JPH0915581A - Substrate for liquid crystal display device - Google Patents

Abstract

PURPOSE: To make the discontinuity of a transparent electrodes small, to stabilize the characteristic of a device and improve display quality of a picture by allowing transparent electrode formed on the filter layers on a base via an insulating film to be provided with bent at the upper parts of a almost center parts of the filter layers. CONSTITUTION: Plural filter layers 2 consisting of light shielding filters 21 and coloring filters 2R, 2G, 2B of red, green and blue are provided on the surface of a base 1 consisting of transparent flat plates, etc. Transparent electrodes 3 consisting of many lines provided on the filter layers 2 via an insulating film 4 are respectively arranged parallel each other in a display area and are provided with bent parts at the upper parts of almost center parts of the filter layer 2. The transparent electrodes 3 are provided by being made to be almost orthogonal to stripes of coloring filters in a display area and many of the bent parts of the transparent electrode 3 are arranged in the filter layer of a specific color. Consequently, in the bent parts 30, the deformations of a pattern shape are generated at smooth or flat part and also mutual influences with respect transparent electrodes are made constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display substrate having a color filter layer.

[0002]

2. Description of the Related Art In recent years, in so-called liquid crystal displays in which liquid crystal is sandwiched between substrates, there are increasing numbers of those which provide a color filter on a liquid crystal display substrate to perform color display. Such a liquid crystal display substrate is disclosed in Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Publication No. 17626, a filter layer, an insulating layer, a transparent electrode, and an alignment film are laminated in this order on the surface of a base.

[0003]

By the way, when the display capacity of a liquid crystal display increases, the number of electrodes increases, and the positions and arrangement of terminals provided on the extension of the electrodes also increase. The transparent electrode cannot be linearly arranged up to the terminal portion, and the pattern must be bent and provided. When the transparent electrode is bent and drawn around in this way, the resistance value of the transparent electrode increases, and the contrast of the liquid crystal display changes depending on the location, and the transparent electrode is often broken.

[0004]

The present invention has been made in consideration of the above points, and includes a base, a filter layer provided on the surface of the base, and an insulating film on the filter layer. In a liquid crystal display substrate having a transparent electrode provided as an alignment film and an alignment film covering the transparent electrode, the transparent electrode has a bent portion above a substantially central portion of the filter layer, and is more preferable. Is a colored filter in which the filter layer is provided in a stripe pattern arranged at intervals, the transparent electrode is provided substantially orthogonal to the stripe of the filter layer in the display part, and the bent part of the transparent electrode is adjacent transparent. Many are arranged in a filter layer of a specific color together with the electrodes.

[0005]

As a result, the surface of the specific filter layer and the transparent electrode maintain a substantially constant surface relationship, and the adjacent transparent electrodes are supported by the underlying layer under common conditions, so that the transparent electrode is stabilized.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view a and a side sectional view b of an essential part of a substrate for a liquid crystal display according to an embodiment of the present invention, in which 1 is a base made of a transparent flat plate or the like. Has an overcoat. Reference numeral 2 denotes a plurality of filter layers provided on the surface of the base 1, which includes a light blocking filter 21 and red, green, and blue colored filters 2R, 2G, and 2B. 2B may be formed of a resin layer containing a dye or a pigment. Reference numeral 3 denotes a transparent electrode composed of a large number of electrodes provided on the filter layer 2 with an insulating film 4 interposed therebetween. The transparent electrodes 3 are arranged in parallel with each other in the display area and are bent above the substantially central portion of the filter layer 2. It has a section 30. That is, when focusing on any one of the transparent electrodes 3, the transparent electrode is divided into a display electrode section in the effective display surface (left side of the figure) and a terminal section of the substrate peripheral section (right side of the figure), the display electrode section and the terminal section. The display electrode portions are arranged in parallel with the adjacent transparent electrodes with a predetermined width and at a predetermined interval, and the terminal portions are arranged in an array so as to be connected to a driving element or the like. The lead portion may have a constant width, but the width is changed and the lead portion is bent. The bent portion 30 of the transparent electrode 3 is placed above the central portion of any one of the filters 2R, 2G and 2B. Reference numeral 5 is an alignment film that covers the transparent electrode 3.

A more specific description will be given. The base 1 may be made of plastic or the like as long as it can secure a certain degree of flatness. However, for the purpose of strictly controlling the thickness of the liquid crystal, for example, a birefringence type liquid crystal display or a high density transparent electrode wiring, a glass is used. Is preferred. In the filter layer 2, the light-shielding filter 21 is a metal film having a thickness of about 0.1 μm or a resin film having a thickness of about 1 μm in a lattice shape.
Each of R, 2G, and 2B is a resin layer having a thickness of about 1 μm, but it is preferable that the light-shielding filter 21 is formed of a metal thin film, and the coloring filters 2R, 2G, and 2R are resin layers so that the surface of the coloring filter layer is flat. It is more preferable because the property is obtained. The flatness does not mean a perfectly horizontal plane, but means that it is suitable as a base layer for a transparent electrode. And the colored filters 2R, 2G, 2B
At least one of them is more preferably provided in stripes arranged at intervals with respect to the column of pixels, and it is preferable that its cross section has a protruding edge rather than a blunt edge. The insulating film 4 has a thickness of 1 to 3 μm, is made of an organic polymer, an inorganic material, or a laminated body of these, and prevents the substance that affects the liquid crystal from seeping out from the filter layer 2 and flattens the surface. is there.

The transparent electrode 3 is preferably provided substantially orthogonal to the stripes of the colored filter in the display portion in order to keep the pattern edge clear, and the bent portions 30 of the transparent electrode 3 are arranged in many filter layers of a specific color. It was done. For example, the pixel size is 63 μm × 229 μ
m, the pixel pitch is 83 μm pitch and 249 μm pitch, the stripe coloring filter 2R having a width of 70 μm, 2
The transparent electrode 3 having a width of 232 μm in the display electrode portion, which is orthogonal to G and 2B, is 65 μ above the green colored filter 2G.
In a region of m × 500 μm, 128 units connected to one drive element are set as a unit, and substantially all transparent electrodes of the unit are bent at a maximum of about 130 degrees (50 degrees). In this case, the surface shape of the coloring filter is slightly gentle and appears on the surface of the insulating layer 4, and the shape of the surface of the coloring filter (for example, U-shape, L-shape,
Or it is flat, and in the green example 2G of FIG.
And the shape (cross-sectional shape) formed by the transparent electrode substantially match, and the bent portion 30 of the transparent electrode is an area including the center of the shape formed by the surface of the colored filter 2G, so that the pattern shape is deformed in a gentle or flat portion. And the mutual influence on the adjacent transparent electrodes 3 is also constant, and it is considered that cracks, disconnections, and peeling of the transparent electrodes are less likely to occur.

For example, in the conventional case in which the bent portion of the transparent electrode is arranged without being aware of the colored filter portion, cracks of various sizes occur in almost all of the liquid crystal display substrate. 5 to 5 in a lot
20% had a transparent electrode with a broken wire at the bent portion, but as one embodiment of the present invention, for example, all the bent portions of the transparent electrode have a green colored filter layer 2G as described above.
When it was provided on the above, no crack that could cause a disconnection was found. As a result of various other experiments, the cracks that cause such disconnection are flatness of the surface of the underlying insulating layer, etc. (because of the unevenness, it does not need to be a perfect flat surface, but may be an inclined surface, etc.). ) And the stress propagation to the adjacent transparent electrode through the insulating layer and the filter layer at the time of electrode patterning of the transparent electrode and the like are presumed to lead to cracks.

[0010]

As described above, according to the present invention, when the transparent electrode is provided on the filter layer via the insulating film, the transparent electrode has the bent portion above the substantially central portion of the filter layer. More preferably, the filter layer is provided in stripes arranged at intervals, the transparent electrode is provided in the display portion substantially orthogonal to the stripe of the filter layer, and the bent portion of the transparent electrode is specified. I placed many in the color filter layer, so
There are few cracks, disconnections, and peeling of the transparent electrode, and the characteristics are stable. Therefore, in a liquid crystal display using such a substrate for a liquid crystal display, a high-quality liquid crystal display can be provided even when a high-density transparent electrode wiring is formed or a liquid crystal display utilizing birefringence is used.

[Brief description of the drawings]

FIG. 1 is a plan view a and a side sectional view b of a main part of a liquid crystal display substrate according to an embodiment of the present invention.

[Explanation of symbols]

 1 base 2 filter layer 3 transparent electrode 4 insulating film 5 alignment film

Claims (1)

[Claims] 1. A base, a filter layer provided on the surface of the base, a transparent electrode provided on the filter layer via an insulating film, and an alignment film covering the transparent electrode. In the substrate for a liquid crystal display described above, the transparent electrode has a bent portion above a substantially central portion of the filter layer.