KR970008404B1 - Optical path regulator - Google Patents

Abstract

The optical path controller for use of an image displaying apparatus based on a projection type comprises a driving substrate in which transistors are installed, pads electrically connected with the transistors are contained and a formation is provided between the pads; and actuators installed to be electrically connected to the driving substrate, the actuators being provided with a formation of signal and bias electrodes having mutually different thickness on the lower and upper surfaces of transforming parts made of piezoelectric polymer.

Description

Optical path adjuster of projection image display device

1 is a cross-sectional view of an optical path adjuster of an optical path adjuster of a conventional projection type image display apparatus.

2 is a cross-sectional view of the light path controller of the light path control device of the projection image display device according to the present invention.

* Explanation of symbols for main parts of the drawings

30: optical path controller 31: drive engine

33: groove 35: pad

37: Actuator 39: signal electrode

41: deformation portion 43: bias electrode

45 mirror surface

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical path controller of a projection image display device, and more particularly, to an optical path controller of a projection image display device using a polymer piezoelectric material.

An image display apparatus is classified into a direct view type image display apparatus and a projection type image display apparatus according to a display method. The direct view type image display apparatus includes a CRT (Cathobe Ray Tube). Such a CRT image display apparatus has good image quality, but there is a problem of increasing the weight and thickness and increasing the price as the screen is enlarged.

Projection type image display apparatuses include a large crystal display (hereinafter referred to as an LCD), and such a large-screen LCD can be thinned to reduce weight. However, such LCDs have a high loss of light due to a polarizing plate, and thin film transistors for forming LCDs are formed for each pixel, so that there is a limit in increasing the aperture ratio (light transmission area).

In order to make up for the drawbacks of LCD, a projection type image display device using actuated mirror arrays (hereinafter referred to as AMA) has been developed among Aura. A projection image display device using AMA separates white light emitted from a light source into red, green, and blue light beams, and then reflects these light beams to reflectors inclined by the deformation of actuators, respectively. display the image by adjusting the paht) and controlling the amount of light of these beams to project on the screen. The AMA is classified into a one-dimensional AMA having an M × 1 gang and a two-dimensional AMA having an M × N, depending on the driving method. The actuator includes a deformable part and electrodes formed of a piezoelectric material or a warping material, and deforms when an electric field is generated to tilt the mirror on the top.

1 is a cross-sectional view of an optical path controller 10 of a conventional projection image display device.

The optical path controller 10 includes a driving substrate 11, an actuator array 13, a mirror 29, and the like.

The driving substrate 11 is made of an insulating material, and M × N transistors (not shown) are embedded in a matrix form.

In addition, a pad (not shown) is formed on the surface of the driving substrate 11 to be electrically connected to the transistors.

The actuator array 13 is made of the first and second deformable portions 15 and 17, the signal electrode 19, the first and second vise electrodes 21 and 23, and the insulating layer 25. N unit actuators (indicated by dashed lines) are arranged. The first and second deformable parts 15 and 17 are formed of piezoelectric ceramics or electrodistorter ceramics polarized in opposite directions along the vertical axis. The first and second deformable parts 15 and 17 form a body, but the upper part is separated by the U-shaped grooves 27, and the second and first deformable parts 17 and 15 of adjacent actuators are formed. )

Signal electrodes 19 are formed on lower surfaces of the first and second deformable parts 15 and 17, and first and second bias electrodes 21 and 23 are formed on an upper surface thereof. When the signal electrodes 19 contact the pads of the driving substrate 11, the signal electrodes 19 are spaced apart from the signal electrodes 19 of adjacent actuators to input respective image signals. Each bias voltage is applied to the first and second bias electrodes 23 and 21 in common with the second and first bias electrodes 23 and 21 of adjacent actuators. In addition, insulating layers 25 are formed on surfaces of the first and second bias electrodes 21 and 23. The insulating layers 25 protrude toward the center of the grooves 27 to block the mirrors 29 and are separated from neighboring insulating layers 25.

The mirrors 29 form 'T' shapes and are supported by the insulating layers 25, and are insulated from the first and second bias electrodes 21 and 23 by the insulating layers 25.

However, the conventional optical path controller has a problem in that when the deformation parts are formed of piezoelectric ceramics, they must be polarized in a high electric field of about several tens of KV / cm. In addition, since the processing by the diced has a problem that the manufacturing time is long and the dimensions are not uniform due to mechanical tolerances.

Accordingly, an object of the present invention is to provide an optical path controller of a projection type image display device which is very easy to polarize and simple.

An optical path adjusting device of a projection image display device according to the present invention for achieving the above objects includes a drive substrate having pads with built-in registers and electrically connected to the transistors on a surface thereof, and having a space formed between the pads; Actuators are mounted to be electrically connected to the substrate, and actuators having different thicknesses of signal and bias electrodes are formed on the lower and upper surfaces of the deformation parts made of piezoelectric polymers.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view of the optical path adjuster 30 of the projection image display apparatus according to the present invention.

The optical path adjusting device 30 includes a driving substrate 31, actuators 37 and mirror surfaces 45.

The convex substrate 30 is made of a glass material in which M × N transistors (not shown) are embedded in a matrix, or a material such as alumina (Al ₂ O ₃ ), or a semiconductor such as single crystal silicon. In addition, the driving substrate 30 has pads 33 electrically connected to transistors on a surface thereof, and grooves 35 on the surface between the pads 33 serve as driving spaces of the actuators 37. In particular, the actuators 37 are not in contact with the driving substrate 31 when bent down.

The actuators 37 have a signal electrode 39 and a bias electrode 43 formed on the lower and upper surfaces of the deformation part 41 made of a piezoelectric polymer film such as polyvinylidene fluoride (PVDE). One end of the 39 is mounted on the driving substrate 31 to be in contact with the pads 33. The deformation part 41 has a thickness of about 10 to 40 μm and is polarized in one vertical direction, and the direction of the electric field by the image signal applied to prevent depolarization of the image signal during driving. Should be the same. The signal and bias electrodes 39 and 43 are formed of a conductive metal such as aluminum, silver, copper, gold, titanium, or platinum, each having a different thickness, and any thickened one of the signal and bias electrodes 39, 43 is formed. It functions as an elastic deformation part. The deformation part 41 is deformed not only in the vertical direction but also in the horizontal direction when the polarization direction and the direction of the electric field coincide. In addition, a polymer such as PVDE constituting the deformable portion 41 has a much lower modulus of elasticity than the signal and bias electrodes 39 and 43. Therefore, the deformation 41 is bent toward the thicker electrode by a force that is larger in the horizontal direction than the electrodes 39 and 43. That is, the signal electrode 39 is 0.1 to 0.2 µm electric, the bias electrode 43 is formed to a thickness of about 1 to 2 µm, and the deformation portion 41 is bent toward the bias electrode 43. In addition, if the thicknesses of the signal electrode 39 and the bias electrode 43 are opposite, the deformable portion 41 is bent toward the signal electrode 39.

The mirror surface 45 is a metal having good reflection characteristics such as aluminum or silver on the bias electrode 43 surface of the actuator 37, and is formed to a thickness of about 0.05 μm to about 0.1 μm. Therefore, the mirror surface 45 reflects the incident light inclined according to the composition of the actuator 37 by adjusting a path.

In the above-described optical path controller 30, it is assumed that the deformable part 41 is polarized from the signal electrode 39 toward the bias electrode 43 and the bias electrode 43 is formed thicker than the signal electrode 39. When the image signal is applied to the signal electrode 39 through the transistor and the mud 33 of the driving substrate 31 from an external circuit (not shown), and the bias electrode 43 is grounded, the deformable portion 41 is formed. It is deformed not only vertically but also horizontally. Therefore, stress is generated between the deformable portion 41 and the bias electrode 43 to bend toward the bias electrode 43.

The optical path controller 30 forms the driving substrate 31 in the longitudinal direction with the grooves 35 between the pads 33 by a conventional photolithography process. In addition, the signal electrodes 37 may be pads (eg, the signal electrodes 39 may be formed on one surface thereof and the deformation portions 41 may be formed of piezoelectric polymer such as PVDF on which the bias electrode and the mirror surfaces 43 and 45 may be coated on the other surface thereof). 33 is mounted on the driving substrate 31 so as to be in contact with them. The mirror surfaces 45 and the actuators are then separated by laser cutting or photolithography.

In addition, the above-described optical path controller is shown that the bias electrode and the mirror surface are respectively formed, but if the signal electrode is formed of a conductive metal having a good reflection characteristics, the bias electrode may also function as a mirror surface. In addition, although the driving space of the actuators is secured by the grooves etched in the driving substrate, the driving space may be secured by the support part formed of photoresist, polyimide, or insulating ceramics. In this case, a plus is required to electrically connect the pad and the signal electrode inside the support.

As described above, the onset is polarized, and an actuator having thickened signal and bias electrodes formed on both side surfaces of the deformable portion made of piezoelectric polymer film such as PVDF that deforms in the vertical and horizontal directions when an electric field is generated to function as an elastic portion. They are mounted on a driving substrate in which grooves used as driving spaces of actuators between pads are formed, and the actuators are separated by cutting by a laser and bent toward the electrode functioning as an elastic part during driving.

Therefore, the optical path controller of the projection image display device according to the present invention has advantages in that the manufacturing is simple and the tolerance can be reduced by minimizing the mechanical function.

As described above, the present invention has been described and illustrated with reference to the preferred embodiments, but those skilled in the art can make various modifications without departing from the spirit and scope of the present invention.

Claims (11)

A drive substrate having transistors embedded therein and electrically connected to the transistors on a surface thereof, the drive substrate having these pads and having a space formed therebetween, and a deformation portion formed of a piezoelectric polymer mounted to be electrically connected to the drive substrate. An optical path adjuster for a projection image display device having actuators having different thicknesses of signal and bias electrodes formed on lower and upper surfaces thereof. The optical path controller of claim 1, wherein the driving substrate is provided with grooves forming a space between the paddles. The optical path controller of claim 1, wherein the driving substrate is provided with a support part spaced above the pads. The optical path controller of claim 3, wherein a plug is electrically connected to a pad in the support. The optical path controller of claim 1, wherein the deformation parts are formed of a piezoelectric polymer polarized in one vertical direction. The optical path controller of claim 5, wherein the deformation parts are formed in a thickness of 10 to 40 μm. The optical path controller of claim 1, wherein the signal and bias electrodes are formed of gold, silver, aluminum, copper, titanium, or platinum. 8. The optical path adjuster for a projection image display device according to claim 7, wherein any one of the signal and the bias electrode is 0.1 to 0.2 mu m, and the other is 1 to 2 mu m thick. The optical path controller of claim 1, further comprising a mirror surface of the bias electrode. 10. The optical path controller of claim 9, wherein the mirror surface is formed of on or aluminum. The optical path adjuster for a projection image display device according to claim 10, wherein the mirror surface has a thickness of 0.05 to 0.1 탆.