JPH0634999A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To facilitate the alignment of respective leader electrodes of a pair of substrates facing each other, to lessen the voltage drop near the leader electrodes and to improve image quality. CONSTITUTION:This liquid crystal display device consists of a pair of substrates which faces each other holding a liquid crystal compsn. therebetween. At least one of these substrates is consisting of a color filter having light shielding layers 2 which consist of the metal patterned and formed by opening picture element parts on one main surface of the transparent substrates 1 and colored layers 3a, to 3c formed in the picture element parts of the light shielding layers 2 and transparent electrodes 4 formed on the colored layers. Further, the integrally projecting leader electrodes 2a are formed on the peripheral edges of the light shielding layers 2 and further, the transparent electrodes 4 are extended to the light shielding layers 2 and are electrically connected thereto.

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 device,
In particular, it relates to the improvement of the color filter.

[0002]

2. Description of the Related Art Generally, a liquid crystal display device has (1) a passive display with extremely low power consumption, (2) a low voltage drive, (3) a panel type device, and (4) a large display (5) Low cost, and other features not found in light-emitting displays, including laptop-type and book-type portable computers and word processors, and various other types. Widely used as a display for OA equipment. In particular, in recent years, it has attracted attention as the only display capable of full color display other than the color CRT.

Such a liquid crystal display device is roughly divided into a simple matrix type and an active matrix type according to a driving method, and basically, transparent electrodes are formed on a facing surface of transparent substrates which are arranged facing each other so as to form a large number of pixels. Then
It has a structure in which a liquid crystal composition is held between these electrodes,
For full-color display, for example, the plan view of FIG. 3 and FIG.
The color filter shown in the sectional view of FIG.

In this color filter, a light-shielding layer (black matrix) 2 is formed on a part of the main surface of the transparent substrate 1 which partitions the individual pixel portions, and the pixel portions partitioned by the light-shielding layer 2 are R-shaped. Colored layers 3a, 3b, 3c composed of (red), G (green), and B (blue) are formed.
A transparent electrode 4 and an alignment film 5 are sequentially formed on a, 3b and 3c. In FIG. 3, the hatched portion is the transparent electrode 4, and a plurality of lead electrodes 4a that integrally project are formed on the peripheral edge of the transparent electrode 4.

In the above case, a glass substrate or the like is used as the transparent substrate 1, and the light shielding layer 2 is formed by the pattern etching method of the Cr film formed by the sputtering method. Furthermore, the colored layers 3a, 3b, 3c are R (red),
A method of arranging three kinds of pigments corresponding to the three primary colors of G (green) and B (blue) in each pixel portion one by one is used, and the arrangement method includes a dyeing method, a dye dispersion method, and a pigment dispersion method. Law,
Printing methods, electrodeposition methods, dye vapor deposition methods, etc. are known. still,
An ITO (Indium Tin Oxide) film is used for the transparent electrode 4, and a polyimide film is generally used for the alignment film 5.

A color liquid crystal display device using such a color filter is constructed, for example, as shown in FIG. That is, this figure is an exploded perspective view of a three-terminal type TFT (thin film transistor) active matrix type color liquid crystal display device. In the figure, reference numeral 6 is a color filter, and the same portions as those in FIG. The alignment film 5 is omitted in FIG.
An array substrate 7 is arranged so as to face the color filter 6, and a pixel electrode 9 made of an amorphous silicon thin film transistor is formed on a transparent substrate 8 of the array substrate 7. The liquid crystal composition 10 is sandwiched between the color filter 6 and the array substrate 7. Further, polarizing plates 11 and 7 are provided outside the color filter 6 and the array substrate 7, respectively.
12 are stacked, and a three-wavelength type backlight source 13 is arranged outside the polarizing plate 13.

In operation, when the red liquid crystal pixels are in the transmissive state (thin film transistor is in the off state), only red light is transmitted. Similarly, by selecting pixels, only green light and blue light can be transmitted, and three primary colors can be obtained by the additive color mixing method. Further, by adjusting the switching timing, it is possible to add gradation and full color display is possible.

[0008]

In the color filter of the conventional liquid crystal display device described above, the transparent electrode 4 is used.
When the number of the extraction electrodes 4a integrated with is increased, the patterning becomes more sophisticated and it becomes difficult to align the extraction electrodes of the array substrate 7 and the color filter 6 at the same time. In addition, the voltage loss near the extraction electrode is large.

The present invention has been made in view of the above circumstances, and it is easy to align the extraction electrodes of the pair of substrates facing each other, the voltage loss near the extraction electrodes is small, and the image quality can be improved. An object is to provide a display device.

[0010]

According to the present invention, at least one of a pair of substrates sandwiching a liquid crystal composition and facing each other is:
A light-shielding layer made of metal and formed by patterning the pixel portion on one main surface of the transparent substrate, a colored layer formed in the pixel portion of the light-shielding layer, and a transparent layer formed on the colored layer. A liquid crystal display device comprising a color filter having an electrode, an extraction electrode integrally formed on the periphery of the light shielding layer, and a transparent electrode extended to and electrically connected to the light shielding layer. is there.

[0011]

According to the present invention, the lead-out electrode which is integrally projected is formed at the peripheral portion of the light-shielding layer made of metal, but it is the first layer, so that it can be formed accurately. Therefore, the array substrate and the color
It is easy to align the respective extraction electrodes of the filter. In addition, the extraction electrode of the color filter is ITO
Since the resistance is halved because it is a metal, the voltage loss near the extraction electrode is small.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

The present invention is an improvement of the color filter of the liquid crystal display device, and only the color filter will be described. That is, the color filter in the liquid crystal display device of the present invention is configured as shown in FIGS.
The same parts as those in the conventional example (FIGS. 3 and 4) are designated by the same reference numerals. Reference numeral 1 in the figure is a transparent substrate obtained by subjecting a borosilicate glass plate having a thickness of 1.1 mm to a surface cleaning treatment. A light shielding layer (black matrix) 2 made of metal is formed on a portion of the transparent substrate 1 that separates individual pixel portions from one main surface. The light-shielding layer 2 is formed in a predetermined pattern by forming a Cr film having a thickness of 0.15 μm by a sputtering method or the like and then etching away unnecessary portions by a photolithography method. Further, a plurality of lead-out electrodes 2a that are integrally projected are formed at the corners of the peripheral edge of the light-shielding layer 2. The extraction electrode 2a is located at a position corresponding to the extraction electrode on the array substrate. Colored layers 3a, 3b, and 3c are formed in the pixel section defined by the light-shielding layer 2. In this case, each of the colored layers 3a, 3b and 3c made of R (red), G (green) and B (blue) having a thickness of 2 μm is formed by a photolithography method using a color resist containing each color pigment. By a predetermined pattern, that is, each colored layer 3a, 3b,
3c is formed so as to be arranged at a predetermined position in each of the openings of the light shielding layer 2 which constitutes at least a pixel.
A thickness of 750 to 150 is applied on the colored layers 3a, 3b, 3c.
A transparent electrode 4 of 0 angstrom and an alignment film (not shown) having a thickness of 40 nm are sequentially laminated. In FIG. 1, the shaded portion is the transparent electrode 4, and as shown in FIG.
Is electrically connected to. As a result, the transparent electrode 4
The lead electrode 2a formed on the light shielding layer 2 and the lead electrode 2a are electrically connected to each other.

Since the liquid crystal display device of the present invention has the same structure as the above-described liquid crystal display device shown in FIG. 5 except for the color filter, detailed description thereof will be omitted.

[0015]

According to the present invention, the lead-out electrode that integrally projects is formed at the peripheral portion of the light-shielding layer made of metal, but since it is the first layer, it can be formed accurately. Therefore, it is easy to align the extraction electrodes of the array substrate and the color filter. Also, since the extraction electrode of the color filter is made of metal rather than ITO, the resistance value is halved, so the voltage loss near the extraction electrode is small, and the crosstalk in the image quality after cell formation is reduced. Can be improved.

[Brief description of drawings]

FIG. 1 is a plan view showing a color filter in a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a plan view showing a color filter in a conventional liquid crystal display device.

FIG. 4 is a sectional view of FIG.

FIG. 5 is an exploded perspective view of a general color liquid crystal display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate, 2 ... Light-shielding layer, 2a ... Extraction electrode, 3
a, 3b, 3c ... Colored layer, 4 ... Transparent electrode.

Claims (1)

[Claims] 1. A light-shielding layer made of metal, wherein at least one of a pair of substrates sandwiching a liquid crystal composition and facing each other comprises a metal formed by patterning a pixel portion on one main surface of a transparent substrate. In a liquid crystal display device comprising a color filter having a colored layer formed in the pixel portion of the light shielding layer and a transparent electrode formed on the colored layer, a lead-out unit integrally protruding to the peripheral portion of the light shielding layer. A liquid crystal display device comprising an electrode, and the transparent electrode extended to and electrically connected to the light shielding layer.