JPH03132717A - Electrode structure of plzt display device - Google Patents

Abstract

PURPOSE:To increase the aperture rate, to lower the driving voltage, and to reduce crosstalk by forming aninter-digital diving electrode and a common electrode which surrounds the driving electrode and is put in the comb pattern of the driving electrode on a substrate of transparent ceramic (PLZT). CONSTITUTION:On a glass substrate 6, a wiring pattern is formed of an ITO transparent conductive film and a bump 7 which is connected to the driving electrode 3 is formed by plating technique, etc. Then the glass substrate 6 is superposed upon the substrate 1 of PLZT and they are adhered with a transpar ent adhesive 8. Consequently, the common electrode (GND) 5 which surrounds the inter-digital driving electrode 3 and has a rectangular electrode part 4 to be put in the comb teeth of the driving electrode 3 is formed on the substrate 1. In such constitution, the driving electrode 3 is surrounded with the common electrode 5, so the aperture ratio of a shutter which can be increased in the area of an opening part can be increased.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to the electrode structure of a PLZT display device that utilizes the birefringence of PLZT (transparent ceramic), and more specifically to the electrode structure of a PLZT display device that utilizes the birefringence of PLZT (transparent ceramic). The present invention relates to an electrode structure for a PLZT display device that improves the aperture ratio and reduces crosstalk between adjacent shutters.

[Conventional example] In recent years, transparent ceramic P made by adding La to PZT has been developed.
LZT (PbO, LaO, ZrO, Tie) is about to be used for optical shutters and display devices. This PL
When ZT is used in a two-dimensional optical shutter or a flat display, the electrode structures shown in FIGS. 5 and 6, for example, are adopted.

As shown by diagonal lines in these figures, a comb-shaped common electrode (GND electrode) 2 and a drive electrode 3 are formed on the PLZT substrate 1 so as to fit between the combs. Although FIG. 6 shows an example in which the common electrode 2 and drive electrode 3 are surface electrodes, it is also possible to consider a groove-type electrode in which a groove is formed by some method and the electrode is embedded in the groove. As a result, further reduction in driving voltage can be expected.

Then, light is transmitted between the common electrode 2 and the drive electrode 3.
When a signal S is applied to the drive electrode 3 (when a voltage is applied), an electric field is generated in the PLZT substrate 1, and in response to this electric field, a blocking opening is provided. The transmission/blocking of light is controlled.

[Problems to be Solved by the Invention] By the way, the above-mentioned comb-shaped electrode structure is effective in lowering the drive voltage, but there are problems such as a low aperture ratio, and if a groove-shaped electrode is used, For example, in machining using a dicing cutter or the like, it is difficult to form the grooves into a comb shape, and furthermore, it is difficult to lower the driving voltage.

Furthermore, as shown in FIG. 5, since one side of the comb-shaped drive electrode 3 is not surrounded by the common electrode 2, crosstalk may occur between adjacent shutters.

This invention was made in view of the above problems, and its purpose is to improve the aperture ratio, reduce the drive voltage, and reduce crosstalk even with comb-shaped electrodes. An object of the present invention is to provide an electrode structure for a PLZT display device.

[Means for Solving the Problems] In order to achieve the above object, the electrode structure of a PLZT display device of the present invention includes the following: In the electrode structure of a two-dimensional display device using PLZT, a comb-shaped structure is formed on the PLZT substrate. A drive electrode and a common electrode that surrounds the drive electrode and has an electrode part that enters between the combs of the drive electrode are formed, and the drive electrode is taken out to the outside through a bump. do.

Further, a common electrode surrounding the drive electrode is formed in a checkerboard shape, and the common electrode is a groove-shaped electrode.

[Function] Due to the structure described above, the common electrode surrounds the drive electrode and enters between the combs of the drive electrode. Therefore, compared to a conventional combination of comb-shaped electrodes, the aperture ratio of the shutter becomes larger, and when an optical shutter array is used, for example, crosstalk does not occur between adjacent shutters.

In addition, since the part of the common electrode surrounding the drive electrode has a checkerboard shape, a groove is formed in the PLZT substrate by machining, for example, with a dicing cutter, and this groove is used as an electrode (groove electrode). It becomes possible to further lower the driving voltage.

[Embodiment] Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 4. In FIG. 1, parts that are the same as those in FIGS. 5 and 6 are designated by the same reference numerals, and redundant explanation will be omitted.

In FIGS. 1 and 2, a common type i ( G
ND) 5 is formed. That is, the electrode portion 4
A comb-shaped electrode is formed by the common electrode 5 and the common electrode 5.

As shown in FIG. 3, when the PLZT display device with the above electrode structure is used for a two-dimensional optical shutter array or a flat display, the common electrode 4 is formed in a checkerboard shape, and within this month A comb-shaped drive electrode 3 is formed, and the electrode section 4 is formed between the combs of the quick-acting electrode 3. Note that the drive electrode 3 and common type $45 are as follows:
As in the past, after forming a metal film by sputtering method etc.
It may be formed by a photolithography process.

Further, since the drive electrode 3 is surrounded by the common electrode 5, the drive electrode 3 can be replaced with PLZT using bump technology, for example.
It is taken out to the outside. That is, as shown in FIG. 2, a wiring pattern is formed using an ITO transparent conductive film on a glass substrate 6, and bumps 7 connected to the drive electrodes 3 are formed by, for example, a plating technique. Then, the glass substrate 6 is stacked on the PLZT substrate 1, and they are bonded together using a transparent adhesive 8. As a result, the bumps 7 are connected to the drive electrodes 3, as shown by the circle portion of the two-dot chain line in FIGS. 1 and 3, and the drive electrodes 3 are taken out to the outside via the bumps 7 and the wiring pattern. .

Then, as shown in A of Figs. 1 and 3,
The number of openings can be increased, increasing the aperture ratio of the shutter. Further, since the drive electrode 3 is completely surrounded by the common electrode (GND) 5, crosstalk caused by adjacent shutters is reduced when a PLZT optical shutter array is used, for example.

FIG. 4 shows a modified embodiment of the present invention, in which the common electrode 5 is formed in a checkerboard shape.
The common electrode 5 except for is a groove-shaped electrode 9 formed by a dicing cutter or the like, and the electrodes 3 and 4 are groove-shaped electrodes formed by etching.

In this case, vertical and horizontal grooves are formed on the PLZT substrate 1 using a dicing cutter, that is, corresponding to the common electrode 5! II
'Grooves are formed on the board, and then grooves for the drive electrode 3 and the common electrode 4 facing this electrode are formed by etching. Furthermore, after forming a metal film using a sputtering method or the like, an electrode pattern is formed by a photolithography process. In this way, the common electrode 5 is a deep groove electrode 9, for example, a groove of 100μ to 300μ is formed, and the drive electrode 3 and common electrode 4 are shallow groove electrodes.
As shown by the broken line arrow in the figure, the electric field distribution within the PLZT substrate 1 becomes better, making it possible to further reduce the driving voltage.

[Effects of the Invention] As explained above, according to the electrode structure of the PLZT display device of the present invention, a comb-shaped drive electrode is provided on the PLZT substrate, and the drive electrode is surrounded by the drive electrode.

A common electrode (
GND), and the drive electrode is taken out to the outside via the bump, so the drive electrode is completely surrounded by the common electrode, so the number of openings is increased to improve the aperture ratio. It is possible.

Moreover, crosstalk between adjacent shutters of an optical shutter array, for example, can be reduced.

In addition, the common electrode surrounding the drive electrode is shaped like a checkerboard,
Moreover, since the common electrode is a groove-type electrode, the electric field distribution in the PLZT substrate becomes even better, and there is an effect that the driving voltage can be further reduced.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 show a PLZ showing an embodiment of this invention.
FIG. 3 is a schematic front view and cross-sectional view of the electrode structure of the T display device; FIG. 3 is a schematic front view of the electrode structure when the above PLZT display device is applied to an optical shutter array;
The figure is a schematic sectional view of the electrode structure of a PLZT display device showing a modified embodiment of the present invention, and FIGS. 5 and 6 are a schematic front view and sectional view showing the electrode structure of a conventional PLZT display device. In the figure, 1 is )'LZT substrate, 3 is a drive electrode (comb-shaped),
4 is an electrode part, 5 is a common electrode (GND), and 6 is a glass plate (
transparent wiring pattern), 7 is bump, 8 is transparent adhesive, 9
is a groove electrode. Figure 1

Claims (2)

[Claims] (1) In the electrode structure of a two-dimensional display device using PLZT, a common electrode has a comb-shaped drive electrode on the PLZT substrate, and an electrode portion surrounding the drive electrode and entering between the combs of the drive electrode. 1. An electrode structure for a PLZT display device, characterized in that the drive electrode is formed as follows, and the drive electrode is taken out to the outside via a bump. (2) The electrode structure of a PLZT display device according to claim (1), wherein the common electrode surrounding the drive electrode is formed in a checkerboard shape, and the common electrode is a groove-shaped electrode.