JPS62245216A - Liquid crystal electrooptic device - Google Patents

Abstract

PURPOSE:To make a device, where optical turning-on/off is always inverted between picture elements adjacent to each other, high-precision and simple by providing plural areas different in axis of polarization on both outside polarizing plates of substrates holding a ferroelectric liquid crystal between them with respect to one picture element. CONSTITUTION:A polarizing plate 8 is stuck to a substrate 1 of an ON display area 3 so that its axis of polarization is parallel with a side AC, and a polarizing plate 8' is stuck to a substrate 2 so that its axis of polarization is orthogonal to that of the polarizing plate 8. A polarizing plate 9 is stuck to the substrate 1 of an OFF display area 4 so that its axis of polarization is shifted from that of the polarizing plate 8 by 2theta, and a polarizing plate 9' is stuck to the substrate 2 so that its axis of polarization is orthogonal to that of the polarizing plate 9. Charged ferroelectric liquid crystal molecules 10 and 11 are inclined at thetacounterclockwise from the layer normal direction of a line 14 when an electric field 12 is impressed in the direction from the rear face to the front face of the paper, and they are inclined at theta clockwise from said direction when an electric field 13 is impressed in the direction from the front face to the rear face of the paper. If the direction of arrangement of liquid crystal molecules coincides with axes of polarization, the picture element is optically turned off; and if this direction is shifted from axes of polarization of polarizing plates 8 and 9 by 2theta (20-45 deg.), the picture element is optically turned on.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a liquid crystal electro-optical device.

[Conventional technology]

Liquid crystal electro-optics conventionally used as optical shutters@
Transmission of light (hereinafter referred to as ``light on'') and blocking (hereinafter referred to as ``light off'') in the dragon is achieved by combining the optical rotation and birefringence of the liquid crystal with two polarizing plates.

In conventional liquid crystal electro-optical devices using these methods, the time for turning on the light and the time for turning off the light in one pixel constituted by upper and lower transparent IE plates formed on the upper and lower roots are different. Therefore, in a device where two adjacent pixels turn on and turn off light at the same time, a twisted nematic liquid crystal or ferroelectric liquid crystal is used to input separate signals to each pixel, and the two adjacent pixels Is there a way to turn on and turn off the light at the same time?
strength! Using a 4-way liquid crystal, the upper electrode of two pixels and the lower electrode of the other are connected at the top and bottom using polar conductive paste, and the light is turned on and off at the same time by reversing the direction of the two adjacent pixels. Interact with the method.

[Problem that the invention seeks to solve]

However, in the conventional method, signals are input pixel by pixel, so
There are problems in that the entire device including the drive circuit becomes complicated, and in the case where vertical conductive paste is used, the accuracy of the liquid crystal cell thickness deteriorates due to the presence of the paste.

The present invention is intended to solve these problems, and its purpose is to turn on and off light between adjacent pixels.
The goal is to highly refine and simplify the device that constantly reverses the OFF state.

[The tth way to solve the problem]

The liquid crystal electro-optical device of the present invention is characterized in that each pixel has a plurality of regions with different polarization axes of the polarizing plate on the outside of the plane of the substrates holding the ferroelectric liquid crystal.

[Effect]

According to the above configuration of the present invention, by applying a single electric field to one pixel, two states of light-on and light-off can be obtained simultaneously for one pixel.

〔Example〕

FIG. 1 shows how various switches are turned on and off in an embodiment of the present invention.
OF? This is an outside view of a liquid crystal electro-optical device used for display purposes, in which the left half of the device is an ON display area 3, and the right half of the device is an OFF display area 4.

Figure 2 shows a method for aligning the liquid crystals in one line direction on the screen. Polyimide 1!7') was formed on a transparent PT substrate 1 with electrodes by a printing method, and an electric field was applied upward and downward within the cell thickness of 2 microns of the ferroelectric liquid crystal to be used on the side mu-C. Half the opening angle of the molecules (approximately 10~
By performing the rubbing treatment in the direction of approximately 22.5° (hereinafter referred to as θ), the liquid crystal molecules are subjected to strong alignment control from the polyimide film portion. Next, in order to maintain a constant distance between the substrates 1 and 21, a spherical space material number of 2 microns in diameter is distributed on the substrate 1 side, and a companion sealing material 5 for filling the liquid crystal is printed on the substrate 2 side. After overlapping parts 1 and 2 as shown in Figure 1, liquid crystal is injected, and the injection hole is sealed with sealing material 6. Next, FIG. 3 shows a method for attaching a polarizing plate.

A polarizing plate 8 is attached on the substrate 1 in the ON display area 3 so that the side AO and the polarization axis are parallel to each other, and the polarizing plate 8 is attached on the substrate 2.
A polarizing plate 8' is attached so that the polarizing axis is perpendicular to the polarizing plate 8'.

Next OF? A polarizing plate 8 and a polarizing axis f are placed on the substrate 1 in the display area 4.
The polarizing plate 9 is pasted with a shift of 2θ, and the polarized light $ is placed on the substrate 2.
One light beam a9' is attached so that the polarization axis is perpendicular to the light beam a9'.

The light-on/light-off operation of the next cell fabricated using the above method is shown in Figure 5 and Figure 5. Injected nine ferroelectric liquid crystal molecules I
Q, 11 is the electric field 12 (fourth
When applying (O mark in the layer), the electric field 13 is applied counterclockwise from the layer normal direction 14 (No. 4 @ 10), and the electric field 13 is applied in the hollow direction from the front of the paper (■ mark in Fig. 5). At the time of application, it tilts clockwise from the 1 normal direction 14 by θ (10 in the fifth drop).

When the liquid crystal molecule alignment direction matches the polarization axis of the polarizing plates 8 and 9, the light is turned off, and when the liquid crystal molecule alignment direction deviates from the polarization axis of the polarizing plate 8.9 by 20 degrees (approximately 20 to 45 degrees), the light turns off. It turns on. Figure 6 shows the change in light intensity between on and off obtained from the operation in Figure 4.5. Ferroelectric liquid crystals are
Even when no electric field is applied, the orientation of the molecules does not change, which is a so-called memory property, so if you do not want to change the display, you can turn off the electric field. & is light on in ON display area due to electric field 15, light off in 0IPIP display area,
h shows the opposite behavior to a due to the electric field 14. Next, C shows the same behavior as a, and in d, where the electric field is cut off, the liquid crystal molecules slightly return to the layer normal direction 14 due to the rounding of the memory property, so the contrast decreases slightly, but it is almost the same as in C. The state can be maintained, and the same operation can be performed for .

As described above, by applying an electric field in one direction, symmetrical light-on and light-off can be simultaneously obtained with good contrast.

〔Effect of the invention〕

As mentioned above, according to the present invention, it is possible to simultaneously turn on and turn off light using a unidirectional electric field within one pixel.
Since a light-off region is formed, patterning of the transparent electrode is not necessary.

(2) Since light is turned on and turned off within one pixel, wiring auxiliary materials such as vertical conductive materials are not required.

(3) Since the light-on and light-off signals are common within the same transparent electrode, there is no signal delay or deviation.

By utilizing the memory properties of ferroelectric liquid crystals, (4) there is no need to apply an electric field except when switching, so power consumption can be reduced.

[Brief explanation of drawings]

FIG. 1 is an external view of a liquid crystal electro-optical device of the present invention. Figure 2 is a diagram showing the betting direction. FIG. 3 is a diagram showing the direction of the polarization axis of each ON-OFF display area. Figures 4 and 5 show the behavior of liquid crystal molecules under each electric field in the direction from the far side of the page to the front and in the direction from the front to the far side of the page. FIG. 6 shows No. 41. A diagram showing transmitted light # obtained by the fifth south operation. 1... Lower base 2... Upper substrate 5... ON display area 4... OFF display area 5... Sealing material 6... Sealing material 7... Polyimide film 8.8' ...ON display area polarizing plate 9.9'...0FIF display area polarizing plate 10.11...
・Liquid crystal molecules 12.15... Electric field direction 14... Betting line direction or above Applicant: Seiko Epson Corporation Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a liquid crystal electro-optical device comprising a ferroelectric liquid crystal sandwiched between a pair of substrates having transparent electrodes, for one pixel constituted by the transparent electrode, polarizing plates on both outer sides of the pair of substrates have different polarization axes. A liquid crystal electro-optical device characterized by having a plurality of regions.