JPS59128518A - Liquid crystal light valve - Google Patents

Abstract

PURPOSE:To constitute a liquid crystal light valve that can furnish a light writing unit of high performance and low price by enabling the liquid crystal light valve 1/3 time division driving. CONSTITUTION:Selection signals 221-223 are applied to three common electrodes 201-203. Open or close signal 225, 226 is applied to a signal electrode 205 according to write data. At this time, signals 221-224 and signals 225-226 are reverse in phase. Microshutters 211-213 are opened and closed according to signals applied to the signal electrode during the time of selection of signals 221-223, and closed during non-selected period. Thus, electrodes, etc. are disposed to enable 1/3 time division driving, and the electrode shape of the liquid crystal panel is determined to a specified shape.

Description

[Detailed description of the invention] The invention relates to a liquid crystal light valve.

Recent progress in RSW processing technology has been remarkable, and as a result, a printing device, which is one of its output devices, is required to have high performance and high speed. moreover,
Printing devices that meet the requirements for printing quality include laser beam printers (LBP) and optical fiber tubes (OFT) that use electronic photofocus and light buds.
The printer is in practical use. However, despite the strong demands mentioned above, LBP, OF
The fact that both T and T are extremely expensive is a major reason for preventing their widespread use.

The present invention is directed to a liquid crystal light valve type printing device, which has been thought to be difficult to put into practical use due to numerous technical problems, even though it was only an idea in the past! In order to achieve this goal, the objective is to provide an interval #tiF4, high-quality, high-speed optical heating unit LF with a simple configuration, small size, and low cost.

Figure 1 shows the configuration of the Kogokomi unit including the liquid crystal light valve. The optical writing unit consists of a light source for a fluorescent light source, a liquid crystal light valve, and an imaging lens 115, a liquid crystal light valve, a liquid crystal panel, 112, and a liquid crystal drive circuit 1.
13 is mounted on the base plate 114. The light emitted from the light source sword 1 is modulated by a liquid crystal light valve. This original signal 1
An image 16 is formed on the photosensitive drum 102 by an imaging lens 115. An erect image is obtained by using a convergent optical fiber array sound for the imaging lens. FIGS. 2 and 3 show the structure of the liquid crystal panel. The liquid crystal panel has common signal electrodes 119 and 120? ] A liquid crystal assembly by #125'z is sealed between the glass substrate 117 provided with the signal electrodes 121 and 122 and the spacer 126, and polarizing plates 123 and 12 are placed on both sides of the glass substrate.
It consists of 4 pieces.

The common signal electrode consists of a transparent electrode 119 and an optically opaque metal electrode 120, and the signal electrodes 121 and 122 are transparent electrodes. The polarizing plates 125 and 124 are arranged so that the polarized light (1) is orthogonal to each other.

The optically active substance A-(2-metbylbulyl )
-1' -cyanobiphθnyls 'z 3
By using the long-period cholesteric liquid crystal obtained by weight percent modification, a high-speed liquid crystal light pulp can be obtained. Figure 4 shows the same wave number characteristic of the universal potential of this liquid crystal. The frequency at which the dielectric difference is zero is called the difference frequency and is expressed by fc.
Let the U wave number be τfH. The liquid crystal light valve operates by applying signals of frequencies fL and fH to each signal electrode.

Figure 5(b) shows the response of the applied signal and (a) the light incident on the liquid crystal light valve. A signal at time fH indicated by T2 and a signal at time fL at T3 are applied.

TI' is called the commitment period, T2 is called the opening time, and T5'f is called the non-opening time. The V liquid crystal light valve opens by applying the fH signal and closes by the fL signal.By using the method described above, we were able to produce a revolutionary high-speed liquid crystal light pulp. In order to perform printing, it is necessary to arrange microshutters at a density of about 10 microshutters per meter, and in order to print on A4 size paper, it is necessary to reduce the width to 20mm, so the number of microshutters is 2
Becomes 000i[ffl. Therefore, in the method described above,
There are 2,000 signal electrodes per g, and 2,000 drive circuits and 2,000 terminals to mount the signal electrodes, resulting in lower production yields and higher costs.

Therefore, time-division driving has been proposed in order to reduce costs, but the present invention does not provide a liquid crystal panel that fully realizes time-division driving.

1. The pseudo time-division driving method will be briefly described. Figure 6,
FIG. 7 shows the false time-division electrodes and drive waveforms. Selection signals 221, 222, 223 are applied to the three common voltages 2Q1, 202.2[]3, respectively, and the data to be written is applied to the signal electrode 205. An open signal 225 or a close signal 226 is applied depending on the condition. At this time, selection signals 221 to 224 and open signal 2
25, the close signals 226 are in opposite phase to each other. , T1 is the sub-scanning period, Ta is the selection period, and T'b is the non-selection period. and closed during non-selection periods.

Figure 8 shows this situation. I ■ No. 205 to 235
When a signal such as is applied, each micro shutter 211
I skipped the photo response sessions 231-234 of ~213. By realizing the continuous time-division drive as described above, a significant cost reduction can be realized.

However, as the number of time divisions increases, the number of signal electrodes decreases, but the shape of the electrodes tends to become more complex. This is not acceptable in a liquid crystal light valve because any light leakage in areas other than the microshutter will result in a decrease in contrast. However, as shown in FIG. 6, light leakage inevitably occurs in the gaps between the common electrodes and the gaps between the signal electrodes. One of the points is whether to reduce the size to 1 for practical use.

Next, the maximum distance between the microshutters (the distance between the vertical lines 211 and 213 in FIG. 6) is limited by the focusing fiber play used as the imaging lens. When using pure carbon fiber lens arrays, the optical axis force causes the photoelectricity of the image to drop significantly if the optical axis is shifted by more than a certain distance. The ease of alignment, margin, etc. of the fine pattern greatly affect the step M'E9.

FIG. 9 shows an electronic pattern of an inventive liquid crystal panel manufactured with all of the above considerations in mind.It is divided into five parts by a common electrode formed on the first glass. The co-recurrence poles considering the selection signal are 201 to 205, and the co-recurrence poles on both sides are 3.
01 and 302 are dummy electrodes. The oblique part is a metal film such as N1, which is an opaque layer, and the remaining 311.312
, 313° and 314 with transparent polarization. This transparent portion corresponds to the microshutters 211 to 213 in FIG. 6, but due to the manufacturing of the t-pole, there are two types of microshutter positions 312 and 314 corresponding to 212.

Next, FIG. 10 shows the signal electrode formed on the second glass. Since the signal electrode 205 (gainer digital) is arranged, the pitch PJJ of 4V is 300 μm, but when it is mounted, the pitch is μ600 μη1, which greatly improves the reliability of the mounting and the small amount of space required.

The first part of the signal electrode 205 is made of opaque metal.
) 11 to 314, where the transparent conductors 511 to 314 are common electrodes
A micro-shutter is formed between the shutter and the shutter.

The pitch P1 of the micro shutters arranged in a staggered manner is 10.
0 μm1 The distance between micro shutters is 11 (
'311-312) is 33μrx, J, (311-3
14 interval) is 233prn, and j13 (511313 interval) is 267μm.Conditions for not shifting the dots forming a horizontal straight line when driving in time division!
Sub-scanning period T1. When the moving speed of the photoreceptor is v, the interval between the microshutters J = (-10n) x TV, (m
=1.2,3. n-1, 1, 2 = Satisfied. However, T = 2m air and V = 5 cm/see.

More than two pieces of glass? Figure 11 shows the +4 net.

Since the surfaces with electrodes are overlapped, it is actually a mirror image of either Figure 9 or Figure 10.

As shown in Fig. 11, since the shaded area is entirely opaque, the light incident on the liquid crystal panel is from the micro shutter 311 to
At 314, it is adjusted to f and becomes Mitsuyoshi-gomi 1g. Also, since light is always leaking from the light beams 321 and 32, 1g of light
If we look at the m1 point 71>, we get an offset ni. This offset is distributed between the valley micro-shutters, and the micro-shutters 211 to 214 and 1
The light leakage parts 321 to 324 are arranged so as to correspond to each other on a one-to-one basis. The width was 10 μm×10 μm. Actually this? The desired amount of g is
If the size of the microshutter is 100 μm x 90 μm, the duty? Even as a guardian, it's only 3%. - Considering the manufacturing yield of 10,000 yen, what is the total length of the minimum line width? In order to make it as small as possible, the minimum line width t was set only in the vicinity of the portion where light leakage occurs.

As described above, 75 pieces of the liquid crystal according to the present invention (liquid crystal driven in continuous time division due to the shape of the electrodes of the liquid crystal) were made. As a result, we were able to create a liquid crystal light system that can provide high-performance, low-cost light-included units.

[Brief explanation of drawings]

FIG. 1 shows a light accumulation signal generating section. Figures 2 and 3 show the structure of the liquid crystal panel, Figure 4 shows the frequency custom made by Chiang Dian Anifang of the liquid crystal material used in the present invention, and Figure 5 shows the structure of the liquid crystal panel.
The figure is a diagram showing the custom response of the liquid crystal material used in the present invention and the driving signal at that time. FIGS. 6 and 7 show the principle diagram of the starting time division electrode structure and the drive signal waveform 7. Figure 8 shows the optical response and drive waveform of the valley microshutter during relaxation time-division driving. Figure 11 shows the shape of the electrodes when two pieces of glass are connected. 201%2Q3...Common electrode 205...Signal electrodes 211-214, 311-314...・Micro shutter 321 to 624...Light overlapping part Fig. 1 t4 Fig. 2 Fig. 3 Fig. 4 Fig. 5 cx rLrLf'L two-face box/22 A-/Zz mouth for ZC13m river co- Figure 7 Figure 8 Figure 9 [1 Figure 10

Claims (1)

[Scope of Claims] [1] In a liquid crystal light valve driven in L/s time division, the liquid crystal panel is divided into a first glass having a common electrode 'r-''M divided into at least three parts, The signal electrode is made of silk glass having a plurality of signal electrodes having a gap between the common electrodes and the opposing portions are inappropriate, and the first and second glasses are arranged to cross each other, and In the meantime, the cross frequency f at which the electrical anisotropy becomes zero at room temperature
We regret that the liquid crystal light valve is encapsulated on a liquid crystal material made by adding all optically active substances to a nematic liquid crystal whose c is 100 KHz or more. (2) In the liquid crystal panel, the microshutters constituted by the common electric current and the No. 4g electrode are arranged in a staggered manner, and when the movement speed of the secondary periodic tray Tl photoreceptor reaches 2v, the microshutters are arranged in a staggered manner. -+n)xT,xV(m=1.2.
3.n=, 0, 1.2...) The liquid crystal light valve according to claim 1, wherein all the characteristics are given by: (3) The area of the light secondary portion other than the micro-shutter is sufficiently small compared to the micro-shutter;
2. The liquid crystal light valve according to claim 1, wherein the micro shutter and the light leakage portion have a one-to-one correspondence. (4) At least the electrode pattern near the light leakage portion is
The liquid crystal light valve according to claim 1, characterized in that the liquid crystal panel has a minimum line width.