KR970003009B1 - Optical path regulating apparatus of projector - Google Patents

Abstract

a substrate where a transistor is built in and whose surface contact terminals are formed on; an actuator where a signal electrode and a common ground electrode are deposited on the surfaces of a first and a second transformation part; and a reflective mirror formed on top of the actuator. The actuator comprises the first and the second transformation part which are polarized in the same direction each other, and the top parts of the transformation parts are connected with each other, being sloped to be crossed each other.

Description

Optical path adjuster for projection image display

1 is a cross-sectional view of an optical path adjusting apparatus for a conventional projection image display device.

2 is a cross-sectional view of an optical path control apparatus for a projection image display device according to the present invention.

* Explanation of symbols for main parts of the drawings

40: optical path control device 41: substrate

43: contact terminal 44: actuator

45,47: first and second variant 49: deformation part

51, 53: signal and common ground electrode 55: reflector

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical path control apparatus for a projection image display apparatus, and more particularly, to an optical path control apparatus for a projection image display apparatus that does not require a multi-layer ceramic and can be easily manufactured and improves reliability.

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 device includes a CRT (Cathode Ray Tube), but the CRT image display device has a good image quality, but there is a problem in that a large screen has an increase in weight and thickness and a price is expensive, and thus there is a limitation in implementing a large screen. . Projection type image display apparatuses include a large screen liquid crystal display (hereinafter, referred to as an LCD), and such large screen LCDs can be thinned to reduce weight. However, such LCDs have a high loss of light due to the polarizing plate, and thin film transistors for driving the LCD are formed for each pixel, so that there is a limit in increasing the aperture ratio (light-transmitting area).

In order to make up for the shortcomings of LCD, Aura, United States of America, has developed a projection type image display device using Actuated Mirror Arrays (hereinafter referred to as AMA). 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 that are inclined to the deformation of the actuators. ) And display the image by adjusting the amount of light of these luminous fluxes and projecting it onto the screen. The AMA is classified into a one-dimensional AMA having an actuator of M × 1 and a two-dimensional AMA having an M × N according to the driving method. The actuator includes a deformable part and electrodes formed of a piezoelectric material or a warping material and is deformed when an electric field is generated to tilt the mirror on the upper side.

1 is a cross-sectional view of a conventional optical path control device 10.

The optical path control apparatus 10 includes a substrate 11, an actuator 14, and a reflector 23. The substrate 11 is made of an insulating material such as glass or Al ₂ O ₃ and has thin film transistors (not shown) for each pixel, and a conductive pattern 13 having a matrix shape is formed on a surface thereof. In addition, the substrate 11 may be formed of a single crystal silicon wafer.

The actuator 14 is composed of the first and second deformation parts 15 and 17 and the signal and common ground electrodes 19 and 21. In the above, the first and second deformation parts 15 and 17 have an `` L '' shape and are disposed in a mirror image so as to have iron ( ) Is mounted on the substrate 11 in a shape. The first and second deformable parts 15 and 17 are made of piezoelectric ceramics, and a reflector 23 is positioned on an upper portion thereof. The first and second deformation parts 15 and 17 have common ground electrodes 19 formed on a surface of the signal electrode 19 facing the signal electrode 19. The polarization is polarized in one direction perpendicular to the first and second deformations 15 and 17. The signal electrode 19 is electrically connected to the conductive line pattern 13, and the common electrodes 21 are connected to the common electrode of adjacent optical path control means by an external conductive pattern (not shown).

In addition, the signal and the common electrodes 19 and 21 are formed of a conductive material such as metal, and deform the first and second deformation parts 15 and 17 at the signal voltage. That is, for example, when a signal voltage is applied to the signal electrode 19 in a state in which the first deformation unit 15 is polarized in the direction of the second deformation unit 17, the polarization direction and the electric field direction are the first deformation unit 17. ) Does not coincide, but coincides in the second deformation unit 19. Therefore, the first deformable portion 15 contracts in the horizontal direction and expands in the vertical direction, and the second deformed portion 17 expands in the horizontal direction and contracts in the vertical direction. Therefore, the reflector 23 is inclined from the first deformable portion 15 toward the second deformable portion 17 to have an inclination angle. The inclination angle of the reflector 23 is in proportion to the length of the upper portions of the first and second deformation parts 15 and 17 and inversely proportional to the square of the thickness. Therefore, in order to increase the inclination angle of the reflector 23 to increase the optical path control range, the thickness of the upper part of the first and second deformation parts 15 and 17 must be reduced or increased.

The above-described optical path control apparatus for projection type image display apparatuses can be made in two dimensions with M × N actuators. To do this, a plurality of piezoelectric ceramic layers are deformed using ceramic wafers made of ceramic wafers made by thinly cutting the multilayer ceramic perpendicularly to the metal layers. Process the signal electrodes to be

However, the optical path control apparatus for the projection type image display device described above has a very high temperature during sintering of the multilayer ceramic, so that the metal layers are melted or warped, making it difficult to form uniform signal electrodes, and the thickness of the deformed portions is not constant. There was a problem.

Accordingly, an object of the present invention is to provide an optical path device for a projection type image display device which is easy to form electrodes.

Another object of the present invention is to provide a projection type image display apparatus furnace apparatus having a constant thickness of the deformable portions and having good operating characteristics.

The optical path control apparatus for a projection image display device according to the present invention for achieving the above objects is a substrate in which a transistor is built and contact terminals are formed on the surface, and signal and common ground electrodes are coated on the surfaces of the first and second deformation parts. An optical path adjusting device for a projection type image display device having a mounted actuator and a reflecting mirror mounted on an upper portion of the actuator, wherein the actuator has first and second deformed portions polarized in the same direction and the upper portions thereof face each other at the same constant angle. It is characterized by a projection-type image display device that is tilted to look at the ends are connected to one body.

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

2 is a cross-sectional view of an optical path control apparatus 40 for a projection type image display apparatus according to an embodiment of the present invention. The optical path control device 40 includes a substrate 41, actuators 44, and a reflector 55.

The substrate 41 is made of an insulating substrate such as Al ₂ O ₃ and has thin film transistors (not shown) and contact terminals 43 which are used as driving elements for each pixel. In addition, the substrate 41 may be formed of a semiconductor wafer such as single crystal silicon. In this case, a MOS transistor is incorporated as a driving element.

The actuator 44 is applied to one side of the first and second deformable parts 45 and 47 and the contact terminal 43 in one body. It consists of the signal electrode 51 and the common ground electrode 53 applied to the other side and grounded in common. The first and second deformation parts 45 and 47 are made of piezoceramic such as BaTiO ₃ , PZT (Pb (Zr, Ti) O ₃ ) or PLZT ((Pb, La) (Zr, Ti) O ₃ ). It is polarized in the X or -X direction. The first and second deformation parts 45 and 47 are oriented at the same constant angle to face one side of the upper side, and the other sides are also inclined at the same angle as the respective one side. The first and second deformable portions 45 and 47 have one ends that meet each other to form a body, and the upper surface of the meeting portion is flat. The first and second deformation parts 45 and 47 are made by thinly cutting a piezoelectric ceramic in a bulk state to form a ceramic wafer, and then forming upper and lower surfaces of the ceramic wafer to form V-shaped grooves.

The signal and common ground electrodes 51 and 53 are made of gold (Au), silver (Ag), nickel (Ni), or chromium (Cr), and are coated by a method such as sputtering or vacuum deposition. The signal electrode 51 is contacted with the contact terminal 43 so as to be separated from the signal electrodes of adjacent actuators so that an image signal applied from the outside is input through the transistor, and the common ground electrodes 53 are common to the adjacent actuators. The ground electrode is electrically connected to the ground electrodes.

The actuator 44 generates electric fields in opposite directions to the first and second deformable parts 45 and 47 by an image signal input from the outside through the contact terminal 43. Therefore, either one of the first and second deformable portions 45, 47 extends in the X direction and contracts in the y direction by matching the direction of the electric field and the polarization. In addition, the other one does not match the direction of the electric field and polarization is reversed, shrink in the x direction and extend in the y direction. Therefore, the first and second deformable parts 45 and 47 have a height difference, so that the flat upper surface is inclined toward the same direction of the electric field and polarization.

The reflector 5 is made of a thin film of metal such as aluminum (Al), and is attached to and mounted on an upper surface where the first and second deformation parts 45 and 47 meet and are flattened. The reflector 55 is attached to the upper surfaces of the first and second deformation parts 45 and 47 so as to be electrically insulated from the common ground electrodes 53 by a nonconductive adhesive. Therefore, the reflector 55 is inclined in the direction of the first deformable portion 45 or the second deformable portion 47 in conjunction with the first and second deformable portions 45 and 47.

The operation of the optical path control device 40 having the above-described structure will be described.

The image signal applied from the external circuit is switched to a transistor (not shown) embedded in the substrate 41 and transmitted to the signal electrode 51 of the actuator 44 through the contact terminal 43. In addition, the common ground electrodes 53 of the actuator 44 are grounded. Therefore, electric fields are generated in the first and second deformation parts 45 and 47 which are polarized in the same direction along the x axis in opposite directions along the x axis. Accordingly, the coincidence between the direction of the electric field and the polarization direction among the first and second deformation parts 45 and 47 is contracted along the y axis, and the discordant and opposite directions are stretched along the y axis, so that the first and second deformation parts 45 and 47 extend. The upper surface where the two deformation parts 45 and 47 meet and become flat is inclined toward the deformation part in which the direction of the electric field and the direction of polarization coincide. For example, when the first and second deformation parts 45 and 47 are polarized in the x direction (left to right) and an image signal of '+' potential is input to the signal electrode 51, The direction of polarization extends along the y axis in the first deformable portion 45 and the second deformed portion 47 contracts along the y axis. Therefore, the upper surface on which the first and second deformable portions 45 and 47 meet and become flat is inclined in the direction (clockwise) of the second deformable portion 47, whereby the reflector 55 is also in the same direction. Interlocked. In the above, if the first and second deformation parts 45 and 47 are polarized in the -x direction (right to left) or the image signal input to the signal electrode 51 is a potential of '-', the first The upper surface of which the second deformation parts 45 and 47 meet and become flat is operated in the opposite manner to the above, so that the reflector 55 is inclined in the direction (counterclockwise direction) of the first deformation part 45. Since the amount of displacement of the piezoelectric ceramic is adjusted according to the magnitude of the applied electric field, the inclination of the reflector 55 may be adjusted by adjusting the magnitude of the image signal input to the signal electrode 51.

As described above, the optical path control device is inputted to the first and second deformation parts which are polarized in the same direction along the x axis, the upper parts having the same constant angle and inclined in opposite directions so that the ends are connected so that the upper surface is flat. The generated image signals generate electric fields in opposite directions along the x axis. Therefore, any one of the first and second deformed portions whose one of the electric field direction and the polarization direction coincide with each other and extend along the y-axis so that the first and second deformed portions meet and become flat is the deformable body whose electric field direction and the polarization direction coincide It is tilted toward, and in conjunction with this, the reflector is also tilted.

Therefore, the present invention can easily form an electrode by applying a conductive film on the surface of the first and second deformation parts made by digging V grooves on the upper and lower surfaces of the ceramic wafer made by thinly processing the piezoceramic formed in bulk. In addition, when the V groove is sold, the thicknesses of the first and second deformation parts may be constantly adjusted to have good operating characteristics.

Claims (2)

An optical path for a projection type image display device having a substrate in which a transistor is built, an actuator having a contact terminal formed on a surface thereof, an actuator coated with signal electrodes and a common ground electrode on surfaces of the first and second modified parts, and a reflector mounted on an upper portion of the actuator. In the adjusting device, the actuator is an optical control device for a projection image display device, wherein the first and second deformation parts are polarized in the same direction, and the upper parts thereof face each other at the same constant angle, and the ends are connected to form a body. The optical path control apparatus of claim 1, wherein the signal electrode and the common ground electrode are any one selected from gold, silver, nickel or chromium.