JPH0339714A - Electrode formation method for PLZT light valve - Google Patents

Abstract

PURPOSE:To nearly make the electric field distribution uniform in picture elements and to obviate the generation of the degradation in contrast ratio by packing conductive paste into electrode forming parts, opposing the electrode plate planes in parallel with each other via PLZT and forming electrodes for forming picture elements in Parallel with the optical axis of incident light. CONSTITUTION:Recesses 29 as the electrode forming parts are formed in a PLZT sheet 27. The conductive paste is then packed into the recesses 29 by screen printing, etc., and is calcined at a prescribed temp., by which the picture element forming electrodes 33, 35 for forming the picture elements 31 are formed. The electrode plate planes of the electrodes 33 and 35 oppose parallel with each other and parallel with the optical axis 2 of the incident light when the prescribed picture elements 31 are selected by impressing prescribed voltages to the electrodes 33, 35 of the PLZT light valve formed with the picture element forming electrodes 33, 35 in such a manner. The electric field distribution in the picture elements 31 is nearly made uniform in this way and the degradation in the contrast ratio is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming electrodes of PLZT light valves used in projection displays, direct-view displays, and the like.

[Prior art] In recent years, PLZT (for example, (P be-sz Lao, a
s) PLZ using (Zra-@41@*IK)03)
Research and development of T light bulbs has become active. Projection displays and direct-view displays using such PLZT light valves are expected to have high brightness and high definition, but their electrode structures have been a problem.

The conventional PLZT light valve using PLZT is based on the one-surface electrode method or the one-surface electrode method as explained in the "prior art" section of Japanese Patent Application No. 108648/1983 (hereinafter referred to as "already filed"), which the present applicant had already proposed. The pixel forming electrode group was formed using a parallel plate electrode method or the like. Namely.

In principle, the pixel 1 formed by the surface electrode method is a PLZT whose plate surface is perpendicular to the optical axis 2 of the incident light, as shown in FIG.
Paired pixel forming electrodes 4.5 are provided on the same plate surface of the plate 3.
was forming. Furthermore, the pixel 11 formed by the parallel plate electrode method is, in principle, a PLZT13 as shown in FIG.
The plate surface of the pixel forming electrodes 14 and 15 provided in the PLZ
parallel to each other via T13 and the optical axis 2 of the incident light.
It was formed parallel to the

[The problem that the invention tries to solve! [fi] However, as explained in the "Problem to be Solved by the Invention" section of the previous application, the one-surface electrode method has the problem that the electric field distribution inside the PLZT becomes non-uniform and the contrast ratio decreases. However, the parallel plate electrode method has a problem in that the processing process is complicated and high processing accuracy is required. Namely.

As shown in FIG. 3, the pixel 1 formed by the surface electrode method has a pair of pixel forming electrodes 4 on the same plate surface of the PLZT plate 3 whose plate surface is perpendicular to the optical axis 2 of the incident light. .
This is because, as shown in the figure, the electric field distribution inside the pixel 1 becomes non-uniform and the contrast ratio decreases. In addition, the pixel 11 formed by the parallel plate electrode method is formed using the pixel forming electrodes 14 and 15 provided on the PLZT 13, as shown in FIG.
Since the electrode plates were formed so that they faced each other in parallel via the PLZT 13 and were parallel to the optical axis 2 of the incident light, the electric force generated when a predetermined voltage was applied from the power source 6 between the electrodes 14 and 15 Although there is no problem that the line 17 becomes as shown in FIG. 6 and the electric field distribution within one pixel 11 becomes non-uniform,
This is because the processing steps for forming the structure shown in the figure are complex and require high processing accuracy.

The present invention has been made in view of the above-mentioned problem, and proposes a method different from the green sheet process of the existing application, which makes the electric field distribution inside one pixel uniform (that is, the principle (Make sure the electric lines of force are similar to Figure 6)
A pixel forming electrode group that does not reduce contrast ratio,
The object is to provide a method that allows easy formation.

[Means for solving the problem] Book 1. The second invention is to produce a fired PLZT green sheet by subjecting a PLZT green sheet, which is easy to process, to a predetermined process.
ZT Green Sheet (i.e.

6. The first invention is the same in that a predetermined pixel forming electrode group is formed by forming a plurality of electrode forming portions on a PLZT sheet and filling these electrode forming portions with conductive paste. A method for forming electrodes of PLZT light pulp by embedding a plurality of embedded pieces in a PLZT green sheet, then firing the PLZT green sheet and removing the plurality of embedded pieces to form a plurality of electrode forming parts, A pixel forming electrode group is formed by filling the electrode forming portion with a conductive paste so that the electrode plate surfaces face each other in parallel through the PLZT and are parallel to the optical axis of the incident light. It is something.

In order to reduce the number of steps, the buried piece is made of a resin material that can be removed by thermal decomposition during firing of the PLZT green sheet.

In addition, the second invention method includes forming a plurality of electrode forming portions on the sheet surface of a PLZT green sheet, and then forming the PLZT green sheet.
By firing the green sheet and then filling the plurality of electrode forming parts with conductive paste, the electrode plate surface becomes P
It is characterized by forming a group of pixel forming electrodes that face each other in parallel via LZT and are parallel to the optical axis of incident light.

[Function] In the first invention, a plurality of embedded pieces are embedded in a PLZT green sheet, and then a plurality of electrode forming parts are formed by firing the PLZT green sheet and removing the embedded pieces, and these electrode forming parts are by filling it with conductive paste.

Pixel forming electrodes are formed whose electrode plate surfaces are parallel to each other via PLZT and are parallel to the optical axis of incident light. At this time, since the plurality of embedded pieces are embedded in a PLZT green sheet that is easy to process, the embedding process is easy. P
Since a plurality of electrode forming portions are formed by firing the LZT green sheet and removing buried pieces, it is possible to improve the accuracy of the arrangement position of the electrode group for forming one pixel. and.

If the buried piece is formed of a resin material that can be removed by thermal decomposition during firing of the PLZT green sheet, the process of removing the buried piece becomes unnecessary. In addition, in the second invention method,
A predetermined pixel forming electrode group is formed by forming an electrode forming portion on the sheet surface of the PLZT green sheet, then firing the PLZT green sheet, and then filling the electrode forming portion with a conductive paste. At this time, unlike the first invention, there is no embedding and removal of buried pieces, so processing is easy.

[Example] An embodiment of the first invention will be described below using FIG.

An embodiment of the second invention will be described with reference to FIG.

First, an embodiment of the first invention will be described.

(a) First, as shown in FIG. 1(a), a resin film 23 is applied to both sides of a PLZT green sheet 21. Said P
The LZT green sheet 21 is made of PLZT (for example, (P ba
-at Las-am) (Zr++-si Ti@-a
The resin film 23 is made of a resin material that is decomposed and evaporated and removed by heating to a predetermined temperature.

(b) Next, the unnecessary portion 23e of the resin film 23 is removed by photolithography, and as shown in FIG. 1(b), the PLZ
Embedded pieces 25 for forming recesses as electrode forming parts on both sides of the T green sheet 21. ... to form.

(C) Then, by pressing etc., the image shown in Fig. 1 (C)
Embedded pieces 25, . . . are embedded in the PLZT green sheet 21 as shown in FIG.

(d) Next, by firing the PLZT green sheet 21 in a firing furnace, P which is an electro-optic ceramic is produced.
In addition to the LZT sheet 27, the buried pieces 25,...
is thermally decomposed and evaporated, as shown in Figure 1(d),
Four parts 29. are formed on the PLZT sheet 27 as electrode forming parts.・
... to form.

(e) Next, the recesses 29. of the PLZT sheet 27 are formed by screen printing or the like. ... filled with conductive paste.

By firing at a predetermined temperature, pixel forming electrodes 33, 33, 35, 35, . . . for forming pixels 31, . ... to form.

A PL in which pixel forming electrodes 33, 33, 35, 35, . . . are formed as described in (a) to (e) above.
In the ZT light valve, when a predetermined voltage is applied to the pixel forming electrodes 33 and 33 and 35 and 35 to select a predetermined pixel 31, the pixel forming electrodes 33, 33 and 3
5.35 are parallel to each other through the PLZT, and are parallel to the optical axis 2 of the incident light. For this reason,
The electric field distribution inside the pixel 31 becomes almost uniform, and the contrast ratio does not decrease.

In the above embodiment, as shown in FIG. 1(a), PLZT
The resin film 23 formed on both sides of the green sheet 21 is made of a resin material that evaporates when heated to a predetermined temperature in order to reduce the number of required steps.・・・
Although the present invention is not limited to this, for example, the buried pieces may be removed by a mechanical or chemical method after firing.

In the above embodiment, as shown in FIGS. 1(a) and 1(b),
First, the resin film 23 is coated on both sides of the PLZT green sheet 21.
, and then remove unnecessary portions of the resin film 23 to provide embedded pieces 25 on both sides of the PLZT green sheet 21, but the present invention is not limited to this. For example, An embedded piece may be provided on one side of the PLZT green sheet by forming a resin film on one side of the PLZT green sheet and then removing unnecessary parts, or directly by screen printing a resin material paste. Embedded pieces may be provided on both sides or one side.

Next, an embodiment of the second invention will be described.

(a) First, as shown in FIG. 2(a), recesses 29a, . . . as electrode forming portions are formed on both sides of the PLZT green sheet 21 by punching or the like.

(b) Next, by firing the PLZT green sheet 21 in a firing furnace, as shown in FIG. 2(b),
PLZT sheet 27, which is electro-optic ceramics, is formed. (c) Next, the concave portion 29a of the PLZT sheet 27,...
By filling conductive paste in the 31. ...
Pixel forming electrodes 33.33 and 35.3 for forming
5,... is formed.

A PL in which pixel forming electrodes 33, 33, 35, 35, . . . are formed as described in (a) to (c) above.
In the ZT light valve, the plate surfaces of the electrodes 33 and 35 for forming one pixel are parallel to each other via PLZT and are parallel to the optical axis 2 of the incident light, similar to the one shown in FIG. Therefore, the electric field distribution inside one pixel 31 becomes almost uniform, and - there is no decrease in the contrast ratio.

In the embodiments shown in FIGS. 1 and 2, the plurality of electrode formation parts are formed by a plurality of recesses; however, the present invention is not limited to this. For example, the plurality of electrode formation parts are formed by a plurality of through holes. When formed with a plurality of through holes in this manner, the number of 11 connection poles for connecting the m pole groups for forming one pixel to an external circuit can be halved.

[Effects of the Invention] As described above, the method for forming electrodes of a PLZT light valve according to the first invention includes the steps of embedding a plurality of embedded pieces in a PLZT green sheet that is easy to process, and firing the PLZT green sheet to remove the embedded pieces. The process consists of a process of removing and forming a plurality of electrode forming parts, and a process of forming a predetermined pixel forming electrode by filling these electrode forming parts with conductive paste, so that the electric field distribution inside the pixel is It is possible to easily form a pixel forming electrode group for configuring a high wI fine image with uniform image quality and no reduction in contrast ratio. Furthermore, if the buried piece is made of a resin material that can be removed by thermal decomposition during firing of the PLZT green sheet, the process of removing the buried piece becomes unnecessary and becomes even simpler. Also.

In the second invention method, a plurality of Q forming portions are formed on the sheet surface of a PLZT green sheet that is easy to process, and then the PLZ
The process consists of the process of firing the T-green sheet and the process of filling these electrode forming areas with conductive paste to form the predetermined pixel forming electrodes, so the electric field distribution inside one pixel is uniform and the contrast ratio is high. A group of electrodes for forming pixels to create high-definition images that do not deteriorate.

Can be easily formed.

[Brief explanation of drawings]

11th (a) = (a) is PLZT according to the first invention
Explanatory diagrams of steps showing an example of a method for forming electrodes of a light valve, FIGS. 2(a) to 2(c) are PLZ according to the second invention.
FIG. 3 is a perspective view showing the configuration of one pixel in which the internal electric field formed by the conventional surface electrode method is non-uniform; FIG.
The figure is an explanatory diagram explaining the electric field distribution in Figure 3, Figure 5 is a perspective view showing the configuration of one pixel in which the internal electric field formed by the conventional parallel plate electrode method etc. is uniform, and Figure 6 is the It is an explanatory diagram explaining electric field distribution of a figure. 1.11... Pixel, 2... Optical axis of incident light, 3...
PLZT plate, 7, 17... Electric force lines, 13... PL
ZT, 14.15.22... Pixel forming electrode, 21
... PLZT green sheet, 23 ... resin film, 2
5... Buried piece, 27... PLZT sheet, 29.2
9a-Concave portion (fl! Polar acid forming portion 31...pixel, 33
．． 35... Pixel forming electrode.

Claims (3)

[Claims] (1) A plurality of embedded pieces are embedded in a PLZT green sheet, and then a plurality of electrode forming parts are formed by firing the PLZT green sheet and removing the plurality of embedded pieces, and a conductive paste is applied to these electrode forming parts. A method for forming electrodes in a PLZT light valve, characterized in that a group of electrodes for forming a pixel is formed by filling the pixel-forming electrode group in which the electrode plate surfaces face each other in parallel through the PLZT and are parallel to the optical axis of incident light. . (2) Claim (1) The buried piece is formed of a resin material that can be removed by thermal decomposition during firing of the PLZT green sheet.
) A method for forming electrodes of a PLZT light valve as described above. (3) By forming a plurality of electrode formation parts on the sheet surface of the PLZT green sheet, firing the PLZT green sheet, and then filling the plurality of electrode formation parts with conductive paste, the electrode plate surface becomes PLZT. 1. A method of forming electrodes for a PLZT light valve, comprising forming a group of pixel forming electrodes that face each other in parallel with each other and are parallel to the optical axis of incident light.