JPS6187191A - Color liquid crystal display element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention is directed to a first substrate provided with an array of transistors each having a plurality of electrodes serving as display element units; The present invention relates to a display device that has a second substrate provided with electrodes and displays images by electro-optical changes occurring between these substrates, and in particular relates to a color liquid crystal display element that displays colors by providing a color filter. It is something.

[Prior Art] Conventionally, this type of device has used materials such as liquid crystal, EC (electrochromy), and EL (electroluminescence) as electro-optic modulation materials, and has a single structure that allows the modulation to be performed on a substrate. A structure is used in which a first substrate provided with a driving semiconductor array and a second substrate provided with a counter electrode are used, and a layer of electro-optical modulation material is sandwiched between these substrates.

Hereinafter, as a typical example, a liquid crystal display device having an f4 semiconductor structure will be explained using the factors.

3 and 4 are examples of substrates having thin film semiconductors,
An example of configuring this as a liquid crystal display *zI is shown in FIG. 5. In other words, FIG. 3 shows the substrate (
thin 1lI2 drive transistors (1lI2 transistors for driving) arranged in a matrix at a density of about 2 to 10 pieces/■ on the glass etc.
: Th1n Film Transistor). The TF wire includes a cable (made of a transparent or metal thin conductive TrL film) formed on the substrate 6, a gate electrode l provided on the gate electrode, and an insulating film 13 formed on the gate electrode. thin film semiconductor 2,
It is made up of a 4M source line (consisting of four electrical films) 3a provided in contact with one end of the semiconductor, a train electrode 4 provided at the other end of the semiconductor, and the like. The drain electrode 4 constitutes an electrode serving as a display element unit. FIG. 4 is a top view viewed from the direction of arrow B in FIG. 3, showing a part of the matrix drive circuit.

In addition, FIG. 5 shows that the substrate shown in FIG. 3 and the counter electrode substrate are 4
1i, and is a sectional view corresponding to line AA' shown in FIG. 4. FIG.

In FIG. 5, 6 and 6a are substrates such as glass, 4 is the aforementioned drain electrode, and 7 is a counter electrode.

4.7, In203. Toru 1!1 of 5n02 etc.
A conductive film or, depending on the case, a metal thin film such as u, Al, or Pd is used. l and 3a are the gate electrode and source line, respectively, ^l, Au, ^g, pt, ρd
, Cu% metal is used. 5 is the insulating film 13 1a
A special example is shown where the gate line is formed only on the gate line.
Further, 8 is an insulating film provided as necessary, and 2, which can also serve as an alignment film, is CdS, CdSe, Te,
7 is a semi-i-former such as morphosilicon, 91i spacer, and 10 is a liquid crystal layer. Note that one display device uses dynamic scattering mode (DSM) and twisted array nematic (T
N) Depending on which display mode is used, or whether the device is transmissive or reflective, various alignment states of liquid crystal molecules and optical detection means such as a polarizing plate, an in/quarter plate, a reflecting plate, etc. can be adjusted as appropriate. Set.

In such a device, as a means for color display,
A common method is to form a color filter on either the substrate on which the driving semiconductor array is provided or the opposing electrode substrate.

Color filters made of such dyes are easily discolored by light, and the fading deterioration is particularly severe due to ultraviolet rays.Therefore, in order to prevent such fading deterioration, conventionally, liquid crystal display elements incorporating color filters are shown in Figure 2. like,
A glass-like ultraviolet cut filter 12 was incorporated. For this reason, the display element has had the disadvantage that it is necessarily thick due to its structure.

Therefore, the present inventors formed a transparent electrode on an electrode substrate,
A dye layer is formed on top of this via an insulating film, and a polyimide resin that serves as an alignment material and ultraviolet cut filter is formed on top of that via a transparent insulating layer, and the surface of the color liquid crystal is subjected to alignment treatment. We proposed a display element. This color liquid crystal display element achieved thinness and light resistance without providing an external ultraviolet cut filter.

[Problems to be Solved by the Invention] However, this display element has the disadvantage that many steps are required to form each layer, and there is room for further improvement in terms of the thickness of the element.

The present invention was conceived in view of the above points, and an object of the present invention is to provide a color liquid crystal display element that is easy to use as a display element incorporating a color filter, has light resistance, and shortens the manufacturing process.

[Means for Solving the Problems] In order to reduce the number of manufacturing steps and make the element thinner, it is necessary to eliminate the insulating layer formed between each layer and to rearrange each layer. The problem here is the polyimide resin, which functions as an alignment material and a UV cut filter.

Polyimide resin uses, for example, -methylpyrrolidone as a solvent for its precursor polyamic acid resin component, and because this solvent dissolves the pigment layer during coating, it is impossible to form it directly on the pigment layer. Can not.

Therefore, in the present invention, in order to avoid the adverse effects of the solvent contained in the coating solution of polyamic acid, which is a precursor of polyimide resin, the dye layer 1 formed on the electrode substrate
1. Also serves the purpose of protecting the pigment layer 12 between the resin layer 14 and the resin layer 14. Toru 01]? An It pole layer was formed.

Further, the multifaceted polyimide resin is subjected to an alignment treatment by a rubbing method to give the liquid crystal molecules a nine direction = simple orientation.

[Effect? As is clear from the above description, polyimide resin (for example, the polyimide resin described in US Pat. No. 3,179Ei34 can be used) has a function as an alignment material as well as a filter that cuts ultraviolet rays. Therefore, it is not necessary to provide an ultraviolet cut filter outside the display element 1, and since the transparent electrode functions as an insulating film between the polyimide resin layer 14 and the dye layer 12, there is no need to laminate another transparent IJ1 insulating film.

[Example〕 An embodiment of the invention is described in FIG.

Substrate shown in Figure 1 (glass; Corning 17059) 6
First, a positive resist (
Product name, 0FPR800, manufactured by Tokyo Ohka) Total 5000~
0-order coating on the pixel electrode with a film thickness of 90°C
After 30 minutes of pre-beta, the mask was exposed to ultraviolet light, immersed in a special developer for 1 minute, and immersed in a special rinsing solution for 1 minute to form a resist mask. The entire surface of the formed photosensor array was exposed to light to make it soluble in a solvent. Next, the photosensor array and the copper phthalocyanine packed in the No port were installed in a vacuum container, and the vacuum level was 10"-104T.
* In rr, the No port was heated to 450 to 550° C., and copper phthalocyanine was vapor-deposited to a film thickness of 4000 μm.

Thereafter, a patterned blue dye layer was formed by immersing and stirring in a developer exclusively for 0FPR and removing unnecessary portions of the resist mask while dissolving the resist mask. Subsequently, 0FPR800 was applied in the same process on the photosensor array on which the patterned blue dye layer was formed, and then exposed and developed.

A resist mask corresponding to the following patterned green dye was formed. After the entire surface is exposed, it is installed in a vacuum evaporator, and this time, p
b Phthalocyanine at 450-550'C! 't' was deposited to obtain a film of 3,000 people. Thereafter, it was immersed in a developer and stirred to form a patterned green dye layer. Furthermore, in exactly the same process, Irgazine L/D BP (trade name CI No. 71127 manufactured by Ciba Geigy) was added as a perylenetetracarboxylic acid derivative red pigment at 400 to 500°C.
Approximately 3,000 people were deposited using the method, and a patterned red dye layer was obtained by processing with a developer.

By the method explained above, the dye layer 15 corresponding to one pixel is
After forming, a transparent electrode (
A drain electrode 4) was formed, a polyimide resin layer 14 was formed on this transparent electrode (drain electrode 4), and the surface thereof was subjected to an alignment treatment using a rubbing method.

Polyimide resin layer 14 imparted with an orientation function in this way
A color liquid crystal display element can be constructed by arranging an electrode substrate consisting of one electrode substrate and the other counter electrode substrate and injecting liquid crystal into the gap between them.

Another method for forming one dye layer 15 is to form the dye layer not only on the electrode substrate on which the thin film transistor is formed as shown in FIG. 3, but also on the other electrode substrate as shown in FIG. Therefore, it can also be configured as a color liquid crystal display element.

[Effect of the invention] The present invention has the following unique effects.

1. Since the polyimide 4#l resin as the orientation and material plays the role of an ultraviolet cut filter, the light resistance of the color filter made of one color JW is improved, and 1. the fading and deterioration of the display element is prevented.

2. There is no need to provide an ultraviolet cut filter outside the device, and the entire device can be made thinner.

3. The transparent electrode layer formed on the color filter also serves as a protective film for the color filter, so there is no need to form an insulating film between the polyimide resin and the color filter, which can further reduce the manufacturing process. can.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, the iSZ diagram is a cross-sectional view showing an example of a conventional color liquid crystal display element, and FIG. 3 is a perspective view of a substrate having a thin film semiconductor. FIG. 4 is a plan view viewed from the direction of arrow B in FIG. FIG. 5 is a sectional view of a display panel composed of a substrate and a counter electrode corresponding to the AA' section in FIG. 4, and FIG. 6 is a sectional view showing another embodiment of the present invention. l: gate electrode, 1a: gate line. 2: thin film semiconductor, 3: source electrode, 3a = source line, 4: drain electrode. 6.8a: Substrate, 7: Counter electrode, 10: Liquid crystal layer, 12:
Ultraviolet cut filter, 13: insulating film, 14 = polyimide resin layer, 15: dye layer (color filter).

Claims (1)

[Claims] In a liquid crystal display element using a thin film transistor in which a liquid crystal is sandwiched between upper and lower electrode substrates, a color filter consisting of a dye layer is first formed on one of the electrode substrates, and then a color filter is formed on the color filter. A thin film transistor is used, characterized in that a transparent electrode layer is formed, a polyimide resin layer is further formed on the transparent electrode, and then an alignment function for aligning liquid crystal molecules is imparted to the surface of the polyimide resin layer. Color liquid crystal display element.