JPH0695118A - Liquid crystal display plate - Google Patents

Abstract

PURPOSE:To enhance the brightness as the liquid crystal display plate by efficiently utilizing a back light for the black matrix type liquid crystal display plate. CONSTITUTION:This liquid crystal display plate is constituted by disposing a first liquid crystal plate constituted by coating the plural parallel transparent electrodes formed on the other surface of a transparent glass substrate attached with a polarizing plate on one surface with an oriented film and a second liquid crystal plate 2 constituted by coating the plural parallel transparent electrodes formed via a black matrix on the other surface of a transparent glass substrate attached with a polarizing plate on one surface with an oriented film while maintaining a required gap in such a manner that the polarization directions of the respective polarizing plates and the transparent electrodes intersect orthogonally with each other and that the oriented films face each other, then encapsulating liquid crystalline bodies into a gap. The above-mentioned liquid crystal plates 21, 22 are provided with means capable of preventing the liquid crystalline bodies 13 existing in the regions corresponding to the non-opening parts of a black matrix 162 having the opening windows in the regions corresponding to the respective intersected points of the transparent electrodes 122, 165 from receiving the influence of the oriented films.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a black matrix type liquid crystal display panel, and more particularly to a liquid crystal display panel which realizes high brightness as a liquid crystal display panel by efficiently utilizing a backlight.

In the field of personal computers, word processors, etc., conventional cathode ray tubes (CR) are used as information display means.
T) As an alternative to the display, a liquid crystal display device that can realize thinness, lightness, and low power consumption has been widely used.

In a liquid crystal display panel constituting such a liquid crystal display device, an STN (Supe) is constructed by forming a simple electrode line matrix with two transparent substrates and then enclosing a liquid crystal body.
r Twist Nematic) A liquid crystal display panel, for example, an electrode line matrix where each intersection does not short-circuit on one transparent substrate, and a thin film transistor connected to the X and Y electrode lines in the vicinity of each intersection is patterned, and then another transparent substrate is formed. And a TFT (Thin Film Transistor) liquid crystal display panel in which a liquid crystal body is sealed between the two.

[0004]

2. Description of the Related Art FIG. 6 is a diagram schematically illustrating an example of a general configuration of a conventional liquid crystal display plate, and FIG. 7 is a diagram illustrating the operation of the liquid crystal display plate in principle.

In FIG. 6, which is a partially enlarged cross-sectional view, the liquid crystal display panel 1 includes a first liquid crystal panel 12 having a first polarizing plate 11 attached to the surface of the backlight L ₁ side and a transmitted light L _2. The second liquid crystal plate 16 having the second polarizing plate 15 attached to the side surface, that is, the operator observation side surface, and the liquid crystal body 13 enclosed between the first and second liquid crystal plates 12 and 16. It is configured.

In the first liquid crystal plate 12, a plurality of transparent electrodes 122 having the longitudinal direction of arrow A are formed in parallel on one inner surface (upper surface in the figure) of a transparent glass substrate 121, and then a liquid crystal molecule array is formed. A first alignment film 123 made of a polyimide resin for adjustment is formed by coating so as to cover each transparent electrode 122.

The second liquid crystal plate 16 is a transparent glass substrate 16.
A black mask made of chrome (Cr) or the like having an opening window 162a at a predetermined position described later on one inner surface (lower surface in the figure) of 1.
A color filter 163 is layered in the area of the opening 162a and the opening 162a, and the entire surface of the black mask 162 including the color filter 163 is covered with a top coat 164 as a protective film, and then the surface of the top coat 164 (see FIG. Then, a plurality of transparent electrodes 165 having arrow B in the longitudinal direction are formed in parallel on the lower surface), and a second alignment film 166 made of polyimide resin for adjusting the alignment of liquid crystal molecules is further provided so as to cover each transparent electrode 165. It is formed by coating.

Each opening window 16 of the black mask 162
2a is formed in the entire intersection area of the transparent electrodes 122 and 165 when the first liquid crystal plate 12 and the second liquid crystal plate 16 are positioned and opposed to each other.

Therefore, the first and second alignment films 123 and 16 are formed.
The first and second liquid crystal plates 12 and 16 are positioned and fixed by a frame (not shown) so as to face each other with a predetermined gap, and then the liquid crystal body 13 is sealed in the gap region.
The required liquid crystal display plate 1 can be constructed by attaching the first and second polarizing plates 11 and 15 to the outer surfaces of the second liquid crystal plates 11 and 16 so that their polarization directions are orthogonal to each other. .

In such a liquid crystal display panel 1, the first liquid crystal panel 12
The backlight L _{1 which} is incident from the entire surface of the black mask 16, that is, the entire surface on the side of the first polarizing plate 11 is located in the matrix of the black mask 16 described above, and the opening window 162a and the color filter 16
Since the light can be transmitted only in the region 3, the required characters or symbols can be displayed by blocking or passing the light transmitted through the opening windows 162a.

FIG. 7 for explaining the operation of the liquid crystal display panel is a partially enlarged view of the cross section of FIG. 6, and (7-1) shows the case where the voltage between the transparent electrodes 122 and 165 is zero, and Shows the state when only the light L ₁ is turned on, and (7-2)
Shows the state when a required voltage is applied between the transparent electrodes 122 and 165 when the backlight L _{1 is} turned on.

In the figure, the same members as those in FIG. 6 are represented by the same symbols. That is, in (7-1), the backlight L ₁ becomes only the light L ₁ ′ which is polarized by the first polarizing plate 11 in the direction along the paper surface, for example, and passes through the first liquid crystal plate 12, but The light L whose alignment of liquid crystal molecules is arranged by the alignment film 123
_Since the polarization direction of 1'is rotated by 90 degrees by the liquid crystal body 13, it passes through the color filter formed in the opening window 162a of the black mask 162, and then the second polarizing plate 15 has the polarization direction in the thickness direction of the paper. Can be transmitted and can be transmitted light L ₂ transmitted through the liquid crystal display panel 1.

On the other hand, when a required voltage is applied between the transparent electrodes 122 and 165, the regions where the electrodes 122 and 165 face each other, in other words, the liquid crystal molecule alignment direction of the liquid crystal molecules located in all the intersection regions of the electrodes 122 and 165 is (7-2). The light L ₁ ′ which is polarized by the first polarizing plate 11 in the direction along the plane of the drawing and is transmitted through the first liquid crystal plate 12 is transmitted through the second polarizing plate 15 as shown in FIG. As a result, the observer located above the second polarizing plate 15 cannot see it as the transmitted light L ₂ .

Therefore, a desired character or symbol can be displayed by controlling the voltage applied between the electrodes 122 and 165 for each area of all the intersections to emit or block the transmitted light L ₂ .

[0015]

However, in the conventional liquid crystal display panel, the transparent electrodes 122 and 165 do not face each other at the position where they are blocked by the black mask (hereinafter referred to as the non-opening portion). The liquid crystal body always maintains the same twisted state regardless of whether or not the voltage is applied, and as a result, the backlight light incident on the non-opening portion is wasted.

Therefore, in order to increase the display brightness of the liquid crystal display panel, the ratio of the total area of the opening window to the total area of the black mask (hereinafter referred to as the opening ratio of the black mask) is increased or a high brightness backlight is used. The thickness of the color filter is reduced in order to improve the light transmittance, but the aperture ratio of the black mask is currently 50 to 60% in the STN liquid crystal display panel in order to increase the aperture ratio.
The liquid crystal display panel has already been formed to a maximum value of about 40%, which means that it is impossible to further increase the aperture ratio, and there is a problem in that power consumption increases when a high brightness backlight is used. Further, there is a problem in that the hue and the color purity are lowered when the color filter is made thin.

[0017]

[Means for Solving the Problems] The above problems are
The first liquid crystal plate having a plurality of parallel transparent electrodes formed on the other surface of the transparent glass substrate having the polarizing plate attached thereto and covered with an alignment film, and the second polarizing plate attached to one surface thereof. A second liquid crystal plate having a plurality of parallel transparent electrodes formed through a black mask on the other surface of the transparent glass substrate and covered with an alignment film, and a polarization direction of each polarizing plate. A liquid crystal display panel, comprising: a liquid crystal display panel, wherein a liquid crystal body is sealed in a predetermined gap so that each alignment film faces each other in a direction orthogonal to each transparent electrode. The liquid crystal plate of (1) has a means for making a liquid crystal body located in a region corresponding to the non-opening portion of the black mask having an opening window in a region corresponding to each intersection of the transparent electrodes so as not to be affected by the alignment film. On the LCD panel that is configured with It is achieved me.

[0018]

When the liquid crystal display panel is configured so that the backlight incident on the non-aperture area of the black mask can be effectively used, the liquid crystal display can be displayed without changing the aperture ratio of the black mask, the backlight, the color filter film thickness and the like. The display brightness as a plate can be increased from the current level.

Therefore, in the present invention, by randomizing the molecular alignment direction of the liquid crystal located in the area corresponding to the non-opening portion of the black mask, the backlight incident on the area is scattered and the amount of light incident on the opening portion. I am trying to increase.

This means that the amount of light emitted from the liquid crystal display plate is increased, and as a result, the display brightness of the liquid crystal display plate is increased. Therefore, it is possible to realize a liquid crystal display panel having a large display brightness while suppressing an increase in power consumption, a decrease in hue and a color purity.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 which is a sectional view similar to FIG. 7 is a principle diagram for explaining the constitution of a liquid crystal display panel according to the present invention together with its action. Like FIG. 7, (1-1) shows only the backlight L ₁ lit. The state when the transparent electrodes 122 and 165 are applied is shown, and (1-2) shows the state when a required voltage is applied between the transparent electrodes 122 and 165.

FIG. 2 is a diagram for explaining a constitutional example of a liquid crystal display plate for realizing the present invention, FIG. 3 is a diagram for explaining a method for removing the alignment film of FIG. 2, and FIG. 4 is another constitutional example of the liquid crystal display plate. FIG. 5 is a diagram illustrating the configuration method thereof, and FIG. 5 is a diagram illustrating a third configuration example of the liquid crystal display panel together with the configuration method thereof.

In each of the drawings, the case of a liquid crystal display panel having the same structure as in FIGS. 6 and 7 is taken as an example, and therefore, the same object members as those in FIGS. 6 and 7 are represented by the same symbols. There is.

In (1-1) of FIG. 1, the liquid crystal display plate 2 has a first liquid crystal plate 21 having a first polarizing plate 11 attached to the surface of the backlight L ₁ side and a surface of the transmitted light L ₂ side. It is composed of a second liquid crystal plate 22 to which a second polarizing plate 15 is attached, and a liquid crystal body 13 enclosed between them.

Then, the first and second liquid crystal plates 21 and 22
7 is different from the first and second liquid crystal plates 12 and 16 in FIG. 7 in that the region of the liquid crystal body 13 sandwiched between the first and second liquid crystal plates 21 and 22 corresponds to the opening window of the black mask 162. In other words, it is formed in the region C affected by the alignment films 123, 166 in the color filter corresponding region, and in the region D unaffected by the alignment films 123, 166 in the non-opening region of the black mask 162. .

In such a liquid crystal display panel 2, the liquid crystal molecules of the liquid crystal body 13 located in the area C have their respective alignment films 123 'and 166'.
Although the liquid crystal molecules of the liquid crystal body 13 located in the area D are not aligned due to the influence of the alignment film, they are oriented in a random direction.

Therefore, the backlight which becomes the light L ₁ ′ which is polarized in the direction along the plane of the drawing by the first polarizing plate 11 and which is transmitted through the first liquid crystal plate 21 is, as shown in FIG.
It swirls to form transmitted light L ₂ , and in region D, it is scattered by randomized liquid crystal molecules, so a part of the scattered light that enters region C can be extracted as transmitted light L _{2, and} as a result, The transmitted light L ₂ can be increased more than in the case of FIG. 7.

Therefore, as described with reference to FIG. 7, the electrodes 122, 16 are
By controlling the voltage applied between 5 for each of all the intersection areas, and transmitting or blocking the transmitted light L ₂ , it is possible to display a desired character or symbol with a brightness higher than that in the case of FIG. 7.

In FIG. 2, (2-1) is the backlight L in which an example of means for eliminating the influence of the alignment film in the non-opening region (the above-mentioned region D) of the black mask is realized by removing the alignment film. Shows the state when only ₁ is lit, and (2-
2) shows the state when the required voltage is applied between the electrodes 122 and 165.

In FIG. 2, the liquid crystal display plate 3 includes a first liquid crystal plate 31 having a first polarizing plate 11 attached to the surface of the backlight L ₁ side.
A second liquid crystal plate 32 having a second polarizing plate 15 attached to the surface of the transmitted light L ₂ side, and a liquid crystal body 13.

Then, the first and second liquid crystal plates 31, 32
Is different from the first and second liquid crystal plates 12 and 16 in FIG. 7 in that each alignment film formed on the first and second liquid crystal plates 12 and 16 is different.
Alignment film 31 formed by limiting 123,166 only to the area corresponding to the opening window of the black mask 162, that is, the area corresponding to the color filter 31
This is a point replaced with 1,321.

In such a liquid crystal display panel 3, a black mask is used.
The liquid crystal molecules of the liquid crystal 13 in the area corresponding to the opening window of 162 are shown in FIG.
Although aligned in the same manner, the alignment direction of the liquid crystal molecules in the region corresponding to the non-opening portion is randomized as in FIG.

Therefore, as in the case described with reference to FIG. 1, the transmitted light L ₂ emitted from the liquid crystal display plate 3 can be increased more than in the case of FIG. Alignment films 311, 321 described in FIG.
In FIG. 3 showing an example of a method of forming the
The second liquid crystal plate 16 on which the black mask 162 is formed.
The case where the alignment film 321 is formed by using is explained, but the description of the alignment film 311 will be omitted because it can be similarly formed by using the first liquid crystal plate 12 of FIG.

In FIG. 3, (3-1) is the second liquid crystal plate in FIG.
16 is an upside down representation of a single unit,
161 is a glass substrate, 162 is a black mask, 163 is a color filter, 164 is a top coat, 165 is a transparent electrode, 16
6 represents the alignment film.

Further, (3-2) shows a method of forming the alignment film 321.
(3-3) shows a state after the alignment film 321 is formed.
Then, as shown in (3-2), on the alignment film 166 made of polyimide resin of the second liquid crystal plate 16 in the state of (3-1), for example, on the transparent glass substrate, only the non-opening portion of the black mask 162 is formed. After a mask 35 having a chrome (Cr) film or the like formed thereon is positioned and mounted so as to form an opening window 35a, ozone (O ₃ ) is irradiated as shown by arrow E by an ozone asher method to open the opening window 35a. By removing the alignment film 166 in the region,
(3-3) A second liquid crystal plate having the alignment film 321 shown in FIG.
You can get 32.

The first film having the alignment film 311 described in FIG.
The liquid crystal plate 31 can also be similarly formed by using the first liquid crystal plate 12 shown in FIG. FIG. 4 showing another configuration example of the liquid crystal display panel shows an example in which the second liquid crystal panel 16 on which the black mask 162 of FIG. 7 is formed is used as in FIG. 1) is the same as (3-1) in FIG.

Further, (4-2) and (4-3) show a method of forming means for eliminating the influence of the alignment film, and (4-4) shows a state after completion. Then, as shown in (4-2), for example, a photosensitive polyimide resin film 36 is applied on the alignment film 166 of the second liquid crystal plate 16 in the state of (4-1) by a spinner or a roll coater, and then, as shown in FIG. The mask 35 described in 1) is positioned and mounted, and the photosensitive polyimide resin film 36 is aligned by a photo-etching method in which ultraviolet rays are irradiated as shown by arrow F as shown in (4-3).
166 A second liquid crystal plate 41 corresponding to the second liquid crystal plate 22 of FIG. 1 is formed by curing and remaining as a thin film-shaped protruding portion 411 at a position corresponding to the non-opening portion of the black mask 162. Four)
Can be obtained as shown in.

By applying the same photoetching method to the first liquid crystal plate 12 in FIG. 7, a first liquid crystal plate (not shown) corresponding to the second liquid crystal plate 41 can be obtained. The first liquid crystal plate and the second liquid crystal plate (not shown).
In the liquid crystal display panel constituted by facing 41, the alignment film 166 is covered with the thin film-like protrusions 411 formed in the non-opening portion of the black mask 162, and therefore the influence as the alignment film 166 is eliminated. As a result, the effect described with reference to FIG. 1 can be obtained.

FIG. 5 shows a protrusion 51 made of a light-scattering material such as a plastic spacer or glass fiber at the same position as the protrusion 411 of the photosensitive polyimide resin film 36 described in FIG.
A liquid crystal display plate 5 is composed of first and second liquid crystal plates 51 and 52 formed by attaching 1 by means of adhesion or the like, a liquid crystal body 13 and first and second polarizing plates 11 and 15. is there.

In the liquid crystal display panel 5, since the backlight L ₁ entering the liquid crystal body 13 is scattered by the protrusion 511 made of each light scattering material and becomes the transmitted light L ₂ , the aperture ratio of the black mask is increased. Similarly to the case described with reference to FIG. 1, the display brightness of the liquid crystal display panel can be increased from the current state without changing the backlight, the color filter, the thickness of the color filter, or the like.

[0041]

As described above, according to the present invention, it is possible to provide a liquid crystal display panel which realizes high brightness as a liquid crystal display panel by efficiently utilizing a backlight.

[Brief description of drawings]

FIG. 1 is a principle diagram for explaining the configuration of a liquid crystal display panel according to the present invention together with the operation.

FIG. 2 is a diagram illustrating a configuration example of a liquid crystal display panel that realizes the present invention.

FIG. 3 is a diagram illustrating a method for removing an alignment film in FIG.

FIG. 4 is a diagram for explaining another configuration example of the liquid crystal display plate together with the configuration method thereof.

FIG. 5 is a diagram illustrating a third configuration example of a liquid crystal display board together with a method of configuring the same.

FIG. 6 is a diagram schematically illustrating a general configuration example as a conventional liquid crystal display panel.

FIG. 7 is a diagram for explaining the principle of operation as a liquid crystal display plate.

[Explanation of symbols]

 2,3,5 liquid crystal display plate 11 first polarizing plate 13 liquid crystal body 15 second polarizing plate 16,22,32,41,52 second liquid crystal plate 21,31,51 first liquid crystal plate 35 mask 35a Opening window 36 Photosensitive polyimide resin layer 122,165 Transparent electrode 123,166, 123 ′, 166 ′, 311,321 Alignment film 161 Glass substrate 162 Black mask 163 Color filter 164 Top coat 411,511 Projection

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiichi Yamazaki 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited

Claims (4)

[Claims] 1. A first liquid crystal plate in which a plurality of parallel transparent electrodes formed on the other surface of a transparent glass substrate having a first polarizing plate attached to one surface thereof are covered with an alignment film, A second liquid crystal plate having a transparent glass substrate having a second polarizing plate attached to one surface thereof, and a plurality of parallel transparent electrodes formed through a black mask on the other surface of the transparent glass substrate and covered with an alignment film; , A liquid crystal display panel in which a liquid crystal body is sealed in the gaps after arranging them so that the alignment films face each other in the direction orthogonal to the polarization direction of each polarizing plate and each transparent electrode. The first and second liquid crystal plates (21, 22) are transparent electrodes (12
2,165) which has an opening window in the area corresponding to each intersection of the liquid crystal body (13) located in the area corresponding to the non-opening part of the black mask (162) so as not to be affected by the alignment film. A liquid crystal display panel characterized by being configured with. 2. The first liquid crystal plate or the second liquid crystal plate is a means capable of preventing a liquid crystal body located in a region corresponding to the non-opening portion of the black mask according to claim 1 from being affected by the alignment film.
2. A liquid crystal display panel, characterized by being formed by removing an alignment film formed on each of the liquid crystal panel or the corresponding area of both. 3. The first liquid crystal plate or the second liquid crystal plate is a means capable of preventing the liquid crystal body located in the region corresponding to the non-opening portion of the black mask according to claim 1 from being affected by the alignment film.
The liquid crystal characterized in that it is composed of a thin film-shaped protrusion (411) made of a polyimide resin protruding from the alignment film in each corresponding region on the liquid crystal plate or both alignment films. Display board. 4. The first liquid crystal plate or the second liquid crystal plate is a means that can prevent the liquid crystal located in the region corresponding to the non-opening portion of the black mask from being affected by the alignment film.
The liquid crystal display characterized in that each of the corresponding regions on the liquid crystal plate of the liquid crystal plate or both of them is formed with a projection (511) made of a light-scattering material and formed so as to project from the alignment film. Board.