JPH0693062B2 - Electrode structure of PLZT display device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrode structure of a PLZT display device using the birefringence of PLZT (transparent ceramic), and more specifically, to an opening in a two-dimensional optical shutter or a flat display. The present invention relates to an electrode structure of a PLZT display device that improves the efficiency and reduces crosstalk between adjacent shutters.

[Conventional example] In recent years, PLZT (PbO, L
aO, ZrO, TiO) are about to be used for optical shutters and displays. When this PLZT is used for a two-dimensional optical shutter or a flat display, for example, the electrode structure shown in FIGS. 5 and 6 is adopted.

As shown by the diagonal lines in these figures, the comb-shaped common electrode (GND electrode) 2 and drive electrode 3 are provided on the PLZT substrate 1.
Are formed so as to be inserted between the combs. In addition,
FIG. 6 shows an example in which the common electrode 2 and the drive electrode 3 are surface electrodes. For example, a groove type electrode in which a groove is formed by some method and the electrode is embedded in this groove is also considered.
Furthermore, the driving voltage can be expected to decrease.

Then, light is transmitted between the common electrode 2 and the driving electrode 3
An opening for blocking is provided, and when a signal S is applied to the drive electrode 3 (when a voltage is applied), an electric field is generated in the substrate 1 of the PLZT according to the electric field, as shown by the broken line arrow in FIG. The light is controlled to be transmitted / blocked.

[Problems to be Solved by the Invention] The above-mentioned comb-shaped electrode structure is effective in reducing the driving voltage, but has a problem that the aperture ratio is low.
If a groove-shaped electrode is used, it is difficult to form the groove in a comb shape by machining such as a dicing cutter, and it is difficult to reduce the driving voltage.

Further, 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.

The present invention has been made in view of the above problems, and an object thereof is to improve the aperture ratio, reduce the driving voltage, and reduce crosstalk even with a comb-shaped electrode. Another object of the present invention is to provide an electrode structure of the PLZT display device.

[Means for Solving the Problems] In order to achieve the above object, an electrode structure of a PLZT display device according to the present invention is a two-dimensional display device electrode structure using PLZT. The gist of the invention is to form a drive electrode and a common electrode that surrounds the drive electrode and has an electrode portion that is inserted between the combs of the drive electrode, and takes out the drive electrode to the outside through a bump. .

Further, a common electrode surrounding the drive electrode is formed in a grid pattern, and the common electrode is a groove type electrode.

[Operation] With the above configuration, the common electrode surrounds the drive electrode and is inserted between the combs of the drive electrode. Therefore, compared with the conventional combination of comb-shaped electrodes, the aperture ratio of the shutter is large, and in the case of an optical shutter array, for example, crosstalk does not occur between adjacent shutters. Further, of the common electrode, since the portion surrounding the drive electrode has a grid pattern, a groove is formed on the PLZT substrate by machining such as dicing cutter,
The drive voltage can be further reduced by using the groove as an electrode (groove-type electrode).

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. In the figure, the same parts as those in FIG. 5 and FIG. 6 are designated by the same reference numerals, and a duplicate description will be omitted.

In FIGS. 1 and 2, a common electrode (GND) 5 that surrounds the comb-shaped drive electrode 3 and has a rectangular electrode portion 4 that is inserted between the combs of the drive electrode 3 is provided on the substrate 1 of the PLZT. Has been formed. That is, a comb-shaped electrode is formed by the electrode portion 4 and the common electrode 5.

Then, as shown in FIG. 3, the electrode structure
When the PLZT display device is used for a two-dimensional optical shutter array or flat display, the common electrode 4 is formed in a grid pattern, and the comb-shaped drive electrode 3 is formed in the grid.
In addition, the electrode portion 4 is formed between the combs of the drive electrodes 3. The drive electrode 3 and the common electrode 5 may be formed by a photolithography process after forming a metal film by a sputtering method or the like, as in the conventional case.

Further, since the drive electrode 3 is surrounded by the common electrode 5, the drive electrode 3 is taken out of the PLZT by using, for example, a bump technique. That is, as shown in FIG. 2, a wiring pattern is formed on the glass substrate 6 by the ITO transparent conductive film, and the bumps 7 connected to the drive electrodes 3 are formed by, for example, a plating technique. And
The glass substrate 6 is overlaid on the PLZT substrate 1, and they are bonded with a transparent adhesive 8. As a result, FIG. 1 and FIG.
As shown by the circled portion of the chain double-dashed line in the figure, since the bump 7 is connected to the drive electrode 3, the drive electrode 3 is taken out through the bump 7 and the wiring pattern.

Then, as shown in A of FIGS. 1 and 3, the number of openings can be increased, and the aperture ratio of the shutter is increased. Moreover, since the drive electrode 3 is completely surrounded by the common electrode (GND) 5, for example, in the case of a PLZT optical shutter array, crosstalk due to adjacent shutters is reduced.

FIG. 4 shows a modified embodiment of the present invention. Since the common electrode 5 is formed in a grid pattern, the electrode portion 4 is formed.
The common electrode 5 except for is a groove type electrode 9 formed by a dicing cutter or the like, and the electrodes 3 and 4 are groove type electrodes formed by etching.

In this case, vertical and horizontal grooves are formed on the PLZT substrate 1 by a dicing cutter, that is, grooves of a grid pattern corresponding to the common electrode 5, and then the driving electrode 3 and the common electrode 4 facing the electrode are formed by etching. To form a groove. further,
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 used as the deep groove type electrode 9 and, for example, from 100 μm to 3 μm.
Since the groove of 0 μm is formed and the drive electrode 3 and the common electrode 4 are shallow groove electrodes, the electric field distribution in the substrate 1 of the PLZT becomes good as shown by the broken line arrow in the figure. Therefore, the drive voltage can be further reduced.

[Effects of the Invention] As described above, according to the electrode structure of the PLZT display device of the present invention, the comb-shaped drive electrode and the inter-combination of the drive electrodes are formed on the substrate of the PLZT and surround the drive electrode. Forming a common electrode (GND) having an electrode part that goes in,
Moreover, since the drive electrode is taken out through the pump, the drive electrode is completely surrounded by the common electrode, so that the number of openings can be increased and the aperture ratio can be improved. Strokes in adjacent shutters of the optical shutter array can be reduced.

In addition, the common electrode surrounding the drive electrode is formed in a grid pattern,
Moreover, since the common electrode is a thin electrode, the electric field distribution of the PLZT substrate is further improved, and the drive voltage can be further lowered.

[Brief description of drawings]

1 and 2 are schematic front and sectional views of an electrode structure of a PLZT display device showing an embodiment of the present invention,
FIG. 3 is a schematic front view of an electrode structure when the PLZT display device is applied to an optical shutter array, and FIG. 4 is a schematic sectional view of an electrode structure of a PLZT display device showing a modified embodiment of the present invention. 5 and 6 are a schematic front view and a sectional view showing an electrode structure of a conventional PLZT display device. In the figure, 1 is a PLZT substrate, 3 is a drive electrode (comb type), 4 is an electrode part, 5 is a common electrode (GND), 6 is a glass plate (transparent wiring pattern), 7 is a bump, and 8 is a transparent adhesive. , 9 are groove-type electrodes.

Claims (2)

[Claims] 1. An electrode structure of a two-dimensional display device using PLZT, wherein comb-shaped drive electrodes are provided on the substrate of PLZT.
A PLZT display device characterized in that it is formed with a common electrode that surrounds the drive electrode and has an electrode portion that enters between the combs of the drive electrode, and that the drive electrode is taken out to the outside through a bump. Electrode structure. 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 grid pattern, and the common electrode is a groove type electrode.