JPS60243637A - Liquid crystal color display body device - Google Patents

Abstract

PURPOSE:To prevent generation of rain-like domains by setting the spacings between the respective colors of color filters in such a manner as to decrease the regions coinciding with the spacing between source lines and picture element electrodes or between gate lines and the picture element electrodes. CONSTITUTION:The color filter layers 4 are so positioned that the adjacent spacings in the source line 14 direction sandwiched by the outside shapes 23 of said layers do not overlap the part above the spacings between the source lines and the picture element electrodes and particularly that the adjacent spacings of the color filters 4 come just above the source lines 14. Since an image signal is constantly conveyed to the lines 14, electric lines 25 of force are generated between said lines and transparent electrodes 11 and the liquid crystal molecules positioned in the regions of the adjacent spacings receive the electric lines 25 of force having good perpendicularity and therefore the generation of the rain- like domains is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The misfire relates to liquid crystal color display devices. Furthermore, the present invention relates to the display quality of a liquid crystal color display device, and sometimes to alignment in the manufacture of color filters thereof.

Liquid crystal displays can be driven at low voltage and low power.
In recent years, the number of small and thin flat panel displays has been rapidly increasing, and their practical application as an image display device that can replace CRTs is also on the rise. There are two driving methods for liquid crystal displays: a time-division drive method and an active mask (IJ) drive method, and compact LCD TVs using both of these methods have already been released or prototypes have been announced. Furthermore, by combining an LCD panel with a color filter, a prototype of a vivid full-color LCD TV was announced. In the future, liquid crystal displays are expected to have a wide range of applications as small and thin flat displays.

[Prior art]

Figure 1 shows three color filters and thin film transistors (
1 is a cross-sectional view of a liquid crystal color display device combining an active matrix drive type liquid crystal shutter using TF'T)Y. The display device includes a TPT substrate 1 on which pixel electrodes 2yt are formed, a color filter substrate 3 on which three color filter layers 4 of red (R), green (1, and ff(l) and a completely transparent electrode 11 are formed, and a sealing material 5 It has a structure in which 10 layers of nematic liquid crystal are sealed in the gap created by bonding them together via a .(12 is a protective film (intermediate film)).
Polarizing plates 6 and 7 are attached to the top and bottom of the display device so as to form crossed Nicols. Since this display device uses a color filter and is normally used as a transmission type, a backlight 9 is installed on the back side. Further, it is customary to use a cutout &8 to hide the peripheral portion of the display device.

This display device controls the light from the backlight 9 using a so-called twisted nematic mode in which the luminosity of the liquid crystal layer is controlled by the voltage applied to each pixel electrode 2.

FIG. 2 is an enlarged view of the pixel electrode part, which also includes a gate line 13 running in the horizontal direction, a source line 14 running in the vertical direction, a pixel electrode 15, a double gate 15, a source 16, and a drain 17 of a polycrystalline silicon transistor. ing.

FIG. 3 shows the cross-sectional structure of a polycrystalline transistor. After forming a polycrystalline silicon channel 18 on a transparent glass substrate 1 and forming a gate oxide film 21 on the surface, a polycrystalline silicon gate 15 and an interlayer insulating film 20 are laminated, and then source and drain contacts are formed. The structure is such that a hole is made and finally a source 16, a drain 17, and a pixel electrode 6 of the TO film are formed.

By adopting such a structure, a liquid crystal color display device can reduce the number of structural process steps and improve yield, but it has the following drawbacks.

That is, when the power of the display device was turned from OFF to ON, countless white areas appeared along the source line running in the vertical direction, and a phenomenon similar to that of rain falling on the screen occurred. FIG. 4 is a diagram schematically showing this macroscopic state. We call this phenomenon a cocoon-like domain because the domain looks like rain. This cocoon-like domain causes a significant deterioration in display quality. Now, good observation using a microscope has revealed that the shape of the color filter plays a role in the generation of cocoon-like domains. FIG. 5 is an enlarged plan view of the color filter, and FIG. 6 shows the cross-sectional structure taken along line segment 21. As shown in the figure, since the color filter single layer 4 is dyed after forming the dyed base material, the surface of the final δ retaining film (intermediate film) 12 is between the adjacent color filter layers and the color filter substrate 3. It forms a concave shape,
As a result, the transparent X-pole 11 is also manufactured along the shape.

Hereinafter, this region of the depression will be referred to as an adjacent gap fa22. Now, when the pixel portion of the completed display body is enlarged, it becomes as shown in FIG. 7. Here, color filter f- plate extinction 9F,
6. The source line and the pixel are located including the gap between the poles.

In this state, when the switch 4 of the display device is turned on from OFF to observe the generation of cocoon-like domains, the outer shape IW2 in the figure is
The occurrence of cocoon-like domains can be seen in the area surrounded by 4. However, as a result of more detailed observation, it was found that the cocoon-like domain is particularly characterized by the presence of a crack electrode in the gap between the source line and the pixel electrode, compared to the area where the pixel electrode is located on the active matrix substrate, even in the area of the adjacent mountain gap. It was found that the occurrence was more pronounced in the areas where it was not observed. Here, the principle of occurrence of this phenomenon will be briefly explained. FIG. 8 is an enlarged cross-sectional view of FIG. 7. In the figure, the electric lines of force 25 generated when the switch is turned on are generated linearly toward the transparent electrode 11 provided on the color filter side above the pixel electrode and the source line, so they have a positive dielectric anisotropy. Either the liquid crystal molecules tend to move to make their die letters parallel to the lines of electric force, or in areas where there are no electrodes on the substrate, the linearity of the lines of electric force is impaired, causing the liquid crystal molecules to not stand up and become cocoons. The domain is particularly violent. Image-like domains not only make it difficult to see the display but also reduce the contrast of the screen, so it is necessary to take measures to prevent this from occurring.

〔the purpose〕

The present invention was invented to solve the display quality problems of such conventional liquid crystal color display devices, and includes:
The purpose is to prevent the above-mentioned picture domain from causing a deterioration in display quality.

〔overview〕

In order to prevent the occurrence of significant image-like domains in a liquid crystal color display device, the present invention provides a color filter whose concave adjacent gap is located between the source line and the pixel electrode of the active matrix substrate, or between the gate and the source line of the active matrix substrate. It is characterized by positioning the color filter so that it does not coincide with the upper part of the gap between the line and the pixel part 1 gloss as much as possible.

〔Example〕

Embodiment 1 - No. 9 is an enlarged view of the pixel electrode portion of Embodiment 1 to which the present invention is applied, compared to the conventional example of FIG. 7.

It is positioned so that it does not overlap with the adjacent gap in the direction of the source line sandwiched between the outer cedar 26 of one layer of color filters, or the gap between the source line and the pixel electrode. Its characteristic lies in the fact that it is positioned above the .

FIG. 10 shows the cross-sectional structure of the ninth factor. Since the source line constantly carries image signals, electric lines of force are generated between the source line and the transparent electrode 11, and the liquid crystal tends to rise in the same way as the pixel area, so the adjacent gap of the color filter is positioned above it. Compared to the conventional technology, it is possible to suppress the generation of image-like domains due to the effect of the liquid crystal molecules located in the adjacent gap region or the electric lines of force with good verticality, and display with 0J' ability and contrast. It will improve.

Example λ Example 2 is a more complete version of Example 1, in which adjacent gaps in the gate line direction of the color filter are positioned above the gate line.

FIG. 11 is an enlarged view of the pixel section when the second embodiment is applied. A cross-sectional view including above the gate line is shown in FIG. Here, in order to increase the retention performance of the charge introduced into the pixel, the gate line 15 and the pixel 't! A capacitance is built in by the gate oxide film 21 sandwiched between the L poles 6. If the alignment is made so that the adjacent gap of the color filter is slightly on the gate line, the pixel electrode will be located below the 1ijI contact gap, and the liquid crystal in this area will contain almost no information written to the pixel. Therefore, domains in the gate line direction caused by adjacent gaps no longer occur. Moreover, since the liquid crystal layer below the adjacent gap is driven by image information, display quality is significantly improved.

〔effect〕

According to the present invention, the generation of image-like domains caused by adjacent gaps between filters formed during the manufacturing of color filters can be suppressed, and the domain areas that have been caused to deteriorate in domain size can be minimized, and display quality can be improved. This is a significant improvement, so the effects of the present invention are very large. In the cargo,
There is no need to change the manufacturing process of color filters or active matrix substrates, so there is no need to reduce yield (
This is effective in improving display quality.

In the present invention, a color filter is used as an example of a counter substrate of an active matrix substrate, but it is obvious that the present invention can be applied not only to this but also to cases where the electrode surface of the counter substrate has depressions due to manufacturing.

[Brief explanation of drawings]

FIG. 1: A cross-sectional structural diagram of a liquid crystal color display device. DESCRIPTION OF SYMBOLS 1... TPT substrate, 2... Pixel electrode, 3... Color filter saw substrate, 4... Color filter layer, 5...
・Sealant, 6...Polarizing plate, 7...Polarizing plate, 8...
Parting plate, 9...Backlight, 10...Liquid crystal layer, 11...Full surface transparent electrode, FIG. 2...Pixel pattern diagram of a liquid crystal color display device. 13... Gate line, 14... Source line, 1
5...Double gate, 16...Source, 17...
Drain Figure 6: Cross section of thin film transistor □□□. 18... Channel, 19... Gate oxide film, 20
. . . Interlayer insulating film FIG. 4 . . . Schematic diagram of a screen in which mountain-like domains are generated. Fig. 5: A plan view of the color filter. 21...Transverse line Figure 6...Cross-sectional structural diagram of the color filter. 22...Adjacent gap portion Fig. 7...An enlarged view of the vicinity of the pixel/sensation pole when the image-like domain occurs. 23...Outline of one layer of color filter 24...Outline surrounding the area where the image-like domain has occurred. FIG. 8: Cross-sectional view of the cross-sectional structure of the liquid crystal color display device near the pixel electrode and the lines of electric force. 25...Electric lines of force. FIG. 9: A plan view of the liquid crystal color display device of Example 1. FIG. 10: A cross-sectional structural diagram and lines of electric force of the liquid crystal color display device of Example 1. FIG. 11: A plan view of a liquid crystal color display device of Example 2. Fig. 12: A cross-sectional structural diagram and electric lines of force of the liquid crystal color display device of Example 2. Applicant Suwa Seikosha Co., Ltd. Figure 1 Figure 3 Figure 5 Figure 6 Figure 6 tV Figure 8 Figure 12

Claims (1)

[Claims] A transparent substrate in which a plurality of source lines and gate lines are formed in a matrix shape on a transparent substrate, and a pixel electrode and a thin film transistor are formed at each intersection, and a pixel 1! of the substrate. After arranging color filters of the three primary colors corresponding to the poles, transparent substrates on which transparent electrodes are formed on the entire surface are bonded together with a certain gap Y, and a liquid crystal is sealed between the nuclei. In an active matrix drive type liquid crystal color display device, the area where the gap between each color of the color filter and the gap between the source line and the pixel electrode or between the gate line and the pixel electrode coincide is as small as possible. A liquid crystal color display device characterized in that the digits r1t and digits are matched.