JPS5981621A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To enable sharp color display and to obtain superior drive characteristics by applying the electrooptical effect of a liquid crystal compsn. and using a semiconductor substrate having plural active elements formed on one of electrodes constituting a display device. CONSTITUTION:Two transistors 305, 306 connected in series formed in each unit cell 301 are scanned by an X scanning circuit 302 and a Y scanning circuit 303. When both transistor gates come into active states in accord, a time modulated display signal 304 given to the source is written on the drain. All the dots of a dot matrix display device are scanned and this scanning is repeated to obtain optional characters and figures. In addition, the scanning speed at which observers feel no flicker is necessary for the display. In order to improve deterioration of image quality of a displayed image due to the low response speed of the liquid crystals and the performance of the switching transistors at the time of nonaction, it is effective to form a capacitor in parallel to each unit cell.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a display device that utilizes the electro-optic effect of a liquid crystal composition consisting of a pleochroic dye and a nematic liquid crystal, in which a plurality of active elements are provided on one electrode constituting the entire display cell. The present invention relates to a liquid crystal 1 display device characterized by using the formed semiconductor substrate.

Liquid crystal display elements have been applied to displays in calculators and watches due to their low power and low profile characteristics, but their characteristics as general-purpose displays are not satisfactory. In other words, when using a multi-blep sensor drive, the necessary conditions include fast response speed, no change in characteristics due to temperature, and no viewing angle dependence, but in the case of liquid crystal display elements, these conditions are It cannot be said that it is a minute of light.

Therefore, its use is limited in terms of application.

The purpose of the present invention is to eliminate such drawbacks in the characteristics of liquid crystal display devices by using an electro-optic sound effect of a liquid crystal composition consisting of a pleochroic dye and a nematic fluid. A transistor is formed for each unit display element constituting the display device, and a transistor is formed for each unit display element to input the Guinamink matrix signal to drive a liquid crystal that operates in a static state.Furthermore, surface images can be displayed with arbitrary gradations. It is something to do.

Nematic liquid crystals containing pleochroic dyes have a lower market pressure than DISM liquid crystals. The present invention provides a display device that can be driven with low power consumption and eliminates the need for a polarizing sheet metal, making it suitable for thin and small portable devices.・Furthermore, FFi using conventional twisted nematic liquid crystal and original filter
By applying a display method that uses the electro-optical effect of a nematic liquid crystal composition containing a pleochroic dye, which is different from the conventional liquid crystal display method, it is possible to display clear colors and has excellent drive characteristics. The present invention provides a new liquid crystal display device.

A display device using an electro-optical effect of a nematic liquid crystal composition containing a pleochroic dye can be used to create a white pattern on a shicolor bank or a color pattern on a white bank by selecting the positive or negative polarity of the dielectric anisotropy of the nematic liquid crystal. There are several methods, and any of them can be used in the present invention.

FIG. 1 is a principle wedge diagram showing the electro-optic effect of a nematic liquid crystal composition containing a pleochroic dye. FIG. 1a shows the case where the dielectric anisotropy of the nematic liquid crystal composition serving as the matrix is negative. A conductive film 106 that is transparent to incident light 109
A fully equipped transparent flat plate 101 and an electric wire placed in parallel, i@1
A 1N nematic liquid crystal 106 containing a pleochroic dye +05 and having negative electrical anisotropy is sealed between the 04 and 04. In order to apply an electric field to this liquid crystal cell, lead wires are spread out from each electrode terminal and connected between the power source 108° switch. In this case, the inner surface of the electrode is treated so that the liquid crystal molecules are vertically aligned as shown in the figure.

In Figure 1, the electric field was set to zero. It is a model diagram of a battle. When the switch 117 is turned on between the transparent electrode 111 and the counter electrode 112, an electric field is applied, and the composition 115,1 sealed inside is
16 is oriented perpendicular to the electric field according to the direction of the tie ball of the nematic liquid crystal.

Then, the multicolor dye contained in the composition changes from state a before the application of the electric field to state b after the application of the electric field, causing a change in color tone peculiar to the dye. For example, in the case of a dichroic dye, specifically, state a is almost colorless, but state b exhibits a unique color pattern.

In the present invention, a semiconductor substrate having a semiconductor switching element is disposed in a part of the panel. Figure 2 shows the structure of the panel. A syringe gate M is formed on a silicon substrate 201.
To form an OS transistor, a gate electrode 2 iJ 2 made of polysilicon and a source 206° 2 made of a diffused VC of a conductivity type different from that of the wiring layer and substrate are used.
05 and a drain 204.204. The wiring from the source, drain, or gate electrode is made of aluminum or aluminum silicon.
Furthermore, a back electrode 2 of the unit cell is used to control the voltage applied to the liquid crystal composition 208 made of the pleochroic dye and nematic liquid crystal by the drain output and to make the element effect remarkable.
09 is provided. As the back electrode, a thin film made of a white aluminum alloy or a combination of a transparent electrode on a white insulating film can be used. Upper transparent electrode 210
And said back electric $i! , 209, the above-mentioned liquid crystal composition is sealed after being subjected to alignment treatment by rubbing or an alignment treatment agent. As the above-mentioned switching element, a silicon gate transistor has a simple manufacturing process, low operating threshold voltage, easy cell alignment and multilayer wiring, and the area occupied by the active element is small, so the effective 1r1 product of the back electrode is used. Although it has the advantage of being able to obtain a large amount of metal, other λ4 gates such as aluminum gates or
A 08 type transistor may also be used.

FIG. 3 shows a circuit of the don't-matrix liquid crystal display device of the present invention. Two series transistors 50'5 and 506 provided for each unit cell 601 connect the X scanning circuit 302 and the
It is scanned by a scanning circuit 306. When the gates of the two transistors coincide and become operational, the time modulated display signal 504 applied to the source is written to all drains.

Any character can be created by scanning all the dots on the DonTomato Links display and scanning repeatedly.

You can get shapes.

Furthermore, the scanning speed for display needs to be at a speed (20H2 or higher) at which no flicker is felt, but the image quality of the displayed image may be affected by the slow response speed of the liquid crystal and the performance of the switching transistor when not in operation. It is effective to form a capacitor in parallel with the unit cell to improve the overall drop.

This capacitor Q is an oxidation process in the semiconductor manufacturing process. Nitriding process.

It can be easily produced using a diffusion process.

Although any circuit such as a left register or a ring force transistor can be used as the above-mentioned scanning circuit, by forming it on the same substrate as the switching transistor for driving the display body, the entire mounting process can be made simpler and faster. . Further, in the circuit according to the present invention, since the digital circuit, which is a digital circuit, and the display signal, which is an analog quantity, are completely separated, gradation display can be easily performed. Furthermore, by synchronizing the circuit for selecting the potential level of the upper transparent common electrode of the display body and the circuit for inverting the display signal, it is possible to drive the 52" liquid crystal. It is possible to increase the longevity of the body.

FIG. 4 shows the implementation of a panel to provide a television-like image stand. Figure 4a shows a single semiconductor body substrate 401.
This is due to the power supply line, which is the input circuit for semiconductor circuits. video signal line. A scanning signal tail 404 is guided from the lower semiconductor substrate 401 to the electrode wiring of the upper transparent substrate 402 through a conductor layer 403 made of a metal piece or conductive paste. Therefore, connections with external circuit components are made using the upper transparent substrate, and costs can be reduced compared to a structure in which surface output is output from the lower silicon substrate. .

FIG. 4 shows the structure of a rebellion device using a plurality of silicon substrates. A coefficient number of semiconductor substrates 411 and 412 are buried flat and well on a φ5 green substrate 410 using thermoplastic resin. The interconnection 416 of the semiconductor 11t% substrate and the output electrode 414 are interconnected using a photo-etching method or a photo-etching method. Lighten things.

This invention is half 2! Although an example of a circuit configuration using MO8 type transistors on the weight plate has been described, it can also be configured using electrostatic induction type transistors having multiple gates, bihole transistors, and engineered ILs.

Furthermore, as an example of the Don Tomato Links driver jllb circuit,
We have described an example of image scanning using two transistor gates (N number of scans), but gate (
Image scanning can also be performed by S scan and source Shingetsu scan. In addition to the voltage difference method for displaying 11 gradations using '-f/' and 1 frame, it is also possible to display 11 gradations using a signal pulse width.

As described above, in the present invention, the upper substrate is a single transparent substrate, the lower substrate is formed of a plurality of semiconductor substrates, and the plurality of semiconductor substrates are placed on a fixing member while maintaining flatness in a box. Therefore, it is not necessary to determine the size of the liquid crystal display device based on the size of the single crystal semiconductor substrate, and a liquid crystal display device with a large screen of any size can be realized.

[Brief explanation of drawings]

Figure 1 shows the operating principle of an electro-optical display device based on a liquid crystal composition consisting of a pleochroic dye and nematic liquid crystal. 11 (Fig. 3 is the circuit diagram of the display panel, and Fig. 4 is the mounting structure of the display panel. Applicant: Suwa Seiko Co., Ltd., Patent Attorney, Patent Attorney) -1/ipl/ /1(α)
(G) Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A liquid crystal display device comprising a transparent upper substrate, a transparent electrode provided on the upper substrate, a lower substrate opposed to the upper substrate leaving a space, and a liquid crystal composition sealed in the space,
The liquid crystal composition is composed of a pleochroic dye and a nematic liquid crystal, the lower substrate is a semiconductor substrate, a plurality of active elements are formed on the semiconductor substrate, and a plurality of active elements are formed in a matrix on the semiconductor substrate. The upper substrate is formed of a single transparent substrate, the lower substrate is formed of a plurality of semiconductor substrates, and the plurality of semiconductor substrates are A liquid crystal display device characterized in that it is installed on a fixed member while maintaining flatness.