JPH02204716A - Plzt sintered body for optical shutter array and method for preventing fluctuation in transmitted light intensity by using this sintered body - Google Patents

Abstract

PURPOSE:To obtain the PLZT sintered body suitable for an optical shutter array of a high resolution and to prevent the fluctuation in transmitted light intensity by specifying the average grain size of the PLZT forming the sintered body to <=5mum and the average grain sectional area to <=1/150 the area of formed dots. CONSTITUTION:The PLZT sintered body which is an oxide sintered body contg. Pb, La, Zr, and Ti is used as the optical shutter array used for forming the dots corresponding to transmitted light by controlling an impressed voltage and changing light transmittability. The average grain size of the PLZT forming this sintered body is specified to <=5mum, more preferably 1 to 3mum, by which the width in the fluctuation of the transmission quantity of the light forming the respective dots is narrowed. In addition, the average grain sectional area of the PLZT is specified to <=1/150 area of the formed dots, by which the fluctuation in the transmitted light intensity of the respective dots is controlled to <=3%.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a Pb
, La, Zr, Ti oxide sintered body (hereinafter simply referred to as "
The present invention relates to a method of using this PLZT sintered body to prevent variations in light transmission intensity of dots formed by light transmitted through an optical shutter array.

Technical Background of the Invention and its Problems The use of PLZT sintered bodies as optical shutter arrays for copying machines, dot printers, etc. has been studied. Such an optical shutter array has P
A sintered body obtained by firing LZT powder is sliced and polished to obtain a thin plate, and then the resulting P
It is manufactured by attaching an electrode such as a comb-shaped electrode to the surface of a thin plate of an LZT sintered body, and then sandwiching it between two polarizing plates. By applying a voltage to the electrodes of the optical shutter array manufactured in this way, the light transmittance of the optical shutter array is changed.

Then, by converting the dots formed by the light transmitted through the optical shutter array into static electricity or heat and making them visible using toner or a thermal transfer recording medium, an image can be formed as a collection of dots. .

Therefore, PLZT used as an optical shutter array
The sintered body is required to have excellent light transmittance.

The transparency of such a PLZT sintered body is due to light scattering at the interface of the PLZT grains that make up the sintered body, light scattering due to bubbles or impurity crystals present in the sintered body, and the composition during the production of PLZT. It decreases due to changes in the light transmittance of PLZT itself due to changes.

Conventionally, in order to improve the transparency of PLZT sintered bodies, there has been a method of using high-purity PLZT and performing firing under strict control of conditions, and a method of increasing the particle size of PLZT grains to improve the dalein interface within the dots. A method has been adopted to reduce the number of By employing such a method, the transparency of the PLZT sintered body is improved, and excellent optical shutter arrays are being provided.

However, recently, attempts have been made to form high-quality images, and in order to form such high-quality images, it is necessary to improve the resolution of the optical shutter array itself. In such optical shutter arrays for forming high-quality images, the area of one dot formed by passing through the optical shutter array is gradually becoming smaller.

In other words, the dots formed by conventional optical shutter arrays generally have a side length of about several hundred micrometers, but in response to the above-mentioned demand for high resolution, recent high-resolution devices have 100 x 100 μm or less, further 60
The use of an optical shutter array that can form dots of x60 μm or less is being considered.

When manufacturing optical shutter arrays used in high-resolution devices such as those described above, the present inventor uses high-purity raw materials and performs firing under strict control of conditions to produce PLZT sintered bodies with large grain sizes. This PLZT sintered body was used to manufacture an optical shutter array for a high-resolution device in which each dot has a narrow area.

However, in narrow-area dots (for example, dots of 60×60 μm or less) formed by such an optical shutter array, the intensity of transmitted light varies considerably from dot to dot.

For this reason, even though an attempt has been made to obtain a high quality image by narrowing the dot area, the quality of the obtained image does not improve that much. Furthermore, since the intensity of transmitted light of each dot varies widely, the quality of the formed image may even deteriorate.

The conventional methods used to manufacture highly transparent PLZT sintered bodies could not be used to manufacture optical shutter arrays used in high-resolution devices where each dot has a narrow area. .

OBJECTS OF THE INVENTION The object of the present invention is to provide a PLZT sintered body suitable for optical shutter arrays used in devices that particularly require high resolution.

A further object of the present invention is to provide a method for preventing variations in transmitted light intensity using the sintered body.

Summary of the Invention The PLZT sintered body for optical shutter array according to the present invention is
By changing the optical transparency by controlling the applied voltage,
In a PLZT sintered body for an optical shutter array used to form dots corresponding to transmitted light, the average grain size of PLZT forming the sintered body is 5.
μm or less, and the average grain cross-sectional area of the PLZT is.

It is characterized in that the area is 1/150 or less of the area of the dots to be formed.

Furthermore, the method for preventing variations in transmitted light intensity according to the present invention is as follows:
When forming dots corresponding to the transmitted light by controlling the voltage applied to the optical shutter array using a PLZT sintered body and adjusting the light transmittance of the optical shutter array, as the optical shutter array, The average grain size of the PLZT is 5 μm or less, and the PLZ
It is characterized by using a PLZT sintered body in which the average grain cross-sectional area of T is 1/150 or less of the area of the dots to be formed.

Detailed description of the invention Next, the present invention will be specifically explained.

The PLZT sintered body used in the present invention is Pb1L a
s Z r % Ti oxide ceramics,
Generally, it is expressed by the following formula.

(Pb La') CZr Ti t-y)
1-x/4 o81-x x y However, in the above formula, x/y/1-y is 9/65/35 for the most commonly used PLZT sintered body.
It is an oxide with the following relationship. Also in the present invention, a PLZT sintered body having the above composition is basically used. However, X and y in the above formula may vary somewhat depending on manufacturing conditions, etc. Therefore, the PLZT sintered body used in the present invention has the above x / y / 1- y
has a relationship of 9±0.5/65±5/35±5
Contains LZT.

Note that it is desirable that the PLZT sintered body used in the present invention has high purity in consideration of light transmittance, but in the present invention, if the amount is 100 ppm or less, PLZT
The sintered body may contain components other than PbSLaSZr, TI, and oxygen.

Examples of other components that may be included in the PLZT sintered body of the present invention include Na5Mg5Ca.

AI, Si, YSFe, Cu, Co5Pr5Nd.

One example is SI.

By forming an electrode, such as a comb-shaped electrode, on the surface of a thin plate of PLZT sintered body having the above composition, and then sandwiching it between two polarizing plates with the change axis 90' apart and 4' apart. An optical shutter array is created. By controlling the voltage applied to this electrode, the light transmittance of the optical shutter array can be changed.

In order to obtain high-quality images, comb-shaped electrodes have been formed so that the dots formed are 1,010,000 u (for example, 100 x 100 μm) or less.
For example, an optical shutter array having a dot area of 3600 μm 2 or less has particularly good resolution.

The PLZT sintered body according to the present invention is particularly suitably used as an optical shutter array used to form such a dot area.

That is, in the PLZT sintered body according to the present invention, the average grain size of PLZT is 5 μm or less. Furthermore, it is preferable that this average grain size is 1 to 3 μm. By setting the grain size within this range, the range of variation in the amount of light transmitted forming each dot is significantly narrowed, and the PLZT sintered body having an average grain size within the above range can be produced using special equipment, etc. It also has the advantage that it can be manufactured by adjusting the manufacturing conditions, for example, without using.

The PLZT sintered body according to the present invention has the average grain size as described above, and the average cross-sectional area of the grains is 1/150 or less of the area of the dots formed using this PLZT sintered body. It is necessary that there be. For example, the PLZT sintered body used when forming dots of 60 x 60 μm (dot area: 3600 μm2) is
It is necessary that the average area of the grains is 24 μm 2 or less. Furthermore, by setting the average cross-sectional area of the grains within the range of 1/180 to 1/3600 of the dot area,
The variation in the transmitted light intensity of each dot can be controlled to 3% or less. Note that the average cross-sectional area of the grain is
The PLZT sintered body is observed using a microscope or the like to determine the average grain size, that is, the average diameter of the grains, which approximately matches the area of a circle calculated based on this diameter.

Figure 1 shows a PLZT sintered body with an average grain size of 2.5 μm (Figure A-1) and 6. ．． A micrograph of a 0 μm PLZT sintered body (Figure B-1) is shown.

An enlarged photograph of the formed dots is shown in Figure B-2. In addition, A
In Figure 2 and Figure B-2, areas corresponding to dots of 60 x 60 μm are shown divided by frames.

As is clear from Figure A-2 and Figure B-2, 6.0μ
When a PLZT sintered body having an average grain size of m is used, a relatively large mottled pattern is formed by areas with high intensity of transmitted light (black areas) and areas with low intensity of transmitted light (black areas). On the other hand, when a PLZT sintered body having an average grain size of 2.5 μm is used, the texture of this mottled pattern becomes finer. Therefore, when a PLZT sintered body having a grain size of 6.0 μm is used, the average transmitted light intensity within the frame changes significantly depending on the position where the frame is provided. On the other hand, when a PLZT sintered body having a grain size of 2.5 μm is used, the variation in transmitted light intensity depending on the position of the frame is reduced.

FIG. 2 shows the transmitted light intensity of each dot of an optical shutter array using PLZT sintered bodies having average grain sizes of 10 μm, 5 μm, 3 μm, and 2 μm. Note that the size of the dot in this case is 60×60 μm.

As is clear from Fig. 2, the transmitted light intensity of the dots formed using the PLZT sintered body having an average grain size of 10 μm is 99% at the maximum value (dot Nα7), but the minimum value (dot Nα7) is 99%. Dot Nos. 3 and 8) are 95%, and there is a difference of 4% between the maximum and minimum values. In contrast, for example, PL with an average grain size of 3 μm
The transmitted light intensity of the dots formed using the ZT sintered body is
The difference in transmitted light intensity between dots is approximately 96%, and the difference in transmitted light intensity between dots is small (here, the unit of transmitted light intensity is 10% of the theoretically calculated value).
(This is the value when it is set to 0%). Therefore, the PLZ of the present invention
By using an optical shutter array formed using a T sintered body, variations in the transmitted light intensity of each dot are reduced, so it is possible to form an image with high resolution.

The above-mentioned PLZT sintered body can be manufactured by performing sintering under conditions such that grains do not grow excessively during sintering. That is, the PLZT sintered product of the present invention can be manufactured by setting conditions such as temperature and pressure during sintering so that PLZT grains do not grow.

By using such a PLZT sintered body,
Fluctuations in the light transmission intensity of the formed dots are reduced. Therefore, by manufacturing an optical shutter array with a dot area of 3600 μm or less using the PLZT sintered body of the present invention, the resolution of a device such as a copying machine or a printer incorporating such an optical shutter array can be significantly improved. improves. Note that the PLZT sintered body of the present invention is
As mentioned above, it is particularly useful for optical shutter arrays with a narrow dot area, but even when the dot area is wide, by using the PLZT sintered body of the present invention, the light of the formed dots can be reduced. Since the variation in transmitted intensity is reduced, the resolution of devices such as copying machines and printers incorporating such optical shutter arrays does not deteriorate compared to conventional devices, but rather tends to be improved.

Effects of the Invention The PLZT sintered body for optical shutter array according to the present invention is as follows:
Since the average duplex area and average grain size relative to the area of the formed dots are below a certain level, fluctuations in the light transmission intensity of the formed dots are reduced.

Therefore, by using an optical shutter array manufactured using such a PLZT sintered body in devices such as copying machines and printers, the resolution of these devices can be improved.

Next, examples of the present invention will be shown, but the present invention is not limited to these examples.

Example 1 The average grain size of the obtained PLZT sintered body obtained by employing the hot press sintering method and performing sintering by setting the raw materials and firing conditions such as temperature and pressure to suitable values is It was 5 μm.

After slicing this PLZT sintered body to a thickness of 0.35 mm and polishing the surface, comb-shaped electrodes were laid on the surface, and the PLZT sintered body with the comb-shaped electrodes was then placed between two polarizing plates. An optical shutter array was manufactured by sandwiching the two. Note that the comb-shaped electrodes were laid so as to form dots of 60×60 μm.

The transmitted light intensity of each dot (N11 to N10) formed by the optical shutter array manufactured as described above was measured. The value of the transmitted light intensity was expressed as 100% of the theoretically calculated value.

The results are shown in Figure 2.

Examples 2 to 4 In Example 1, PLZT sintered bodies with average grain sizes of 5 μm (Example 2), 3 μm (Example 3), and 2 am (Example 4) were prepared by changing the sintering conditions, An optical shutter array was manufactured in the same manner except that this PLZT sintered body was used.

The transmitted light intensity of each dot (Nα1 to Nα10) formed by the optical shutter array manufactured as described above was measured.

The results are shown in Figure 2.

Comparative Example 1 In Example 1, a PLZT sintered body with an average grain size of 10 μm was prepared by changing the sintering conditions.
An optical shutter array was manufactured in the same manner except that a sintered body was used.

The transmitted light intensity of each door 1- (No. 1 to 10) formed by the optical shutter array manufactured as described above was measured.

The results are shown in Figure 2.

[Brief explanation of the drawing]

Figure 1 shows PLZT with an average grain size of 265 μm.
Sintered body (Figure A-1) and 6. It is a photograph showing the state of O, czm. FIG. 2 is a graph showing the dependence of the transmitted light intensity for each dot on the brane size. 1st drawing

Claims (2)

[Claims] (1) In a PLZT sintered body for an optical shutter array, which is used to change the light transmittance by controlling the applied voltage and form dots corresponding to the transmitted light, the PLZT forming the sintered body A PLZT sintered body for an optical shutter array, characterized in that the average grain size of the PLZT is 5 μm or less, and the average grain cross-sectional area of the PLZT is 1/150 or less of the area of the dots to be formed. (2) When forming dots corresponding to the transmitted light by controlling the applied voltage to the optical shutter array using the PLZT sintered body and adjusting the light transmittance of the optical shutter, the optical shutter array , the average grain size of the PLZT is 5 μm or less, and the PLZ
A method for preventing variations in transmitted light intensity, characterized by using a PLZT sintered body whose T grain cross-sectional area is 1/150 or less of the area of an average dot to be formed.