JP2004126606A - Liquid crystal apparatus and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal apparatus which can decrease a blur in display to improve the display quality and which can display a bright image, and to provide an electronic equipment equipped with the liquid crystal apparatus. <P>SOLUTION: The liquid crystal apparatus equipped with a pair of substrates 17, 28, a liquid crystal layer 15, a reflecting layer 31, and a directional forward scattering film 18, is characterized in that the directional forward scattering film 18 is disposed on the liquid crystal panel 10 in such a manner that light from a light source K disposed in one face side of the directional forward scattering film 18 is made incident on the film, the transmitted light in parallel beams of the whole transmitted light through the film 18 excluding diffused transmitted light is observed by a light receiving part J disposed on the other face side of the film 18, and the direction of the polar angle θ showing the minimum transmittance is aligned to the lighting side, while the direction of the polar angle showing the maximum transmittance is aligned to the observation direction. <P>COPYRIGHT: (C)2004,JPO

Description

INDUSTRIAL APPLICABILITY The present invention is applicable to a reflective or transflective liquid crystal display device to eliminate blurring (blur) of a display, to obtain a bright and clear display, and to enable such a bright and clear display. The present invention relates to a technology capable of providing an electronic device including a liquid crystal device.

(2) A liquid crystal display device with low power consumption is frequently used as a display unit in various electronic devices such as a notebook personal computer, a portable game machine, and an electronic organizer. In particular, in recent years, demand for a liquid crystal display device capable of performing color display has been increasing with the frequent use of display contents. In addition, in response to a demand for extending the battery driving time of the electronic device, a reflective color liquid crystal display device that does not require a backlight device has been developed.

An outline of a configuration example of a conventional reflection type color liquid crystal display device will be described below with reference to the drawings.

FIGS. 15A and 15B are enlarged schematic cross-sectional views showing the main parts of a conventional reflective color liquid crystal display device. Among these, FIG. 15A shows a forward scattering plate type reflection type liquid crystal display device, and FIG. 15B shows an inner surface scattering reflection type liquid crystal display device.

In the liquid crystal display device of the forward scattering plate type shown in FIG. 15A, a liquid crystal layer 102 is sandwiched between a pair of glass substrates 100 and 101, and one (upper side in the drawing) of the glass substrate 101 on the liquid crystal layer 102 side. A color filter 104 is provided on the surface. Further, on the upper surface side of the glass substrate 101, a forward scattering film 105 in which metal oxide particles are dispersed as a filler in a base material made of, for example, triallyl cyanate having a thickness of 50 to 200 μm is provided with a transparent adhesive material or adhesive sheet ( (Not shown), and a polarizing plate 106 is provided thereon.

In such a forward scattering type reflection type liquid crystal device, the incident light L1 passes through the polarizing plate 106, the forward scattering film 105, the glass substrate 101, the liquid crystal layer 102, and the color filter 104, and then passes through the light reflection layer 103 serving as a drive electrode. The light reflected by the surface is emitted from the liquid crystal device via the liquid crystal layer 102, the color filter 104, the glass substrate 101, the forward scattering film 105, and the polarizing plate 106, and is visually recognized by the observer E as the reflected light L2. . Here, the light emitted from the liquid crystal device is controlled by the state of the liquid crystal layer 102, that is, the polarization state of the reflected light is controlled by the arrangement state of the liquid crystal molecules in the liquid crystal layer 102, and the polarization state of the reflected light is When they coincide with the polarization axis, the light passes through the polarizing plate 106 to display a desired color.

The liquid crystal device of the internal scattering reflector type shown in FIG. 15B includes a pair of glass substrates 100 and 101 and a liquid crystal layer 102, and the surface of the glass substrate 100 on the liquid crystal layer 102 side also serves as a light reflection layer. A pixel electrode 107 made of an Al thin film or the like is formed in a state where irregularities for irregularly reflecting light are provided on the surface.

Here, a color filter 104 is formed on the surface of the glass substrate 101 on the light incident side on the liquid crystal layer 102 side, and a polarizing plate 106 is provided on the upper surface side of the glass substrate 101. In such a reflection type liquid crystal display device of the inner surface scattering plate type, the incident light L1 passes through the polarizing plate 106, the glass substrate 101, the color filter 104, and the liquid crystal layer 102, and then has the uneven light reflection layer 107 also serving as a pixel electrode. After the light is irregularly reflected on the surface of the liquid crystal layer 102 and the polarization is changed according to the state of the liquid crystal layer 102, the reflected light passes through the color filter 104, the glass substrate 101, and the polarizing plate 106, and is transmitted through the polarizing plate 106 due to the polarization state of the reflected light. It is opaque, and when transmitted, it enters the observer's naked eye E as scattered light L3 and is visually recognized as a color display.

By the way, in the conventional structure shown in FIG. 15A, when the light reflection layer 103 is a mirror reflection layer, the forward scattering film 105 weakens strong mirror reflection (specular reflection) in a specific direction unique to the mirror surface, It is used for the purpose of enabling a bright display in the widest possible range.

This type of forward scattering film 105 is generally made of an acrylic resin layer (for example, a refractive index n = 1.48 to 1.49) having a thickness of about 25 to 30 μm (25 to 30 × 10 −6 m). It has a structure in which a large number of beads (for example, a refractive index n = 1.4) having a particle size of about 4 μm (4 × 10 −6 m) are dispersed therein, and is a reflective liquid crystal display device for mobile phones, portable information. It is widely used in reflection type liquid crystal display devices such as equipment.

As a liquid crystal display device of a portable device, a transflective liquid crystal display device having a backlight in addition to a reflective liquid crystal display device is also known. In this type of conventional transflective liquid crystal display device, the reflective layer is configured as a transflective layer, and in the case of transmissive display, light from the backlight is transmitted to the observer through the transflective layer to transmit light. When a display is performed and the backlight is not used, the reflection type liquid crystal display device is configured so that reflected light can be effectively used.

However, the above-mentioned forward scattering film 105 has a problem that different information in different pixels tends to be mixed until the user recognizes the information, so that blurring (blurring) of display is likely to occur. Had a point. This is due to scattering by the forward scattering film 105 that occurs from the time when the incident light is reflected by the reflective layer 103 to the time when the light reaches the user in the reflective liquid crystal display device as shown in FIG. If white display and black display are performed by matching pixels, the boundary between the white display and the black display tends to be difficult to understand due to the scattering effect of the forward scattering film 105, and the display is blurred (blurred). The present inventor thinks that it does. In addition, when considering the blurring (blurring) of the display of the liquid crystal device provided with the color filter 104, the boundary of the color display tends to be difficult to discriminate, and there is a possibility that color mixing may occur, and good color developability cannot be obtained. There is a risk.

{Circle around (1)} such a situation that such a display is blurred or that sufficient color developability cannot be obtained also applies to a case where a reflective display is performed in a transflective liquid crystal display device.

Next, in the configuration provided with the light-reflective pixel electrode 107 provided with unevenness as shown in FIG. 15B (internal scattering structure), there is little possibility that the above-described display bleeding on the forward scattering film occurs. However, a special processing step and man-hours are required to manufacture the pixel electrode 107 having the unevenness, so that there is a problem that the manufacturing cost is increased.

Furthermore, in the cases of FIGS. 15A and 15B, a reflective display in which the specular reflection direction of incident light is the brightest can be obtained. However, since this specular reflection direction is also the liquid crystal device surface reflection direction, the observer usually observes the reflection display in a direction slightly deviated from this direction (reason: the illumination is reflected in the specular reflection direction). In this case, it was difficult to obtain a sufficiently bright display.

From the above background, the present inventors have focused on the forward scattering film and conducted further research. As a result, the scattering of the forward scattering film is made directional so that the display of the liquid crystal display device is blurred. The inventors have found that (blur) can be eliminated, and have reached the present invention. Further, as a result of the present inventors' repeated studies on the forward scattering film, when the forward scattering film 105 is arranged on the liquid crystal display device having the structure shown in FIG. The scattered light generated when the light passes through the display is unlikely to greatly affect the bleeding (blur) of the display. However, the diffusion that occurs when the light passes through the forward scattering film 105 again as reflected light is observed by the observer E. It has been found that the scattered light when the reflected light passes through the scattering film 105 has a large effect on blurring (blur) of display.

The present invention has been made in view of the above-described problems, and it is possible to improve display quality by reducing display bleeding, to enable clear display, and to provide a liquid crystal device having an internal scattering plate. Another object of the present invention is to provide a liquid crystal device which can simplify the configuration, reduce the manufacturing cost while providing a clear display, and an electronic device including the liquid crystal device.

In order to solve the above problems, the present invention provides a pair of substrates, a liquid crystal layer sandwiched between these substrates, a reflective layer provided on the liquid crystal layer side of the one substrate, and a liquid crystal of the other substrate. A liquid crystal panel comprising a directional forward scattering film provided on the side opposite to the layer side, wherein light is incident from a light source disposed on one surface side of the directional forward scattering film, and the directional In the light receiving portion disposed on the other surface side of the forward scattering film, of the total transmitted light transmitted through the directional forward scattering film, when observing parallel-line transmitted light excluding diffuse transmitted light, the directional forward scattering film The incident angle of the incident light with respect to the normal line is defined as a polar angle θn, the incident light angle in the in-plane direction of the directional forward scattering film is defined as an azimuth angle φm, and the maximum transmittance of the parallel line transmitted light is Tmax ( φ1, θ1) When the minimum transmittance of the overlight is defined as Tmin (φ2, θ2), the maximum transmittance is set so that the incident light side in the case of the polar angle and the azimuth indicating the minimum transmittance is the lighting side of the liquid crystal panel. Wherein the directional forward scattering film is disposed on the liquid crystal panel such that the incident light side in the case of the polar angle and the azimuth angle which is shown in the figure is on the viewing direction side of the liquid crystal panel.

In a reflection type liquid crystal display device provided with a directional forward scattering film, the polar angle indicating the maximum transmittance so that the incident light side when indicating the minimum transmittance and the azimuth angle are the daylighting side of the liquid crystal panel. And the directional forward scattering film is arranged on the liquid crystal panel so that the incident light side indicating the azimuth angle is on the viewing direction side of the liquid crystal panel. φ2 is the direction of the incident angle, and the azimuth φ1 when the maximum transmittance of the parallel-line transmitted light is shown is the direction of the observer. With a liquid crystal panel having a directional forward scattering film arranged in this way, light incident on the directional forward scattering film is strongly scattered at the time of incidence, but after being reflected by a reflective layer inside the liquid crystal panel. Since the amount of light scattered when passing through the directional forward scattering film is reduced, the effect on display blur (blurring) is small, and a clear display form with less display blur (blurring) is obtained.

In order to solve the above-mentioned problem, the present invention can be applied to a transflective liquid crystal device having a transflective layer instead of the reflective layer of the liquid crystal device having the above-described structure. .

The present invention is effective when performing reflective display even in a liquid crystal device having a semi-transmissive reflective layer, and similarly to the case of the above structure, the azimuth φ2 when the minimum transmittance of parallel-line transmitted light is obtained is The azimuth angle φ1 in the incident angle direction side and showing the maximum transmittance of the parallel line transmitted light is on the observer direction side. With the directional forward scattering film arranged in this way, the light incident on the directional forward scattering film is strongly scattered at the time of incidence, but is reflected by the reflective layer inside the liquid crystal panel and is directional. Since the amount of light passing through the scattering film is scattered less, a clear display form with less blur (blur) of the display can be obtained.

Next, in order to solve the above-mentioned problems, in the present invention, in a liquid crystal device provided with the above-mentioned reflective layer or semi-transmissive reflective layer, the maximum transmittance of parallel ray transmitted light is Tmax (φ1, θ1), When the minimum transmittance of light is Tmin (φ2, θ2), the relation is φ1 = φ2 ± 180 °.

In a reflective or semi-transmissive reflective liquid crystal display device provided with a directional forward scattering film, the azimuth φ2 when the minimum transmittance of parallel line transmitted light is obtained by setting φ1 = φ2 ± 180 °. The azimuth angle φ1 in the direction of the front incidence angle of the liquid crystal panel and showing the maximum transmittance of the parallel-line transmitted light is in the direction of the observer. When this relationship is 180 °, the most ideal arrangement relationship is obtained. Light incident on the directional forward scattering film is strongly scattered at the time of incidence, and is reflected by the reflective layer or semi-transmissive reflective layer inside the liquid crystal panel, and the light passing through the directional forward scattering film for the second time is scattered. Since the amount is small, a clear display mode with little blur (blurring) of the display can be reliably obtained.

According to the present invention, in order to solve the above-mentioned problem, in the liquid crystal device, the maximum transmittance Tmax and the minimum transmittance Tmin of the parallel-line transmitted light can be in a relationship of (Tmax / Tmin) ≧ 2.

By satisfying the relationship of (Tmax / Tmin) ≧ 2, sufficient scattering can be obtained at the time of incidence of light in the directional forward scattering film, so that the display is brighter than the liquid crystal device having the conventional isotropic forward scattering film. A clear (clear) display is obtained.

In order to solve the above-mentioned problems, the present invention provides the liquid crystal device, wherein the polar angle θ1 or θ2 when the parallel ray transmitted light is the maximum is −40 ° ≦ θ1 (or θ2) ≦ 0 ° or 0 ° ≦ θ1 (or θ2) ≦ 40 °.

By setting the polar angle θ1 or θ2 in the above range, a liquid crystal panel which is brighter and clearer than a liquid crystal panel having a conventional isotropic directional scattering film in an actual use environment can be obtained.

In order to solve the above problem, the present invention provides the liquid crystal device, wherein the polar angle θ1 or θ2 when the parallel ray transmitted light is maximum is -30 ° ≦ θ1 (or θ2) ≦ −10 ° or 10 °. ≦ θ1 (or θ2) ≦ 30 °.

By setting the polar angle θ1 or θ2 in the above range, a brighter and clearer display can be obtained in a practical use environment than in a conventional liquid crystal panel having an isotropic directional scattering film.

In order to solve the above-mentioned problem, the present invention provides a liquid crystal device in which the parallel line transmittance in the normal direction of the directional forward scattering film is defined as T (0,0), where 3% ≦ T (0,0). ) ≦ 50% can be satisfied. Further, it is also possible to satisfy the relationship of 5% ≦ T (0,0) ≦ 40% in the above range.

In these cases, a brighter and clearer display can be obtained in a practical use environment than in a liquid crystal device having a conventional isotropic forward scattering film.

The present invention, in order to solve the above-mentioned problem, in the case where the azimuthal angle φ of the directional forward scattering film is defined in the range of φ1 ± 60 ° and φ2 ± 60 ° in the liquid crystal device, the parallel line transmittance is always θ1. It can be made to show a maximum and show a minimum of the parallel line transmittance at θ2.

If a maximum and a minimum are shown in such an azimuth range, light can be scattered not only in one direction of φ2 but also in such an azimuth range (range of ± 60 °). And a bright reflective display can be realized in a wide range.

In order to solve the above problem, the present invention provides, in the liquid crystal device, an azimuth angle φ of the directional forward scattering film of φ1 ± 60 °, and φ2 ± 60 °, when the parallel line transmittance is specified. The ratio between the minimum value and the maximum value can be 1.5 or more.

By increasing the ratio of the maximum value and the minimum value of the parallel line transmittance, it is possible to increase the scattering property when entering the directional forward scattering film, and to reduce the scattering property after passing through the directional forward scattering film. Since it can be suppressed low, it is possible to obtain a clear display with little blur (blurring) of the display.

In order to solve the above-mentioned problems, the present invention sets a polar angle in a direction orthogonal to the azimuth angle φ1 indicating the maximum transmittance of the parallel line transmitted light and the azimuth angle φ2 indicating the minimum transmittance of the parallel line transmitted light to −40 ° to The parallel line transmittance when changed to + 40 ° was equal to or higher than the normal direction transmittance of the directional forward scattering film.

に す る By doing so, a clear reflective display mode with less blurring (blur) of display can be obtained even when the liquid crystal panel of the liquid crystal device is observed from the lateral direction.

In order to solve the above problem, the present invention sets the parallel line transmittance T (φ, θ) to 2% or more and 50% or less when the polar angle θ is in a range of −60 ° ≦ θ ≦ + 60 °. be able to.

(4) By setting T (φ, θ) in the range of 2% or more and 50% or less in this range, a bright, clear display without blur (blurring) of the display can be obtained.

In order to solve the above-mentioned problems, the present invention is characterized in that electrodes for driving liquid crystal are provided on the liquid crystal layer side of the one substrate and the liquid crystal layer side of the other substrate.

(4) The orientation of the liquid crystal is controlled by the electrodes sandwiching the liquid crystal layer, and switching between display, non-display, and halftone display can be performed.

According to the present invention, in order to solve the above-mentioned problems, in the liquid crystal device, a color filter may be provided on one of the pair of substrates on one liquid crystal layer side.

(4) By providing a color filter, color display can be performed, and by adopting any of the above structures, a display having a clear color display with less blur of display can be obtained.

When the reflective layer or the transflective layer has fine irregularities, the present invention strongly scatters incident light and guides the incident light to the reflective layer or transflective layer. The glare caused by the layer having fine irregularities can be reduced, and the reflected light by the reflective layer or the semi-transmissive reflective layer is not strongly scattered by the directional forward scattering film, so that the display is not scattered. A clear display with little bleeding can be obtained.

(5) The directional scattering film has a function of scattering and diffracting incident light from the azimuth side showing the minimum transmittance Tmin (φ2, θ2).

According to this means, since the incident light can be scattered and diffracted at the same time, a bright reflective display can be obtained in a direction other than the regular reflection direction (surface reflection direction) of the incident light. Further, when at least one of a transparent protective plate, a light guide of a front light illuminating device, and a touch key is disposed on the observation side of the liquid crystal device, there is surface reflection occurring on the front surface or the rear surface thereof, The reflection display becomes difficult to see. However, in the present invention, since the directional forward scattering film has a diffraction function, it is possible to obtain a bright and easy-to-see reflection display in directions other than the surface reflection direction.

According to another aspect of the invention, an electronic apparatus includes any one of the above-described liquid crystal devices as a display unit.

(4) If the electronic apparatus is provided with the above-described liquid crystal device having an excellent display mode, it is possible to obtain an electronic apparatus having a display mode with a clear display with less blur of display.

As described above, according to the liquid crystal device of the present invention, in a reflective or transflective liquid crystal display device provided with a directional forward scattering film, the polar angle direction showing the minimum transmittance is set to the lighting side. By arranging the directional forward scattering film on the liquid crystal panel so that the polar angle direction showing the maximum transmittance is on the viewing direction side, the azimuth angle φ2 when the minimum transmittance of the parallel line transmitted light is incident The azimuth φ1 in the case of the angular direction and the maximum transmittance of the parallel line transmitted light is the direction of the observer. Light incident on the directional forward scattering film is strongly scattered at the time of incidence, but light that is reflected by the reflective layer or semi-transmissive reflective layer inside the liquid crystal panel and passes through the directional forward scattering film again is scattered. Since the amount is small, a clear display form with little blur (blurring) of the display is obtained as a result.

Further, in the present invention, when the maximum transmittance of the parallel line transmitted light is Tmax (φ1, θ1) and the minimum transmittance of the parallel line transmitted light is Tmin (φ2, θ2), the relationship of φ1 = φ2 ± 180 ° is satisfied. By doing so, it is possible to obtain a clear display mode with less blur (blur) of the display.

Further, the relationship of (Tmax / Tmin) ≧ 2 is satisfied, the polar angle θ1 is in a range of −40 ° ≦ θ1 ≦ 0 ° or 0 ° ≦ θ1 ≦ 40 °, and θ1 is −30 ° ≦ θ1. By setting the range of ≦ −10 ° or 10 ° ≦ θ1 ≦ 30 °, a clear display mode with less blur (blurring) of the display can be obtained.

Further, according to the present invention, when the parallel line transmittance in the normal direction of the directional forward scattering film is defined as T (0,0), the relationship of 3% ≦ T (0,0) ≦ 50% is satisfied, or By satisfying the relationship of 5% ≦ T (0,0) ≦ 40%, a clear display mode with less blur (blurring) of the display can be obtained.

Further, in the present invention, when specified in the range of φ1 ± 60 ° and φ2 ± 60 °, always show the maximum of the parallel line transmittance at θ1, and show the minimum of the parallel line transmittance at θ2, φ1 ± 60 ° and When the angle is defined in the range of φ2 ± 60 °, a clear display mode with less blur (blurring) of the display can be obtained even when the ratio between the minimum value and the maximum value of the parallel line transmittance is 1.5 or more.

Further, in the present invention, the parallel line transmittance when the polar angle in the direction orthogonal to φ1 and φ2 is changed from −40 ° to + 40 ° is not less than the normal direction transmittance of the directional forward scattering film. When the polar angle? A display form is obtained.

Further, if the electronic device has a liquid crystal device having the above-described various structures, it is possible to provide an electronic device which can display sharp and high-quality images without blur (blurring) of display.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment of Liquid Crystal Device)
A liquid crystal panel according to a first embodiment of the liquid crystal device according to the present invention will be described below with reference to FIGS. FIG. 1 is a plan view showing a first embodiment in which the present invention is applied to a simple matrix type reflection type liquid crystal panel. FIG. 2 is a partial cross-sectional view of the liquid crystal panel shown in FIG. FIG. 3 is an enlarged sectional view of a color filter portion incorporated in the liquid crystal display device. A liquid crystal display device (liquid crystal device) as a final product is configured by attaching ancillary elements such as a liquid crystal driving IC and a support to the liquid crystal panel 10 of this embodiment.

The liquid crystal panel 10 according to this embodiment has a pair of rectangular substrate units 13 and 14 which are substantially rectangular in plan view and are attached to each other via a ring-shaped sealing member 12 so as to face each other with a cell gap therebetween. , A liquid crystal layer 15 sandwiched between and sandwiched together with the sealant 12, a directional forward scattering film 18 provided on the upper surface side of one of the substrate units 13 (upper side in FIG. 2), and a retardation plate 19 and the polarizing plate 16. Among the substrate units 13 and 14, the substrate unit 13 is a front (upper) substrate unit provided facing the observer, and the substrate unit 14 is provided on the opposite side, in other words, a substrate unit provided on the back side (lower side). It is.

The upper substrate unit 13 includes, for example, a substrate 17 made of a transparent material such as glass, a directional forward scattering film 18 sequentially provided on the front side of the substrate 17 (the upper surface side, the observer side in FIG. 2), and a retardation plate. 19, a polarizing plate 16, a color filter layer 20, an overcoat layer 21 sequentially formed on the back side (in other words, the liquid crystal layer 15 side) of the substrate 17, and a color filter layer 20 formed on the surface of the overcoat layer 21 on the liquid crystal layer 15 side. And a plurality of striped electrode layers 23 for driving liquid crystal. In an actual liquid crystal device, alignment films are respectively formed on the liquid crystal layer 15 side of the electrode layer 23 and the liquid crystal layer 15 side of the striped electrode layer 35 on the lower substrate side, which will be described later. In these drawings, these alignment films are omitted and the description is omitted, and illustration and description of the alignment films are also omitted in other embodiments which will be sequentially described below. The cross-sectional structure of the liquid crystal device shown in FIG. 2 and each of the following drawings is shown by adjusting the thickness of each layer to a thickness different from that of the actual liquid crystal device so that each layer can be easily seen in the drawing.

In the present embodiment, the drive electrode layers 23 on the upper substrate side are formed of a transparent conductive material such as ITO (Indium Tin Oxide) in a stripe shape in a plan view. The required number is formed according to the area and the number of pixels.

In the present embodiment, the color filter layer 20 is provided on the lower surface of the upper substrate 17 (in other words, the surface on the liquid crystal layer 15 side) as shown in FIG. Are formed by forming the respective RGB patterns 27. Further, the overcoat layer 21 is coated as a transparent protective flattening film for protecting the RGB pattern 27.

The black mask 26 is formed by patterning a metal thin film of chromium or the like having a thickness of about 100 to 200 nm by, for example, a sputtering method or a vacuum evaporation method. Each of the RGB patterns 27 has a red pattern (R), a green pattern (G), and a blue pattern (B) arranged in a desired pattern shape. For example, a pigment using a photosensitive resin containing a predetermined coloring material is used. It is formed by various methods such as a dispersion method, various printing methods, an electrodeposition method, a transfer method, and a dyeing method.

On the other hand, the lower substrate unit 14 is sequentially formed on a substrate 28 made of a transparent material such as glass or other opaque material, and on the surface side of the substrate 28 (the upper surface side in FIG. 2, in other words, the liquid crystal layer 15 side). It comprises a reflective layer 31, an overcoat layer 33, and a plurality of stripe-shaped driving electrode layers 35 formed on the surface of the overcoat layer 33 on the liquid crystal layer 15 side. Like the electrode layer 23, the required number of these electrode layers 35 are formed in accordance with the display area of the liquid crystal panel 10 and the number of pixels.

Next, the reflective layer 31 of the present embodiment is made of a metal material having excellent light reflectivity and conductivity, such as Ag or Al, and is formed on the substrate 28 by an evaporation method, a sputtering method, or the like. However, it is not essential that the reflective layer 31 is made of a conductive material, and a structure in which a drive electrode layer made of a conductive material is provided separately from the reflective layer 31 and the reflective layer 31 and the drive electrode are separately provided may be employed. Absent.

Next, the directional forward scattering film 18 attached to the upper substrate unit 13 will be described in detail below.

The directional forward scattering film 18 used in the present embodiment has the directivity disclosed in JP-A-2000-035356, JP-A-2000-0666026, JP-A-2000-180607, etc., from the viewpoint of the basic structure. A forward scattering film can be used as appropriate. For example, as disclosed in Japanese Patent Application Laid-Open No. 2000-035356, a resin sheet which is a mixture of two or more types of photopolymerizable monomers or oligomers having different refractive indices is irradiated with an ultraviolet ray in a diagonal direction to obtain a specific resin sheet. A material having a function of efficiently scattering light only in a wide direction, or an on-line holographic diffusion sheet disclosed in Japanese Patent Application Laid-Open No. 2000-066606, is irradiated with a laser beam to a hologram photosensitive material to partially reduce the refractive index. Those manufactured so that different regions have a layer structure can be used as appropriate.

Here, in the directional forward scattering film 18 used in the present embodiment, various parameters such as the parallel line transmittance described below have a specific positional relationship suitable for the liquid crystal display device.

First, as shown in FIG. 4, it is assumed that the directional forward scattering film 18 having a rectangular shape in a plan view is installed horizontally. Although the horizontal installation state is easy to explain in FIG. 4, the horizontal installation state will be described. However, the direction in which the directional forward scattering film 18 is installed is not limited to the horizontal direction, and may be any direction. It suffices if the positional relationship (polar angle θ, azimuth φ described later) between K, light receiving unit J, and directional forward scattering film 18 can be clearly defined. In the present embodiment, the horizontal direction of the directional forward scattering film 18 will be described as an example in which the direction is easy to understand.

In FIG. 4, it is assumed that incident light L1 from the light source K is incident from the obliquely upper right side of the directional forward scattering film 18 toward the origin O at the center of the directional forward scattering film 18. Then, a measurement system is assumed in which the transmitted light that passes through the directional forward scattering film 18 through the origin O of the directional forward scattering film 18 and travels straight ahead is received by a light receiving unit J such as an optical sensor.

Here, in order to specify the direction of the incident light L1 to the directional forward scattering film 18, the directional forward scattering film 18 is formed in a rectangular shape by coordinate axes of 0 °, 90 °, 180 °, and 270 ° as shown in FIG. Assuming coordinates that pass through the origin O in the central part by dividing into four equal parts (in other words, by dividing the center of each side of the directional forward scattering film 18 into four parts such that one end of the coordinate axis passes through), The horizontal rotation angle of the incident light L1 vertically projected on the surface of the directional forward scattering film 18 (a clockwise angle from the 0 ° coordinate axis is +, and a counterclockwise angle from the 0 ° coordinate axis is −. ) Is defined as the azimuth angle φ. Next, the normal H of the directional forward scattering film to the direction of the incident light L1 horizontally projected on a vertical plane (the plane indicated by the symbol M1 in FIG. 4) including the coordinate axes of 0 ° and 180 °. The angle formed is defined as the polar angle θ of the incident light L1. In other words, the polar angle θ indicates the incident angle of the incident light L1 in the vertical plane with respect to the directional forward scattering film 18 installed horizontally, and the azimuth φ corresponds to the rotation angle of the incident light L1 in the horizontal plane.

In this state, for example, when the polar angle of the incident light L1 is 0 ° and the azimuth is 0 °, the incident light L1 is incident on the directional front film 18 at a right angle as shown in FIG. 5, the directional forward scattering film 18 is in the state indicated by reference numeral 18 in FIG. 5, and when the polar angle θ is + 60 °, the light source K, the light receiving unit J, and the The positional relationship with the film 18 is such that the directional forward scattering film 18 is disposed as shown by reference numeral 18A in FIG. 5, and when the polar angle θ is −60 °, the light source K, the light receiving unit J, and the directional forward scattering The positional relationship with the film 18 means that the directional forward scattering film 18 is arranged as shown by reference numeral 18B.

Next, as shown in FIG. 6A, the incident light L1 emitted from the light source provided on one surface side (the left side in FIG. 6A) of the directional forward scattering film 18 When the light passes through and passes through the other side of the directional forward scattering film 18 (the right side in FIG. 6A), the light scattered on one side (the left side) of the directional forward scattering film 18 is referred to as backscattered light LR. Light transmitted through the directional forward scattering film 18 is referred to as forward scattered light. As for the forward scattered light transmitted through the directional forward scatter film 18, the light intensity of the forward scattered light L3 traveling straight in the same direction with an angle error within ± 2 ° with respect to the traveling direction of the incident light L1 is defined as the incident light L1. Is defined as the parallel line transmittance, and the ratio of the forward scattered light LT that obliquely diffuses to the surrounding side beyond ± 2 ° with respect to the light intensity of the incident light L1 is defined as the diffuse transmittance. And the ratio of the total transmitted light to the incident light is defined as the total light transmittance. From the above definition, it can be defined that the value obtained by subtracting the diffuse transmittance from the total light transmittance is the parallel line transmittance. FIG. 1 also shows the relationship between the incident light L1, the azimuth angle φ, and the parallel transmitted light L3 to make the above description easier to understand.

In the field of optics, a transmittance scale called haze is also generally known. Haze is a value obtained by dividing a diffuse transmittance by a total light transmittance and expressing%. This is a definition of a concept completely different from the parallel line transmittance used in the present embodiment.

Next, when the maximum transmittance of the parallel line transmittance is described using the polar angle θ and the azimuth angle φ, it is defined as Tmax (φ1, θ1), and the minimum transmittance of the parallel line transmittance is defined. Is defined as Tmin (φ2, θ2). In other words, from the property of the directional forward scattering film, the condition where the maximum transmittance is exhibited is the condition where the scattering is the weakest, and the condition where the transmittance is the minimum is the condition where the scattering is the strongest.

For example, if the maximum transmittance is shown when the polar angle θ = 0 ° and the azimuth angle = 0 °, it is denoted as Tmax (0,0). (This means that the parallel line transmittance along the normal direction of the directional forward scattering film is the maximum. In other words, the scattering along the direction of the normal H of the directional forward scattering film is the weakest. In the case where the polarizer shows the minimum transmittance when the polar angle θ is 10 ° and the azimuth angle is 45 °, it is denoted as Tmin (10, 45). In this case, it is indicated that the scattering in this direction is the strongest. means.

各 Based on the above definition, each characteristic of the directional forward scattering film 18 that is preferable to be applied to the liquid crystal display device will be described below.

As described above, in the directional forward scattering film 18, the angle at which the parallel line transmittance shows the maximum transmittance is the angle at which the scattering is weakest, and the angle at which the parallel transmittance shows the minimum is the angle at which the scattering is strongest.

In other words, in other words, as shown in FIG. 2, in the reflective liquid crystal display device, it is considered that ambient light to the liquid crystal panel 10 is used as incident light L1, and the light reflected by the reflective layer 31 is recognized as reflected light by the observer. In the coordinate axes of FIG. 4, incident light enters the liquid crystal panel 10 from a direction in which scattering is strong when light enters (in other words, a direction in which the parallel line transmittance is low), and scattering is weak when an observer observes reflected light. When viewed from the direction (in other words, the direction in which the parallel line transmittance is high), it is considered that a state in which the display is less blurred (blurred) can be obtained. This is because the first scattering at the time of incidence on the directional forward scattering film 18, which the present inventors have found, does not easily affect the bleeding (blur) of the display. This is based on the finding that scattering at the time of passing the second time greatly affects blurring (blur) of display.

That is, in the present embodiment, when the incident light L1 passes through the directional forward scattering film 18 for the first time, it is better to scatter the light to prevent the specular reflection (mirror reflection) of the reflection layer 31 and achieve a wide viewing angle. This is preferable for the purpose of obtaining a bright display. Further, when the light reflected by the reflective layer 31 inside the liquid crystal device passes through the directional forward scattering film 18 for the second time, the one with less scattering is preferable. This is because it is considered preferable for reducing blurring (blur). Therefore, in the characteristics of the directional forward scattering film 18, the polar angle and the azimuth indicating the minimum transmittance, in other words, the polar angle and the azimuth of the incident light having the strongest scattering are directed to the daylighting side of the liquid crystal panel 10. Then, it is preferable that the polarizer is directed to the opposite side to the observer side, and the polar angle and the azimuth at which the parallel line transmittance shows the maximum transmittance, in other words, the incident light angle and the incident direction where the scattering is weakest are toward the observer side of the liquid crystal panel 10. It is necessary to turn.

Here, FIG. 6B shows a cross-sectional structure of the directional forward scattering film 18 used in the present embodiment, and the polar and azimuthal states described above will be described.

As shown in FIG. 6B, the cross-sectional structure model of the directional forward scattering film 18 used in the present embodiment is such that a portion having a refractive index of n1 and a portion having a refractive index of n2 have a cross-sectional structure of the directional forward scattering film 18. This is a structure in which layers are alternately arranged in a diagonal direction at a predetermined angle. Assuming that the incident light L1 is incident on the directional forward scattering film 18 having this structure at an appropriate polar angle from an oblique direction, the incident light L1 is scattered at the boundary between the layers having different refractive indices and a part of the scattered light. Is reflected by the reflection layer 31 after passing through the liquid crystal layer 15, the reflected light R1 passes through the liquid crystal layer 15 again and passes through the directional forward scattering film 18 at a polar angle different from that of the incident light L1. However, the reflected light R1 can pass through the directional forward scattering film 18 with little scattering.

In order to satisfy such a relationship, it is most preferable that the relationship between the azimuth angles φ1 and φ2 is φ1 = φ2 ± 180 °. This means that φ2 is the incident angle direction and φ1 is the observation direction, and these angles differ by 180 ° when applied to an actual liquid crystal device. In this case, the light incident on the liquid crystal device is strongly scattered at the time of incidence, and the light reflected on the reflection layer 31 is hard to be scattered. Therefore, a sharp display mode without blur (blurring) of the display can be obtained. However, considering that the directional forward scattering film 18 in which layers having different refractive indexes are alternately arranged in layers in a diagonal direction with a predetermined angle as described above is not systematically completely uniform, The ideal relationship between the angles φ1 and φ2 is φ1 = φ2 ± 180 °, which is ideal, but the present invention encompasses angles that deviate from the angle by about ± 10 ° based on the relationship φ1 = φ2 ± 180 °. It shall be. If the angle deviates by more than ± 10 °, it becomes difficult to obtain a sharp display form without blur (blurring) of the display.

Next, it is preferable that the value of (Tmax / Tmin) satisfies the relationship of (Tmax / Tmin) ≧ 2. With this relationship, sufficient scattering is obtained at the time of incidence, and a bright and sharp reflective display is obtained. By satisfying this relationship, a brighter reflective display can be realized than in the case where a conventionally known isotropic scattering film is used.

Next, looking at the polar angles θ1 and θ2 individually, in order to obtain a display brighter than the isotropic scattering film, the range of −40 ° ≦ θ1 <0 ° and 0 ° <θ2 ≦ 40 ° It is more preferable that -30 ° ≦ θ1 ≦ −10 ° and 10 ° ≦ θ2 ≦ 30 °.

Next, when the parallel line transmittance in the normal direction (directly in front) of the directional forward scattering film 18 is defined as T (0,0), a display brighter than a conventionally known isotropic scattering film is obtained. In order to obtain, when θ1 = θ2 = 20 °, T (0,0) is preferably 3% or more and 50% or less, and T (0,0) is 5% or more and 40% or less. More preferably, there is. If T (0,0) is less than 3%, the scattering is too strong and the display becomes blurred, and if T (0,0) exceeds 40%, the front scattering is too weak to be close to mirror reflection.

Next, when the azimuth angle φ of the directional forward scattering film is defined as a range of φ1 ± 60 ° (φ2 ± 60 °), the maximum (maximum) of the parallel line transmittance is always taken at θ1, and the parallel line transmittance is taken at θ2. It is preferable to take the minimum value (minimum value) of the ratio and make the ratio of the maximum value (maximum value) to the minimum value (minimum value) 1.5 or more. With such a feature, not only one direction of φ2 but also light of azimuth up to ± 60 ° can be scattered, so that it is easy to cope with each environment, Bright display can be realized.

Next, when the polar angle θ in a direction orthogonal to the azimuth angle φ1 indicating the maximum transmittance and the azimuth angle φ2 indicating the minimum transmittance is changed from −40 ° to + 40 °, the parallel line transmittance is directed in this range. When the transmittance is equal to or higher than the transmittance in the normal direction of the forward scattering film, a sharp display without blur (blurring) of the display can be obtained even when the liquid crystal device is observed from the lateral direction. That is, it is preferable that the relationship T (0,0) ≦ T (φ1 ± 90, θ) be satisfied, and the relationship T (0,0) ≦ T (φ2 ± 90, θ) be satisfied.

Next, when the polar angle θ is in the range of −60 ° ≦ θ ≦ + 60 °, the parallel line transmittance T (φ, θ) is 2% or more, and preferably 50% or less. That is, it is preferable to satisfy the relationship of 2% ≦ T (φ, θ) ≦ 50%, provided that −60 ° ≦ θ ≦ + 60 °.

(4) With such a relationship, it is possible to obtain a sharp display that is bright and has no display blur.

(Second embodiment of liquid crystal device)
FIG. 7 is a partial sectional view showing a liquid crystal panel 40 of a liquid crystal device according to a second embodiment of the present invention.

The liquid crystal panel 40 of this embodiment has a simple matrix structure of the reflection type provided with the directional forward scattering film 18, similarly to the liquid crystal panel 10 of the first embodiment described with reference to FIGS. Since the basic structure is the same as that of the first embodiment, the same components are denoted by the same reference numerals, and the description of those components will be omitted. The following mainly describes different components.

The liquid crystal panel 40 of the present embodiment is configured such that the liquid crystal layer 15 is sandwiched between the opposed substrate units 41 and 42 by the sealing material 12. The upper substrate unit 41 is the same as the substrate unit 13 of the first embodiment except that the color filter layer 20 is omitted, and the color filter layer 20 is formed on the reflection layer 31 of the lower substrate unit 42 on the opposite side. The configuration of this portion is different from the structure of the first embodiment. That is, in the liquid crystal panel 40 shown in FIG. 4, the color filter layer 20 provided on the upper side (observer side) of the substrate unit 13 in the first embodiment is changed to the lower side of the liquid crystal layer 15 (observer side). This is a structure provided on the substrate unit 42 side (opposite side). The structure of the color filter layer 20 is the same as that of the first embodiment, but since the color filter layer 20 is formed on the upper surface side of the substrate 28, the laminated structure of the color filter layer 20 shown in FIG. Is upside down with respect to the state.

Also in the structure of the second embodiment, since the directional forward scattering film 18 is provided in the same manner as the structure of the first embodiment, the blur of the reflective display (blur) is the structure of the first embodiment. The same effect as can be obtained.

Further, in the liquid crystal device 40 shown in FIG. 4, since the color filter layer 20 is formed immediately above the reflection layer 31, light incident on the liquid crystal device 40 reaches the reflection layer 31 via the liquid crystal layer 15 and is reflected. Since it passes through the color filter 32 immediately after being processed, it has a feature that the problem of color misregistration hardly occurs.

反射 In the present embodiment, the reflection layer 31 is in a mirror (mirror surface) state, but may have fine irregularities of about 1 to 20 μm.

(Third Embodiment of Liquid Crystal Device)
FIG. 8 is a sectional view showing a liquid crystal panel 50 of a liquid crystal device according to a third embodiment of the present invention.

The liquid crystal panel 50 of this embodiment is a substrate unit having a transflective layer 52 instead of the reflective layer 31 provided in the liquid crystal panel 10 of the first embodiment described with reference to FIGS. 55, which are the same as those of the first embodiment in other basic structures, and the description of those components is omitted. Hereinafter, different components will be mainly described.

When a liquid crystal display device is used as the transmission type, the lower substrate 28 'needs to be formed of a transparent substrate such as glass.

The structure of the liquid crystal panel 50 is different from that of the first embodiment in that a transflective layer 52 is provided, and a light source 60 such as a backlight is provided behind the liquid crystal panel 50 (the lower side in FIG. 8). Are provided, and a retardation plate 56 and a polarizing plate 57 are added.

The transflective layer 52 is a transflective layer (for example, a film having a thickness of several hundred angstroms) having a thickness sufficient to transmit transmitted light emitted from a light source 60 such as a backlight on the rear side (the lower side in FIG. 8). Widely used in transflective liquid crystal display devices, such as a thick thin film Al or a thin film Ag, or a structure in which a large number of fine holes are formed in a part of a reflective film to enhance light transmittance. Can be appropriately adopted.

In the liquid crystal device according to the third embodiment, a transmissive liquid crystal display mode is used when light transmitted from a light source 60 such as a backlight is used, and reflection using ambient light is used when light from the light source is not used. The display can be used as a reflective liquid crystal display device. When a display mode as a reflection type liquid crystal display device is adopted, sharp reflection in which display blur (blurring) is eliminated is caused by the presence of the directional forward scattering film 18, as in the case of the first embodiment. It is possible to obtain a type display mode.

In the first, second, and third embodiments described above, an example in which the present invention is applied to a simple matrix type reflection type liquid crystal display device has been described. Of course, the present invention may be applied to an active matrix type reflective liquid crystal display device or a transflective liquid crystal display device having a terminal type switching element.

When applied to these active matrix type liquid crystal display devices, a common electrode is provided on one substrate side instead of the striped electrodes shown in FIGS. 2, 7, and 8, and a large number of pixels are provided on the other substrate side. An electrode is provided for each pixel, and a TFT (thin film transistor) driving type structure in which each pixel electrode is individually driven by a thin film transistor which is a three-terminal switching element, a stripe-shaped electrode is provided on one substrate side, and the other is provided. It is needless to say that the present invention can be applied to a two-terminal linear element driving type liquid crystal display device in which pixel electrodes are provided for each pixel on the substrate side, and these pixel electrodes are individually driven by a thin film diode which is a two-terminal linear element. The present invention can be applied to any of these types of liquid crystal display devices only by arranging the directional scattering film on the liquid crystal panel in the specific direction described above. It has a feature that can be very easily applied to a liquid crystal display device of various forms.

(Fourth Embodiment of Liquid Crystal Device)
FIG. 16 is a sectional view showing a liquid crystal panel according to a fourth embodiment of the liquid crystal device according to the present invention.

The liquid crystal panel according to this embodiment includes a pair of rectangular substrates 17 and 18 that are substantially rectangular in plan view and are attached to each other with a cell gap therebetween via an annular sealing member 12 so as to face each other. The liquid crystal layer 15 is sandwiched and surrounded by the sealing material 12 therebetween, and a directional forward scattering film 18, a retardation plate 19, and a polarizing plate 16 provided on the upper surface side of one substrate 17 are mainly constituted. Have been.

The upper substrate unit includes a substrate 17 made of a transparent material such as glass, and a directional forward scattering film 18 and a retardation plate 19 sequentially provided on the front side of the substrate 17 (the upper side in FIG. 16, the observer side). And a polarizing plate 16 and a plurality of stripe-shaped electrode layers 23 for driving liquid crystal formed on the back side of the substrate 17 (in other words, on the liquid crystal layer 15 side). In an actual liquid crystal device, alignment films are respectively formed on the liquid crystal layer 15 side of the electrode layer 23 and the liquid crystal layer 15 side of the striped electrode layer 35 on the lower substrate side, which will be described later. Then, these alignment films are omitted and the description is also omitted. On the liquid crystal layer 15 side of the lower substrate 28, a reflective layer 31, a color filter layer 20, an overcoat layer 33, and an electrode layer 35, which are sequentially provided with irregularities, are formed. In the cross-sectional structure of the liquid crystal device shown in FIG. 16, the thickness of each layer is adjusted to be different from that of an actual liquid crystal device so that each layer is easy to see in the drawing.

In the present embodiment, each of the drive electrode layers 23 on the upper substrate side is formed of a transparent conductive material such as ITO (Indium Tin Oxide: indium tin oxide) in a stripe shape in a plan view. The required number is formed according to the number of pixels.

The reflective layer 31 of the present embodiment is made of a metal material having excellent light reflectivity and conductivity such as Ag or Al, and is formed by forming irregularities on the substrate 28 with an acrylic resin or etching a glass substrate with hydrofluoric acid, followed by a vapor deposition method. Alternatively, it is formed by a sputtering method or the like. This reflective layer 31 may be used as a drive electrode.

In the case of the embodiment of FIG. 16, a front light guide plate 1602 and a touch key input device 1601 are arranged on the viewer 1603 side of the liquid crystal device.

(4) On the surface of the front light guide plate 1602 or the touch key input device 1601, surface reflections L161 and L162 are present as shown in FIG. 16, so that the liquid crystal device is not normally observed from this direction. Since the liquid crystal device of the present invention has a function of diffracting and scattering the incident light L163 as shown in FIG. 6B, the observer 1603 can obtain a bright display regardless of the surface reflections L161 and L162. Can be.

(4) Further, since light is strongly scattered at the time of incidence and is not strongly scattered at the time of emission, a clear display is obtained. The glare of the reflective layer having irregularities could be reduced by scattering at the time of incidence.

(Embodiment of electronic device)
Next, a specific example of an electronic device including any one of the liquid crystal panels 10, 40, and 50 according to the first to third embodiments will be described.

FIG. 9A is a perspective view showing an example of a mobile phone.

In FIG. 9A, reference numeral 200 denotes a main body of the mobile phone, and reference numeral 201 denotes a liquid crystal display unit using any one of the liquid crystal panels 10, 40, and 50.

FIG. 9B is a perspective view showing an example of a portable information processing device such as a word processor or a personal computer.

9B, reference numeral 300 denotes an information processing device, reference numeral 301 denotes an input unit such as a keyboard, reference numeral 303 denotes a main body of the information processing device, and reference numeral 302 denotes a liquid crystal using any one of the liquid crystal panels 10, 40, and 50. The display unit is shown.

FIG. 9C is a perspective view illustrating an example of a wristwatch-type electronic device.

In FIG. 9C, reference numeral 400 denotes a watch main body, and reference numeral 401 denotes a liquid crystal display unit using any one of the liquid crystal panels 10, 40, and 50.

Each of the electronic devices shown in FIGS. 9A to 9C includes a liquid crystal display unit using any one of the liquid crystal panels 10, 40, and 50, and therefore has display blur (blurring). Not sharp and excellent in display quality.

"Test Example 1"
A transmittance measurement test was performed using a directional forward scattering film created by a transmission hologram technique.

Light from a light source of a halogen lamp (installed at a position 300 mm away from the directional forward scattering film) is incident on the center of the surface of a horizontally-directed 50 × 40 mm rectangular directional forward scattering film in a plan view, and is directional forward. A light receiving unit having a light receiving element made of a CCD on the back side of the scattering film (installed at a position 300 mm away from the directional forward scattering film) is installed in a direction facing the incident light from the light source in a normal direction. The polar angle and the azimuth were defined as shown in FIG. 4, and the parallel line transmittance was measured in the light receiving section in a 2-degree field of view.

Adjusting the polar angle θ of the light source (the incident angle of the incident light with respect to the normal line of the directional forward scattering film) in the range of ± 60 °, and measuring the parallel line transmittance (%) at each polar angle. It is shown in FIG. As for the azimuth angles, 0 °, + 30 °, + 60 °, + 90 °, and + 180 ° (all in the clockwise direction shown in FIG. 4), −30 °, −60 °, and −90 ° (in FIG. (Counterclockwise direction shown in Fig. 10) was measured and collectively shown in Fig. 10.

From the results shown in FIG. 10, the measurement results at 0 ° and 180 ° are exactly the same curve, and the relationship between the maximum transmittance Tmax and the minimum transmittance Tmin of the parallel line transmitted light is (Tmax / Tmin) ≒ 50. : 6 ≒ 8.33, a value exceeding 2 desired in the present invention.

Next, FIG. 11 shows the result of a similar transmittance measurement test performed using another directional forward scattering film created by a transmission type hologram technology. FIG. 12 shows the results of a similar transmittance measurement test performed using the forward scattering film.

Looking at the characteristics shown in FIG. 11, the relationship between the maximum transmittance Tmax and the minimum transmittance Tmin of the parallel line transmitted light is (Tmax / Tmin) ≒ 12: 3 ≒ 4, which exceeds 2 desired in the present invention. The value was shown.

Looking at the characteristics shown in FIG. 12, the relationship between the maximum transmittance Tmax and the minimum transmittance Tmin of the parallel line transmitted light is (Tmax / Tmin) ≒ 52: 26 ≒ 2, which is the desired value of 2 in the present invention. showed that.

Further, in the directional forward scattering films of any of the examples shown in FIGS. 10, 11 and 12, it is clear that the maximum value and the minimum value generally exist at almost the same angle in the range of ± 60 °. Was. For example, from the results shown in FIG. 10, the local maximum value is a polar angle of −30 °, the local minimum value is a polar angle of + 23 °, and from the results shown in FIG. From the results shown in FIG. 12, when the polar angle was + 18 °, the maximum value was a case where the polar angle was −30 °, and the minimum value was a case where the polar angle was + 25 °.

Next, in the directional forward scattering films of the examples shown in FIGS. 10, 11 and 12, when φ is ± 90 °, the transmittance is lowest when the polar angle θ is 0 in any of the examples. Also turned out. It is also clear that in the directional forward scattering films of the examples shown in FIGS. 10, 11, and 12, the transmittance in all the conditions is in the range of 2 to 50%.

Next, when the polar angle θ was fixed and the azimuth angle φ was changed, in other words, when only the directional forward scattering film was rotated in a horizontal plane, the transmittance of the directional forward scattering film was measured. FIG. 13 shows the results.

According to the results shown in FIG. 13, under the condition of θ = 0 °, light is incident in the normal direction of the directional forward scattering film, but the transmittance is almost constant, and θ = −20 °, − In the case of 40 ° and −60 °, the azimuth shows a curve in which the transmittance takes the maximum convex upward in the range of 0 ± 90 °, and in the case of θ = + 20 °, + 40 ° and + 60 °, the azimuth is 0 ±. In the range of 90 °, the transmittance showed a tendency to show a curve in which the transmittance takes the minimum of convex downward (concave upward). From this, it was clearly shown that the directional forward scattering film used in the present example exhibited a maximum and a minimum transmittance in accordance with the polar angle and the azimuth angle.

When analyzing the relationship between the transmittances shown in FIG. 13, the azimuth angle φ is within ± 30 ° at a negative polar angle θ (−20 °, −40 °, −60 °), that is, φ = −30 ° or more. In the range of + 30 °, the maximum value of the transmittance is suppressed to within 5%, and the azimuth angle φ is within ± 30 ° at positive polar angles θ (+ 20 °, + 40 °, + 60 °), that is, φ = In the range of -30 ° to + 30 °, the minimum value of the transmittance is suppressed to within 5%.

FIG. 14 shows the relationship between polar angle and transmittance for each azimuth angle in a sample of a liquid crystal device configured using a conventional isotropic forward scattering film (trade name: IDS-16K, manufactured by Dai Nippon Printing Co., Ltd.). 1 shows the measurement results. In the test, the results were obtained by using the same liquid crystal device as in the first test example, and changing the anisotropic forward scattering film to the isotropic scattering film used this time.

From the results shown in FIG. 14, the transmittance of the parallel line transmitted light shows almost no change at any azimuth angle, almost overlaps with one curve, and the polar angle is maximized when the polar angle is 0 °. It is clear that even if it is changed to the minus region, it changes only about a few percent. From this result, it is clear that the effect of the present invention cannot be obtained even when the isotropic forward scattering film is used for a liquid crystal device.

"Test Example 2"
Next, the brightness of the reflective type color liquid crystal display device when the polar angle θ1 and the polar angle θ2 in the previous test were variously changed was compared in an office under a fluorescent lamp lighting. As the brightness, a reflection type color liquid crystal display device using a conventional isotropic forward scattering film (a reflection type color liquid crystal display device using an isotropic scattering film used in the measurement shown in FIG. 14 described above) and In comparison, the following Table 1 shows that the image was recognized as brighter than the conventional reflective color liquid crystal display device, Δ was equivalent, and × was dark.

"Table 1"
θ1 (°) -80 -70 -60 -50 -40 -30 -20 -10 0 θ2 (°) 0 0 0 0 0 0 0 0 0
Evaluation result × × × × × △ △ △ × θ1 (°) -80 -70 -60 -50 -40 -30 -20 -10 -10 0
θ2 (°) 10 10 10 10 10 10 10 10 10 10
Evaluation result × × × × △ 〇 〇 〇 ×
θ1 (°) -80 -70 -60 -50 -40 -30 -20 -10 0
θ2 (°) 20 20 20 20 20 20 20 20 20 Evaluation result × × × × △ 〇 〇 〇 × θ1 (°) -80 -70 -60 -50 -40 -30 -30 -20 -10 0
θ2 (°) 30 30 30 30 30 30 30 30 30 Evaluation result × × × × △ 〇 〇 〇 × θ1 (°) -80 -70 -60 -50 -40 -30 -30 -20 -10 0
θ2 (°) 40 40 40 40 40 40 40 40 40
Evaluation result × × × × × △ △ △ ×
As is clear from the measurement results shown in Table 1, when the polar angle θ1 when the parallel ray transmitted light is the maximum is in the range of −40 ° ≦ θ1 ≦ 0 ° and in the range of 0 ° ≦ θ2 ≦ 40 °. A liquid crystal display device which can secure the same level of brightness as the conventional product, and which is superior in brightness to the conventional product as long as it is in the range of −30 ° ≦ θ1 ≦ −10 ° and in the range of 10 ° ≦ θ2 ≦ 30 °. It can be seen that it can be obtained.

"Test Example 3"
A directional forward scattering film in which the parallel line transmittance T (0,0) in the normal direction of the directional forward scattering film is changed to various values is prepared, and the brightness of a liquid crystal display device provided with the directional forward scattering film is adjusted. The results were compared in offices under fluorescent lighting. The compared conventional product is the same as that used in the previous test example. Table 2 below shows a case in which the image was recognized brighter than the conventional reflective color liquid crystal display device, a case in which the image was equivalent, and a case in which the image was dark.

"Table 2"
T (0,0) 3% 5% 10% 20% 30% 40% 50% 60%
Evaluation result △ 〇 〇 〇 〇 〇 △ ×
As is clear from the results shown in Table 2, in the range of 3% ≦ T (0,0) ≦ 60%, more preferably 5% ≦ T (0,0) ≦ 40%, under the actual use environment. It is clear that a reflective color liquid crystal display device that is brighter than in the prior art can be provided.

Next, from the results shown in FIGS. 10, 11, and 12, when the azimuth angle φ of the directional forward scattering film is defined in the range of φ1 ± 60 ° and φ2 ± 60 °, the parallel line transmittance always becomes θ1. It is also evident that the peak shows a maximum and the parallel line transmittance shows a minimum at θ2.

"Test Example 4"
Next, a large number of directional forward scattering films prepared by the transmission hologram technology are prepared, and the brightness of the reflection type color display device when the value of (Tmax / Tmin) is adjusted to various values is set to the value of the conventional product. Table 3 below shows the result of comparison with the liquid crystal display device. In the case where the recognition was more than twice as bright as the conventional liquid crystal display device, it was evaluated as 、, in the case where it was recognized as being brighter than the conventional product, in 〇, in the case of equivalent, in △, and in the case of dark, ×.

"Table 3"
Tmax / Tmin 10.0 5.0 3.0 2.0 1.8 1.5 1.0
Evaluation result ◎ ◎ ◎ ◎ △ △ △
From the results shown in Table 3, it is clear that the recognition was particularly bright when the ratio between the minimum value and the maximum value of the parallel line transmittance described above was 2 or more.

"Test Example 5"
Assuming that the azimuth when the parallel line transmittance takes the minimum value or the maximum value is φ2 or φ1, the maximum value of the transmitted light characteristic measured by changing the polar angle θ in the range of φ2 ± 60 ° and φ1 ± 60 ° And the minimum value were measured. By changing this ratio, the brightness of the reflective type color liquid crystal display device was compared in an office under fluorescent lamp lighting. The compared conventional product is the same as that used in the previous test example. Table 4 below shows a case in which the image was recognized brighter than the conventional reflective color liquid crystal display device, a case in which the image was equivalent, and a case in which the image was dark.

"Table 4"
Maximum value / Minimum value 5.0 3.5 2.0 1.5 1.5 1.2 1.0
Evaluation result 〇 〇 〇 〇 △ △
From the results shown in Table 4, it was clarified that the value of the maximum value / the minimum value is preferably 1.5 or more. That is, when the azimuth angle φ of the directional forward scattering film is defined in the range of φ1 ± 60 ° and φ2 ± 60 °, it is apparent that the ratio of the minimum value and the maximum value of the parallel line transmittance is 1.5 or more. It is.

"Test Example 6"
When the polar angle θ is −60 ° ≦ θ ≦ + 60 °, the maximum value and the minimum value of the parallel line transmittance T are changed, and the brightness of the reflective color liquid crystal display device is compared in an office under fluorescent lamp lighting. did. The compared conventional product is the same as that used in the previous test example. In Table 5, the following items were indicated as Δ, those which were recognized brighter than the conventional reflection type color liquid crystal display device, Δ as those equivalent, and × as dark.

"Table 5"
Maximum transmittance Tmax 60% 50% 40% 30% 20% 10%
Minimum transmittance Tmin 1% 1% 1% 1% 1% 1% 1%
Evaluation result × × △ △ △ ×
Maximum transmittance Tmax 60% 50% 40% 30% 20% 10%
Minimum transmittance Tmin 2% 2% 2% 2% 2% 2%
Evaluation result × 〇 〇 〇 〇 〇 Maximum transmittance Tmax 60% 50% 40% 30% 20% 10%
Minimum transmittance Tmin 5% 5% 5% 5% 5% 5% 5%
Evaluation result △ 〇 〇 〇 〇 〇 Maximum transmittance Tmax 60% 50% 40% 30% 20% 10%
Minimum transmittance Tmin 10% 10% 10% 10% 10% 10% Evaluation result △ 〇 〇 〇 〇 △
Maximum transmittance Tmax 60% 50% 40% 30% 20% 10%
Minimum transmittance Tmin 20% 20% 20% 20% 20% 20% 20% Evaluation result × 〇 〇 △ △ ×
Maximum transmittance Tmax 60% 50% 40% 30% 20% 10%
Minimum transmittance Tmin 30% 30% 30% 30% 30% 30% 30% Evaluation result × △ △ × × ×
Maximum transmittance Tmax 60% 50% 40% 30% 20% 10%
Minimum transmittance Tmin 40% 40% 40% 40% 40% 40% 40% Evaluation result × × × × × ×
From the results shown in Table 5, it can be seen that the maximum value / minimum value ≧ 2 is required and that the transmittance is 2% or more and 50% or less.

FIG. 1 is a plan view of a liquid crystal panel according to a first embodiment of the present invention. FIG. 2 is a schematic partial cross-sectional view taken along line AA of the liquid crystal panel shown in FIG. 1. FIG. 3 is an enlarged sectional view showing a color filter portion of the liquid crystal panel shown in FIG. FIG. 4 is an explanatory diagram showing a positional relationship among a directional forward scattering film, a light source, a light receiving section, a polar angle, an azimuth angle, and parallel line transmitted light. FIG. 5 is an explanatory diagram showing the positional relationship between the directional forward scattering film, the light source, and the light receiving unit. FIG. 6A is an explanatory diagram showing the relationship between incident light, parallel-line transmitted light, diffuse transmitted light, and backscattered light and forward scattered light with respect to the directional forward scattering film, and FIG. 6B is a directional forward scattering film. FIG. 3 is an explanatory diagram showing a relationship between an example of the cross-sectional structure of FIG. FIG. 7 is a sectional view of a liquid crystal panel according to a second embodiment of the present invention. FIG. 8 is a sectional view of a liquid crystal panel according to a third embodiment of the present invention. FIG. 9A is a perspective view showing a portable telephone, FIG. 9B is a perspective view showing an example of a portable information processing apparatus, and FIG. 1 is a perspective view showing an example of a wristwatch-type electronic device. FIG. 10 is a diagram illustrating a result of measuring a first example of the relationship between the polar angle and the transmittance measured in the example for each azimuth angle. FIG. 11 shows the result of measuring the second example of the relationship between the polar angle and the transmittance measured in the example for each azimuth angle, and the measurement result when the ratio between the minimum value and the maximum value of the parallel line transmittance is 4 FIG. FIG. 12 shows the results of measuring the third example of the relationship between the polar angle and the transmittance measured in the example for each azimuth angle, and the measurement result when the ratio between the minimum value and the maximum value of the parallel line transmittance is 2 FIG. FIG. 13 is a diagram showing the result of measuring the relationship between the azimuth angle and the transmittance measured in the example for each polar angle. FIG. 14 is a diagram illustrating the result of measuring the relationship between the polar angle and the transmittance measured for each azimuth angle in the comparative example. 15A and 15B show a conventional reflection type liquid crystal device. FIG. 15A is a schematic sectional view showing an example of a reflection type liquid crystal device provided with a scattering film, and FIG. 1 is a schematic cross-sectional view illustrating an example of a liquid crystal device. FIG. 16 is a sectional view of a liquid crystal panel according to a fourth embodiment of the present invention.

Explanation of reference numerals

θ: polar angle,
φ ... azimuth,
K: Light source,
J: light receiving section,
LT: diffuse transmission light,
L3: parallel line transmitted light,
Tmax (φ1, θ1): maximum transmittance,
Tmin (φ2, θ2): minimum transmittance,
10, 40, 50 ... liquid crystal panel,
15 ... Liquid crystal layer,
17, 28, 28 '... substrate,
18 ... directional forward scattering film,
20 ... color filter layer,
23, 35 ... electrode layer,
31 ... reflection layer,
52 ... transflective layer,
200 ... mobile phone body,
300 ··· Portable information processing equipment,
400: Wristwatch type electronic device.

Claims (20)

A pair of substrates, a liquid crystal layer sandwiched between these substrates, a reflective layer provided on the liquid crystal layer side of the one substrate, and a directivity provided on the side opposite to the liquid crystal layer side of the other substrate. A liquid crystal panel comprising a forward scattering film, and light is incident on the directional forward scattering film from a light source disposed on one surface side of the directional forward scattering film, and light is disposed on the other surface side of the directional forward scattering film. In the portion, of the total transmitted light transmitted through the directional forward scattering film, when observing parallel-line transmitted light except diffuse transmitted light,
The incident angle of the incident light with respect to the normal line of the directional forward scattering film is defined as a polar angle θn, the incident light angle in the in-plane direction of the directional forward scattering film is defined as an azimuth φm, and When the maximum transmittance is defined as Tmax (φ1, θ1) and the minimum transmittance of the parallel transmitted light is defined as Tmin (φ2, θ2), the incident light side at the polar angle and the azimuth indicating the minimum transmittance The directional forward scattering film so as to be on the daylighting side of the liquid crystal panel, so that the incident light side in the case of the polar angle and azimuth indicating the maximum transmittance is on the viewing direction side of the liquid crystal panel. A liquid crystal device characterized by being arranged on a panel. A pair of substrates, a liquid crystal layer sandwiched between these substrates, a semi-transmissive reflective layer provided on the liquid crystal layer side of the one substrate, and a liquid crystal layer provided on the other substrate opposite to the liquid crystal layer side. Comprising a liquid crystal panel with a directional forward scattering film,
Light is incident on the directional forward scattering film from a light source disposed on one surface thereof, and is transmitted through the directional forward scattering film at a light receiving unit disposed on the other surface of the directional forward scattering film. When observing the parallel transmitted light excluding the diffuse transmitted light,
The incident angle of the incident light with respect to the normal line of the directional forward scattering film is defined as a polar angle θn, the incident light angle in the in-plane direction of the directional forward scattering film is defined as an azimuth φm, and When the maximum transmittance is defined as Tmax (φ1, θ1) and the minimum transmittance of the parallel transmitted light is defined as Tmin (φ2, θ2), the incident light side at the polar angle and the azimuth indicating the minimum transmittance The directional forward scattering film so as to be on the daylighting side of the liquid crystal panel, so that the incident light side in the case of the polar angle and azimuth indicating the maximum transmittance is on the viewing direction side of the liquid crystal panel. A liquid crystal device characterized by being arranged on a panel. When the maximum transmittance of the parallel light is Tmax (φ1, θ1) and the minimum transmittance of the parallel light is Tmin (φ2, θ2), the relationship of φ1 = φ2 ± 180 ° is satisfied. The liquid crystal device according to claim 1, wherein: The liquid crystal device according to claim 1, wherein a ratio of a maximum transmittance Tmax and a minimum transmittance Tmin of the parallel line transmitted light has a relationship of (Tmax / Tmin) ≧ 2. 5. The polar angle θ <b> 1 when the parallel ray transmitted light is maximum is in a range of −40 ° ≦ θ1 ≦ 0 ° or 0 ° ≦ θ1 ≦ 40 °. The liquid crystal device according to the above. 5. The polar angle θ1 when the parallel ray transmitted light is maximum is in a range of −30 ° ≦ θ1 ≦ −10 ° or 10 ° ≦ θ1 ≦ 30 °. 3. The liquid crystal device according to claim 1. The polar angle θ2 when the parallel ray transmitted light is minimized is in a range of −40 ° ≦ θ2 ≦ 0 ° or 0 ° ≦ θ2 ≦ 40 °. The liquid crystal device according to the above. The polar angle θ2 when the parallel ray transmitted light is minimized is in a range of −30 ° ≦ θ2 ≦ −10 ° or 10 ° ≦ θ2 ≦ 30 °. 3. The liquid crystal device according to claim 1. The parallel line transmittance in the normal direction of the directional forward scattering film is defined as T (0,0), and satisfies a relationship of 3% ≦ T (0,0) ≦ 50%. 9. The liquid crystal device according to any one of 1 to 8. When the parallel line transmittance in the normal direction of the directional forward scattering film is defined as T (0,0), the relationship of 5% ≦ T (0,0) ≦ 40% is satisfied. 9. The liquid crystal device according to any one of 1 to 8. When the azimuthal angle φ of the directional forward scattering film is defined in the range of φ1 ± 60 ° and φ2 ± 60 °, it always shows the maximum of the parallel line transmittance at θ1 and always shows the minimum of the parallel line transmittance at θ2. The liquid crystal device according to claim 1, wherein: When the azimuthal angle φ of the directional forward scattering film is defined in the range of φ1 ± 60 ° and φ2 ± 60 °, the ratio between the minimum value and the maximum value of the parallel line transmittance is 1.5 or more. The liquid crystal device according to claim 1. Parallel line transmission when the polar angle in the direction orthogonal to the azimuth angle φ1 indicating the maximum transmittance of the parallel line transmitted light and the azimuth angle φ2 indicating the minimum transmittance of the parallel line transmitted light is changed from −40 ° to + 40 °. The liquid crystal device according to claim 1, wherein a transmittance is equal to or higher than a transmittance in a normal direction of the directional forward scattering film. 14. When the polar angle θ is in the range of −60 ° ≦ θ ≦ + 60 °, the transmittance T (φ, θ) is 2% or more and 50% or less. 3. The liquid crystal device according to claim 1. The liquid crystal device according to claim 1, wherein a liquid crystal driving electrode is provided on the liquid crystal layer of the one substrate and the liquid crystal layer of the other substrate. The liquid crystal device according to any one of claims 1 to 15, wherein a color filter is provided on one of the pair of substrates on one liquid crystal layer side. 17. The liquid crystal device according to claim 1, wherein the reflection layer or the transflective layer has fine irregularities. 18. The directional scattering film according to claim 1, wherein the directional scattering film has a function of scattering and diffracting incident light from the azimuth side showing the minimum transmittance Tmin (φ2, θ2). Liquid crystal device. 19. A liquid crystal device according to claim 1, wherein at least one of a transparent protective plate, a light guide of a front light illuminating device, and a touch key is arranged on an observation side of the liquid crystal device. The liquid crystal device according to claim 1. 20. An electronic apparatus comprising the liquid crystal device according to claim 1 as display means.

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