JP3411375B2 - LCD panel - Google Patents

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 liquid crystal display panel.

[0002]

2. Description of the Related Art A liquid crystal display panel has been widely used as a display device which replaces a CRT due to advantages such as low power consumption, light weight and small size. In order to improve the visibility and expressiveness of liquid crystal display panels, many color liquid crystal panels are now in practical use.

Color display is generally realized by forming color filters (coloring layers) of three primary colors of red (red), blue (blue), and green (green) according to the pixels of the liquid crystal panel. It is preferable to form a colored layer under the pixel electrode in view of the electric characteristics. In addition, in order to prevent light from leaking from the part where the liquid crystal does not work as an optical shutter (pixel gap, space between adjacent electrodes, pixel gap), and lowering the display contrast, a matrix-shaped light-shielding film is provided in the pixel gap. By providing a color filter or overlapping the color filter at the pixel gap, the light blocking effect is obtained.

On the other hand, the optical shutter characteristic of liquid crystal is greatly influenced by the thickness of the liquid crystal layer. Therefore, the uniformity is extremely important, and if the thickness (cell gap) of the liquid crystal layer in the liquid crystal panel is not uniform, uneven display contrast is noticeable, and in the case of color display, uneven color appears. Especially in a Super Twisted Nematic (STN) liquid crystal panel, the uniformization of the cell gap is a big issue.

FIG. 2 shows a partial structural sectional view of a conventional color liquid crystal panel. The first colored layer 2, the second colored layer 3, and the third colored layer 4 are regularly arranged on the substrate 1 with their adjacent portions overlapping each other. The insulating film 5 is formed so as to cover each colored layer, and the pixel electrode 6 is formed thereon. The pixel electrode 8 is formed on the other substrate 7.
Are formed, and the two substrates maintain the cell gap by the spacer 9. A portion where the pixel electrode 6 and the pixel electrode 8 intersect three-dimensionally corresponds to a display pixel.

In FIG. 2, the colored layers overlap each other. Ideally, the colored layers do not overlap each other and there are no gaps, but there is a limit to the placement accuracy. If there is a gap, the light will be completely transmitted, so it must be prevented even with the worst placement accuracy. If the overlap width is too small, the height of the protrusion becomes unstable. Since the spacer 9 rides on the protrusion portion with certain probability, the height of the protrusion must also be stable, and a design that can obtain a stable overlap amount even with the worst placement accuracy is required. Since the projection has a cell gap different from that of the pixel portion, a large amount of light leaks, and although the colored layers overlap to reduce the transmittance, the light blocking rate is incomplete. Therefore, the display contrast of the entire panel is not so good.

FIG. 3 is a partial structural sectional view of a conventional color liquid crystal panel provided with a light shielding film. The first colored layer 2, the second colored layer 3, and the third colored layer 4 which are independent of each other are regularly arranged on the substrate 1, and the light-shielding film 10 is previously formed so as to fill the gap between the colored layers. Has been formed. As in FIG. 2, the insulating film 5 and the pixel electrode 6 are formed on the colored layer, and the spacer 9 maintains the cell gap with the substrate 7 having the pixel electrode 8 on the surface.

In FIG. 3, the colored layer overlap, which is a cell gap instability element, is avoided, and the colored layers are arranged with a gap, and the gap is filled with a light shielding film 10. A black colored layer having the same quality as the pixel portion may be used as the material of the light shielding film 10. However, in order to avoid a gap formed when the accuracy of arranging the colored layers is poor, it is necessary to overlap the thick light shielding colored layer with the pixel portion colored layer.
Similarly, it is disadvantageous with respect to cell gap stability. Therefore, as a material of the light-shielding film 10 when high contrast is required, an opaque metal thin film such as chromium (Cr) having a sufficient light-shielding property is suitable even if it is a thin film. Generally, the thickness of the colored layer is 1-2 μm, while the thickness of the chromium thin film is 0.05-0.1 μm.
Even if the light-shielding film 10 and each colored layer overlap with each other, there is no fear of a protrusion because a sufficient light-shielding property is obtained. When a metal thin film is used for the light-shielding film 10, the display contrast is remarkably improved as compared with the color layer overlapping method of FIG.

However, although the metal thin film has a high light-shielding property, it also has a high reflectance. Even if the leakage of the illumination light positioned behind the panel is shielded from the viewer, if the external light from the viewer is reflected, the display contrast is reduced accordingly.
Therefore, for a liquid crystal panel module, it is advantageous to arrange the substrate with the light-shielding film on the illumination side (not in front of the viewer), but still it is necessary to completely suppress the reflection in the gap between the colored layers. I can't. If you want to reduce the reflected light as much as possible and further improve the display contrast,
Although it is possible to use a method in which a thin film having a different refractive index is separately formed on the base or surface of the original light-shielding film to reduce the reflectance, there is a problem in terms of cost.

On the other hand, the spacer 9 causes the pixel electrode 6 to move due to the pressure applied to the substrates during the manufacture of the liquid crystal panel and the impact after completion.
There may be a phenomenon that the user is absorbed in the phenomenon. Shading film 1
When 0 is conductive, the pixel electrode 6 and the light-shielding film 10 are caught when the pixel electrode 6 is rolled up and sunk when the spacer 9 is recessed.
May be conducted. In particular, if there is a gap in the colored layer, the distance between the pixel electrode 6 and the light shielding film 10 will be narrow and the frequency of occurrence will be high. When such a phenomenon occurs, the light shielding film 1 is formed on the pixel electrode 6.
There is a problem that the capacity of 0 is added and the liquid crystal driving capability is lowered, and the image display quality is periodically or totally impaired.

[0011]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a colored layer arrangement in which cell gap control is easy,
Further, it is an object of the present invention to provide a structure of a liquid crystal panel that maintains good image display with less occurrence of defects in which the pixel electrode and the light shielding film are electrically connected even when a conductive thin film is used as the light shielding film.

[0012]

[Means for Solving the Problems] The means for achieving the above object of the present invention is to reduce the number of two substrates having electrodes.
At least one substrate is the pixel electrode and the pixel electrode and the pixel electrode.
Has a pixel gap between the pole and at least one of
The substrate having a plurality of colored layers of a plurality of hues;
In a liquid crystal panel having a substrate, at least the substrate
On one side, the colored layer has a different color on the part corresponding to the pixel electrode.
A plurality of stages are arranged in a phase, and the first pixel electrode and the first pixel electrode
The second pixel electrode adjacent to the pixel electrode is straddled over the second electrode.
A hue is disposed and the colored layer is disposed in the pixel gap.
Characterized in that it is arranged so as to cover the light shielding film
It

The colored layer is composed of three kinds of single hues.
Two pixel electrodes are arranged in succession to the pixel electrode, and
Coloring of other species above or below the monochromatic coloring layer
Characterized by the fact that part of the layers overlap with the pixel electrodes
It

Due to the overlapping of the above three kinds of monochromatic colored layers
The hue is the first colored layer and the second colored layer among the three types of colored phases.
The second colored layer and the third layer
The third colored layer that exhibits a blue color due to the two layers with the colored layer
It has a green color due to the two layers of
Characterize things.

The above three types of monochromatic colored layers are light blue (shear).
And yellow (yellow) and purple (magenta)
It is characterized by

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

Since one colored layer block is continuous for two display pixels, the colored layer covers the light shielding film between the two pixels. Since the three types of colored layers are regularly stacked in a two-tiered manner in which half each of them is laminated, the entire surface of the light shielding film in the pixel portion is covered with the colored layer.

As a result, the reflectance of the light-shielding film is reduced by the coating of the colored layer, and at the same time, the surface insulation of the conductive light-shielding film is further increased by the amount of the colored layer, so that the pixel electrode and the light-shielding film become conductive as the spacer sinks. It is possible to reduce defective products.

Although the colored layers are overlapped with each other, since the entire pixel portion is laminated in two stages, a partial projection shape is not formed, and even if the arrangement accuracy of the colored layers is poor, cell gap control is hindered. There is nothing.

When cyan, yellow, and magenta are used for the respective hues of the colored layer, green is green in the two-tiered stack of cyan and yellow, red is the two-tiered stack of yellow and magenta, and two-tiered of the magenta and cyan. Blue can be expressed by stacking layers.

[0033]

FIG. 1 is a partial structural sectional view of a color liquid crystal display panel showing an embodiment of the present invention. Further, the same reference numerals are used for the portions common to the conventional example of FIG. 2 and FIG.

First, the light-shielding film 10 is formed on the surface of the substrate 1, and the first colored layer 2, the second colored layer 3, and the third colored layer 4 are formed on the light-shielding film 10 as a block continuous for two display pixels. They are arranged regularly while stacking two halves of each other. The insulating film 5 is formed so as to cover each colored layer, and the pixel electrode 6 is formed thereon. A pixel electrode 8 is formed on the other substrate 7, and the two substrates maintain a cell gap with a spacer 9.

The hue of the first colored layer 2 is cyan, the hue of the second colored layer 3 is yellow, and the hue of the third colored layer 4 is magenta. As a result, the first colored layer 2 and the second colored layer 3
And green by the two-step stacking of the second colored layer 3 and the third colored layer 4, and red by the two-step stacked layer of the third colored layer 4 and the first colored layer 2. It will be a matter.

In FIG. 1, the respective colored layers cover the light-shielding film 10 without folding and overlapping with each other, but no protrusions are formed. As a result, the surface reflectance of the light-shielding film 10 is reduced, and the insulating property is improved against inadvertent conduction between the light-shielding film 10 and the pixel electrode 6. The even to some extent poor placement accuracy of each of the colored layer, it is easy to cell gap control Lumpur since there is no protrusion.

In the embodiment shown in FIG. 1, the present inventor used a photoreactive transparent resist colored by a dyeing method for each colored layer. However, the material for forming each colored layer is not necessarily limited to the dyeing method. It is also possible to use a photoreactive resist in which a dye is internally added in advance,
A coloring material having no photoreactivity may be formed by a printing method.

Further, although the above-mentioned embodiment is for the simple matrix type color liquid crystal panel, if it is a liquid crystal panel which expresses colors using the three primary colors of red, blue and green, other active matrix type liquid crystal panels and It goes without saying that the present invention can also be applied to the case of liquid crystal panels having different operation modes such as ferroelectric and antiferroelectric.

Further, although cyan, yellow, and magenta are used for the three kinds of colored layers in the above-mentioned embodiment, if the color mixing results obtained by stacking two layers of each colored layer are the three colors which are originally required, respectively. The effect of the present invention is satisfied, and when the required three colors are other than red, blue and green,
The hue selection of the colored layer according to the present invention is not necessarily limited to cyan, yellow and magenta.

In color expression using light of a color liquid crystal panel, CRT, etc. (approaching white due to color mixture, additive color mixture), it is common to express with three primary colors of red, blue and green, but color printed matter It is general to use cyan, yellow, and magenta for the color specifications (subtractive color mixture that approaches black due to color mixture). With these experiences, it can be easily inferred that it is not difficult to set the hues of cyan, yellow, and magenta that correspond to the required red, blue, and green, and there is no difficulty in variations.

[0041]

As described above, according to the present invention, the structure which expresses the hue of the coloring layer originally required in the two-stage stacking does not cause a partial protrusion due to the overlapping of the coloring layers, and the cell gap control is easy. Even in the state, the surface reflectance of the light-shielding film and the ratio of inadvertent conduction failure with the pixel electrode can be significantly reduced. In addition, it is not necessary to make any changes to the conventional liquid crystal display panel such as the structure of other portions, the panel driving method, and the number of manufacturing steps, as long as the hue of the colored layer is selected and arranged. Further, since the single-hue colored layer block has a size of two pixels as compared with the conventional one, the required resolution can be increased to one-half that of the conventional one when considered paradoxically. As described above, the effects of the present invention greatly contribute to the stabilization of the quality of the liquid crystal display panel and the improvement of the display quality.

[Brief description of drawings]

FIG. 1 is a partial structural sectional view of a color liquid crystal display panel according to the present invention.

FIG. 2 is a partial structural cross-sectional view of a conventional color liquid crystal display panel.

FIG. 3 is a partial structural sectional view of a conventional color liquid crystal display panel using a light shielding film.

[Explanation of symbols]

1, 7 substrate 2 First colored layer 3 Second colored layer 4 Third colored layer 5 insulating film 6,8 Pixel electrode 9 Spacer 10 Light-shielding film

Claims (4)

(57) [Claims] [Claim 1] and least two substrates comprising a electrode <br/> also one of the substrates and the pixel electrode and the pixel electrode and the pixel electrode
At least one substrate having a pixel gap between
Wherein the substrate has a plurality of colored layers having a plurality of hues
In a liquid crystal panel having a plurality of stages, a colored layer is provided on at least one side of the substrate in a plurality of stages with different hues in a portion corresponding to a pixel electrode .
Pixel electrode and second pixel electrode adjacent to the first pixel electrode
And the colored layer is disposed over the
It is arranged so as to cover the light shielding film arranged in the element gap.
It made it a liquid crystal panel according to claim. 2. A or on the colored layers of the colored layer is disposed on the pixel electrode continuously configured <br/> Contact has two partial in three monochrome phase and 1 species of monochromatic phase liquid Akirapa panel of claim 1, part of the colored layers of a single color phase of other species and wherein the Ru Tei overlapping with the pixel electrode in the lower. 3. Due to the overlapping of the colored layers of the three monochromatic colors
That hue, blue (blue by two-stage and the second colored layer and the third colored layer exhibits more red (the red) in two stages with the first colored layer and the second colored layer among the three colored phase liquid Akirapa panel according to claim 4, characterized in that more exhibited green (green) in two stages with the third colored layer and the first colored layer exhibits). Wherein said three liquid according to claim 4 or claim 3 colored layer of a single color phase is characterized by comprising a light blue (cyan) and yellow (yellow) and purple (magenta) Akirapa Ne <br/> Le.