JPH0315821A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To obtain an image of high uniform display quality even at the time of high-time-division driving by providing an insulating film on the internal surface of substrate where no color filter layer is provided and orienting liquid crystal molecules homogeneously so as to form a spiral structure which has a >=180 deg. twist angle. CONSTITUTION:The insulating film 27 is formed on a 2nd substrate 2 of the liquid crystal device consisting of a 1st substrate 1 which has color filter layers 12, 13 and 14, an electrode layer 15 and an orienting film 16 and the 2nd substrate 2 which has an electrode layer 25 and an orienting film 26, and the molecules of liquid crystal 4 are oriented homogeneously in the spiral structure having the twist angle of >=180 deg.. Therefore, the insulating film 27 prevents the upper and lower electrodes 15 and 25 from being short-circuited and the layers on the substrates 1 and 2 are relatively thin and hold the liquid crystal thin and constant at the part which is used for a display, which is therefore uniform even at the time of the high-time-division driving. Consequently, the image of high quality is obtained even in the display mode of the high-time- division driving.

Description

DETAILED DESCRIPTION OF THE INVENTION A) Field of Industrial Application The present invention relates to a field-effect crystalline display protection having a color filter layer.

B) Conventional technology When color display is conventionally performed using a liquid crystal display,
A color filter layer is used, but if the color filter layer is provided outside the display, misalignment between the color filter and the pixels (electrodes) will occur depending on the viewing direction, so the method disclosed in Japanese Patent Laid-Open No. 102061/1983 It is listed on the bow,
The color filter layer is provided on the inner surface of a substrate such as glass that holds the liquid crystal. In such a display device, since a plurality of layers are stacked on a substrate, it is difficult to control the thickness of the entire layer and the flatness of the surface in contact with the liquid crystal.

On the other hand, in order to improve the high time division characteristics when displaying a large area, it is recommended to homogeneously orient the liquid crystal molecules so that they form a helical structure with a twist angle larger than 180 degrees. This display mode is described in a rare publication, etc., but due to the uneven thickness of the liquid crystal layer, birefringent interference colors due to night crystals are detected. must be strictly filled.

C) Problems to be Solved by the Invention In order to provide a color filter layer on the inner surface in a high time division drive display mode, it is necessary to make the filter layer flat and to make the entire layer thin. For example, when the color filter layer is polished, the colors become lighter and the color filter layer easily peels off.Also, if the liquid crystal layer is thin and the layer on the base is thin, short-circuit accidents may occur between the electrodes below. Cheap.

2) Means for Solving the Problems The present invention was developed in consideration of the above points, and uses a display mode in which liquid crystal molecules are homogeneously aligned so as to form a spiral structure with a twist angle larger than 180 degrees. In doing so, an insulating film is provided on the inner surface of the substrate where no color filter layer is provided.

Further, the present invention provides l! color filter layers provided on the same substrate! 'IXe electrode layer 2 is provided in a stripe shape longer than the region where the electrode layer is provided.

E) Effect: As a result, short circuits between the upper and lower electrodes are prevented by the insulating film, and the layers of each curtain plate are made relatively thin.In the area used for display, the thickness of the liquid crystal can be kept thin and constant, so that the high time sum of 1 Uniform display is also achieved during driving.

Embodiment FIGS. 1 and 2 are cross-sectional views of essential parts of a liquid crystal display according to the present invention in the ldl direction and the Y-axis direction. (1) is a color filter layer (+2) (13) (1) on a base (11) such as glass.
4), an electrode layer (l5), and an alignment film (lG).
This is the board.

(2) is a second substrate having an electrode j1 (25), an insulating film (27), and an alignment film (26), which is arranged in parallel with the first substrate (1), and whose peripheral part is coated with a sealant. (3) is attached to form a liquid crystal cell. (4) is a liquid crystal layer sandwiched between these first and second substrates (1) and (2). Nematic liquid product with positive Rt anisotropy. The liquid crystal molecules consist of spiral grooves with a twist angle larger than 180 degrees, specifically 180 to 360 degrees.
The selected angle is 220 degrees, for example, and the C is homogeneously oriented.

2) The two-sided crystal display is arranged so that the liquid crystal layer (4) is sandwiched between the two.
A polarizer (5) is provided, and when the birefringence Di t of the liquid crystal changes, a phase [(6) is inserted between the liquid crystal layer (4) and the polarizer (5).

With such caution, the color filter layer (l2) (+
3) (14) is provided in stripes of three colors so as to sequentially fill the holes of a black contour filter (18) having stripe-shaped holes provided in advance. For example, these striped filter layers can be obtained as follows! L.

First, a varnish of, for example, an acrylic polymer resin is applied to the base tj (1 l) using a svinner to form a film with a thickness of l, 5 μn1, and on this, for example, varnishes of 300 μm in width and 23 μm apart are applied.
A pattern of striped holes of m is formed. After that, a black contour filter (l8) can be obtained by dipping it in a solvent mixed with an acidic dye or by coating it with a solvent and dyeing it to fix the dye.

Next, this base (11) is again coated with an acrylic polymer f-t.
M-based varnish is applied with a tinner to form a film with a thickness of about 1.5 μm, and this is patterned by matching every two striped holes of the contour filter (18). Then, the filter layer (12) of the first color can be obtained by immersing it in a solvent mixed with an acidic dye of a predetermined color or applying a solvent and dyeing it to fix the dye.

By repeating this process while shifting the position of the two putters, the area surrounded by the contour filter (l8) is
A color filter layer (12)(13)<14) of color can be obtained.

After this, the color filter layers (12), (13), and (11) are surface-treated, and a flattening film (19) is applied on top of them as necessary.
A transparent electrode film (13) and an alignment film (
16) are stacked in this order, and the alignment film (l6) is subjected to an alignment treatment such as rubbing to complete the l-th JlfI plate (]).

In such a first substrate (1), a color filter N
Although (12), (13), and (14) are applied multiple times, since they are provided to fill the striped holes, by controlling the coating direction and coating speed of the filter base, such as the position of the spinner, Since the central part of the substrate can be flattened, unevenness will occur only at the edges of the striped filter in the longitudinal direction, and even if flattening M (19) is provided, the liquid crystal will not be visible in this area. Unevenness in thickness is unavoidable, and alignment unevenness and domains are likely to occur.

Therefore, the electrode layer (l5) is the color filter layer (12) (
13J (14) near the striped longitudinal edge,
For example, it may be provided at a distance of 0.2 to 2.5 mrn or more from the center.

On the other hand, the second substrate (2) is coated with various films by vapor deposition, spinner, etc., and the insulation M (27-) is surrounded by SIOt, a silane compound, a titanium compound, etc. If this insulating film (27) is provided on the lth substrate, the overall thickness of the layer will increase, resulting in poor stability of the stack, unnecessarily high driving voltage, or uneven orientation. Undesirable. When providing it on the second substrate, it is necessary to maintain the stability of the film quality and take care not to make the driving voltage too high. Therefore, in order to insulate to prevent short circuits, an inorganic film with a thickness of 200 μm-l is required. Although it is sufficient if the thickness is SOO μm, it is preferably 800 to 2000 μo1 for an inorganic film and 900 to 3000 μm for an agitated film.

g) 5P. Effect of brightness The chromaticity coordinates and transmittance of the color filter layer formed in this way are black (x=0.3 1 5, y=o, 298) when measured in the state of a liquid crystal display number substrate, for example. Red (0.
628, 0, green (L 297, O. old' (0, 1 3 5, 0., 2
In a 30×14 liquid crystal display, each pixel with an effective display area of Omm could be clearly distinguished in color. In addition, short circuits between the 1E and IE electrodes are prevented by the insulating coating, and the layers of each substrate are relatively thin, allowing the thickness of the liquid crystal to be kept thin and constant in areas that are used infrequently, even in high time division driving. A uniform image with high display quality was obtained.

[Brief explanation of drawings]

Figures 1 and 2 show XIdl of the liquid crystal display according to the present invention.
It is a sectional view of the main part in the direction and the Y-axis direction.

Claims (1)

[Claims] 1) A first substrate having a color filter layer, an electrode layer, and an alignment film, a second substrate having an electrode layer and an alignment film, and a liquid crystal sandwiched between these substrates. In the liquid crystal display device, the second substrate is provided with an insulating film, and the molecules of the liquid crystal are homogeneously aligned in a helical structure with a twist angle larger than 180 degrees. A liquid crystal display featuring 2) In a liquid crystal display comprising a substrate having a color filter layer, an electrode layer, and an alignment film, a substrate having an electrode layer and an alignment film, and a liquid crystal layer sandwiched between these substrates, the color The filter layer is provided in a stripe shape that is longer than the area where the electrode layer is provided on the same substrate, and the liquid crystal molecules have a helical structure with a twist angle larger than 180 degrees. A liquid crystal display characterized by being homogeneously aligned.