JPH0432820A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To obviate the deterioration of thin-film transistors (TFTRs), etc., and image quality by providing the TFTRs which arrange liquid crystal materials by each picture element on the opposite surfaces of substrates and providing plural projections as spacing holding members off the regions of the TFTRs. CONSTITUTION:The liquid crystal display device constituted by sealing the liquid crystal materials between two sheets of the substrates 41 and 50 is provided with the TFTRs which arrange the liquid crystals by each picture element on the opposite surfaces of the substrates and the plural projecting parts 53 as the spacing holding members off the regions of the TFTRs and the picture elements. The deterioration of the TFTRs and the image quality is obviated even with the liquid crystal display device of a dynamic driving type in this way and the damaging of the TRs and display electrodes 48 is obviated as well.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a liquid crystal display device, and more particularly to a dynamic drive type liquid crystal display device having a plurality of protrusions as spacing members between two substrates.

(Prior Art and its Problems) Conventionally, there has been a liquid crystal display device in which two substrates are arranged with a distance of 2 to 15 μm apart, and a liquid crystal substance is sealed between the substrates.

In this conventional liquid crystal display device, a predetermined amount of a spherical spacing member made of glass or the like is mixed into the liquid crystal material to maintain a predetermined spacing between the two substrates, thereby achieving uniform precision in all pixel areas. I wanted to be able to make a good display of this.

However, in a dynamic drive type liquid crystal display device in which a thin film transistor or the like is formed on a substrate to drive each pixel, if such a spherical spacing member is placed on the thin film transistor, the spherical spacing will not be maintained. There is a problem in that the members press against the thin film transistor, causing deterioration of the thin film transistor or inducing failure.

There is also the problem that the spherical spacing member deforms due to thermal expansion or contraction, resulting in a change in spacing and deterioration of image quality.

The present invention has been devised in view of such problems, and provides a liquid crystal display device that does not cause deterioration of thin film transistors or deterioration of image quality even in a dynamic drive type liquid crystal display device. The purpose is to

(Means for Solving the Problems) According to the present invention, in a liquid crystal display device in which a liquid crystal material is sealed between two substrates, thin film transistors are provided on opposing surfaces of the substrates to arrange the liquid crystal material for each pixel. In addition, there is provided a liquid crystal display device characterized by comprising a plurality of protrusions as spacing members outside the area of the thin film transistor, thereby achieving the above object.

(Example) Hereinafter, the present invention will be explained in detail based on the accompanying drawings.

FIG. 1 is a schematic diagram showing the basic configuration of a transistor matrix array. The display screen is divided into a matrix of m lengths and n widths, and is divided into a total of m"n unit pixels.The intersections of each matrix are C1, 15, C1, 2,
...C1,j...Cm,n constitute a pixel circuit with a switching function, in which image information of each pixel is stored, and according to this information, each pixel of the liquid crystal layer provided on the matrix array is The display is realized in an area corresponding to the .

FIG. 2 shows a specific pixel circuit. In order to obtain a high-definition display screen, the matrix size m·n becomes extremely large, and in order to create a matrix array with high yield, a simpler circuit is desired. To that end, the second
A simple configuration as shown in the figure is used.

In FIG. 2, 21 is a switching transistor;
2 is a liquid crystal layer, and 23 is a capacitor for storing image signals. The gate of transistor 21 is connected to the first address line
i, and the source electrode is connected to the jth data line Y
connected to j. Address line Xi and data line Yj are V(Xi) and V(Yj), respectively.
power is connected.

When a signal that turns on the transistor 21 is input to the address line Xi, the channel of the transistor 21 becomes conductive, and at this time, the image signal prepared for the data line Yj is stored in the capacitor 23, and the gate voltage V (Xi ) is While zero, the signal is stored in C8. The liquid crystal 22 is driven in accordance with this accumulated image signal. Note that all other transistors on the address line X are also turned on at the same time.
The image signals V (Yl') and V (Y2
'), ·V(Yn) is each pixel circuit CiL Ci2...C
stored in. Similarly, Xi+1, Xi+2
By sequentially driving each address line, image signals are accumulated one after another, and signals for the entire screen are written.

FIG. 3 is a cross-sectional view of the transistor and display electrode portion.

A ground conductor film 42 and an address line 44 which also serves as a gate electrode of a transistor are provided on the entire surface of an insulating substrate 41. A semiconductor thin film 46 is formed on each pixel region via an insulating film 45 serving as a gate insulating film, and a source electrode 47 connected to a Y address line (not shown),
A display electrode 48 serving as both a drain electrode and a storage capacitor electrode is provided. Further, the surface of this substrate is covered with an insulating film 49 having holes in the display pixel area. As described above, the storage capacitor is constructed using the display electrode 48 as one terminal electrode, the ground conductor film 42 as the other terminal electrode, and the insulating films 43 and 45 sandwiched between them. Transistor matrix array and transparent electrode 5 configured in this way
A liquid crystal display device is constructed by sandwiching a liquid crystal material 52 between a glass substrate 50 and a glass substrate 50 on which a liquid crystal material 52 is formed.

A liquid crystal display device as described above is formed according to the following steps.

First, on a glass substrate 41, a plurality of ground conductor films 42 made of transparent conductive films and an address line 44 which also serves as a gate electrode are patterned. Ground conductor film 42 and address line 4
4 are parallel and the gap therebetween is about 5 μm. Next, normal pressure C
A 5i02 film 45, which will become a gate oxide film, is deposited to a thickness of approximately 1500 nm by a VD method or the like. After that, an amorphous silicon film 46 (461,462
) is deposited to a thickness of 1,500 layers and patterned into a desired size using exposure etching technology. Then, source electrode/data lines 47 (471, 472, . . . ) and drain electrodes 48 (481, 482, . . . ) are formed using an AI film with a thickness of 5,000. Then, a sputtered 5i02 film 41 having a thickness of 2 to 10 μm is deposited, and the 5i02 film on the display electrode 48 is removed by etching to complete the matrix array. Note that the surface portion of the sputtered S i 02 film 41 on this transistor is removed by etching to a film thickness of 2,500 mm.

In this case, as shown in FIG. 4, a plurality of protrusions 53 having a thickness of 2 to 10 μm are left outside the area of the display electrode 48 and outside the area of the transistor by etching. When the plurality of protrusions 53 are formed using the S i 02 film in this way, they can be formed at the same time as the thin film transistor forming process, and the plurality of protrusions 53
No special process is required to form the . Further, since the plurality of protrusions 53 are formed in areas other than the thin film transistor and the display electrode 48, the transistor and the display electrode will not be damaged.

The entire process is completed by placing a glass substrate 50 on which a transparent electrode 51 is formed to be used as a display panel, facing the matrix array, and holding a liquid crystal 52 sealed therebetween. When the glass substrate 50 is placed opposite the glass substrate 41, the plurality of protrusions 53 formed at predetermined portions on the glass substrate 41 come into contact with other glass substrates 50, and the glass substrates 41 and 50 are held at a constant distance. That will happen. Note that it is sufficient for the plurality of protrusions to occupy 0.5 to 2% of the total panel area.

Note that the present invention is not limited to the above embodiments.

For example, the ground conductor is not limited to a transparent conductive film, and may be any patternable metal material such as AI or Mo, and the address line is not limited to MO. Further, the insulating film is not limited to the 5i02 film, and its manufacture can also be performed using a CVD method, a sputtering method, a tube coating method, an anodic oxidation method, or the like. Also,
Thin film transistors are not limited to those using amorphous silicon, but may also be polycrystalline silicon, or those made by irradiating amorphous silicon or polycrystalline silicon with a light energy beam such as an electron beam or a laser beam to form a single crystal.

(Effects of the Invention) As described above, according to the liquid crystal display device according to the present invention, in a liquid crystal display device in which a liquid crystal substance is sealed between two substrates,
A dynamic drive type liquid crystal display is provided, in which thin film transistors are provided on opposing surfaces of the substrate for arranging liquid crystal material for each pixel, and a plurality of protrusions as spacing members are provided outside the area between the thin film transistors and the pixels. Also, it is possible to provide a liquid crystal display device that does not cause deterioration of thin film transistors or the like and does not cause deterioration of image quality.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the basic configuration of a transistor matrix array, FIG. 2 is a diagram showing a specific pixel circuit configuration,
FIG. 3 is a sectional view showing an embodiment of the liquid crystal display device according to the present invention, and FIG. 4 is a plan view of the pixel portion. Figure 2 41.50 Glass substrate 52: Liquid crystal 53: Protrusion

Claims (1)

[Claims] In a liquid crystal display device in which a liquid crystal material is sealed between two substrates, a thin film transistor is provided on opposing surfaces of the substrates to arrange the liquid crystal material for each pixel, and a spacing member is provided outside the area between the thin film transistor and the pixel. A liquid crystal display device comprising a plurality of protrusions.