JPH06337643A - Liquid crystal display panel - Google Patents

Abstract

PURPOSE:To provide a color liquid crystal display panel which is small in size and weight and is capable of realizing good multilayered color display having no parallax with a simple driving circuit. CONSTITUTION:This liquid crystal display panel is constituted by successively laminating plural layers of color developing layer (for example, first color developing layer 35, second color developing layer 36 and third color developing layer 37, etc.) consisting of liquid crystals 9 dispersed into a solid 8 for dispersedly supporting the liquid crystals and driving electrodes (for example, first driving electrodes 33 consisting of ITO and second driving electrodes 34 consisting of ITO, etc.) which are connected to substrate side electrodes 33, 32, etc., for supplying voltages via electrode contact openings formed in these color developing layers and pixel electrodes 3 on a glass substrate 1 formed with the pixel electrodes 3 and the substrate side electrodes 31, 32, etc., for supplying the voltages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel which is capable of color display without causing parallax, and which is reduced in size and weight.

At present, there has been a remarkable progress in liquid crystal display technology, and accordingly, there is a demand for the realization of a small and light color liquid crystal display panel. In order to cope with this, the transmission efficiency of light is improved. There is a need for improvements in the type display panel and the color reflective display panel that does not use a backlight.

[0003]

2. Description of the Related Art FIG. 23 is a side sectional view showing a main part of a standard liquid crystal display panel for explaining a conventional technique. In the figure, 1 and 2 are a glass substrate, 3 is a pixel electrode, 4 is a common electrode facing the pixel electrode, and 5 is a liquid crystal layer. In general, various color liquid crystal display panels have been proposed based on the structure of the illustrated liquid crystal display panel.

As one of the color liquid crystal display panels, liquid crystal display panels having a single color guest-host (GH) liquid crystal, for example, those corresponding to yellow, cyan, and magenta are laminated to form a multi-layered color. A color reflection type display panel which realizes a high quality bright color display is known.

However, according to the above-mentioned conventional technique, since the number of glass substrates is simply six, if the pixel is small, for example, about 300 [μm] depending on the parallax between them, the viewing angle characteristics. There was a problem that was extremely bad.

Therefore, by stacking polymer-dispersed liquid crystals having different operating voltages and applying different voltages to each layer for driving, or by driving by two frequencies, the thickness direction is increased. A technique for selecting a driving layer has also been proposed (if necessary, “BG Wu et a
l. , SID90 DIGEST, pp. 217-21
9, (1990) ").

[0007]

In the case of the conventional example in which the polymer-dispersed liquid crystals having different operating voltages are simply multi-layered, the viewing angle characteristics are deteriorated due to the parallax. The displayed color is limited. (There is cross talk) There are problems such as the drive circuit becoming complicated.

An object of the present invention is to obtain a color liquid crystal display panel which is compact and lightweight, and which can realize good multi-layered color display without parallax with a simple drive circuit.

[0009]

In the present invention, a color forming layer composed of a liquid crystal dispersed and supported in a solid is laminated, and the color formation of each of the laminated color forming layers can be independently controlled. It is basically that there is no glass substrate between the layers.

From the above, in the liquid crystal display panel according to the present invention, (1) the pixel electrode (for example, the pixel electrode 3) and the voltage supply substrate side electrode (for example, the substrate side electrode 31 for supplying voltage) And 32) and the like are formed on a transparent substrate (eg, glass substrate 1) on which a color forming layer (eg, a liquid crystal 9) dispersed and supported in a solid (eg, a solid 8 that disperses and supports liquid crystal). One coloring layer 35, second coloring layer 36,
The third color developing layer 37 and the like) and the electrode contact openings (for example, the electrode contact openings 35A and 35B and the like: see FIG. 6) formed in the color developing layer, and are connected to the voltage supply substrate side electrode and the pixel electrode. Corresponding to the drive electrodes (for example, the first drive electrode 33 made of ITO and the ITO
A plurality of layers such as the second drive electrode 34) are sequentially laminated, or

(2) In the above (1), the solid which disperses and supports the liquid crystal is composed of a cross-linked photosensitive polymer, or

(3) In the above (1), the solid that disperses and supports the liquid crystal is made of an etchable material, or

(4) In the above (1), the solid that disperses and supports the liquid crystal is composed of a polymerized prepolymer, or

(5) The above (1) is characterized in that the dichroic dyes of different colors such as yellow, cyan or magenta are separately added to the plurality of color forming layers, or Alternatively,

(6) In the above (1), a substrate in which a coloring layer made of only liquid crystal is sealed is formed on the side opposite to the transparent substrate on which the pixel electrode and the substrate side electrode for voltage supply are formed. Or

(7) In the above (6), the color forming layer is characterized in that a three-dimensional network polymer is interposed.

[0017]

By adopting the above-mentioned means, the drive electrode penetrates the solid-state color-supporting liquid crystal coloring layer and is electrically and mechanically connected to the voltage supply substrate side electrode on the substrate. Since it is basically unnecessary to form a substrate for supporting the drive electrode on the side opposite to the substrate, the liquid crystal display panel becomes small and lightweight. Further, even if the layers are formed, it is not necessary to insert a transparent substrate at the interface of each layer, and therefore, parallax does not occur between the coloring layers. Furthermore,
Since each color forming layer can be controlled to operate completely independently and multi-frequency driving is not performed, the driving circuit can be simple.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cutaway side view of a main portion of a color liquid crystal display panel for explaining a first embodiment of the product according to the present invention, and the same symbols as those used in FIG. They represent parts or have the same meaning.

In the figure, 8 is a solid which disperses and supports a liquid crystal, 9 is a liquid crystal which is dispersively supported in a solid 8, 31 and 3
2 is a substrate side electrode for supplying voltage, 33 is ITO (i
a first drive electrode made of n tin tin oxide), 34 a second drive electrode made of ITO, 35 a first coloring layer, 36 a second coloring layer, and 37 a third coloring layer. .

In this embodiment, there is no member corresponding to the glass substrate 2 found in the liquid crystal display panel shown in FIG. 23, and the liquid crystal display panel, such as yellow, cyan,
It is lightweight because there is no glass substrate at the lamination interface of each liquid crystal display panel as in the case of laminating those corresponding to each magenta to form a multi-layered color. From the viewpoint of weight reduction, in the first embodiment, the first coloring layer 3 on the glass substrate 1 on which each electrode such as the pixel electrode 3 is formed.
If only No. 5 is used and the entire surface is covered with Al electrodes to form a common electrode, the lightest liquid crystal display panel can be constructed although it is monochrome.

The first coloring layer 35 is composed of a liquid crystal layer in which a liquid crystal 9 containing magenta which is a dichroic dye is dispersed and supported in a solid 8. The second coloring layer 36 is composed of a liquid crystal layer in which a liquid crystal 9 to which cyan which is also a dichroic dye is added is dispersed and supported in a solid 8. The third coloring layer 37 is composed of a liquid crystal layer in which a liquid crystal 9 to which yellow which is also a dichroic dye is added is dispersed and supported in a solid 8.

To the pixel electrode 3, the first drive electrode 33, and the second drive electrode 34, a voltage having a voltage difference required to drive each color forming layer 35, 36, 37 is applied.

That is, the first coloring layer 35 is driven by the voltage supplied to the pixel electrode 3. The second coloring layer 36 is driven by the voltage supplied to the first driving electrode 33 penetrating the first coloring layer 35 and connected to the substrate-side electrode 31. The third coloring layer 37 is the first coloring layer 35 and the first driving electrode 3
It is driven by the voltage supplied to the second driving electrode 34 which is connected to the substrate side electrode 32 through the third and second coloring layers 36.

FIG. 2 is an explanatory plan view of an essential part for explaining the structure of the electrode formed on the glass substrate, and FIG. 3 is a sectional side view of the essential part seen in the direction of arrow X shown in FIG. Therefore, in each drawing, the same symbols as those used in FIG. 1 represent the same parts or have the same meanings.

In the figure, 41, 42 and 43 are scan side electrodes, 44 is a data side electrode, and 46, 47 and 48 are thin film switching elements. As a thin film switching element, a TFT (thin
film transistor) is used.

Each of the thin film switching elements 46, 47 and 48 is a second drive electrode via the electrode 32, a first drive electrode via the electrode 31, and a third color forming layer on the pixel electrode 3, respectively. A voltage for driving the second coloring layer and the first coloring layer is supplied.

FIGS. 4 to 11 are side sectional views showing essential parts of a liquid crystal display panel in process steps for explaining the first embodiment of the method according to the present invention. Will be described with reference to. The same symbols as those used in FIGS. 1 to 3 represent the same parts or have the same meanings. In addition, here, it is assumed that the formation of the electrodes 3, 31, 32, etc. on the glass substrate 1 has already been completed by applying a normal technique.

See FIG. 4. 4- (1) Photosensitizers such as dichromates and diazo resins, or photosensitive polyvinyl alcohols containing styrylpyridinium (SBQ) groups introduced therein.
A liquid crystal 8 in which a magenta dichroic dye is dissolved is added to an aqueous solution of (hol: PVA), and the mixed solution is emulsified by a homogenizer or the like to obtain an emulsified solution.

4- (2) After applying the emulsified solution prepared in the step 4- (1) on the glass substrate 1 using a screen printing device or the like,
The water is evaporated to form the first coloring layer 35 having a thickness of, for example, 8 [μm]. When the emulsified solution solidifies, it becomes a solid 9.

See FIG. 5 5- (1) Through the photo mask 51, ultraviolet rays are radiated to selectively cross-link the first color forming layer 35 except right above the electrodes 31 and 32.

See FIG. 6 6- (1) When washed off with warm water, the non-crosslinked portions of the first color forming layer 35 are removed to form the electrode contact openings 35A and 35B.

See FIG. 7 7- (1) By applying the sputtering method, the thickness 100
A first drive electrode 33 made of ITO of [nm] is formed. In addition, not only the sputtering method is applied to the formation of the ITO film, but also a transparent conductive ink such as X-101 is used.
(Product name: Sumitomo Metal Mining Co., Ltd.) may be applied.

See FIG. 8 8- (1) A resist film 52 is formed on the entire surface by applying a resist process in the lithography technique.

See FIG. 9 9- (1) By irradiating ultraviolet rays through the photo mask 53,
The resist film 52 is selectively exposed.

10- (1) The resist film 52 is patterned by development. The patterned resist film 52 serves as a mask when processing the first drive electrode 33.

See FIG. 11 11- (1) By applying a wet etching method containing ferric chloride as a main component, the etchant is used to etch the first drive electrode 33 made of ITO to separate it into pixel units. At the same time, the opening 35B for exposing the electrode 32 is formed again. Of course, a dry etching method may be applied to the etching in this case. 11- (2) After that, the steps described with reference to FIGS. 4 to 11 are repeated to complete the color liquid crystal display panel having the configuration shown in FIG.

FIGS. 12 to 14 are side sectional views showing an essential part of a liquid crystal display panel in the process steps for explaining the second embodiment of the method according to the present invention. Will be described with reference to. The same symbols as those used in FIGS. 1 to 11 represent the same parts or have the same meanings (in order to carry out this second method, “Y.H.
irai, et al, Proc. of SPIE, V
ol. 1257, pp. 2-8, (1990) "is helpful).

See FIG. 12 12- (1) A mixture of an acrylate prepolymer, a photopolymerization initiator, a liquid crystal, a dichroic dye, etc. is applied to the glass substrate 1 to form a first color forming layer 55.

See FIG. 13 13- (1) Through the photo mask 51, ultraviolet rays are irradiated to selectively photopolymerize the first color forming layer 55 except right above the electrodes 31 and 32.

See FIG. 14 14- (1) When immersed in a solvent and developed, the portions not photopolymerized in the first color forming layer 35 are removed to form the electrode contact openings 55A and 55B. 14- (2) After this, although the material of the color-developing layer is different, the steps similar to the first method are performed to complete the process.

FIG. 15 to FIG. 18 are side sectional views showing the main part of the liquid crystal display panel in the process steps for explaining the third embodiment of the method according to the present invention. Will be described with reference to. The same symbols as those used in FIGS. 1 to 14 represent the same parts or have the same meanings.

15- (1) PVA or polymethylmethacrylate (polymethylmethacrylate) on the glass substrate 1.
A first coloring layer 65 in which a liquid crystal is dispersed and supported by an etchable solid such as PMMA) is formed. 15- (2) The photoresist film 66 is formed by applying a resist process in a normal lithography technique.

16- (1) The resist film 66 is exposed through the photo mask 51 except right above the electrodes 31 and 32 to selectively cure it. 16- (2) The resist film 66 is developed to obtain a pattern for forming an electrode contact opening.

See FIG. 17 17- (1) By immersing the liquid crystal described in the above step 15- (1) in a solid solvent in which dispersion is supported, and performing wet etching, the portion not covered with the resist film 66 is removed. Then, the electrode contact openings 65A and 65B are formed.

See FIG. 18 18- (1) The resist film 66 is removed, and thereafter, the steps similar to those of the first method such as formation of the first drive electrode are completed.

FIG. 19 and FIG. 20 are side sectional views showing the main part of the liquid crystal display panel in the process steps for explaining the fourth embodiment of the method according to the present invention. Will be described with reference to. The same symbols as those used in FIGS. 1 to 18 represent the same parts or have the same meanings.

See FIG. 19 19- (1) The emulsified solution of the liquid crystal used in the first method, or the liquid mixture of the liquid crystal and the dichroic dye dissolved in the UV-polymerizable prepolymer is placed on the printing roller 70. It is applied to the required pattern of the coloring layer 75.

See FIG. 20. 20- (1) The coloring layer 75 on the printing roller 70 is printed and transferred onto the glass substrate 1. Since the above-mentioned liquid crystal emulsified solution or the liquid mixture of liquid crystal and dichroic dye dissolved in the UV-polymerizable prepolymer is ink-like, offset printing or screen printing can be arbitrarily performed. 20- (2) The color-developing layer 75 transferred by printing is cured.

FIG. 21 is a sectional side view of a main part of a color liquid crystal display panel for explaining the second embodiment of the product according to the present invention. The same symbols as those used in FIG. Or have the same meaning.

In the figure, 87 is a third color developing layer, 88 is a three-dimensional network polymer, 89 is a common electrode facing the pixel electrode, and 90 is a glass substrate. In this embodiment, as the third coloring layer 87, a three-dimensional network polymer is formed in the liquid crystal to which the dichroic dye is added.

When a mechanically strong material such as glass or a plastic film is used as a member for supporting the common electrode facing the pixel electrode, it is preferable to use a material having no self-supporting property as the color forming layer adjacent to the electrode. Possible (if desired, "T. Fujisawa, et al.,
JAPAN DISPLAY '89, pp. 690-6
93, (1989) ").

In comparison with the first embodiment, the second embodiment has
The third color-forming layer is not a liquid crystal that is dispersed and supported in a solid,
Even though a three-dimensional network polymer is interposed, it is composed of liquid crystal itself, so to support it,
Although the glass substrate 90 is used, even if it is, for example, it is much lighter than a liquid crystal display panel in which layers corresponding to each of yellow, cyan, and magenta of the liquid crystal display panel are laminated to form a multi-layer color. Is.

Comparing the second embodiment and the first embodiment,
In the second embodiment, since the liquid crystal is brought into contact with the glass substrate 90, it is easy to bring the glass substrate 90 and the liquid crystal into close contact with each other.

FIG. 22 is a side sectional view showing a main part of a color liquid crystal display panel for explaining the third embodiment of the product according to the present invention. The same symbols as those used in FIG. Or have the same meaning.

In this embodiment, as the third coloring layer 97,
This is an example in which a nematic liquid crystal, a chiral, and a phase transition type liquid crystal to which a dichroic dye is added are used, and the three-dimensional network polymer as in the second embodiment is not used.

Also in the third embodiment, since the glass substrate 90 and the liquid crystal are in contact with each other, it is easy to bring the glass substrate 90 and the liquid crystal into close contact with each other, as in the second embodiment.

[0057]

In the liquid crystal display panel and the method for manufacturing the same according to the present invention, the liquid crystal is dispersed and supported in a solid state on a transparent substrate on which pixel electrodes, voltage supply substrate side electrodes and the like are formed. A plurality of layers of drive electrodes, which are connected to the voltage supply substrate side electrodes via the color forming layer and the electrode contact openings formed in the color forming layer and correspond to the pixel electrodes, are sequentially stacked.

By adopting the above configuration, the drive electrode penetrates the color forming layer made of liquid crystal that is solidly dispersed and supported, and is electrically and mechanically connected to the voltage supply substrate side electrode on the substrate. Since it is basically unnecessary to form a substrate for supporting the drive electrode on the side opposite to the substrate,
The liquid crystal display panel will be small and lightweight. Further, even if the layers are formed, it is not necessary to insert a transparent substrate at the interface of each layer, and therefore, parallax does not occur between the coloring layers. Furthermore, each color-forming layer can be controlled to operate completely independently, and multi-frequency driving is not performed, so that the driving circuit can be simple.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a main part of a color liquid crystal display panel for explaining a first embodiment of an object according to the present invention.

FIG. 2 is a plan view of a principal part for explaining a configuration of an electrode formed on a glass substrate.

FIG. 3 is a side sectional view of a main part as seen in a direction of an arrow X seen in FIG.

FIG. 4 is a side sectional view showing a main part of a liquid crystal display panel at a process step for explaining a first embodiment of a method according to the present invention.

FIG. 5 is a side sectional view showing a main part of a liquid crystal display panel at a process step for explaining the first embodiment of the method of the present invention.

FIG. 6 is a side sectional view showing a main part of a liquid crystal display panel at a process step for explaining a first embodiment of a method according to the present invention.

FIG. 7 is a side sectional view showing an essential part of a liquid crystal display panel at a process key point for explaining a first embodiment of a method according to the present invention.

FIG. 8 is a side sectional view showing an essential part of a liquid crystal display panel at a process step for explaining a first embodiment of a method according to the present invention.

FIG. 9 is a side sectional view showing an essential part of a liquid crystal display panel at a process step for explaining a first embodiment of a method according to the present invention.

FIG. 10 is a side sectional view showing a main part of a liquid crystal display panel in a process main part for explaining a first embodiment of a method according to the present invention.

FIG. 11 is a side sectional view showing a main part of a liquid crystal display panel in a process main part for explaining a first embodiment of a method according to the present invention.

FIG. 12 is a side sectional view showing a main part of a liquid crystal display panel in a process key part for explaining a second embodiment of the method according to the present invention.

FIG. 13 is a cutaway side view of an essential part showing a liquid crystal display panel in a process key point for explaining a second embodiment of the method according to the present invention.

FIG. 14 is a side sectional view showing a main part of a liquid crystal display panel in a process main part for explaining a second embodiment of the method according to the present invention.

FIG. 15 is a side sectional view showing a main part of a liquid crystal display panel in a process main part for explaining a third embodiment of a method according to the present invention.

FIG. 16 is a side sectional view showing a main part of a liquid crystal display panel in a process step for explaining a third embodiment of the method according to the present invention.

FIG. 17 is a side sectional view showing an essential part of a liquid crystal display panel at a process step for explaining a third embodiment of the method according to the present invention.

FIG. 18 is a side sectional view showing an essential part of a liquid crystal display panel in a process essential part for explaining a third embodiment of the method according to the present invention.

FIG. 19 is a side sectional view showing an essential part of a liquid crystal display panel at a process step for explaining a fourth embodiment of the method of the present invention.

FIG. 20 is a side sectional view showing an essential part of a liquid crystal display panel at a process step for explaining a fourth embodiment of the method according to the present invention.

FIG. 21 is a side sectional view showing a main part of a color liquid crystal display panel for explaining a second embodiment of the product according to the present invention.

FIG. 22 is a side sectional view showing a main part of a color liquid crystal display panel for explaining a third embodiment of the product according to the present invention.

FIG. 23 is a side sectional view showing a main part of a standard liquid crystal display panel for explaining a conventional technique.

[Explanation of symbols]

 1 Glass Substrate 2 Glass Substrate 3 Pixel Electrode 4 Common Electrode 5 Facing Pixel Electrode 5 Liquid Crystal Layer 8 Solid 9 Dispersing and Supporting Liquid Crystal 9 Liquid Crystal 31 Dispersed and Supported in Solid 8 Substrate Side Electrode 32 for Supplying Voltage 32 Voltage Substrate side electrode for supplying 33 First drive electrode 34 made of ITO 34 Second drive electrode 35 made of ITO 35 First color development layer 36 Second color development layer 37 Third color development layer 41 Scan side electrode 42 Scan Side electrode 43 scan side electrode 44 data side electrode 46 thin film switching element 47 thin film switching element 48 thin film switching element

Claims (7)

[Claims] 1. A color forming layer made of liquid crystal dispersed and supported in a solid state on a transparent substrate on which a pixel electrode and a voltage supply substrate side electrode are formed, and an electrode contact opening formed in the color forming layer. A liquid crystal display panel, wherein a plurality of layers of driving electrodes connected to the voltage supply substrate side electrodes and corresponding to the pixel electrodes are sequentially stacked. 2. The liquid crystal display panel according to claim 1, wherein the solid material which disperses and supports the liquid crystal is composed of a crosslinked photosensitive polymer. 3. The liquid crystal display panel according to claim 1, wherein the solid material that disperses and supports the liquid crystal is made of an etchable substance. 4. The liquid crystal display panel according to claim 1, wherein the solid material that supports the liquid crystal in a dispersed state is formed of a polymerized prepolymer. 5. A liquid crystal display panel according to claim 1, wherein dichroic dyes of different colors such as yellow, cyan and magenta are separately added to the plurality of color forming layers. 6. A substrate in which a color forming layer made of only liquid crystal is sealed is formed on a side opposite to a transparent substrate on which a pixel electrode and a voltage supply substrate side electrode are formed. The liquid crystal display panel described. 7. The liquid crystal display panel according to claim 6, wherein a three-dimensional network polymer is interposed in the color forming layer.