was formed. Since the UV transmittance adjusting layer 525 is formed through a stripe mask (quartz substrate) made of a metal chromium having a line width of 25 μm to a width of 25 μm, it has an area of about 1/2 of one pixel.

Next, a transparent electrode layer 523a having a thickness of 1000 angstroms formed of an indium tin oxide film (ITO film) was formed on the surface of the plate 521 on which the UV transmittance adjusting layer 525 was formed. (S502). Then, an insulating film material (trade name: AL1051, manufactured by Nippon Synthetic Rubber Co., Ltd.) was spin-coated on the transparent electrode layer 523a, and cured by heat treatment at 108 캜 for 30 minutes to form an insulating film 524a ( S503).

Meanwhile, a thin film transistor and a transparent electrode layer 523b are formed on the lower substrate 522 by a conventionally known method (S504). Then, spinner coating AL1051 (trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.) as an insulating film was formed on the transparent electrode layer 523b, and cured at 108 DEG C for 30 minutes to form an insulating film 524b (S505).

A thermosetting sealing material (Structe Bond: manufactured by Mitsui Otsu Chemical Co., Ltd.) was formed on the plate 521 so as to provide a liquid crystal injection hole. At this time, the coating shape of the sealing material was to be a residual image pattern in which portions of the liquid crystal inlet were formed in plan view. The upper plate 521 and the lower plate 522 were bonded to each other through a micropearl (trade name, manufactured by Infineon Co., Ltd.), which is a plastic spacer having a diameter of 12 µm. Subsequently, heat treatment was performed at 150 ° C. for 2 hours to completely cure the sealing material to produce an empty cell (S506).

36, only the part which concerns on this invention is shown, and some components, such as an active element, a spacer, and a sealing material, are abbreviate | omitted.

Next, 8.50 g of TL-213 (trade name, manufactured by Melk Corporation) as the liquid crystal material, 0.80 g of 2-ethylhexane acrylate (trade name, copper curing agent) as the polymerizable monomer, 0.60 g of polyurethane acrylate as the oligomer and the photopolymerization initiator 0.05 g of Dalocure 1173 (trade name, manufactured by Chiba-Geigi Co., Ltd.) were mixed and sufficiently stirred in a 25 ° C environment to prepare a uniform liquid crystal-polymer precursor solution (S507).

The liquid crystal polymer precursor solution was vacuum-injected into the empty cell through a liquid crystal inlet (sealed part) under an environment of 25 ° C. (S508). Thereafter, the resultant was sealed with Loctia (trade name, manufactured by Loctia Japan Co., Ltd.), an ultraviolet curing sealing resin, to form a liquid crystal-polymer precursor-like liquid layer 526.

Next, as shown in FIG. 36, ultraviolet light is irradiated onto the liquid crystal-polymer precursor solution layer 526 (light source: high pressure mercury lamp) to initiate a polymerization reaction of the polymerizable monomer by the action of a photopolymerization initiator. The polymer was phase separated (S509). In addition, the irradiation conditions of ultraviolet-ray were made into ultraviolet-ray intensity 200mW / cm <^2> , irradiation time 60 second, and temperature 25 degreeC.

By the ultraviolet irradiation step, the liquid crystal droplet 517 having an average particle diameter corresponding to the ultraviolet ray intensity was formed in the region where the ultraviolet ray was irradiated without interposing the ultraviolet ray transmittance adjusting layer 515. On the other hand, in the region where ultraviolet rays are irradiated through the ultraviolet ray transmittance adjusting layer 515, a portion of ultraviolet rays are absorbed by the ultraviolet ray transmittance adjusting layer 515, and thus ultraviolet rays whose intensity is weaker than when the light source is emitted are irradiated. Therefore, in the region corresponding to the UV transmittance adjusting layer 515, a liquid crystal droplet 518 having a larger average particle diameter than the liquid crystal droplet 517 was formed. This is due to the change in the average particle diameter or the average mesh size R of the liquid crystal droplets in the polymer dispersed liquid crystal cell due to the strength and weakness of the ultraviolet intensity. For example, when the ultraviolet intensity is weak, a liquid crystal liquid having a large particle diameter is formed. On the other hand, in the case of ultraviolet irradiation, ultraviolet rays are irradiated through ultraviolet cut filter-527 (trade name: UV-35, manufactured by Osiba Glass Co., Ltd.), and ultraviolet rays having a wavelength of 350 nm or less are cut to prevent decomposition of the liquid crystal. In this embodiment, no special ultraviolet light source such as a light source capable of irradiating parallel light is used.

In this way, a polymer dispersed liquid crystal cell in which liquid crystals 517 and 518 having different particle diameters were dispersed in the matrix polymer 516 in one pixel as shown in FIG. 35 was obtained.

In the polymer dispersed liquid crystal cell, the shape, particle size, and the like of the liquid crystal droplets 517 and 518 were investigated by the following method. That is, the polymer dispersed liquid crystal cell was decomposed to wash and remove the liquid crystal material with isopropyl alcohol, and the phase separation structure of the polymer dispersed liquid crystal cell was observed by an optical microscope. The liquid crystals 517 and 518 were not perfectly spherical but had a crooked shape. It was also observed that the liquid crystals were continuously connected to adjacent liquid crystals. The average particle diameter R in the area | region observed from the observation result on the optical microscope was calculated | required. As a result, in the polymer dispersed liquid crystal cell of the present embodiment, the liquid crystal droplets 517 had an average of 1.0 µm and the liquid crystal droplets 518 had an average of 1.4 µm.

Further, the scattering gain G of the polymer dispersed liquid crystal cell according to the present embodiment was investigated.

Scattering gain G is used as an index for quantifying the scattering characteristics of the polymer dispersed liquid crystal cell. When the illuminance on the light irradiated surface of the polymer dispersed liquid crystal cell is E, and the luminance on the side opposite to the light irradiated side of the polymer dispersed liquid crystal cell is B and the circumferential ratio is π, the following equation (E-1) is shown. Is defined as:

G = πB / E... (E-1)

The measurement was performed as follows. That is, light was irradiated perpendicularly to the substrate surface of the polymer dispersed liquid crystal cell, and the illuminance E was measured with an illuminometer (Minolta T-1M) disposed on the substrate surface of the polymer dispersed liquid crystal cell. Moreover, the brightness B in the surface on the opposite side to the light irradiation side of the polymer dispersion liquid crystal cell was measured with a luminance meter (BM-8 made by TOPCON). These measured values were substituted into the above formula (E-1) to calculate the scattering gain G. As a result, the scattering gain G of the polymer dispersed liquid crystal cell according to the present example was 0.9.

On the other hand, for reference, the scattering gain G is 0.5 when the polymer dispersed liquid crystal cell is a complete scatterer. In addition, the contrast of the polymer dispersed liquid crystal cell is proportional to the inverse of the scattering gain G. The scattering gain G is described in "Liquid Crystal Video Projector Technology" (Sasaki Jung, 1990, Oct. 29, p. 139).

In addition, the applied voltage-light transmittance characteristics of the polymer dispersed liquid crystal cell according to this embodiment were examined. 39 is a graph showing the relationship between the applied voltage and the transmittance in the polymer dispersed liquid crystal cell. The measurement conditions were conducted by applying a rectangular wave of 30Hz as applied, and the measuring temperature 30 ℃, acceptance angle of 0.2 ⁰ voltage.

The two curves in Fig. 39 respectively show applied voltage-light transmittance characteristics when the applied voltage is increased from 0V to 30V, and applied voltage-light transmittance characteristics when the applied voltage is reduced from 30V to 0V. Both curves are not exactly the same, and some hysteresis is observed. Assuming that the largest optical hysteresis is called maximum optical hysteresis (ΔTc), the ΔTc of the polymer dispersed liquid crystal cell produced in this example was 0.9%. In addition, γ value at this time is because _{Vc 10 = 3.0V, Vc 90 =} 6.0V, was Vc ₉₀ / Vc ₁₀ = 2.0.

Comparative Example E

The liquid crystal display device according to this comparative example has a liquid crystal and polymer composite layer having almost the same average particle diameter in the liquid crystal and polymer composite layer as compared with the polymer dispersed liquid crystal cell according to Example E-1, and does not have an ultraviolet transmittance adjustment layer. The point is different. Hereinafter, the specific structure of the liquid crystal display element which concerns on this comparative example is explained in full detail.

40 is a schematic sectional view showing an outline of the liquid crystal display device.

The liquid crystal display element 560 includes a lower substrate 562 and a liquid crystal-polymer composite layer 563 disposed between the lower substrate 561 and the lower substrate 562 and the upper substrate 561. Has The lower plate 562 and the upper plate 561 are transparent substrates made of glass. On this base substrate 562, a thin film transistor (TFT), metal wiring (scanning signal line, image signal line), transparent pixel electrode 564b, and the like are formed. These metal wires, the TFT, the pixel electrode 564b and the like are covered with the insulating film 565b. In FIG. 40, metal wirings, TFTs, and the like are omitted.

A transparent counter electrode 564a is formed on the inner surface of the plate 561, and the counter electrode 564a is covered with an insulating film 565a. The pixel electrode 564b and the counter electrode 564a are made of indium tin oxide (ITO: Iudium Tin 0xide).

The liquid crystal-polymer composite layer 563 is a polymer dispersed liquid crystal (PDLC) layer having a structure in which a liquid crystal group is independently dispersed in a polymer matrix. In more detail, it consists of a polymer 566 and two types of liquid crystal 567a, 567b. As for the liquid crystal in liquid crystal 567a, 567b, the positive dielectric anisotropy is used. The liquid crystal droplets 567a exist inside the liquid crystal and polymer composite layer 563, and are formed in a substantially spherical shape. On the other hand, the liquid crystal droplets 567b are formed on each of the insulating films 565a and 565b and are formed in a dome shape that bulges inward of the liquid crystal and polymer composite layer 563.

The liquid crystal display device 560 according to this comparative example was produced in the same manner as in Example E-1 except for the step of forming the UV transmittance adjusting layer.

Further, for the liquid crystal display device 560, the change in transmittance with respect to the applied voltage was measured with a luminance meter as in Example E-1. As shown in Fig. 41, ₁₀ = 3.6V and Va, Va ₉₀ = 6.2V, γ values ₍₉₀ = Va / Va _l0) was 1.7. The maximum optical hysteresis (ΔTa) was 1.6%. Further, at this time the Va ₉₀ is approximately 6.2V, almost the same as in Example E-1.

On the other hand, the comparative example described above is for clarifying the effect of the hysteresis reduction of Example E-1. Although the comparative example is made for Example E-1, the applied voltage-light transmittance characteristics have different areas. It is included in an Example from the viewpoint of the structure (it corresponds to Claim 2 concerning 1st invention group.).

(result)

As is clear from Example E-1 and Comparative Example, it can be seen that the optical hysteresis is the largest in the low voltage region in the applied voltage-light transmittance curve. Like the polymer dispersed liquid crystal cell of Example E-1, by providing a plurality of average particle diameters and other regions of the liquid crystal droplet in one pixel, the steepness of the applied voltage-light transmittance curve is smoothly in the low voltage region. It was possible to reduce the optical hysteresis in comparison with the comparative example.

The steepness of the applied voltage-light transmittance curve is gentle due to the reasons mentioned below. Fig. 42 is a graph showing applied voltage-light transmittance characteristics of a polymer dispersed liquid crystal cell. When there are two kinds of regions having different particle diameters, that is, drive voltages, and their applied voltage-light transmittance curves are set to VTa (smaller particle size) and VTb (larger particle size), respectively, the value of γ is smaller than 2.0. And optical hysteresis (ΔTa and ΔTb, respectively) also become large values of about 1.6%. However, when the transmittance is viewed as a whole of the pixels, it becomes a characteristic in a positional relationship as shown by the curve VTc and appropriately narrowed by the curve VTa and the curve VTb. Moreover, (DELTA) Tc was 0.9% and was suppressed much lower than the said comparative example.

Here, Vc It should be noted that curve ₉₀ of VTc is that they do not, even though a large γ value In this method the drive voltage is increased to become substantially equal to Va and ₉₀ of the curve VTa. As a method of increasing only the γ value, for example, a method of increasing the orientation regulating force (anchoring) of the insulating film with respect to the liquid crystal is considered. In this method, V ₉₀ itself is also increased and the driving voltage increases.

[Experiment]

Various experiments mentioned below were carried out to investigate appropriate specifications of the polymer dispersed liquid crystal cell according to Example E-1.

(1) Relationship between average particle diameter or average mesh size R of liquid crystal field and threshold voltage

First, a polymer dispersed liquid crystal cell was prepared in which the average particle diameter or average mesh size R (µm) of the liquid crystal droplets was different. All of these liquid crystal cells are conventional polymer dispersed liquid crystal cells in which the ultraviolet transmittance adjusting layer 515 is not included in the components.

An applied voltage was applied to the various types of polymer dispersed liquid crystal cells, and respective threshold voltages were measured. The results are shown in FIG. 43. Fig. 43 is a graph showing the relationship between the average particle diameter or average mesh size R of the liquid crystal droplets and the threshold voltage when the cell thickness is 12 µm.

In the figure, it can be seen that the threshold voltage has a large dependency on the average particle diameter or the average mesh size R of the liquid crystal region. The same can be said for the cell thickness. In addition, as shown in the drawing, in consideration of the practical driving voltage (about 6 to 12V) of the active matrix polymer dispersed liquid crystal using TFT, R is preferably 0.4 µm or more. In view of the power consumption of the device, on the other hand, the upper limit of R is preferably such that the driving voltage is smaller than about 12V.

(2) Relation between average particle diameter or average mesh size R of liquid crystal area and scattering gain G

Scattering gain was also examined with respect to the various polymer dispersed liquid crystal cells used in the above (1). The measurement was performed by the same method as mentioned above. The results are shown in FIG. 44.

Fig. 44 is a graph showing the relationship between the average particle diameter or average mesh size R of the liquid crystal droplets and the scattering gain G when the cell thickness is 12 μm. As shown in the figure, it is understood that the scattering gain G also shows dependence on the average particle diameter (liquid crystal diameter) or the average mesh size (when polymer network structure) R of the liquid crystal drops. In addition, in order to realize high contrast, the value of scattering gain G may be small. Therefore, as can be seen from FIG. 44, a high contrast is obtained when R is 0.6 µm <R <1.6 µm. Therefore, in the polymer dispersed liquid crystal cell of Example E-1, R is more preferably within the numerical range.

(3) Relationship between γ value and optical hysteresis when the particle size ratio (or mesh size ratio) of two regions is changed in the liquid crystal / polymer composite layer

A polymer dispersed liquid crystal cell having the same structure as the polymer dispersed liquid crystal cell according to Example E-1 was prepared except that the particle size ratio and mesh size ratio of the two regions were different. If the particle diameter ratios of the two regions are different, the change in the ratio of the driving voltage (that is, the γ value) is caused by the change in the slope of the applied voltage-light transmittance curve.

45 is a graph showing the relationship between the value of γ and optical hysteresis. As apparent from the above drawings, it can be seen that as the particle size ratio and the like increase, that is, the optical hysteresis decreases as the value of γ increases. In addition, if the γ value (V ₉₀ / V ₁₀₎ is 2.0 or more It can be seen that it is possible to suppress optical hysteresis to less than 1%. The upper limit of V ₉₀ / V ₁₀ is preferably about 5.0 or less in consideration of the practical driving voltage and the number of divisions of the region.

In Figure 45, in order largely to two regions of the particle diameter ratio (= the driving voltage ratio = V p of a large particle size ₉₀ / particle size of the smaller V ₉₀₎ of the one pixel of the γ value is suitable to small. In other words, it is appropriate that the curve VTa and the curve VTb are separated in FIG. 42 described above. However, when the curve VTa and the curve VTb are excessively separated, the effect of reducing optical hysteresis is saturated. In the results of the experiment, the saturation point is when γ ≒ 3 and about 0.5 at the driving voltage ratio (Vb ₉₀ / Va ₉₀ ). For reference, when increasing the number of regions having different applied voltage-light transmittance characteristics, the value of γ at the saturation point becomes larger.

On the other hand, as a result of the provision of the UV transmittance adjusting layer 515, in the region corresponding to the above UV transmittance adjusting layer 515, the thickness of the liquid crystal / polymer composite layer is smaller than that in the region not provided therein. It is thought that γ value also becomes large by this secondary action. In addition, the polymer-dispersed liquid crystal cell according to Example E-1 corresponds to a value of γ of 2.

(4) Relationship between driving voltage ratio (Vb ₉₀ / Va ₉₀ ) and transmittance

A polymer dispersed liquid crystal cell of which the driving voltage ratio was 0.4 and a polymer dispersed liquid crystal cell of which 0.7 was produced, and the transmittance was measured when the applied voltage was increased (raising voltage process) for each. The results are shown in FIG. 46. Fig. 46 is a graph showing the relationship between the applied voltage and the transmittance, Fig. 46A shows the case where the drive voltage ratio is 0.4, and Fig. 46B shows the case where the drive voltage ratio is 0.7.

As shown in Fig. 46A, when the driving voltage ratio Vb ₉₀ / Va ₉₀ is 0.4, the inflection point h is shown on the curve VTd (applied voltage-transmittance curve as the entire pixel). In the vicinity of this inflection point h, although the applied voltage is increasing, the increase in transmittance is slowing down. In short, it is considered that the desired transmittance may not be obtained in this region. Therefore, the case where the drive voltage ratio is 0.4 is not suitable.

On the other hand, when the drive voltage ratio is 0.7, as shown in Fig. 46B, the inflection point h does not appear on the curve VTe. Therefore, in this case, the above problems do not occur. However, when the driving voltage ratio (Vb ₉₀ / Va ₉₀ ) is larger than 0.9, the curve VTa and the curve VTb approach in this case, and the curve VTe does not have two kinds of regions having different particle diameters in one pixel. It became almost the same as the case. That is, the increase effect of (gamma) value was not seen.

Therefore, the following knowledge was obtained from the above experiment result. That is, the increase effect of the value of gamma was confirmed in the range of the drive voltage ratio is 0.6 or more and 0.9 or less. From this, it is preferable to exist in the said numerical range, and also it is more preferable to exist in the range whose drive voltage ratio is 0.7 or more and 0.85 or less.

On the other hand, in the present invention, as described above, a configuration requirement that the plurality of regions having different applied voltage and light transmittance characteristics are different is an essential requirement for achieving the desired effect of the invention. Therefore, the single embodiment or experiment described above, in particular the numerical requirements thereof, is a suitable implementation requirement for achieving the best effect, and it is also possible to adopt the value of the driving voltage ratio where the inflection point appears when a slight deterioration of the transmittance is allowed. Do.

Example E-2

Subsequently, ultraviolet rays were irradiated through a stripe mask made of a metal chromium having a line width of 40 μm-spacer width of 10 μm, and the ultraviolet ray transmittance adjusting layer was formed in the same manner as in Example E-1. A polymer dispersed liquid crystal cell was produced.

The polymer dispersed liquid crystal cell thus produced has two regions having different particle diameters in one pixel, and the area ratio of the two regions is 0.2: 0.8. Moreover, when the optical hysteresis of this polymer dispersion liquid crystal cell was measured, it was 1.4% and (gamma) value was 1.8. Thereby, optical hysteresis can be reduced compared with the case of a comparative example (optical hysteresis 1.6%, (gamma) = 1.7).

Furthermore, compared with the polymer dispersed liquid crystal cell of Example E-1, the optical hysteresis was 0.9% as described above, and it can be seen that compared with the polymer dispersed liquid crystal cell of this Example. have.

From the above, it can be seen that the most significant reduction in optical hysteresis is the case where the area ratio of the region satisfies the formula (E-2). This is because, as a result of satisfying the following formula (E-2), the difference between the applied voltage and the transmittance characteristic is substantially the largest and the steepness becomes more gentle. Therefore, it is more preferable when the area ratio of two areas is 1: 1.

s = S / n... (E-2)

(Wherein n represents the total number of a plurality of regions having different applied voltage and light transmittance characteristics, S represents the total area of one pixel, and s represents the area of each region.)

On the other hand, for reference, even when a plurality of regions having different applied voltage and light transmittance characteristics are formed, the difference in the area between the regions is extremely large, and when the applied voltage and light transmittance characteristics of a certain region are substantially represented, The reduction effect of hysteresis may be small.

(Other matters)

In each of the above examples, a photoresist is used as the UV transmittance adjusting layer. However, the photoresist is not particularly limited as long as it absorbs ultraviolet rays. For example, the same effect can be obtained even if it adds the pigment | dye to an insulating film. In addition, since the transparent electrode actually absorbs ultraviolet rays and visible light substantially, the effect is further obtained by controlling the film formation method and the film thickness of the transparent electrode to vary the degree of absorption. Furthermore, if the film thickness of the transparent electrode is changed for each region having different applied voltage and light transmittance characteristics, the inter-electrode distance can be changed for each of the regions, and this effect is further obtained.

In addition, it is preferable as the ultraviolet transmittance adjusting layer that the light partially absorbs light in ultraviolet rays but hardly absorbs light in the visible region, and the negative photoresist NN700 used in this embodiment exhibits such characteristics.

In each of the above embodiments, the case where the liquid crystal-polymer composite layer is provided with two regions having different average particle diameters of liquid crystal droplets in one pixel is provided. However, this invention is not limited to this at all, It is also possible to set it as 3 area | region or more, for example. For example, one pixel is divided into approximately three equal parts, and in one region, a first ultraviolet transmittance adjusting layer having a predetermined transmittance with respect to ultraviolet rays is formed, and in another region, the ultraviolet transmittance is different from the first ultraviolet transmittance adjusting layer. It is also possible to set it as the aspect which forms a 2nd ultraviolet transmittance adjustment layer and does not form an ultraviolet transmittance adjustment layer in the remainder area | region. In such a configuration, when the liquid crystal and the polymer composite layer are formed by irradiation of ultraviolet rays, three regions having different particle diameters or the like of liquid crystal droplets can be formed. On the other hand, when using the material which consists of the same material for a 1st and 2nd ultraviolet transmittance adjustment layer, it is possible to control an ultraviolet transmittance by changing each film thickness. Moreover, when making each film thickness the same, it is possible to control ultraviolet transmittance by using the material which consists of different materials.

As described above, according to the present invention group E, ultraviolet rays are irradiated through a substrate having a plurality of regions having different ultraviolet transmittances, whereby the average particle diameters or average mesh sizes of the liquid crystals differ in parallel to the substrate. A liquid crystal / polymer composite layer composed of a plurality of regions is formed. Therefore, for example, a high-definition TFT or the like can be sufficiently divided into a plurality of regions. As a result, it is possible to reduce hysteresis while suppressing an increase in driving voltage, thereby realizing a liquid crystal display device having excellent display quality with high contrast. Get the effect.

(Invention Group F)

The central idea of the group F of the present invention is that in the liquid crystal-polymer composite layer, in order to form regions with different applied voltage and light transmittance characteristics in the in-plane direction, the distance between electrodes may be different for each region, and the driving voltage may be different. Thus, the optical hysteresis and the driving voltage can be reduced. In more detail, it discloses in embodiment mentioned below.

(Embodiment F)

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described according to drawing.

Embodiments of the present invention will be described below with reference to FIGS. 47 to 53. However, parts unnecessary for the description are omitted, and there are parts shown to be enlarged or reduced in order to facilitate explanation. The above is also the same with respect to the following drawings.

The present invention provides a liquid crystal-polymer composite layer including a liquid crystal and a polymer resin (polymer) between a pair of substrates, and changes the light scattering state of the liquid crystal-polymer composite layer by applying an electric field to the liquid crystal-polymer composite layer. In a display element for displaying an image or the like, a plurality of regions having different applied voltage and light transmittance characteristics are formed in one pixel, so that liquid crystals are generated in a low applied voltage region, and the gradual steepness of the applied voltage is not increased. It has the externally applied voltage-light transmittance characteristic and reduces optical hysteresis.

In order to obtain the apparent applied voltage-transmittance characteristic as described above, the present invention divides the liquid crystal-polymer composite layer into at least two regions having different characteristics in a direction parallel to the substrate. More specifically, it is as mentioned below.

FIG. 47 is a schematic sectional view showing an outline of a liquid crystal display device according to Embodiment F. FIG. 48 is a schematic sectional view showing a main portion of the liquid crystal display element. The liquid crystal display device includes a base plate 602 disposed to face the plate 601 and the plate 601, and a liquid crystal / polymer composite layer disposed between the plate 601 and the base plate 602. Has 607. On this lower substrate 602, a thin film transistor (TFT) 615 as a pixel switching element (active element), metal wiring (scanning signal line, image signal line), and the like are formed. In addition, a pixel electrode 604 is formed on the lower substrate 602. The pixel electrode 604 includes an electrode layer 604a provided on a lower substrate 602, a stepped film 606 formed in a stripe shape on the electrode layer 604a, and an electrode layer 604b covering the stepped film 606. Is done. In FIG. 47, metal wiring and the like are omitted for ease of understanding of the present invention. On the other hand, a transparent counter electrode 603 is formed on the inner surface of the plate 601. In addition, the upper plate 601 and the lower plate 602 are bonded and sealed by the sealing material 620.

The upper plate 601 and the lower plate 602 are, for example, transparent substrates made of glass. The counter electrode 603 and the pixel electrode 604 are made of, for example, indium tin oxide (ITO).

The liquid crystal-polymer composite layer 607 is a polymer dispersed liquid crystal (PDLC) layer having a structure in which liquid crystals are independently dispersed in a polymer matrix made of a transparent polymer. Each liquid crystal droplet 610... Is formed in a substantially spherical or spheroidal shape, and the liquid crystal molecules in the liquid crystal droplet 610. The liquid crystal-polymer composite layer 607 is not limited to the PDLC layer but may be a polymer network type liquid crystal layer in which a liquid crystal is held in a three-dimensional network polymer resin.

The stepped film 606 is made of a photosensitive material whose pattern is provided in a stripe shape. It does not specifically limit as said photosensitive material, A conventionally well-known thing can be used regardless of an organic type material and an inorganic type material. On the other hand, the refractive index of the stepped film 606 and the polymer resin, which is a component of the liquid crystal and polymer composite layer 607, is preferably about the same. When the refractive index difference between them becomes too large, light is refracted at the interface of the stepped film 606 / liquid crystal / polymer composite layer 607 when light passes through the liquid crystal display element. For this reason, the possibility of causing the fall of the transmittance | permeability of the liquid crystal display element itself, and degrading display performance, such as contrast, is considered.

On the other hand, in the above configuration, the case of the stripe shape when the uneven shape of the surface of the pixel electrode is viewed in plan is mentioned. However, the present invention is not limited to this, and may be a lattice pattern.

Here, as shown in Fig. 48, regions A and B having different applied voltage and light transmittance characteristics are provided in one pixel, and the electrodes between the counter electrode 603 and the pixel electrode 604 in the region A are provided. The first feature of the present invention is that the inter-distance d _n between the counter electrode 603 and the pixel electrode 604 in the inter-distance d _l and the region B satisfies the relationship of the following formula (F-1). By satisfying this, optical hysteresis can be reduced.

d _n / d _l ≦ 0.85... (F-1)

Hereinafter, the applied voltage-light transmittance characteristics of the liquid crystal display device of the present invention will be described in detail, and the reason why the reduction of optical hysteresis is aimed at will be mentioned. Fig. 49 is a graph showing the relationship between transmittance and applied voltage in this liquid crystal display element.

The curves VTa and VTb shown in FIG. 49 show applied voltage-light transmittance characteristics in the region A or the region B, respectively. In general, the driving voltage for driving the liquid crystal display element can be suppressed to a low voltage to the extent that the cell gap is small. In the present embodiment, the area A · the distance between electrodes in the B since the set such that the d _l> d _n, if a comparison of the driving voltage in the region A and the region B, one is the area of the area A Obviously bigger than B. This can be seen from Fig. 49 that the curve VTb has an applied voltage-light transmittance characteristic shifted to the low applied voltage side as compared with the curve VTa. In short, in the liquid crystal display device according to the present embodiment, there are a plurality of regions in which the applied voltage and the light transmittance characteristics are different in one pixel. When the display screen of the liquid crystal display element in which a plurality of regions having different characteristics differ from each other is observed, it is recognized that the liquid crystal display element has an applied voltage-light transmittance characteristic represented by the curve VTc shown in the drawing. Because a plurality of regions having different applied voltage and light transmittance characteristics coexist in one pixel, the observer has an average applied voltage and light transmittance characteristics in these regions, resulting in an apparent applied voltage and light transmittance characteristic represented by the curve VTc. Will be. Specifically referring to the curve VTc, as is apparent from Fig. 49, the low voltage region with a low applied voltage shows a trajectory that follows the curve VTb, while the high voltage region with a high applied voltage shows a trajectory that follows the curve VTa. It is shown between the curve VTa and the curve VTb. Therefore, the liquid crystal display device according to the present embodiment exhibits the appearance-applied voltage-transmittance characteristic in which the optical hysteresis is reduced as described above, and thus can reduce the afterimage or sticking caused by the optical hysteresis. Moreover, since the tailing, blurring, etc. of an image resulting from the same cause are also reduced, the nonuniformity of the display which is recognized by the human eye is improved.

Furthermore, in the present invention, the drive voltage VA in the area A and the drive voltage VB in the area B satisfy the relationship of the following formula (F-2), which is a second feature of the present invention, and satisfies the related relationship. By doing so, optical hysteresis can be reduced.

V _A / V _B? 0.85... (F-2)

On the other hand, the driving voltages VA and VB mean the applied voltages V90 in the areas A and B when the maximum transmittance of the liquid crystal display element is T _max and the maximum transmittance T _max is 90%.

As described above, even when the value of V ₉₀ is different for each region and the relationship of the formula (F-2) is satisfied, the apparent applied voltage-light transmittance characteristic is as shown by the curve VTc shown in FIG. Therefore, the optical hysteresis can be reduced for the same reason as described above, and the occurrence of afterimage or seizure due to the optical hysteresis can be reduced. Moreover, the nonuniformity of the display is also improved.

Next, the manufacturing method of the liquid crystal display element which concerns on this embodiment is demonstrated. 50 is a flowchart for explaining the manufacturing steps of this liquid crystal display element.

First, the counter electrode 603 is formed on the plate 601 by a conventionally known method (counter electrode forming step, S601). On the other hand, the electrode layer 604a is formed on the lower substrate 602 by a conventionally known method. Furthermore, a photoresist film is formed on the electrode layer 604a by coating with a conventionally known method such as a spinner or the like (photoresist film forming step, S602). Here, the film thickness of the photoresist film can be controlled by changing the rotation speed at the time of spinner application. An optical mask having a light shielding portion having a predetermined shape is formed on the photoresist film, and light is irradiated through the optical mask (exposure step S603). Subsequently, the exposed photoresist film is developed, thereby forming a stepped film 606 (development processing step, S604). Next, the electrode layer 604b is formed by covering the stepped film 606. As a result, the electrode layer 604a and the electrode layer 604b are brought into a conductive state to form the pixel electrode 604 (pixel electrode forming step, S605).

On the other hand, as the optical mask, as shown in Figs. 51A and 51B, a mask in the form of a stripe or a lattice pattern may be used. In the figure, the portion drawn in the shape of a dot shows that it is a light shielding portion.

Subsequently, after forming the counter electrode 603 and the pixel electrode 604, the sealing material 620 is formed as follows. That is, the sealing material 620 is apply | coated on either board | substrate of the said board | substrate 601 or the lower board | substrate 602 so that an application shape may become an afterimage pattern which connected the part of a liquid crystal injection hole. Then, the upper plate 601 and the lower plate 602 are joined to face the opposite electrode 603 and the pixel electrode 604 to form an empty cell (empty cell manufacturing process, S606). On the other hand, a mixed composition containing liquid crystal and a polymer material as a main material is prepared in advance (liquid crystal mixture preparation step, S607), and the mixed composition is injected into an empty cell from the liquid crystal inlet (liquid crystal injection step, S608) to form a liquid crystal polymer mixture layer. Form.

Further, the liquid crystal and polymer composite layer 607 is formed by phase separation by polymerization of a polymer material (liquid crystal and polymer composite layer forming step, S609). Examples of the phase separation method include a photopolymerization phase separation method and a thermal polymerization phase separation method. For example, in the case of phase separation by the photopolymerization phase separation method, the liquid crystal-polymer composite layer 607 can be formed as mentioned below. First, ultraviolet rays using a high pressure mercury lamp as a light source are irradiated onto the liquid crystal polymer mixture layer. At this time, the commercially available polymer material and the liquid crystal undergo a phase separation at the same time as the polymerization of the polymer material proceeds and microparticles of the liquid crystal are deposited. These microspheres aggregate and merge with other microspheres in the vicinity, and gradually grow large in liquid crystal. Thereby, the liquid crystal display element which concerns on this embodiment can be manufactured.

On the other hand, in the liquid crystal display device according to the present invention, the liquid crystal is generated in the low voltage region by forming a plurality of regions having different applied voltage-light transmittance characteristics so as to be indicated by the curve VTc shown in Fig. 49, and the applied voltage is not too large. It is the biggest feature that it has an externally applied voltage-light transmittance characteristic which has a moderately steepness.

Therefore, the present invention is not particularly limited as long as it is a liquid crystal display device having a liquid crystal / polymer composite layer having the above applied voltage-light transmittance characteristics. In the regions A and B, the distance between the counter electrode and the pixel electrode is If you want to be different. For example, as shown in FIG. 52, a step is formed by etching the surface of the substrate, and the pixel electrode 614 is formed on the base 612, whereby the pixel electrode ( The surface of 614 may be an uneven | corrugated shape. In this case, a liquid crystal display element is produced by performing the process mentioned below (refer FIG. 53). First, a mask having a predetermined pattern shape is formed on the lower substrate 612 (mask forming step, S611). Subsequently, it is immersed in an etching solution, and the uncoated part of the said mask is melt | dissolved and removed using a chemical reaction in a liquid-solid interface (etching process, S612). Here, by changing the etching treatment conditions such as the composition ratio of the etching solution and the processing time, the step can be made larger or smaller, and as a result, the distance between the counter electrode and the pixel electrode can be controlled. The pixel electrode 614 is formed on the etched base substrate 612 by a conventionally known method (pixel electrode forming step, S613). By repeating the above steps, it is possible to form a liquid crystal display device having a base plate 612 whose surface is irregular.

(Example F)

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not merely intended to limit the scope of the present invention only to them unless specifically described, and are merely illustrative examples. .

Example F-1

The polymer dispersed liquid crystal display device according to Example F-1 has the same configuration as in the above embodiment, and was produced as follows. First, a glass substrate (trade name: 1737 substrate, manufactured by Corning Corporation) on which a transparent electrode layer (electrode layer 604a) made of indium tin oxide is formed is prepared, and a photoresist material (trade name) is formed on the electrode layer 604a. : NN700, Nippon Synthetic Rubber Co., Ltd., refractive index 1.45-1.55) were apply | coated with the spinner, and the photoresist film was formed. The coating conditions using the spinner were set at a rotational speed of 2500 rpm and a rotation time of 30 seconds. Next, an optical mask having a pattern of stripe patterns at a pitch of 30 mu m was disposed on the photoresist film, and mask exposure was performed by irradiating light onto the photoresist film using a high pressure mercury lamp as a light source. Subsequently, after developing with a developing solution (trade name: NSD-TD, manufactured by Tokyo Chemical Industries, Ltd.), the step was cured by firing at a temperature of 180 ° C. for 60 minutes to form a stepped film 606. When the step of the stepped film 606 was measured by a step meter, it was found that the step was 2 μm. Next, on the stepped film 606, a transparent electrode (electrode layer 604b) made of indium tin oxide by sputtering was formed. The film thickness of the electrode layer 604b was 100 nm.

On the other hand, the sealing material 620 serving as a spacer on the plate 601 having the counter electrode 603 made of ITO was coated with an acid anhydride-curable epoxy resin dispersed in a glass fiber having a diameter of 10 μm. It formed so that it might become a definite afterimage pattern. On the other hand, the opening width of the liquid crystal inlet was 3 mm. And the said board | substrate 601 and the base board 602 were adhere | attached under pressure, and the sealing material 620 was hardened and joined by heating at 150 degreeC for 2 hours, and the empty cell was produced.

Here, the distance between the electrodes between the counter electrode 603 and the pixel electrode 604 is measured by the optical interference method, and the distance between the electrodes is d _n = 10 μm in the region A in which the stepped film 606 is convex. And d _l = 12 µm in the concave region B.

Then, the material which forms the liquid crystal polymer composite layer 607 was prepared. That is, 80 parts of liquid crystal materials (brand name: TL-205, the company made by Melk Co., Ltd.), 15.8 parts of 2-ethylhexyl acrylate (made by Nakaray Tesque Co., Ltd., refractive index 1.45-1.5) as a polymerizable monomer, acrylate 4 parts of a system oligomer (trade name: HX620, manufactured by Nippon Kayaku Co., Ltd.) and 0.2 parts of a polymerization initiator (brand name: Dalocua 4265, manufactured by Chiba-Geigi Co., Ltd.) are mixed, and the mixture is sufficiently stirred at a predetermined temperature to make a liquid crystal material and a polymer A mixed solution in which the materials were uniformly mixed was prepared.

This mixed solution was injected into the liquid crystal inlet by vacuum injection, and then the liquid crystal inlet was sealed with a sealing resin to form a liquid crystal polymer mixture layer. Subsequently, the liquid crystal polymer mixture layer was irradiated with ultraviolet rays (a high-pressure mercury lamp was used as the light source) to form a liquid crystal-polymer composite layer 607. As irradiation conditions, irradiation intensity was about 40 mW / cm <^2> and the irradiation time was 60 second at the temperature of 25 degreeC. In addition, the irradiation of the ultraviolet-ray was performed through the light cut filter (brand name: UV35, Toshiba color glass company make). As described above, the liquid crystal display device F1 of the present invention in which the liquid crystal groups were independently dispersed in the polymer resin was produced.

Comparative Example F-1 to Comparative Example F-4

The liquid crystal display device according to Comparative Example F-1 to Comparative Example F-4 is compared to the configuration of the liquid crystal display device F1 of the present invention in Example F-1 in the distance between the electrodes d _l and B in the region A. In the same manner as in Example F-1, except that the inter-electrode distance d _n was as shown in Table F-1 below.

The liquid crystal display elements according to Comparative Examples F-1 to Comparative Example F-4 produced as described above are referred to as liquid crystal display elements Y1 to Y4 for comparison, respectively.

[Example F-2] to [Example F-6]

The liquid crystal display device according to Examples F-2 to F-6 was compared with the configuration of the liquid crystal display device F1 of the present invention in Example F-1 in the distance between the electrodes d _l and B in the region A. It produced by the method similar to Example F-1 except having made the distance d _n between electrodes as shown in following Table F-1.

The liquid crystal display elements according to the present Examples F-2 to F-6 produced as described above are referred to as liquid crystal display elements F2 to F6 of the present invention, respectively.

[Experiment 1]

The performance evaluation of the present invention liquid crystal display elements F1 to F6 and comparative liquid crystal display elements Y1 to Y4 produced as described above was performed by the method mentioned below. That is, green (G) light is irradiated to the liquid crystal display device by disposing a green filter between the white light source and the liquid crystal display device using the LCD 500 (manufactured by Otsuka Electronics Co., Ltd.) as a measuring device. And the applied voltage was measured. The area of the measurement spot was 150 µm ² . First, by applying an alternating current at a frequency of 60 Hz to each liquid crystal display element, the applied voltage-light transmittance characteristics in the case of changing from the scattering state to the transmission state (raising voltage process) were measured. Next, the applied voltage-transmittance characteristic in the case of changing from the transmission state to the scattering state (strong voltage process) by gradually lowering the voltage level of the applied voltage was measured. According to the applied voltage-light transmittance characteristics thus obtained, optical hysteresis was obtained as follows. That is, the applied voltage when the transmittance is 30% (= T _up (V ₃₀ )) in the step- _up process is set to V ₃₀ , and the transmittance is decreased by T _down (V in the step- _down process when the applied voltage is V _{30. 30} ). The values of these transmittances were applied to the following formula (F-3) to calculate optical hysteresis H _t (%).

H _t (%) = (T _down (V ₃₀ ) -T _up (V ₃₀ )) / (T _max -T _o ) × 100... (F-3)

Here, the optical hysteresis when the applied voltage is V ₃₀ as an evaluation criterion is based on the reason mentioned below. That is, conventionally, as a method for evaluating the applied voltage-light transmittance characteristic, optical hysteresis in the case where the transmittance in the step-up voltage becomes 50% is calculated or the like. This evaluation method is useful for evaluating the performance of liquid crystal display devices, but development of a more reliable evaluation method has been desired. By the way, the inventors of the present invention have found that the maximum optical hysteresis is the case where the voltage level of the applied voltage is lower, specifically, the transmittance is about 10% to 30%. Therefore, in this experiment, the transmittance | permeability at the transmittance | permeability 30% was made into the evaluation criterion of optical hysteresis. As a result, it became possible to reliably evaluate the applicability of the applied voltage-light transmittance characteristics. On the other hand, in the above evaluation method, the smaller the value of H _t (%), the smaller the optical hysteresis and the better the performance of the liquid crystal display device.

The correlation between the optical hysteresis H _t (%) obtained as described above and the ratio (Dr = d _n / d _l ) of the distance between electrodes in the area AB of each liquid crystal display device was investigated. Further, the area of the measurement spot was set to 25 µm ² , and the driving voltages of the regions A and B were measured, respectively, and the correlation between the ratio of the driving voltages (V _r = V _B / V _A ) and the optical hysteresis H _{t was} measured. Also investigated. The results are written together in Table F-1 below.

Table F-1

d _l (mm) d _n (mm) * Dr (-) * Vr (-) H _t (%) Invention Liquid Crystal Display F 1 12.0 10.0 0.83 0.81 9.23 Comparative Liquid Crystal Display Y 1 12.0 12.0 1.00 1.00 17.38 Comparative liquid crystal display element Y 2 12.0 11.4 0.95 0.94 15.59 Comparative Liquid Crystal Display Y 3 12.0 10.9 0.91 0.91 13.50 Comparative Liquid Crystal Display Y 4 12.0 10.4 0.87 0.88 10.86 Invention Liquid Crystal Display F 2 12.0 10.2 0.85 0.85 9.67 Invention Liquid Crystal Display F 3 12.0 9.2 0.77 0.74 9.00 Invention Liquid Crystal Display F 4 12.0 8.5 0.71 0.70 8.92 Invention Liquid Crystal Display F 5 12.0 8.0 0.67 0.64 8.78 Invention Liquid Crystal Display F 6 12.0 7.5 0.63 0.59 8.84

* Dr = d _n / d ₁ (-), V _r = V _B / V _A (-)

According to the result of Table F-1, the relationship between the ratio Dr between the electrodes and the optical hysteresis H _t is shown in FIG. 54. 55 shows the relationship between the ratio Vr of the driving voltage and the optical hysteresis H _t .

Example F-7

The liquid crystal display device according to the present Example F-7 is provided with a step by etching the surface of the lower substrate instead of the step film 606 in comparison with the configuration of the liquid crystal display device in the above Example F-1. different. The liquid crystal display element according to Example F-7 was produced by the following method.

First, a hydrogen fluoride layer having a stripe-shaped pattern shape formed at intervals of 30 mu m pitch on a glass substrate was formed and used as a mask. Subsequently, it immersed in the etching solution which consists of hydrogen fluoride aqueous solution, and melt | dissolved and removed the part which is not covered with the said hydrogen fluoride layer. As a result, a glass substrate having an uneven surface having a step of about 2 mu m was formed. Next, a transparent electrode made of indium tin oxide was prepared on the glass substrate by sputtering. The film thickness of the transparent electrode was 100 nm. And the liquid crystal display element F7 of this invention was produced by repeating the process similar to the said Example F-1.

[Comparative Example F-5] to [Comparative Example F-8]

The liquid crystal display device according to Comparative Example F-5 to Comparative Example F-8 was compared with the configuration of the liquid crystal display device A7 of the present invention in Example F-7, and the distance between the electrodes d ₁ and B in the region A was compared. In the same manner as in Example F-1, except that the distance d _n between electrodes was as shown in Table F-2 below.

The liquid crystal display elements according to Comparative Examples F-5 to Comparative Example F-8 produced as described above are referred to as liquid crystal display elements Y5 to Y8 for comparison, respectively.

[Example F-8] to [Example F-12]

The liquid crystal display device according to Examples F-8 to F-12 was compared with the configuration of the liquid crystal display device A7 of the present invention in Example F-7 in the distance between the electrodes d _l and B in the region A. except that as shown in the inter-electrode distance d _n to the table F-2, was produced in the same manner as in example F-7.

The liquid crystal display elements according to the present Examples F-8 to F-12 produced as described above are referred to as the present invention liquid crystal display elements F8 to F12, respectively.

[Experiment 2]

The performance evaluation of the present invention liquid crystal display elements F7 to F12 and comparative liquid crystal display elements Y5 to Y8 produced as described above were performed in the same manner as in Experiment 1. The results are written together in Table F-2 below.

Table F-2

d _l (mm) d _n (mm) * Dr (-) * Vr (-) H _t (%) Invention Liquid Crystal Display F 7 12.0 10.0 0.83 0.81 9.15 Comparative Liquid Crystal Display Y 5 12.0 12.0 1.00 1.00 17.59 Comparative Liquid Crystal Display Y 6 12.0 11.4 0.95 0.95 16.21 Comparative Liquid Crystal Display Y 7 12.0 10.9 0.91 0.91 13.20 Comparative Liquid Crystal Display Y 8 12.0 10.4 0.87 0.88 10.52 Invention Liquid Crystal Display F 8 12.0 10.2 0.85 0.85 9.67 Invention Liquid Crystal Display F 9 12.0 9.2 0.77 0.74 8.89 Invention Liquid Crystal Display F 10 12.0 8.5 0.71 0.69 8.63 Invention Liquid Crystal Display F 11 12.0 8.0 0.67 0.65 8.61 Invention Liquid Crystal Display F 12 12.0 7.6 0.63 0.61 8.55

* Dr = d _n / d ₁ (-), V _r = V _B / V _A (-)

56 shows the relationship between the ratio Dr between the electrode distance and the optical hysteresis H _t according to the result of Table F-2. The relationship between the ratio Vr of the driving voltage and the optical hysteresis H _t is shown in FIG. 57.

[result]

As apparent from the results of Experiments 1 and 2, the optical hysteresis of each of the liquid crystal display elements Fl to F12 of the present invention was obtained. In all, optical hysteresis H _t remained at 10% or less, and the optical hysteresis such as an afterimage resulted. There was no deterioration and excellent display quality was obtained. Moreover, as understood from said Table F-1 and Table F-2, it turned out that optical hysteresis is reduced when the relationship of following formula (F-1) and (F-2) is satisfied.

d _n / d _l ≦ 0.85... (F-1)

V _A / V _B? 0.85... (F-2)

On the other hand, in the above-described examples and comparative examples, the case where all regions having different applied voltage and light transmittance characteristics are formed in a stripe shape is mentioned, but in the case of lattice shape, the same results are obtained.

Group F of the present invention is carried out in the form described above to obtain an effect as mentioned below.

In other words, the liquid crystal-polymer composite layer is formed by arranging a plurality of regions having different applied voltage and light transmittance characteristics in one pixel in a direction parallel to the substrate. It is visually recognized as a light transmittance characteristic. In short, the average voltage applied and the light transmittance characteristics can be averaged to achieve a steep steepness, thereby providing an effect of providing a liquid crystal display device capable of reducing optical hysteresis and a method of manufacturing the same.

Invention Group G

The present invention group G relates to a liquid crystal display device in a light scattering mode using a liquid crystal-polymer composite system, and relates to a liquid crystal display device in a transverse electric field mode, and its central technical concept is in an in-plane direction in a region having different applied voltage and light transmittance characteristics. In this case, the optical hysteresis and the driving voltage can be reduced. In more detail, it becomes clear in embodiment mentioned below.

(Embodiment G)

58 is a simplified perspective view of a liquid crystal display element 701 according to Embodiment G of the present invention, and FIG. 59 is a simplified cross-sectional view of liquid crystal display element 701. The liquid crystal display element 701 according to Embodiment G is a liquid crystal display element in the transverse electric field mode, and the spacing between the comb-shaped electrodes is made different so as to constitute a plurality of regions having different applied voltage and light transmittance characteristics.

Below, the specific structure of the liquid crystal display element 701 is demonstrated. The liquid crystal display device 701 is a liquid crystal display device in the reverse mode, and is sandwiched between the array substrate 730 and the array substrate 730 opposing the array substrate 730 and the array substrate 730 and the counter substrate 731. The liquid crystal / polymer composite layer 732, the drive electrode 733, and the counter electrode 734 are provided. Examples of the array substrate 730 and the counter substrate 731 include glass substrates and the like. The driving electrode 733 and the counter electrode 734 are comb-shaped electrodes and are formed on the inner surface of the array substrate 730. The drive electrode 733 has a plurality of comb electrode portions 733A and a connecting electrode portion 733B connecting each comb electrode portion 733A, as shown clearly in FIG. 60, and each comb electrode portion 733A. Are parallel to each other. The counter electrode 734 has the same configuration as the drive electrode 733 and has a comb electrode portion 734A and a connecting electrode portion 734B. The drive electrode 733 and the counter electrode 734 are arranged in a state where the comb electrode portion 733A and the comb electrode portion 734A are engaged with each other.

On the other hand, as the driving electrode 733 and the counter electrode 734, an opaque electrode made of aluminum or the like is used. By such an electrode configuration, an electric field (transverse electric field) can be applied in parallel to the substrate. The liquid crystal and polymer composite layer 732 is a network liquid crystal layer composed of a liquid crystalline polymer 737 and a liquid crystal 738. The liquid crystalline polymer 737 is a liquid crystalline polymer, and the liquid crystal 738 is used to define dielectric anisotropy. These liquid crystal polymers 737 and liquid crystal 738 are homogeneous at an angle θ (see Fig. 61) from the comb electrode portion 733A by the alignment process of the array substrate 730 and the counter substrate 731. It is an array. Here, angle (theta) is the range of 0 degrees or more and less than 45 degrees.

In addition, the liquid crystal fraction of the liquid crystal and polymer composite layer 732 is set to 80% or more. Therefore, while the liquid crystal fraction of the conventional composite layer is about 60 to 80%, the liquid crystal fraction of the liquid crystal / polymer composite layer 732 is large, so that the liquid crystal is continuously between the array substrate 730 and the counter substrate 731. 738 is charged and the liquid crystalline polymer 737 is dispersed in the liquid crystal 738. In FIG. 59, the liquid crystal 738 represents liquid crystal molecules, and for convenience, a space exists between the individual liquid crystal molecules in order to understand the alignment state of the liquid crystal molecules. In reality, however, the liquid crystal 738 is in a state where all of the space portions except the liquid crystalline polymer 737 are filled. The reason why the composite layer having a large liquid crystal fraction is used in this way is that the liquid crystal is affected by the alignment treatment of the substrate, and the predetermined liquid crystal is arranged in this embodiment (homogeneous array). In addition, when the liquid crystal fraction is lowered to about 60 to 80%, the liquid crystal becomes a droplet and the liquid crystal is dispersed in the polymer, so that the alignment treatment of the substrate does not affect the liquid crystal, and the liquid crystal is arranged in a predetermined arrangement. It is not possible to form a homogeneous array in the form. 58 and 59, reference numerals 740 and 741 are alignment layers, and rubbing may be performed in a predetermined direction. 742 is an insulating layer.

Here, the structure of the comb-shaped electrode which is a main feature of the liquid crystal display element 701 will be described in detail. The spacing of the comb-shaped electrodes is set to two types of optical narrow. That is, the electrode spacing (in the present embodiment, corresponding to the spacing between the comb electrode portion 733A and the comb electrode portion 734A), which is an interval between the driving electrode 733 and the counter electrode 734 in the electric field direction, is two types of optical narrow. Is set to. Specifically, as shown in FIG. 60, the electrode spacing between the driving electrode 733 and the counter electrode 734 is set to two types, d ₃ and d ₄ smaller than d ₃ . By such a configuration of the electrode interval, the magnitude of the electric field is different at the electrode interval d ₃ and the electrode interval d ₄ at the same applied voltage. This means that the applied voltage-light transmittance characteristics of the liquid crystal / polymer composite layer part corresponding to the electrode gap d ₃ and the liquid crystal / polymer composite layer part corresponding to the electrode gap d ₄ are different. In other words, when viewed from the entire display element, it means that the liquid crystal-polymer composite layer is formed in two regions having different applied voltage-light transmittance characteristics. When regions with different applied voltage-light transmittance characteristics exist, the applied voltage-light transmittance curves are averaged in each region, resulting in a gentle curve compared with the case of having a single applied voltage-light transmittance characteristic. That is, the value of γ becomes large, and as a result, optical hysteresis can be reduced.

On the other hand, if the value of γ is increased, the driving voltage also increases in response to it, and if the value of γ becomes too large beyond the allowable range, driving becomes difficult in reality. For this reason, the upper limit of the gamma value is regulated. Therefore, in order to reduce both the optical hysteresis and the driving voltage, an optimal range exists in the γ value. That is, in the present embodiment G, as mentioned in the embodiment A-1 in the invention group A of the first invention group, γ _10-90 is 2 or more in order to make the optical hysteresis 2% or less. What is necessary is just to set and to make drive voltage smaller than 15V, it may be set to 3.1 or less (refer FIG. 11). This makes it possible to achieve both optical hysteresis and reduction in driving voltage.

In said example, it evaluated as (gamma) _10-90 as (gamma) value. However, considering that the peak value of optical hysteresis exists between 20% and 30% of transmittance, it is also effective to evaluate using γ _10-50 . This is because, as the applied voltage-light transmittance curve in the range of 10% to 50% of the transmittance is gentler, the overlapping effect becomes larger and the optical hysteresis becomes smaller. According to the experimental results of the present inventors, as mentioned in Embodiment A-1 of the invention group A of the said 1st invention group, in order to make optical hysteresis 2% or less, (gamma) _10-50 is 1.1 or more and 1.8. It is good to set it as follows (refer FIG. 15). This makes it possible to achieve both optical hysteresis and reduction in driving voltage.

Next, referring to Fig. 62, the display operation of the liquid crystal display element having the above-described configuration will be described. When no voltage is applied, as shown in FIG. 62A, the liquid crystal polymer 737 and the liquid crystal 738 coincide in the same direction in the plane parallel to the array substrate 730 and the opposing substrate 731. There is no difference in refractive index between the 738 and the liquid crystalline polymer 737, and the incident light passes without scattering. Thus, a transparent display state is obtained. When voltage is applied, as shown in FIG. 62B, an electric field is generated in parallel with the array substrate 730 and the counter substrate 731, and at this time, since the dielectric anisotropy of the liquid crystal 738 is positive, The long axis is arranged in the electric field direction. For this reason, the liquid crystal 738 rotates in a plane parallel to the array substrate 730 and the counter substrate 731, so that the angle between the liquid crystal polymer 737 and the liquid crystal 738 is increased. As a result, the axial direction of the birefringence between the liquid crystal polymer 737 and the liquid crystal 738 is greatly different, and the difference in refractive index between the liquid crystal polymer 737 and the liquid crystal 738 increases, so that the scattering intensity increases and the scattering state is obtained. . In this way, the liquid crystal display element in the transverse electric field mode can be realized by using the reverse mode. Furthermore, as described above, the distance between the driving electrodes 733 and the counter electrode 734 is adjusted to set γ _10-90 to 2 or more and 3.1 or less, or γ _10-50 to 1.1 or more and 1.8 or less. By setting it in the range of, the liquid crystal display element in the transverse electric field mode capable of achieving both optical hysteresis and reduction in driving voltage can be realized.

On the other hand, the shape of the electrodes of the drive electrode 733 and the counter electrode 734 is not limited to the above example, and the electrode spacing may be different from the straight electrodes as shown in FIG. 63A. As shown in the drawing, an electrode having a bent portion may be used.

In the above example, a positive dielectric anisotropy liquid crystal is used, but a dielectric anisotropy negative liquid crystal may be used. The present invention can also be widely applied to a liquid crystal display device using a liquid crystal-polymer composite system of a transverse electric field mode having another configuration.

(Example G)

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention to them only, unless specifically stated otherwise. Do.

As an example corresponding to Embodiment G, the liquid crystal display element 701 was produced by the following method.

Aluminum is used as the electrode material to form the comb-shaped drive electrode 733 and the counter electrode 734, and the source line 750, the gate line 751, and the like are provided on the same substrate in the transverse electric field mode. Array substrate 730 was prepared. At this time, the drive electrode 733 and the counter electrode 734 have different electrode spacings within the pixel. The electrode interval d ₃ was 12 μm, and the electrode interval d ₄ was 6 μm.

After the alignment film material was applied to the array substrate 730 and the counter substrate 731, respectively, and cured to form the alignment films 740 and 741, rubbing treatment was performed on them. Rubbing was in the direction of 10 ° C from the drive electrode 733. In other words, the angle θ was set to 10 °. Next, the array substrate 730 and the counter substrate 731 were bonded to each other with a sealing agent at intervals of 10 탆 to form an empty cell in the transverse electric field mode.

Next, a liquid crystal and a polymer precursor solution mixed with 20% of UV curable liquid crystal (manufactured by Dainippon Ink and Chemicals Co., Ltd.) and 80% of liquid crystal TL 205 (trade name, manufactured by Melk Co., Ltd.) were injected into an empty cell, and the intensity was 25 mW / cm ^2. The liquid crystal display device 701 was obtained by polymerization and phase separation with ultraviolet light. The liquid crystal display element 701 thus prepared was a display element of a reverse mode which became transparent when no voltage was applied.

The electro-optical characteristics of this display element were measured, and γ _10-90 was 2.6, which was large and optical hysteresis was 0.7%. On the other hand, γ _10-50 was 1.5.

The distance between the electrodes between the drive electrode and the counter electrode may be set in consideration of? Although the distance between electrodes was made into two types in the said example, this may be two or more types. In addition, as shown in FIG. 63, the electrode spacing varies the distance between a drive electrode and a counter electrode, and can provide a some kind of arbitrary.

When gamma _10-90 is 2 or more and 3.1 or less, both of achieving the optical hysteresis of 2% or less and reducing the driving voltage can be achieved. When optical hysteresis is required about 1% for moving picture display or the like, γ _10-90 needs to be 2.25 or more and 3.1 or less.

As described above, according to the present invention group G, a liquid crystal display device in a light scattering mode using a liquid crystal-polymer composite system, in which a region having different applied voltage-light transmittance characteristics is formed in an in-plane direction in a liquid crystal display device in a transverse electric field mode, By setting the gamma value (gamma _10-90 or gamma _10-50 ) to the optimum range, the effect of achieving both reduction in optical hysteresis and reduction in driving voltage can be obtained.

The specific embodiments or examples described in the detailed description of the present invention are intended to clarify the technical contents of the present invention to the last, and should not be construed as limited to such specific embodiments. Various modifications and changes can be made within the scope of the claims as set forth below.

According to the present invention, it is possible to provide a liquid crystal display device having excellent display quality such as responsiveness and contrast, and a manufacturing method thereof and an evaluation method thereof, by preventing afterimage and seizure due to optical hysteresis.

Claims (123)

A liquid crystal display device comprising a liquid crystal and a polymer composite layer comprising a liquid crystal and a polymer between a pair of substrates, and applying an electric field to the liquid crystal and polymer composite layer to change the light scattering state of the liquid crystal and the polymer composite layer. And said liquid crystal / polymer composite layer is composed of a plurality of regions having different applied voltage and light transmittance characteristics in one pixel. The liquid crystal display device according to claim 1, wherein a plurality of regions having different applied voltage-light transmittance characteristics are arranged in a direction perpendicular to the substrate. 3. The liquid crystal and polymer composite layer according to claim 2, wherein the liquid crystal is dispersed in a polymer matrix including polymers, and the average particle diameter of the liquid crystal droplets is different from each other in response to a plurality of regions having different applied voltage and light transmittance characteristics. Another liquid crystal display device. The liquid crystal and polymer composite layer according to claim 2, wherein the liquid crystal is dispersed and maintained in a mesh of a three-dimensional mesh matrix including polymers, corresponding to a plurality of regions having different applied voltage-transmittance characteristics. A liquid crystal display device characterized in that the average mesh size of the three-dimensional mesh matrix is different. 3. The liquid crystal display device according to claim 2, wherein the liquid crystal / polymer composite layer corresponds to a plurality of regions having different applied voltage-light transmittance characteristics, and the alignment states of liquid crystal molecules in the vicinity of the two substrates are different from each other. 6. The liquid crystal display according to claim 5, wherein liquid crystal molecules in the vicinity of the one substrate are oriented in a vertical direction with respect to the substrate, and liquid crystal molecules in the vicinity of the other substrate are oriented in a parallel direction with respect to the substrate. device. 3. The liquid crystal and polymer composite layer of claim 2, wherein A plurality of polymer dispersed liquid crystal layers in which liquid crystals are dispersed and maintained in a polymer matrix including polymers, and have a structure in which polymer dispersed liquid crystal layers having different applied voltage and light transmittance characteristics are stacked. When the driving voltage at 90% of the maximum transmittance is V ₉₀ and the driving voltage at 10% of the maximum transmittance is V ₁₀ , the ratio V ₉₀ / V ₀ is 2 or more and 3.1 or less. . The liquid crystal display device according to claim 7, wherein the average particle diameter of the liquid crystal droplets is different for each of the plurality of polymer dispersed liquid crystal layers. The liquid crystal display device according to claim 8, wherein the combination of the film thicknesses of the plurality of polymer dispersed liquid crystal layers and the average particle diameter of the liquid crystal droplets is different for each polymer dispersed liquid crystal layer. The liquid crystal display device according to claim 9, wherein the V ₉₀ is 15 V or less. The liquid crystal display element according to claim 10, wherein an active element is formed on one of the pair of substrates. 3. The liquid crystal and polymer composite layer of claim 2, wherein A plurality of polymer dispersed liquid crystal layers in which liquid crystals are dispersed and maintained in a polymer matrix including polymers, and have a structure in which polymer dispersed liquid crystal layers having different applied voltage and light transmittance characteristics are stacked. A liquid crystal display device having a ratio of V ₅₀ / V ₁₀ of 1.1 or more and 1.8 or less when a driving voltage of 50% of the maximum transmittance is V ₅₀ and a driving voltage of 10% of the maximum transmittance is V ₁₀ . The liquid crystal display device according to claim 12, wherein the average particle diameter of the liquid crystal droplets is different for each of the plurality of polymer dispersed liquid crystal layers. The liquid crystal display device according to claim 13, wherein the combination of the film thickness of the plurality of polymer dispersed liquid crystal layers and the average particle diameter of the liquid crystal droplets is different for each polymer dispersed liquid crystal layer. The liquid crystal-polymer composite layer of claim 2, wherein the liquid crystal-polymer composite layer has a structure in which liquid crystal molecules are dispersed and maintained in a polymer matrix including polymers between the pair of substrates provided with an insulating film, In addition, the liquid crystal-polymer composite layer Almost spherical liquid crystals It is a domed liquid crystal present on each of the insulating films and swelled inward of the liquid crystal and polymer composite layer, and has two kinds of liquid crystal droplets of domed liquid crystal droplets whose average particle diameter in the panel gap direction is smaller than the average particle diameter of the spherical liquid crystal droplets. And A V ₉₀ / V ₁₀ is 2.0 or more and 3.1 or less when the driving voltage at 90% of the maximum transmittance is V ₉₀ and the driving voltage at 10% is V ₁₀ . The liquid crystal display device according to claim 15, wherein the V ₉₀ is 15 V or less. The liquid crystal display device according to claim 16, wherein an active element is formed on one of the pair of substrates. The liquid crystal-polymer composite layer of claim 2, wherein the liquid crystal-polymer composite layer has a structure in which a liquid crystal group is dispersed and maintained in a polymer matrix including a polymer between the pair of substrates provided with an insulating film, In addition, the liquid crystal-polymer composite layer Almost spherical liquid crystals It is a domed liquid crystal present on each of the insulating films and swelled inward of the liquid crystal and polymer composite layer, and has two kinds of liquid crystal droplets of domed liquid crystal droplets whose average particle diameter in the panel gap direction is smaller than the average particle diameter of the spherical liquid crystal droplets. And The liquid crystal display device of the driving voltage is 50% of the maximum transmittance of ₅₀ V, when the driving voltage is 10 V% to _l0, non-V ₅₀ / V ₁₀ is at least 1.1, wherein 1.8 or lower. 19. The liquid crystal display device according to claim 18, wherein the V ₅₀ is 15 V or less. 20. The liquid crystal display device according to claim 19, wherein an active element is formed on one of the pair of substrates. 3. The liquid crystal and polymer composite layer according to claim 2, wherein a mixed composition comprising a liquid crystal and a polymer material is provided between the pair of substrates, and the liquid crystal and the polymer material are formed by phase-separation by polymerizing the polymer material. , The interfacial tension is constant at the interface between the liquid crystal and the polymer material, and the interfacial tension γ _ip (dyne / cm) between the insulating film and the polymer material provided inside the substrate is the interface between the liquid crystal and the polymer material. _Has a relationship between the tension γ _LCp (dyne / cm) and the following formula (l), γ _LCp -γ _ip <0. (One) And the insulating film is made of at least two kinds of materials having different interfacial tensions with the liquid crystals. 3. The liquid crystal and polymer composite layer according to claim 2, wherein a mixed composition comprising a liquid crystal and a polymer material is provided between the pair of substrates, and the liquid crystal and the polymer material are formed by phase-separation by polymerizing the polymer material. , The interfacial tension is constant at the interface between the liquid crystal and the polymer material, and the interfacial tension γ _ip (dyne / cm) between the insulating film and the polymer material provided inside the substrate is the interface between the liquid crystal and the polymer material. _Has a relationship between the tension γ _LCp (dyne / cm) and the following equation (2), -l <gamma _LCp -gamma _ip <1. (2) And the insulating film is made of at least two kinds of materials having different interfacial tensions with the liquid crystals. 3. The liquid crystal and polymer composite layer according to claim 2, wherein a mixed composition comprising a liquid crystal and a polymer material is provided between the pair of substrates, and the liquid crystal and the polymer material are formed by phase-separation by polymerizing the polymer material. , The interfacial tension is constant at the interface between the liquid crystal and the polymer material, and the interfacial tension γ _ip (dyne / cm) between the insulating film and the polymer material provided inside the substrate is the interface between the liquid crystal and the polymer material. _Has a relationship between the tension γ _LCp (dyne / cm) and the following equation (3), -1 <gamma _LCp -gamma _ip <0. (3) And the insulating film is made of at least two kinds of materials having different interfacial tensions with the liquid crystals. The insulating film is provided inside the substrate, and the critical surface tension γ _i (dyne / cm) of the insulating film is expressed by the following equation (4) between the surface tension γ _LC (dyne / cm) of the liquid crystal. Having a relationship of, γ _LC -γ _i <0. (4) And the insulating film is made of at least two kinds of materials having different critical surface tensions. 25. The liquid crystal display device according to claim 24, wherein at least two kinds of materials constituting the insulating film comprise: a first insulating film material having a critical surface tension less than the surface tension of the liquid crystal; And a second insulating film material having a critical surface tension greater than the surface tension of the liquid crystal. 27. The liquid crystal display device according to claim 25, wherein the first insulating film material is a fluorine-based surfactant, and the second insulating film material is a polyimide compound. The insulating film is provided inside the substrate, and the critical surface tension γ _i (dyne / cm) of the insulating film is expressed by the following equation (5) between the surface tension γ _LC (dyne / cm) of the liquid crystal. Have a relationship with -1 <γ _LC -γ _i <1. (5) And the insulating film is made of at least two kinds of materials having different critical surface tensions. 28. The liquid crystal display device according to claim 27, wherein at least two kinds of materials constituting said insulating film comprise: a first insulating film material having a critical surface tension less than the surface tension of said liquid crystal; And a second insulating film material having a critical surface tension greater than the surface tension of the liquid crystal. 29. A liquid crystal display device as claimed in claim 28, wherein said first insulating film material is a fluorine-based surfactant and said second insulating film material is a polyimide compound. The insulating film is provided inside the substrate, and the critical surface tension γ _i (dyne / cm) of the insulating film is expressed by the following equation (6) between the surface tension γ _LC (dyne / cm) of the liquid crystal. Have a relationship with -1 <gamma _LC -gamma _i <0. (6) And the insulating film is made of at least two kinds of materials having different critical surface tensions. 31. The material of claim 30, wherein at least two kinds of materials constituting the insulating film are formed of a first insulating film material having a critical surface tension less than the surface tension of the liquid crystal. And a second insulating film material having a critical surface tension greater than the surface tension of the liquid crystal. 32. The liquid crystal display device according to claim 31, wherein the first insulating film material is a fluorine-based surfactant and the second insulating film material is a polyimide compound. 3. An insulating film is provided inside the substrate, wherein when the critical surface tension of the insulating film is γ _i and the critical surface tension of the polymer is γ _P , γ _i and γ _P are represented by the following formula (7): A liquid crystal display device, characterized in that to satisfy the relationship. γ _i ≧ γ _P. (7) The liquid crystal display device according to claim 33, wherein, when the surface tension of the liquid crystal is γ _LC , γ _i and γ _LC satisfy the relationship of the following formula (8). γ _i > γ _LC ... (8) The liquid crystal display device according to claim 33, wherein, when the surface tension of the liquid crystal is γ _LC , γ _i and γ _LC satisfy a relationship of the following formula (9). γ _i <γ _LC ... (9) The liquid crystal display device according to claim 1, wherein a plurality of regions having different applied voltage-light transmittance characteristics are arranged in parallel with the pixel plane. 37. The liquid crystal and polymer composite layer of claim 36, wherein the liquid crystal is dispersed and maintained in a polymer matrix including polymers, and the average particle diameters of the liquid crystal drops correspond to a plurality of regions having different applied voltage and light transmittance characteristics. Another liquid crystal display device. 38. The liquid crystal display device according to claim 37, wherein the average particle diameter R (mu m) of the liquid crystal droplets is in a range of 0.6 <R <1.6. 39. The liquid crystal display device according to claim 38, wherein one of the pair of substrates is an active matrix substrate provided with a plurality of pixel electrodes and an active element for controlling a voltage applied to each pixel electrode. The liquid crystal and polymer composite layer according to claim 36, wherein the liquid crystal is dispersed in a mesh of a three-dimensional mesh matrix including polymers, and corresponding to a plurality of regions having different applied voltage and light transmittance characteristics. A liquid crystal display device characterized in that the average mesh size of the dimensional mesh matrix is different. 41. The liquid crystal display device according to claim 40, wherein the average mesh size R (mu m) of said three-dimensional mesh matrix is in the range of 0.6 &lt; R &lt; 1.6. 42. The liquid crystal display device according to claim 41, wherein one of the pair of substrates is an active matrix substrate provided with a plurality of pixel electrodes and an active element for controlling a voltage applied to each pixel electrode. 37. The liquid crystal display device according to claim 36, wherein the liquid crystal / polymer composite layer has different alignment states of liquid crystal molecules in the vicinity of the substrate, corresponding to a plurality of regions having different applied voltage and light transmittance characteristics. 44. The liquid crystal molecules in the vicinity of the substrate in one of the plurality of regions having different applied voltage-light transmittance characteristics are oriented perpendicular to the substrate, and in the other region, the vicinity of the substrate. The liquid crystal molecules of the liquid crystal display element are oriented parallel to the substrate. 37. The substrate of claim 36, wherein one of the pair of substrates has a plurality of regions having different ultraviolet transmittances within one pixel region. The liquid crystal / polymer composite layer is formed of a structure in which the liquid crystal is dispersed in a polymer matrix including polymers, and is irradiated with ultraviolet rays through one of the substrates in each region where the ultraviolet transmittances differ in one pixel. Corresponding liquid crystal and polymer composite layers in which a plurality of regions having different average particle diameters are formed. And a plurality of regions having different average particle diameters of the liquid crystal droplets also correspond to a plurality of regions having different applied voltage and light transmittance characteristics. 46. A liquid crystal display according to claim 45, wherein an ultraviolet transmittance adjusting layer is formed on an inner surface of one of the pair of substrates to form a plurality of regions having different applied voltage and light transmittance characteristics in one pixel. Display element. 47. The liquid crystal according to claim 46, wherein a transparent electrode layer is provided between the ultraviolet light transmittance adjusting layer and the liquid crystal and polymer composite layer and inside the other substrate on one substrate side of the pair of substrates, respectively. Display element. 48. The liquid crystal display device according to claim 47, wherein insulating films are provided on inner surfaces of the pair of transparent electrode layers, respectively. 49. The liquid crystal display device according to claim 48, wherein the UV transmittance adjusting layer is a photoresist layer. 50. The liquid crystal display device according to claim 49, wherein the plurality of regions having different ultraviolet transmittances have substantially the same transmittance of visible light. The area s of each region satisfies the following expression (10) when the total number of the plurality of regions having different applied voltage-light transmittance characteristics is n and the total area of one pixel is S. Liquid crystal display device. s = S / n... 10 52. The method of claim 51, wherein the liquid crystal display device of the driving voltage is 90% of the maximum transmittance wherein the ratio V ₉₀ / V ₁₀ is 2 or more when a drive voltage is V _90, V 10% to _l0. 53. The liquid crystal display device according to claim 52, wherein an active element is formed on the other of the pair of substrates. 37. The substrate of claim 36, wherein one of the pair of substrates has a plurality of regions having different ultraviolet transmittances within one pixel region. The liquid crystal-polymer composite layer has a structure in which a liquid crystal is dispersed and maintained in a mesh of a three-dimensional mesh-like matrix composed of a polymer, and the ultraviolet transmittance is increased in one pixel by irradiating ultraviolet rays through the one substrate. It is a liquid crystal-polymer composite layer in which a plurality of regions having different average mesh sizes of three-dimensional mesh-like matrices are formed in correspondence with each of the different regions, And a plurality of regions having different average mesh sizes of the three-dimensional mesh matrix also correspond to a plurality of regions having different applied voltage and light transmittance characteristics. 55. The liquid crystal according to claim 54, wherein an ultraviolet transmittance adjusting layer for forming a plurality of regions having different applied voltage and light transmittance characteristics in one pixel is provided on an inner surface of one of the pair of substrates. Display element. 56. The liquid crystal according to claim 55, wherein a transparent electrode layer is provided between the ultraviolet light transmittance adjusting layer and the liquid crystal and polymer composite layer and inside the other substrate on one substrate side of the pair of substrates, respectively. Display element. 57. The liquid crystal display device according to claim 56, wherein insulating films are provided on inner surfaces of the pair of transparent electrode layers, respectively. 60. The liquid crystal display device according to claim 57, wherein the UV transmittance adjusting layer is a photoresist layer. 59. The liquid crystal display device according to claim 58, wherein the plurality of regions having different ultraviolet transmittances have substantially the same transmittance of visible light. 60. The area s of each region satisfies Equation (10) according to claim 59, wherein n is the total number of a plurality of regions having different applied voltage-light transmittance characteristics and S is the total area of one pixel. Liquid crystal display device. s = S / n... 10 The method of claim 60, wherein the liquid crystal display device of the driving voltage is 90% of the maximum transmittance when the drive voltage is ₉₀ V, 10% as V _10, characterized in that the ratio V ₉₀ / V ₁₀ is 2 or more. 62. The liquid crystal display device according to claim 61, wherein an active element is formed on the other of the pair of substrates. The area s of each region satisfies Equation (10) according to claim 36, wherein when the total number of the plurality of regions having different applied voltage and light transmittance characteristics is n and the total area of one pixel is S, Liquid crystal display device. s = S / n... 10 37. The substrate of claim 36, wherein one of the pair of substrates has a plurality of regions having different ultraviolet transmittances within one pixel region. A plurality of liquid crystal and polymer composite layers having a structure in which liquid crystals are dispersed and maintained in a polymer matrix including polymers by irradiating ultraviolet rays through the one substrate include a plurality of average particle diameters of different liquid crystal drops in a direction parallel to the substrate in one pixel. Has an area of The liquid crystal display characterized in that the ratio Vb ₉₀ / Va ₉₀ is 0.6 or more and 0.9 or less when the driving voltages that are 90% of the maximum transmittance of the maximum and minimum regions of the average particle diameter of the liquid crystal region are respectively Vb ₉₀ and Va ₉₀ . device. The method of claim 64, wherein the liquid crystal display device of the driving voltage is 90% of the maximum transmittance when the drive voltage is ₉₀ V, 10% as V _10, characterized in that the ratio V ₉₀ / V ₁₀ is 2 or more. 66. The liquid crystal display element according to claim 65, wherein an active element is formed on the other of the pair of substrates. 37. The substrate of claim 36, wherein one of the substrates has a plurality of regions having different ultraviolet transmittances within one pixel region. The liquid crystal and polymer composite layer formed by a structure in which liquid crystal is dispersed in a mesh of a three-dimensional mesh-like matrix composed of a polymer by irradiating ultraviolet rays through the one substrate has a three-dimensional mesh in a direction parallel to the substrate in one pixel. The shape matrix has a plurality of areas with different average mesh sizes, When the driving voltages that are 90% of the maximum transmittance of the maximum and minimum regions of the average mesh size of the three-dimensional mesh matrix are set to Vb ₉₀ and Va ₉₀ , the ratio Vb ₉₀ / Va ₉₀ is 0.6 or more and 0.9 or less, respectively. A liquid crystal display device characterized by the above-mentioned. The method of claim 67, wherein the liquid crystal display device of the driving voltage is 90% of the maximum transmittance when the drive voltage is ₉₀ V, 10% as V _10, characterized in that the ratio V ₉₀ / V ₁₀ is 2 or more. 69. The liquid crystal display device according to claim 68, wherein an active element is formed on the other of the pair of substrates. 37. The electrode according to claim 36, wherein electrodes are provided inside the pair of substrates, The plurality of regions are provided such that the distance between electrodes between the pair of electrodes is different from each other. A liquid crystal display device as claimed in claim 70, wherein a stepped film having a surface covered by an electrode layer is provided on one of the pair of electrodes, and the electrode and the electrode layer are in a conductive state. 72. The liquid crystal display device according to claim 71, wherein the refractive index of the stepped film is about the same as the refractive index of the polymer constituting the liquid crystal and polymer composite layer. The liquid crystal display device according to claim 70, wherein one of the pair of substrates has a stepped surface in an uneven shape. The method of claim 70, wherein the distance between electrodes in the region of one side selected arbitrarily among the plurality of areas by d _1, and when the distance between electrodes in the region of the other by d _n, wherein d ₁ and d _n The liquid crystal display device characterized by satisfying the relationship of the following formula (11). d _n / d _l ≦ 0.85. (11) 75. The liquid crystal display device according to claim 74, wherein a stepped film having a surface covered by an electrode layer is provided on one of the pair of electrodes, and the electrode and the electrode layer are in a conductive state. 76. The liquid crystal display device according to claim 75, wherein the refractive index of the stepped film is about the same as the refractive index of the polymer constituting the liquid crystal / polymer composite layer. 75. The liquid crystal display device according to claim 74, wherein one of the pair of substrates has a stepped surface in an uneven shape. Of claim 36, wherein the driving voltage in the region of one of said plurality of regions in V _A, and when the driving voltage in the region of the other side to V _B, wherein V _A and V _B is the following formula (12 in A liquid crystal display device characterized by satisfying the relationship of. V _A / V _B ? 0.85... (12) (Wherein, V _A and V _B each represent a driving voltage when the maximum transmittance of the liquid crystal display element is 90%.) 37. The liquid crystal and polymer composite layer according to claim 36, wherein the liquid crystal and the polymer are aligned with each other. On one of the pair of substrates, comb-shaped electrodes for driving in the transverse electric field mode are formed to face each other in the substrate surface, The liquid crystal display device of the driving voltage is 90% of the maximum transmittance when the drive voltage is ₉₀ V, 10 V to _10%, non-V ₉₀ / V ₁₀ is characterized in that 2 or more, and 3.1 or less. 80. The liquid crystal display device according to claim 79, wherein electrode spacing of the comb-shaped electrodes is different in plane. 81. The liquid crystal display device according to claim 80, wherein V ₉₀ is 15 V or less. 84. The liquid crystal display element according to claim 81, wherein an active element is formed on one of the pair of substrates. The liquid crystal and polymer composite layer according to claim 36, wherein the liquid crystal and the polymer are oriented with each other, On one of the pair of substrates, comb-shaped electrodes for driving in the transverse electric field mode are formed to face each other in the substrate surface, The liquid crystal display device of the driving voltage is 50% of the maximum transmittance of ₅₀ V, as when the drive voltage V ₁₀ is 10%, the ratio V ₅₀ / V ₁₀ is 1.1 or higher, wherein less than or equal to 1.8. 84. The liquid crystal display device according to claim 83, wherein electrode spacing of the comb-shaped electrodes is different in plane. A driving voltage of 90% of the maximum transmittance with respect to the liquid crystal display device as V ₉₀ , and a driving voltage of 10% as V ₁₀ , wherein the ratio V ₉₀ / V ₁₀ is 2 or more, 3. A liquid crystal display device characterized by being 1 or less. 86. The liquid crystal display device according to claim 85, wherein V ₉₀ is 15 V or less. 87. The liquid crystal display element according to claim 86, wherein an active element is formed on one of the pair of substrates. A driving voltage of 50% of the maximum transmittance of the liquid crystal display device as V ₅₀ , and a driving voltage of 10% as V ₁₀ , wherein the ratio V ₅₀ / V ₁₀ is 1.1 or more; A liquid crystal display device, characterized in that less than 1.8. The liquid crystal and polymer composite layer according to claim 1, wherein the liquid crystal group is dispersed and maintained in a polymer matrix including polymers, and the average particle diameter R (µm) of the liquid crystal group is in a range of 0.6 <R <1.6. A liquid crystal display device. The liquid crystal and polymer composite layer according to claim 1, wherein the liquid crystal is dispersed in a mesh of a three-dimensional mesh matrix including polymers, and the average mesh size R (µm) of the three-dimensional mesh matrix is 0.6 <R. It is in the range of <1.6, The liquid crystal display element characterized by the above-mentioned. A liquid crystal display comprising a liquid crystal and a polymer composite layer including a liquid crystal and a polymer between a pair of substrates each having an electrode, and applying an electric field to the liquid crystal and polymer composite layer to change the light scattering state of the liquid crystal and the polymer composite layer to display the liquid crystal display. As an element, The liquid crystal display device of the driving voltage is 90% of the maximum transmittance when the drive voltage is ₉₀ V, 10 V to _10%, non-V ₉₀ / V ₁₀ is characterized in that 2 or more, and 3.1 or less. The liquid crystal and polymer composite layer is characterized in that a plurality of regions having different applied voltage and light transmittance characteristics are arranged in parallel with respect to the pixel plane in one pixel. 92. The liquid crystal display device according to claim 91, wherein the liquid crystal / polymer composite layer has a plurality of regions having different applied voltage and light transmittance characteristics arranged in a direction perpendicular to the pixel plane in one pixel. A liquid crystal display comprising a liquid crystal and a polymer composite layer including a liquid crystal and a polymer between a pair of substrates each having an electrode, and applying an electric field to the liquid crystal and polymer composite layer to change the light scattering state of the liquid crystal and the polymer composite layer to display the liquid crystal display. An element, wherein the ratio V ₅₀ / V ₁₀ is 1.1 or more and 1.8 or less when the driving voltage at 50% of the maximum transmittance is V ₅₀ and the driving voltage at 10% is V ₁₀ . 95. The liquid crystal display device according to claim 94, wherein in the liquid crystal / polymer composite layer, a plurality of regions having different applied voltage and light transmittance characteristics are arranged in parallel with respect to the pixel plane in one pixel. 95. The liquid crystal display device according to claim 94, wherein in the liquid crystal / polymer composite layer, a plurality of regions having different applied voltage and light transmittance characteristics are arranged in a direction perpendicular to the pixel plane in one pixel. As a method of manufacturing a liquid crystal display device provided with a liquid crystal and a polymer composite layer containing a liquid crystal and a polymer between a pair of substrates having electrodes, An insulating film forming step of forming an insulating film on an inner surface of the electrode; Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates; A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material, In the insulating film forming step, an insulating film made of at least two kinds of materials having different interfacial tensions between the liquid crystals, the interfacial tensions having a constant relationship at the interface between the liquid crystals and the polymer material, and the inner surface of the electrode. The insulating film provided in the insulating film and the polymer material in which the interfacial tension γ _ip (dyne / cm) satisfies the relationship between the interfacial tension γ _LCp (dyne / cm) and the following formula (1) between the liquid crystal and the polymer material. Method of manufacturing a liquid crystal display device, characterized in that forming a. γ _LCp -γ _ip <0. (One) A method of manufacturing a liquid crystal display device comprising a liquid crystal and a polymer composite layer containing a liquid crystal and a polymer between a pair of substrates each having an electrode, An insulating film forming step of forming an insulating film on an inner surface of the electrode; Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates; A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material, In the insulating film forming step, an insulating film made of at least two kinds of materials having different interfacial tensions between the liquid crystals, the interfacial tensions of which are constant at the interface between the liquid crystals and the polymer material, An insulating film whose interfacial tension γ _ip (dyne / cm) between the prepared insulating film and the polymer material satisfies the relationship between the interfacial tension γ _LCp (dyne / cm) and the following formula (2) between the liquid crystal and the polymer material. Forming a liquid crystal display device. -1 <gamma _LCp -gamma _ip <1. (2) A method of manufacturing a liquid crystal display device comprising a liquid crystal and a polymer composite layer containing a liquid crystal and a polymer between a pair of substrates each having an electrode, An insulating film forming step of forming an insulating film on an inner surface of the electrode; Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates; A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material, In the insulating film forming step, an insulating film made of at least two kinds of materials having different interfacial tensions between the liquid crystals, the interfacial tensions of which are constant at the interface between the liquid crystals and the polymer material, An insulating film whose interfacial tension γ _ip (dyne / cm) between the prepared insulating film and the polymer material satisfies the relationship between the interfacial tension γ _LCp (dyne / cm) and the following formula (3) between the liquid crystal and the polymer material. Forming a liquid crystal display device. -1 <gamma _LCp -gamma _iP <0. (3) A method of manufacturing a liquid crystal display device comprising a liquid crystal and a polymer composite layer containing a liquid crystal and a polymer between a pair of substrates each having an electrode, An insulating film forming step of forming an insulating film on an inner surface of the electrode; Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates; A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material, In the insulating film forming step, an insulating film made of at least two kinds of materials having different critical surface tensions, the interface tension of which is constant at the interface between the liquid crystal and the polymer, and the critical surface tension of the insulating film provided on the inner surface of the electrode. γ _i (dyne / cm) forms an insulating film which satisfies the relationship between the surface tension γ _LC (dyne / cm) and the following formula (4) of the liquid crystal. γ _LC -γ _i <0. (4) 101. The semiconductor device of claim 100, wherein at least two kinds of materials constituting the insulating film include a first insulating film material having a critical surface tension less than the surface tension of the liquid crystal; And a second insulating film material having a critical surface tension greater than the surface tension of the liquid crystal. 102. The liquid crystal display device according to claim 101, wherein the first insulating film material is a fluorine-based surfactant, and the second insulating film material is a polyimide compound. A method of manufacturing a liquid crystal display device comprising a liquid crystal and a polymer composite layer containing a liquid crystal and a polymer between a pair of substrates each having an electrode, An insulating film forming step of forming an insulating film on an inner surface of the electrode; Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates; A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material, In the insulating film forming step, an insulating film made of at least two kinds of materials having different critical surface tensions, the interface tension being constant at the interface between the liquid crystal and the polymer, and the critical surface tension of the insulating film provided on the inner surface of the electrode. γ _i (dyne / cm) forms an insulating film which satisfies the relationship between the surface tension γ _LC (dyne / cm) of the liquid crystal and the following formula (5). -1 <γ _LC -γ _i <1. (5) 103. The semiconductor device of claim 103, wherein at least two kinds of materials constituting the insulating film include: a first insulating film material having a critical surface tension less than the surface tension of the liquid crystal; And a second insulating film material having a critical surface tension greater than the surface tension of the liquid crystal. 107. A liquid crystal display device as claimed in claim 104, wherein said first insulating film material is a fluorine-based surfactant and said second insulating film material is a polyimide compound. A method of manufacturing a liquid crystal display device comprising a liquid crystal and a polymer composite layer containing a liquid crystal and a polymer between a pair of substrates each having an electrode, An insulating film forming step of forming an insulating film on an inner surface of the electrode; Providing a mixed composition comprising the liquid crystal and the polymer material between the pair of substrates; A liquid crystal / polymer composite layer forming step of forming a liquid crystal / polymer composite layer by polymerizing the polymer material, In the insulating film forming step, an insulating film made of at least two kinds of materials having different critical surface tensions, the interface tension of which is constant at the interface between the liquid crystal and the polymer, and the critical surface tension of the insulating film provided on the inner surface of the electrode. γ _i (dyne / cm) forms an insulating film which satisfies the relationship between the surface tension γ _LC (dyne / cm) and the following formula (6) of the liquid crystal. -1 <gamma _LC -gamma _i <0. (6) 107. The semiconductor device of claim 106, wherein at least two kinds of materials constituting the insulating film include a first insulating film material having a critical surface tension less than the surface tension of the liquid crystal; And a second insulating film material having a critical surface tension greater than the surface tension of the liquid crystal. 109. The liquid crystal display device according to claim 107, wherein the first insulating film material is a fluorine-based surfactant, and the second insulating film material is a polyimide compound. A liquid crystal display and a polymer composite layer having a structure in which liquid crystals are dispersed and held in a polymer matrix including a polymer contained between a pair of substrates, and having a plurality of regions having different applied voltage and light transmittance characteristics in one pixel. As a manufacturing method of An electrode forming step of forming an electrode layer on inner surfaces of the pair of substrates; Joining the pair of substrates so that the electrode layers face each other to form an empty cell; Providing a liquid crystal / polymer precursor solution within the empty cell; The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through a filter having a plurality of regions having different UV transmittances, and phase separation of the liquid crystal and the polymer precursor solution is performed. A liquid crystal and polymer composite layer forming step of forming a liquid crystal and a polymer composite layer having a plurality of regions having different particle diameters. A liquid crystal-polymer composite layer having a structure in which a liquid crystal is dispersed and disposed in a mesh of a three-dimensional mesh-like matrix composed of a polymer between a pair of substrates, and a plurality of regions having different applied voltage-transmittance characteristics in the pixel. As a method for manufacturing a liquid crystal display device having a An electrode forming step of forming an electrode layer on inner surfaces of the pair of substrates; Joining the pair of substrates so that the electrode layers face each other to form an empty cell; Providing a liquid crystal / polymer precursor solution within the empty cell; The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through a filter having a plurality of regions having different UV transmittances, and the liquid crystal and polymer precursor solution is phase-separated, and the three-dimensional network in the direction parallel to the substrate in one pixel. A liquid crystal display and a polymer composite layer forming step of forming a liquid crystal and a polymer composite layer having a plurality of regions having different average mesh sizes of the shape matrix. A liquid crystal display and a polymer composite layer having a structure in which liquid crystals are dispersed and held in a polymer matrix including a polymer contained between a pair of substrates, and having a plurality of regions having different applied voltage and light transmittance characteristics in one pixel. As a manufacturing method of A transparent electrode layer forming step of forming a transparent electrode layer on the inner surface of one substrate and the inner surface of the other substrate having a plurality of regions having different UV transmittances; Bonding the pair of substrates together so that the transparent electrode layers face each other to form empty cells; Providing a liquid crystal / polymer precursor solution within the empty cell; The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through a substrate having a plurality of regions having different UV transmittances, and phase separation of the liquid crystal and the polymer precursor solution is performed. A liquid crystal and polymer composite layer forming step of forming a liquid crystal and a polymer composite layer having a plurality of regions having different particle diameters. A liquid crystal-polymer composite layer having a structure in which a liquid crystal is dispersed and disposed in a mesh of a three-dimensional mesh-like matrix composed of a polymer between a pair of substrates, and a plurality of regions having different applied voltage-transmittance characteristics in one pixel. As a method for manufacturing a liquid crystal display device having a A transparent electrode layer forming step of forming a transparent electrode layer on the inner surface of one substrate and the inner surface of the other substrate having a plurality of regions having different UV transmittances; Bonding the pair of substrates together to face the transparent electrode layer to form an empty cell; Providing a liquid crystal / polymer precursor solution within the empty cell; The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through a substrate having a plurality of regions having different UV transmittances, and phase separation of the liquid crystal and the polymer precursor solution is performed. A liquid crystal display and a polymer composite layer forming step of forming a liquid crystal / polymer composite layer having a plurality of regions having different average mesh sizes of the shape matrix. A liquid crystal display and a polymer composite layer having a structure in which liquid crystals are dispersed and held in a polymer matrix composed of a polymer contained between a pair of substrates, and having a plurality of regions having different applied voltage and light transmittance characteristics in one pixel. As a manufacturing method of A UV transmittance adjusting layer forming step of forming an ultraviolet transmittance adjusting layer by applying a photoresist to an inner surface of one of the pair of substrates and irradiating ultraviolet rays through a mask patterned to a predetermined shape on the photoresist. and, Forming a transparent electrode layer on an inner surface of the pair of substrates; Bonding the pair of substrates together to face the transparent electrode layer to form an empty cell; Providing a liquid crystal / polymer precursor solution in the empty cell; The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through the substrate provided with the ultraviolet light transmittance adjusting layer, and the liquid crystal and polymer precursor solution are phase separated. A liquid crystal display and a polymer composite layer forming step of forming a liquid crystal and a polymer composite layer having a plurality of regions, characterized in that the method for producing a liquid crystal display device. A liquid crystal / polymer composite layer having a structure in which a liquid crystal is dispersed and disposed in a mesh of a three-dimensional mesh matrix formed by containing a polymer between a pair of substrates, and a plurality of regions having different applied voltage-transmittance characteristics in one pixel. As a method for manufacturing a liquid crystal display device having a A UV transmittance adjusting layer forming step of forming a UV transmittance adjusting layer by applying a photoresist to an inner surface of one of the pair of substrates and irradiating ultraviolet rays through a mask patterned to a predetermined shape on the photoresist. and, Forming a transparent electrode layer on an inner surface of the pair of substrates; Bonding the pair of substrates so that the transparent electrode layers face each other to form empty cells; Providing a liquid crystal / polymer precursor solution in the empty cell; The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through the substrate provided with the UV transmittance adjusting layer, and the liquid crystal and polymer precursor solution is subjected to phase separation. A liquid crystal display and a polymer composite layer forming step of forming a liquid crystal / polymer composite layer having a plurality of regions having different mesh sizes. A liquid crystal display and a polymer composite layer having a structure in which liquid crystals are dispersed and held in a polymer matrix composed of a polymer contained between a pair of substrates, and having a plurality of regions having different applied voltage and light transmittance characteristics in one pixel. As a manufacturing method of A UV transmittance adjusting layer forming step of forming a UV transmittance adjusting layer by applying a photoresist to an inner surface of one of the pair of substrates and irradiating ultraviolet rays through a mask patterned to a predetermined shape on the photoresist. and, Forming a transparent electrode layer on the pair of substrates; An insulating film forming step of providing an insulating film on the transparent electrode layer; Bonding the pair of substrates to face the insulating film to form an empty cell; Providing a liquid crystal / polymer precursor solution in the empty cell; The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through the substrate provided with the UV transmittance adjusting layer, and the liquid crystal and the polymer precursor solution are phase-separated. A liquid crystal display and a polymer composite layer forming step of forming a liquid crystal and a polymer composite layer having a plurality of regions, characterized in that the method for producing a liquid crystal display device. A liquid crystal-polymer composite layer having a structure in which a liquid crystal is dispersed and disposed in a mesh of a three-dimensional mesh-like matrix composed of a polymer between a pair of substrates, and a plurality of regions having different applied voltage-transmittance characteristics in one pixel. As a method for manufacturing a liquid crystal display device having a A UV transmittance adjusting layer forming step of forming an ultraviolet transmittance adjusting layer by applying a photoresist to an inner surface of one of the pair of substrates and irradiating ultraviolet rays through a mask patterned to a predetermined shape on the photoresist. and, Forming a transparent electrode layer on the pair of substrates; An insulating film forming step of providing an insulating film on the transparent electrode layer; A joining process of joining the pair of substrates to face the insulating film to form an empty cell; Providing a liquid crystal / polymer precursor solution within the empty cell; The liquid crystal and the polymer precursor solution are irradiated with ultraviolet rays through the substrate provided with the UV transmittance adjusting layer, and the liquid crystal and the polymer precursor solution are phase separated to form a three-dimensional mesh matrix in a direction parallel to the substrate in one pixel. A liquid crystal display and a polymer composite layer forming step of forming a liquid crystal / polymer composite layer having a plurality of regions having different average mesh sizes. A liquid crystal display and a polymer composite layer including a liquid crystal and a polymer are provided between a pair of substrates each having an electrode, and the light scattering state of the liquid crystal and polymer composite layer is changed by applying an electric field to the liquid crystal and polymer composite layer. As a manufacturing method, A photoresist film forming step of forming a photoresist film on an electrode in any one of the pair of substrates; A stepped film forming step of forming a stepped film made of the photoresist film on the electrode by irradiating light through the mask having a light blocking portion having a predetermined shape on the photoresist film, and then developing the photoresist film; And an electrode layer forming step of forming an electrode layer so as to cover the stepped film. 118. A method for manufacturing a liquid crystal display device according to claim 117, wherein the pattern of the mask has a stripe shape. 118. A method for manufacturing a liquid crystal display device according to claim 117, wherein the pattern of the mask is lattice. A liquid crystal display comprising a liquid crystal and a polymer composite layer comprising a liquid crystal and a polymer between a pair of substrates each having an electrode, and applying an electric field to the liquid crystal and polymer composite layer to change the light scattering state of the liquid crystal and polymer composite layer to display the liquid crystal display. As a manufacturing method of the device, An etching process of providing a mask having a predetermined shape on the substrate to chemically corrode an area not protected by the mask with an etching solution to form a concave-convex surface on the substrate; And an electrode layer forming step of forming an electrode layer on the substrate having the uneven surface. 129. A method for manufacturing a liquid crystal display device according to claim 120, wherein the pattern of the mask has a stripe shape. 129. A method for manufacturing a liquid crystal display device according to claim 120, wherein the pattern of the mask is lattice. A liquid crystal display comprising a liquid crystal and a polymer composite layer including a liquid crystal and a polymer between a pair of substrates each having an electrode, and applying an electric field to the liquid crystal and the polymer composite layer to change the light scattering state of the liquid crystal and the polymer composite layer to display the liquid crystal display. As the evaluation method of the device, The optical hysteresis H _t (%) in the applied voltage-light transmittance characteristics of the whole liquid crystal-polymer composite layer is evaluated by the following formula (13). H _t (%) = (T _down (V _10-30 ) -T _up (V _10-30 ) / (T _max -T _o ) × 100… (13) (V _10-30 represents the applied voltage when the transmittance is 10% to 30% in the step- _up process, and T _up (V _10-30 ) represents the transmittance at V _10-30 in the step- _up process. T _{do wn} (V _{10 to 30} ) represents the transmittance at V ₁₀ to ₃₀ in the strong voltage process, T _max represents the value when the transmittance is maximized, and T _o is the transmittance when no voltage is applied. Is displayed.)