JPH0323418A - Plzt light valve - Google Patents

Abstract

PURPOSE:To prevent the aperture rate from decreasing owing to an increase in the number of picture elements by forming connecting holes which communicates with specific places of internal electrode groups in an insulating layer formed of a transparent insulator on the surface of a PLZT plate, and wiring connecting conductors on the surface of the insulating layer and connecting the connecting conductors to the internal electrode groups. CONSTITUTION:The transparent insulating layer 1 which is fixed on the surface of the PLZT plate 13 insulates the internal electrodes 11 and 12 and connecting conductors 3 and 4 and the connecting holes 2 formed through the insulating layer 1 at specific positions contribute to the connections between the internal electrode groups 11 and 12 and connecting conductors 3 and 4. Consequently, the transparent connecting conductors 3 and 4 are arranged not only between picture elements, but also on the picture elements 18. Consequently, the aperture ratio is made large even if the number of picture elements increases.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in PLZT light pulses used in projection displays, direct-view displays, and the like. [Conventional technology In recent years, P L ZT (for example, ( P be .s, La
Research and development of PLZT light valves using a-as) (Zro.as TLo-as)Oi) 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 PLZT light pulse using conventional PLZT is based on the surface electrode method and parallel Vertical electrodes and horizontal electrodes were formed using a plate electrode method or the like.

However, as explained in the previous application "Problems to be Solved by the Invention J", the surface electrode method has the problem that the electric field distribution inside the PLZT becomes uneven, causing a decrease in contrast and crosstalk. The parallel plate electrode method has a problem in that the processing process is complex and requires high processing precision.In order to solve these problems, the applicant has developed an electrode method using the green sheet process in an existing application. P
We proposed a PLZT light valve that uses an internal electrode type buried inside the LZT to ensure uniform electric field distribution and is easy to manufacture. That is, in order to obtain a predetermined thickness, a PLZT green sheet on which no electrode group is printed is interposed as necessary,
Internal electrode group 11 for data. PLZT that printed...
A green sheet and a PLZT green sheet on which internal electrode groups l2 for scanning were printed were alternately laminated and crimped and fired, and this laminated crimped and sintered body was cut and the electrode group was buried. A PLZT plate 13 is formed, and internal electrode groups 11. ... and 12, ... to external data signal lines and scanning signal lines, respectively (transparent ITO) 14, ... and l5, ...
..., as shown in FIGS. 5, 6, 7, and 8.
Internal electrode groups 11, .
... was comb-shaped, forming a PLZT light valve whose electrode plate surface was parallel to the optical axis of the incident light 17.

[Problems to be Solved by the Invention] However, in the previously proposed PLZT light valves as shown in FIGS. 5, 6, 7, and 8, the internal electrode group 11. ..., 12, ... are attached to the PLZT board l.
Connecting conductors 14, . . . , 15, .
Since it is connected to the outside at ..., the connection conductor 14, ..., 1
5, . . . are internal electrode groups 11. , 12, . . . and must pass between pixel 18 and pixel l8. Therefore, as the number of pixels 18, . . . increases, the number of connection conductors 14, . . . , 15, . There was a problem in that the ratio of the area of the pixel portion to the total area of the screen decreased, and the aperture ratio decreased. .

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a PLZT light valve whose aperture ratio does not easily decrease even when the number of pixels is increased. A further object of the present invention is to provide a PLZT light valve that can reduce the influence of a connecting conductor on electric field distribution inside a pixel.

[Means for Solving the Problems] The PLZT light valve according to the present invention includes a PLZT plate whose plate surface is perpendicular to the optical axis of the incident light, and a plate surface which is parallel to the optical axis of the incident light. and a transparent connecting conductor for connecting the internal electrode group to the outside. A transparent insulator formed on the PLZT board surface! fixing the four layers, forming a connection hole in this insulating layer that communicates with a predetermined location of the internal electrode group,
The connection conductor is connected to the internal electrode group through the connection hole and is a conductor wired on the surface of the insulating layer. Furthermore, in order to reduce the influence of the connecting conductor on the electric field distribution inside the pixel, the insulating layer is formed of a dielectric material having a lower permittivity than the PLZT board. [Operation: The internal electrode groups that face each other to form pixels are arranged with their electrode plates parallel to the optical axis of the incident light, making the electric field uniform and enabling high brightness and high definition. moreover. PLZ
A translucent insulating layer fixed on the T-plate surface insulates the internal electrode group and the connecting conductor, and a connecting hole formed in a predetermined location of this insulating layer connects the internal electrode group and the connecting conductor. Contributes to the connection of Therefore, the light-transmitting connection conductor can be arranged not only between pixels but also on the pixels. Furthermore, if the insulating layer is made of a dielectric material with a lower dielectric constant than the PLZT board, the influence of the connecting conductor on the electric field distribution inside the pixel can be reduced. [Example] Hereinafter, an example of the present invention will be described based on the drawings.

1, 2, 3 and 4 are P
This figure shows one embodiment of the LZT light valve, and in these figures, the same parts as in FIGS. 5, 6, 7, and 8 are given the same reference numerals. In Figures 1 to 4, l
3 is an electro-optic ceramic P L ZT (for example, (Pbo1x LaO-09) (Zrl1-,, Tlo
-3s) Transparent PL Z of a predetermined thickness formed of Oi)
The PLZT plate 13 is arranged perpendicularly to the optical axis of the incident light [7]. Inside the PLZT board 13,
Internal electrode groups 11, whose electrode plate surfaces are parallel to the optical axis of the incident light 17 and form pixels 18,... between opposing electrode plates.
, 12,... are buried. The internal electrode group 1
1. ..., l2, ... form an upper pixel l8 by a plurality of electrode plates facing each other in a comb shape, and the end thereof is
The PL exposed on the plate surface of the LZT plate 13
On the plate surface of the ZT plate l3, there is a dielectric constant (for example, 4 to 5) smaller than the dielectric constant (for example, 4000) of the PLZT plate 13.
dielectric (for example, Sio, polyimide resin, etc.)
A light-transmitting insulating layer 1 made of is fixed. The internal electrode group 11 of the insulating layer t.・・・． 12,・
A predetermined shape (e.g., 1.0 mm) formed by a method (e.g., lift-off method) in which the etching solution does not come into direct contact with the PLZT plate l3 is placed in a portion corresponding to a predetermined portion of the exposed end of the PLZT plate l3.
(prismatic shape with sides of 10 microns or more) connection hole 2,...
・ is provided. On the #@edge layer 1, light-transmitting connection conductors 3, . . . and 4, . It is being

The connection conductors 3, . . . have one end connected to the connection hole 2.
, . . . through predetermined connection holes 2, . . . The connecting conductors 4, . . . are connected to the connecting holes 2, .
It is connected to the internal electrode group l2, . . . through predetermined connection holes 2, . . . , and the other end is connected to an external scanning signal line.

In the above embodiment, the light-transmitting insulating layer is formed of a dielectric material having a lower permittivity than the PLZT board, but the present invention is not limited to this, and the light-transmitting insulating layer may be formed of a light-transmitting insulating material. Good to have.

[Effects of the Invention] The PLZT light valve according to the present invention has the following effects as described above.
Since the internal electrodes that face each other to form pixels are provided with their plate surfaces parallel to the optical axis of incident light, the electric field becomes uniform and high brightness and high definition are possible. Furthermore, PLZT
The internal electrode group and the connecting conductor are insulated by a translucent insulating layer fixed on the plate surface, and the internal electrode group and the connecting conductor are connected through the connecting hole formed in this X@ edge layer. As a result, the light-transmitting connection conductor can be arranged not only between the IIIj elements but also on the pixels. Therefore, even if the number of pixels increases, the aperture ratio can be increased. Furthermore, when the light-transmitting insulating layer is formed of a dielectric material having a lower permittivity than the PLZT plate, the influence of the connecting conductor on the electric field distribution inside the pixel can be reduced.

[Brief explanation of drawings]

Figures t, 2, 3 and 4 are
This shows one embodiment of the LZT light valve, and FIG. 1 is a sectional view taken along the line A-A in FIG. 2, and FIG. 2 is a front view showing the main parts.
Figure 3 is a sectional view taken along line B-B in Figure 2, and Figure 4 is a cross-sectional view taken along line C in Figure 2.
5, 6, 7, and 8 show the PLZT light valve proposed by the present applicant, and FIG. 5 is the sectional view taken along the line D-D in FIG. 6. Figure 6 is a partial front view, Figure 7 is a sectional view taken along the line E-E in Figure 6, and Figure 8 is a partial front view.
The figure is a sectional view taken along the line FF in FIG. 6. 1... Insulating layer, 2... Connection hole, 3, 4... Connection conductor, 11. 12...Internal electrode, 13...PLZT
Board. 17...Incoming light, l8...Pixel.

Claims (2)

[Claims] (1) A PLZT plate whose plate surface is perpendicular to the optical axis of the incident light, and a PLZT plate whose plate surface is parallel to the optical axis of the incident light.
The PLZT board comprises an internal electrode group embedded in the T plate and forming pixels between opposing electrode plates, and a translucent connection conductor for connecting the internal electrode group to the outside. An insulating layer made of a translucent insulator is fixed on the surface, a connection hole communicating with a predetermined location of the internal electrode group is formed in this insulating layer, and the connection conductor is connected to the connection hole. PLZT is connected to the internal electrode group through the PLZT and serves as a conductor wired on the surface of the insulating layer.
light bulb. (2) The PLZT light valve according to claim 1, wherein the insulating layer is formed of a dielectric material having a lower dielectric constant than the PLZT plate.