JPH10319383A - Color liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of contrast and chromaticity due to leakage light from a boundary part of orientation in a color liquid crystal display panel. SOLUTION: A light shield film 103 is arranged so that the boundary part C of the orientation becomes the inside (right side in Figure) by a distance much of a half or above of at least a panel gap D than an end edge 108a of a color absorption layer 108, and the light shield film 103 is provided on an incident side of light source light by expanding to a display part side (right side in Figure) than the boundary part C by the distance much of the half or above (>=D/2 μm) of the panel gap D (D μm), and the light made incident from an oblique direction without being shielded by the light shield film 103 in an effective view angle among the light transmitting through an area 111 disturbed in orientation is prevented from passing and transmitting through a part having no color absorption layer 108 and the adjacent color absorption layer of a different color.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color liquid crystal display panel constituting a liquid crystal display device.

[0002]

2. Description of the Related Art In a normal liquid crystal panel, a voltage is applied between a display pixel electrode and a counter electrode to control the orientation of the liquid crystal, thereby displaying a monochrome image. At that time, in order to prevent the light from transmitting through portions other than the display pixel electrodes and lowering the contrast, a region other than the display pixel electrodes was covered with a metal shielding film to perform light shielding. Providing a film on a substrate has a problem in that the cost is increased. In order to solve this problem, Japanese Patent Laid-Open No.
No. 67919 has been developed. In this technology, by controlling the orientation of the liquid crystal in the display pixel electrode and the other region separately, a good display quality can be obtained without providing a light-shielding film as described above. Was realized.

In the technique disclosed in Japanese Patent Application Laid-Open No. 3-267919, as shown in FIG. 3, a thin film switching element array (not shown) in which a plurality of metal wirings are arranged as signal lines 106, an alignment film 104, a transparent electrode 102, an interlayer insulating film. A transparent substrate 105a having a film 107, a transparent electrode 110, an alignment film 10
9, the transparent substrate 105b having the color absorption layer 108 is arranged in parallel, and a twisted nematic liquid crystal is injected between the two transparent substrates 105a and 105b. Reference numeral 101 denotes transparent substrates 105a and 105b.
It is a polarizing plate stuck on. In FIG. 3B, solid arrows indicate rubbing on the array substrate side, and dotted arrows indicate rubbing on the opposing substrate side.

[0004]

However, in the technique shown in FIG. 3, as shown in FIG. 4, an alignment disorder region 111 occurs at the boundary C between the transparent electrode 102 and the alignment film formed on the signal line 106. In the dark operation state of FIG. 4A, light crossing the alignment disorder region 111 is transmitted due to the polarization disorder in the alignment disorder region 111, and there is a problem that the contrast is reduced.

In order to solve such a problem, a technique disclosed in Japanese Patent Application Laid-Open No. 5-224210 is disclosed in FIG.
As shown in (b), the light-shielding film 103 is formed at the boundary C of the alignment film.
Was provided. However, in the color liquid crystal panel having the color absorption layer 108 for performing color display on the counter substrate 105b, in the bright state of FIG. There is a problem that chromaticity and contrast are reduced by transmitting through the absorption layer.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color liquid crystal display panel in which light passing through a region in which the orientation of an alignment film having a different orientation is disturbed does not lower contrast or chromaticity.

[0007]

In order to achieve the above object, a color liquid crystal display panel according to the present invention is a color liquid crystal display panel having an array substrate, a counter substrate, and a light-shielding film. The counter substrate has a display portion on the opposing surface, and liquid crystal is injected between the two, and the liquid crystal is oriented so as to transmit light in the display portion, and other than the display portion. The region is oriented so as not to transmit light, and the boundary between the liquid crystal region oriented so as to transmit the light and the liquid crystal region oriented so as not to transmit the light is the display. The light shielding film is provided inside the display unit, and shields light passing through a region other than the display unit, and is provided to be enlarged inside the display unit.

The boundary between the liquid crystal region oriented so as to transmit the light and the liquid crystal region oriented so as not to transmit the light is formed by at least half of the gap between the substrates. This is set inside the display unit.

The light-shielding film is provided so as to be enlarged inside the display section by more than half of a gap dimension between the two substrates.

The light-shielding film is provided on the substrate on the light incident side.

The liquid crystal is a twisted nematic liquid crystal.

[0012]

In the dark operation state shown in FIG. 5 (a), the light-shielding band 103 provided on the light source light incident side of the boundary portion C of the orientation is the panel out of the light that is going to pass through the region 111 whose orientation is disturbed. Cuts light incident almost perpendicularly to the Width of light shielding film 103 (dimension in the direction along the plane side of substrate 105a)
Is wider than the width of the region 111 in which the orientation is disturbed. The width of the region 111 in which the alignment is disturbed is determined by the variation in the position of the alignment boundary C and the characteristics of the liquid crystal.
A sufficient effect is obtained by setting the width of 03 to at least 3 μm or more.

Next, in the bright operation state shown in FIG. 5B, the light-shielding film 103 moves the boundary portion C of the orientation inside the edge 108a of the color absorbing layer 108 by at least a half of the panel gap D (see FIG. 5B). (Right side in the figure), and a light shielding film 103 is provided on the panel gap D
(D μm), and is provided on the display portion side (right side in the drawing) beyond the boundary portion C by a distance equal to or more than half (≧ D / 2 μm) of (D μm). Of these, it is possible to prevent light that is incident from an oblique direction without being blocked by the light-shielding film 103 within the effective viewing angle from passing through a portion without the color absorption layer 108 or an adjacent color absorption layer of a different color. .

Here, twisted nematic (T
In the case of the N) type liquid crystal panel, since there is a strong viewing angle dependency in principle, the contrast is significantly reduced when viewed at a certain viewing angle or more. As a premise, this range is called the effective viewing angle. In the case of a TN type liquid crystal, the above-mentioned effective viewing angle is usually about ± 30 °.

Further, by disposing the light-shielding film 103 inside the color absorbing layer 108 corresponding to the boundary portion C of the orientation with a distance of at least half of the panel gap D,
Light is prevented from leaking into the effective viewing angle range.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view (a cross-sectional view taken along line AA 'of FIG. 2) showing a color liquid crystal panel according to an embodiment of the present invention, and FIG. 2 is a plan view of the same.

In the figure, a color liquid crystal display panel according to an embodiment of the present invention has a transparent electrode 105a on the light incident side of a light source.
And the transparent substrate 105b on the light emission side are arranged in parallel.

The color absorbing layer 108 and the transparent electrodes 102 are provided in a matrix on the opposing surfaces of the pair of transparent substrates 105a and 105b. A thin-film switching element array (not shown) and a signal line 106 are provided in a gap between adjacent transparent electrodes 102 on the opposing surface of the transparent substrate 105a. 110 is a transparent electrode and 107 is an interlayer insulating layer.

Further, the transparent substrate 1 including the transparent electrode 110
An orientation film 109 is formed on the entire surface of the transparent electrode 10b.
An alignment film 104 is formed on the entire surface of the transparent substrate 105a including the signal lines 2 and the signal lines 106. Also, the transparent substrate 105
The polarizing plate 101 is provided in each of a and 105b such that the absorption axis is in a crossed Nicols state.

Also, the opposing transparent substrates 105a and 105
b, twisted nematic liquid crystal is injected, and twisted nematic alignment is performed in the alignment region A between the color absorbing layer 108 and the transparent electrode 102 forming a pair,
In the alignment region B between the transparent electrode 110 and the signal line 106, homogeneous alignment is performed.

Here, as shown in FIG. 4, a disordered orientation region is formed at a boundary portion C between the orientation regions A and B.

Therefore, in the embodiment of the present invention, the boundary C between the orientations of the orientation region B and the normal orientation region A set so as not to transmit light is located inside the edge 108a of the color absorbing layer 108 (see FIG. (Center, right) at least half (D / 2) or more of the panel gap D so that the alignment regions B and B
Light-shielding film 1 facing an alignment disorder region generated at boundary C
03 is provided on the transparent substrate 105a on the light incident side.

Further, the light-shielding film 103 is formed at the boundary C of the orientation.
Is arranged at least a half distance or more of the panel gap D from the edge 108a of the color absorbing layer 108 (on the right side in the drawing), and the light shielding film 10 is disposed on the light source light incident side.
3 is equal to or more than half of the panel gap D (D μm) (≧ D / 2
.mu.m) more than the display area (color absorbing layer 1) than the boundary area C.
08 and the transparent electrode 102) (right side in the figure), so that the light that is going to pass through the region 111 with disordered orientation is obstructed in the effective viewing angle without being blocked by the light shielding film 103. From the color absorbing layer 10
This prevents the light from passing through a portion having no 8 or an adjacent color absorbing layer of a different color.

Further, a thin film transistor having an inverted stagger structure using amorphous silicon is used as the thin film switching element. A transparent electrode 102 made of ITO is used as a display area, and a light-shielding film 103 having a width of 3 μm is formed at a position corresponding to a boundary between the alignment areas A and B in a step of patterning a gate electrode with Cr in a step of forming a thin film switching element. Has formed. Further, as shown in FIG. 2, a polyimide material is printed on the entire surface of the transparent substrate 105a as the orientation 104, and then baked and rubbed at a 45 ° angle to the display portion (the color absorbing layer 108 and the transparent electrode 102). I am giving. In this rubbing process, rubbing on the array substrate 105a side indicated by a solid arrow in FIG. 2 and rubbing on the counter substrate 105b side indicated by a dotted arrow in FIG. 2 are performed.

A color filter having R, G, and B color absorption layers 108 at positions corresponding to the patterns of the transparent electrodes 102 on the array substrate 105a and having a transparent electrode 110 on the entire surface as the counter substrate 105b. A substrate is used. An alignment film 109 which has been selectively rubbed by photolithography on the substrate so that the liquid crystal is divided into a display electrode (region A) and a portion other than the display electrode (region B) so that the liquid crystal is twisted nematic / homogeneous. Is formed. Specifically, in the state of being superimposed on the array substrate 105a, the orientation region A
The rubbing angle is determined so that the alignment region B has an angle of 180 ° and the orientation region B has an angle of 180 °. The selective rubbing treatment is as follows. First, a polyimide film is applied and baked on the whole, and then rubbed at a predetermined angle.
A resist is formed by a photolithography method so as to leave a region other than the inside of μm, rubbed again at another predetermined angle, and then formed by removing the resist.
This division alignment can be performed on the array substrate 105a side, but is performed on the counter substrate 105b side in consideration of the influence of damage to the thin film transistor due to an increase in the number of rubbing processes.

The light-shielding film 103 provided on the array substrate 105a assumes that light from the array substrate 105a is incident on the array substrate 105a. By providing the light-shielding film 103 on the 105b side or widening the width of the light-shielding film 103 to at least as large as the panel gap D, a sufficient light-shielding effect can be obtained.

After forming a seal pattern on the array substrate 105a with epoxy resin by a printing method, and further spraying a spherical resin gap material having a diameter approximately equal to the panel gap D, the opposing substrate 105b is overlaid. The array substrate 105a and the opposing substrate 105b are kept at a constant distance by a gap material, are bonded to each other at a part of the edges of both substrates with a sealant leaving an injection port, and a liquid crystal material is injected between the two substrates 105a and 105b. Then, the injection port is sealed with a resin. After that, the color liquid crystal display panel is completed by attaching the film-shaped polarizing plate 101 to the front and back surfaces of the stacked substrates 105a and 105b with the polarization axis adjusted to the rubbing angle of the substrates.

The light-shielding film 103 provided on the light source light incident side of the boundary portion C of the alignment cuts the light that is almost perpendicular to the panel, out of the light that is going to pass through the region where the alignment is disturbed. A sufficient effect cannot be obtained unless the width of the light-shielding film 103 is larger than the width of the region in which the orientation is disordered. The width of the region in which the alignment is disturbed is determined by the variation in the alignment boundary position and the characteristics of the liquid crystal. A sufficient effect can be obtained by setting the width to at least 3 μm or more.

Next, the boundary portion C of the orientation is disposed inside the color absorbing layer 108 at least a half (D / 2) or more of the panel gap D, and the light shielding film 103 is formed on the light incident side of the panel gap D. Of the light that is to be transmitted through the region where the orientation is disturbed, the light that is incident obliquely without being blocked by the light-shielding film 103 is provided. It is possible to prevent the light from passing through a portion having no absorption layer 108 or an adjacent color absorption layer of a different color.

In the case of the twisted nematic liquid crystal panel according to the embodiment of the present invention shown in FIG. 1, since there is a strong viewing angle dependency in principle, the contrast is significantly reduced when viewed at a certain viewing angle or more. Usually, it is assumed that the device is used within the range of the viewing angle. By arranging the orientation boundary C inside the corresponding color absorbing layer 108 at least a distance equal to or more than half of the panel gap, light is prevented from leaking into a range of an appropriate viewing angle (+ 30 °). be able to.

[0032]

As described above, according to the present invention, portions other than the display portion of an active matrix type liquid crystal display panel in which polarizing plates are provided on the front and back surfaces of the liquid crystal display panel so that the absorption axes are in a crossed Nicols state. In a color liquid crystal display panel in which the alignment state of the liquid crystal is set so as not to transmit light, a decrease in contrast or chromaticity caused by light transmitted through a region having a disordered alignment which occurs at a boundary between the regions having different alignments is called. Good display quality can be obtained by preventing deterioration of display quality.

The reason for this is that the light-shielding film provided on the light source light incident side of the boundary of the alignment cuts the light that is incident on the panel almost perpendicularly among the light that is going to pass through the region where the alignment is disturbed. Then, by aligning the boundary of the alignment at a distance of at least half of the panel gap more than the color absorption layer and inward of the edge of the color absorption layer, of the light that is going to pass through the region of disordered alignment, This is because it is possible to prevent light that is obliquely incident without being blocked by the alignment film from passing through a portion having no color absorbing layer or an adjacent color absorbing layer of a different color.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view taken along the line AA ′ of FIG. 2 showing the first embodiment of the present invention.

FIG. 2 is a plan view showing the first embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional example.

FIG. 4 is a diagram illustrating a problem of a conventional example.

FIG. 5 is a diagram showing the operation of the present invention.

[Explanation of symbols]

 Reference Signs List 101 polarizing plate 102 transparent electrode 103 light shielding film 104 alignment film 105 array substrate 106 signal line 107 interlayer insulating film 108 color absorption layer 109 alignment film 110 transparent electrode 111 region in which alignment is disturbed

Claims (5)

[Claims] 1. A color liquid crystal display panel having an array substrate, an opposing substrate, and a light-shielding film, wherein the array substrate and the opposing substrate have a display portion on an opposing surface, and a liquid crystal is provided between the two. Is injected, and the liquid crystal is aligned so as to transmit light in the display unit, is aligned so as not to transmit light in a region other than the display unit, and transmits the light. A boundary portion between the aligned liquid crystal region and the liquid crystal region aligned so as not to transmit the light is set inside the display unit, and the light shielding film is a region other than the display unit. A color liquid crystal display panel for blocking light passing therethrough and being provided in an enlarged manner inside the display section. 2. A boundary between a liquid crystal region oriented so as to transmit the light and a liquid crystal region oriented so as not to transmit the light is at least half the gap size between the two substrates. The color liquid crystal display panel according to claim 1, wherein the color liquid crystal display panel is set inside the display unit. 3. The color liquid crystal display panel according to claim 1, wherein the light-shielding film is provided so as to be enlarged inside the display unit by more than half of a gap size between the two substrates. . 4. The color liquid crystal display panel according to claim 1, wherein the light-shielding film is provided on a substrate on a light incident side. 5. The color liquid crystal display panel according to claim 1, wherein the liquid crystal is a twisted nematic liquid crystal.