JPS60120321A - Color liquid crystal display device - Google Patents

Abstract

PURPOSE:To improve the effect of a black stripe in absorbing and shielding light by installing the 1st base plate and the 2nd base plate after providing the opposite space by means of a spacer insuch a way that the main surfaces of the two base plates face each other and sealing a liquid crystal in said space. CONSTITUTION:When color filters 3a, 3b of R, G, B are formed on a transparent base plate 6a, a black stripe 3c is formed. A transparent conductive film 5 which is a counter electrode for a transparent conductive film 13 is formed on said filters 3a, 3b. In2O3, SnO2 or the like is formed by room-temp. vapor in consideration for the heat resistance of the color filters. A metal 14 is deposited and formed so as to overlap on the pattern of the black stripe 3c. Aluminum is adequate for the metal to be used as the light transmittance thereof is extremely low and there is no possibility of cracking in the film 5.

Description

DETAILED DESCRIPTION OF THE INVENTION 2. Field of Industrial Application The present invention relates to a color liquid crystal display device, and particularly to a color liquid crystal display device incorporating a nonlinear element such as a thin film field effect transistor (hereinafter abbreviated as TPT).

Conventional configuration and its problems Liquid crystal display devices are thin and can be driven at low voltage, so MO'S
It has excellent features such as good matching with IC and low power consumption.

Traditionally, LCDs were mainly monochrome, but in recent years, liquid crystal display devices capable of displaying full color have begun to appear on the market. Furthermore, combinations with nonlinear elements are also being actively researched.

Non-linear elements include MOSFET, TPT, MIM
(metal-insulating film-metal), varistor, etc., and here, as a conventional example, a conventional color liquid crystal display device in combination with TPT will be explained.

FIGS. 1 and 2 show cross-sectional views of unit picture elements with conventional configurations. 1 is a liquid crystal, 2a and 2b are alignment films, and 3a.

3b is a color filter, 4 is a black stripe, 6a
, 6b is a transparent substrate. TPT has a gate electrode 7, a gate insulating film 8, a semiconductor layer 9, and a source or drain connected to a pole 10.
Consisting of a l 10b, drain electrode (source electrode)
1ob is connected to a transparent conductive film 13 corresponding to a unit picture element. Reference numeral 11 denotes a protective film for the semiconductor layer, and a light shielding film 12 is further formed on top of the protective film. TPT is installed on a transparent glass substrate 6b.

Since the problem is the transparent glass substrate 6a on the opposite side on which the color filters 3a and 3b are formed, it will be described in detail.

Although ea and 6b are specifically defined as transparent glass substrates, liquid crystal display devices with built-in color filters are generally used as transmission type, so in principle, 6a and 6b
It is sufficient if at least one of the two is transparent.

In FIG. 1, first, a transparent conductive film 5 is formed on a transparent glass substrate 6a. Normally, n203 and 5n02 are formed by vapor deposition.

Next, the flux stripes 4 are formed on the substrate 6a in a lattice shape by using metal with a blackened surface, subtractive color mixing of different colors of color filters, or coloring black. The black stripes 4 not only have the effect of suppressing reflections at the boundaries of each color of the color filter to make the image clearer, but also eliminate reflections from the wiring formed on the substrate 6b, and also serve as photoconductor for transistors. It also has a light shielding effect that suppresses the effects. The pattern of black stripe formation will be explained with reference to FIGS. In FIG. 3, 18 is a source wiring (or drain wiring) connected to the source electrode 10a (or drain electrode 10b), 16 is a drain electrode (or source electrode, equivalent to 10b), 17 is a TPT semiconductor layer, 15 is the gate wiring. These are the substrates 6b
is installed at the top of the.

For the reason mentioned above, the black stripe 4 is arranged so as to cover each wiring and the transistor section. The situation is shown in Figure 4. The shaded portion 4 is a black stripe.

Next, color filters 3a and 3b are formed in six pages of squares surrounded by black stripes. Usually, gelatin is dyed red (R), green (G), and blue (B).

An example of its arrangement is shown in FIG.

Finally, the liquid crystal 1 is sealed in the space facing the substrates ea and eb via the alignment films 2a and 2b, and an electric field is applied between the transparent conductive films 6 and 13 to drive the liquid crystal 1.

FIG. 2 is also one of the conventional examples, but the only difference from the structure shown in FIG. 1 is that the color filters 3a, 3b and the transparent conductive film 5 are arranged upside down, and other structures, The arrangement is exactly the same as in FIG.

By the way, in the structure shown in FIG. 1, since the transparent conductive film 5 is located below the color filter 3a (or 3b),
There was a problem in that the effective voltage applied to the liquid crystal decreased due to the color filter. Further, if the black stripe 4 is made of metal with a blackened surface, this will not be much of a problem, but with a blank drive made of gelatin or the like that is simply dyed black, light cannot be completely blocked unless the film thickness is considerably thick.

6 pages or the structure shown in Figure 2, the black stripe 4
If metal is used for the transparent glass substrate 6a and the black stripe 4, there is a problem that the difference in refractive index between the transparent glass substrate 6a and the black stripe 4 is large, and reflection at the interface causes a decrease in contrast.

Purpose of the Invention The present invention was made in view of the above-mentioned drawbacks of the conventional example.
The aim is to further strengthen the light absorption and light shielding effects of the black stripe, and to obtain clearer images and higher quality color liquid crystal display devices.

Structure of the Invention The present invention provides a black stripe of a color filter with a two-layer structure consisting of a black colored layer and a metal layer, thereby further increasing the light absorption of the black stripe and making its black color stand out.
This provides a clear color image. In addition, the present invention improves the light blocking effect of the black stripe, thereby preventing reflections from metal wiring in the dark field, MOSFETs, and
When PT is used as a switching element, suppressing the photoconductive effect of the semiconductor layer and obtaining images with higher contrast ratio7
'It's an expensive thing.

DESCRIPTION OF EMBODIMENTS Here, an embodiment of the present invention will be described for a color liquid crystal display device driven by TPT. FIG. 6 shows a cross-sectional view of the unit picture element.

As explained in the conventional example, TPT has a gate electrode 7, a gate insulating film 8, a semiconductor layer 9, a source or drain electrode 1 oa
, more than 1ob, drain electrode (source electrode) 1ob
is connected to a transparent conductive film 13 corresponding to a unit picture element.

Reference numeral 11 denotes a protective film for the semiconductor layer, and a light shielding film 12 is further formed on top of the protective film. TPT is installed on a transparent glass substrate 6b.

Next, regarding the opposite transparent substrate 6a side, first, the transparent substrate 6
R, G, and B color filters 3a and 3b are formed on the layer a. This can be easily formed by dyeing with an organic substance containing gelatin as a main component or by repeatedly depositing and selectively removing an inorganic pigment.

At that time, the boundaries of each color filter are, for example, R, G, and B.
If you overlay two colors like G and G, you will color it black by subtractive mixing. Alternatively, the boundaries of each color filter may be dyed black from the beginning.

In any case, this results in the formation of black stripes 3C. The pattern is as described above, and the 3rd and 4th
As shown in the figure. That is, it is formed to cover the transistor section installed on the transparent substrate 6b, the source wiring (drain wiring) and the gate wiring connected thereto.

On this color filter, a transparent conductive film 6 which becomes a counter electrode of the transparent conductor 13 is formed. At this time, considering the heat resistance of the color filter, In2O3, SnO2, etc. are formed by vapor deposition at room temperature.

Next, the metal 1 is overlapped with the pattern of the previous black stripe 3C, that is, in the pattern shown in FIGS. 3 and 4.
4 is deposited and formed.

Aluminum is conveniently used as the metal here. This is because aluminum has an extremely low light transmittance even if it is a thin film of about 1,000 people, and its light transmittance is also small, so there is no fear of cracks forming in the transparent conductive film 5, which is the base formed earlier. Further, as mentioned above, since it can be formed as a thin film, no extra steps are formed due to this, and the initial alignment of the liquid crystal is not hindered.

As a result, the plaque stripe has a two-layered structure: black colored phase and metal.

This metal is also formed in the portions shown in FIG. FIG. 7 shows the end portion of the color filter 3a.

At the portions marked with circles in FIG. 7, the transparent conductive film 5 tends to break off, often resulting in disconnection. However, in the present invention, it is also possible to leave the pattern of the metal 14 on top of the metal 14, which eliminates the electrical disconnection and eliminates such problems.

This is particularly effective when combined with MIM. For some reason, after a color filter is formed on the transparent substrate facing the MIM side substrate, the 10-page transparent conductive film 5 is selectively formed. At this time, if the step coverage of the transparent conductive film is poor at the stepped portion at the end of the color filter, there is a possibility of wire breakage there, and line defects are likely to occur.

Transparent substrate 6a with color filters installed as described above
A liquid crystal 1 is sealed between the substrate 6b on the TFT side and the substrate 6b on the TFT side with alignment films 2a and 2b interposed therebetween.

Effects of the Invention By using the black stripe having the above-described structure, reflection at the boundaries between the colors of the color filter can be suppressed, and a clear color image can be obtained. In addition, by layering a metal layer with low light transmittance on the plaque stripe area,
It completely blocks light, suppresses the photoconductive effect of transistors and reflections from metal wiring, lowers the black level in dark field, and achieves a high contrast ratio. Furthermore, it also has the effect of preventing wire breakage at the stepped portion at the end of the color filter.

[Brief explanation of the drawing]

1) The figure is a cross-sectional view of a conventional color liquid crystal display. ! ! ! II
and a schematic plan view showing an example of a pattern for forming color filters. FIG. 6 is a sectional view of a unit picture element of a color liquid crystal display device according to an embodiment of the present invention, and FIG. 7 is a sectional view showing an end portion of a color filter. 1...Liquid crystal, 2a, 2b...Alignment film,
3a, 3b...Color filter, 3C...
...Black stripe, 5...Transparent conductive film, 6a, eb...Transparent substrate, 9...
・Semiconductor layer. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 day Δa

Claims (3)

[Claims] (1) A first method in which a color filter partitioned by black stripes is formed on the first main surface, a transparent conductive film is formed on the top of this color filter, and metal is selectively placed on the top of this transparent conductive film. A substrate and a second substrate having an electrode or a nonlinear element and an electrode on one main surface are placed in a predetermined opposing relationship using a spacer so that the main surface of the first substrate and the main surface of the second substrate are opposite to each other. A color liquid crystal display device, characterized in that the display device is installed with a space provided therebetween, and a liquid crystal is sealed in the opposing space via an alignment film. (2) The color liquid crystal display device according to claim 1, wherein the metal is aluminum. (3) The color liquid crystal display device according to claim 1, wherein the metal is formed in the vicinity of the step portion of the color filter so as to cover the step.