JP2510340Y2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a structure of a black light-shielding film provided in an outline of each pixel in order to enhance display contrast and widen a color reproduction range.

[Conventional technology and its problems]

In the liquid crystal display device, the following description will be given by taking a simple color matrix system as an example.

The structure of the liquid crystal display device is shown in FIG. Transparent top substrate 12
A liquid crystal 24 is enclosed between the lower substrate 14 and the lower substrate 14. The lower substrate 14 has an insulating property, and a row electrode 20 and a black light-shielding film are provided above and below the color filter layer 18 made of red, green, and blue, respectively.
16 and The black light shielding film 16 is made of a black material having a light shielding property such as chrome. Column electrodes 22 on the upper substrate 12
To provide. The column electrodes 22 and the row electrodes 20 are made of a transparent conductive film such as indium tin oxide (ITO).

As shown in FIG. 5, the column electrodes 22 and the row electrodes 20 are configured to be orthogonal to each other, and each intersection of the row electrodes 20 and the column electrodes 22 constitutes a pixel 28. This one by one pixel
An image is displayed by controlling the amount of light transmitted through 28.

The structure of the black light shielding film 16 is described in, for example, Japanese Patent Laid-Open No. 63-184706. As shown in FIG. 6, in the black light-shielding film described in this publication, the black light-shielding film 16 is continuously formed in a mesh shape in the contour of the pixel 28.

Therefore, as shown in the equivalent circuit of the liquid crystal display device of FIG. 7, stray capacitances 26 composed of the black light-shielding film 16, the color filter layer 18 and the row electrodes 20 are formed in each row electrode 20a, 20b, 20c. It Looking at the capacitance between, for example, 20a and 20b of the row electrode 20, all the stray capacitances of 26a, 26b, and 26c are 20a.
It will be applied between the row electrodes of 20b.

As a result, due to the stray capacitance 26, each row electrode 20a, 20b, 20c
Mutual interference occurs between them, and normal image display on the liquid crystal display device is not performed.

An object of the present invention is to provide a black light-shielding film structure for solving the problem of image display in a liquid crystal display device due to the above stray capacitance.

[Means for solving the problem]

In order to achieve the above object, the liquid crystal display device of the present invention is
It is characterized by having the following configuration.

That is, having a signal electrode on one substrate sandwiching the liquid crystal layer, having a color filter layer on the other substrate, having a scanning electrode on one side of the color filter layer, on the other side,
In a liquid crystal display device having a conductive light-shielding film corresponding to a contour of a pixel portion, at least each light-shielding film corresponding to a pixel having a common scanning electrode is electrically insulated from the light-shielding film. The liquid crystal display device suppresses mutual coupling of stray capacitances formed between the light-shielding film and each scanning electrode.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing a first embodiment of the black light shielding film of the present invention. The black light-shielding film 16 is provided with a break region 30 between adjacent black light-shielding films 16a, 16b, 16c, 16d to make the black light-shielding film 16 discontinuous. The size of the break region 30 is set to about 3 μm so that the display contrast of the image display of the liquid crystal display device is not lowered.

As a result, as shown in the equivalent circuit of the liquid crystal display device of FIG. 2, when looking at the capacitance between the row electrodes 20, for example, 20a and 20b, only the stray capacitances of 26a and 26b are shown in the rows of 20a and 20b. Applied between the electrodes.

FIG. 3 is a plan view showing a second embodiment of the black light shielding film of the present invention. In the first embodiment described with reference to FIG. 1, the break region is provided in the direction in which the column electrodes are formed.
The black light shielding film 16 according to the second embodiment of the present invention is provided with break regions 30 in both the direction in which the column electrodes are formed and the direction in which the row electrodes are formed. The longest dimension of the black light shielding film 16 is set to the size of a pixel. In the black light shielding film structure shown in FIG. 3, stray capacitance is reduced by the black light shielding film structure shown in FIG.

In the above description, the color simple matrix method has been described, but the black light shielding film structure of the present invention can also be applied to the black and white simple matrix method. Furthermore, the black matrix film structure of the present invention can be applied to an active matrix system in which active elements such as transistors and diodes are provided in each pixel. In this active matrix system, a stray capacitance is formed by the black light-shielding film, the color filter layer, and the wiring for supplying a signal to the active element.

As a method of forming the black light-shielding film 16, a black light-shielding material such as chromium is formed on the entire surface of the lower substrate 14 by a vacuum vapor deposition method or a sputtering method, and then a photosensitive resin is applied and a photomask is used. The black light-shielding film 16 is formed by using a so-called photo-etching technique in which the photosensitive resin is exposed to light and developed, and the photosensitive resin is used as a mask for etching. Alternatively, on the lower substrate 14, a metal mask having an opening is arranged only in a region where the black light-shielding film 16 is formed, vacuum vapor deposition is performed to form the black light-shielding film 16 in the metal mask opening, or by a printing method. To do.

[Effect of device]

As is clear from the above description, by providing the black light-shielding film with the breakage region and making it discontinuous, the capacitance between the row electrodes is significantly reduced and the mutual interference between the row electrodes is suppressed, and the image of the liquid crystal display device is suppressed. The display characteristics are improved.

[Brief description of drawings]

FIG. 1 is a plan view showing a black light shielding film in a first embodiment of the present invention, FIG. 2 is a circuit diagram showing an equivalent circuit of a liquid crystal display device in the present invention, and FIG. 3 is a second embodiment of the present invention. FIG. 4 is a plan view showing a liquid crystal display device, FIG. 4 is a plan view showing a liquid crystal display device, and FIG.
FIG. 7 is a plan view showing a black light shielding film in a conventional example, and FIG. 7 is a circuit diagram showing an equivalent circuit of a liquid crystal display device in the conventional example. 16 ... Black light-shielding film, 20 ... Row electrode, 22 ... Column electrode, 26 ...
… Stray capacitance, 30 …… breakdown area.

Claims (2)

(57) [Scope of utility model registration request] 1. A signal electrode is provided on one substrate sandwiching a liquid crystal layer, a color filter layer is provided on the other substrate, a scanning electrode is provided on one side of the color filter layer, and a scanning electrode is provided on the other side.
In a liquid crystal display device having a conductive light-shielding film corresponding to the contour of a pixel portion, at least for each light-shielding film corresponding to a pixel having a common scanning electrode, the light-shielding film is electrically insulated from each other. Liquid crystal display device characterized by. 2. The liquid crystal display device according to claim 1, wherein a light-shielding film corresponding to a pixel having a common scanning electrode is electrically insulated for each portion corresponding to each pixel.