KR970006984B1 - Projector type image displaying apparatus - Google Patents

Abstract

A projection-type image display includes an optical source for emitting ray of light, a light modulator for dividing the ray of light into red, green and blue ray of light and reflecting them, a controller of controlling the amount of light for controlling the amount of each ray of light divided and reflected, a scanning mirror for combining the rays of light whose amounts are controlled and scanning them linearly, and lenses for parallelling the rays of light linearly scanned and projecting them on a screen.

Description

Projection type image display device

1 is a schematic diagram of a conventional projection image display apparatus.

2 is a cross-sectional view of the basic unit of the conventional optical path control means.

3 is a schematic diagram of a projection image display apparatus according to the present invention.

4 is a cross-sectional view of the basic unit of the light modulation means according to the present invention.

* Explanation of symbols for main parts of the drawings

31: light source 33: first balance lens

37: light modulation means 39: light amount adjusting means

43: scanning mirror 45: second balance lens

47: projection lens 51: the substrate

52, 53: first and second deformation part 55: internal electrode

57, 59: first and second external electrodes 61: mirror

63: color filter 65: basic unit

The present invention relates to a projection image display apparatus.

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 (Cathod Ray Tube), but such a CRT image display apparatus has good image quality but has a problem such as an increase in weight and thickness as the screen is enlarged, and a price is expensive. There is.

Projection type image display apparatuses include those using a large screen liquid crystal display (hereinafter referred to as LCD). In such an LCD type projection image display apparatus, the screen can be enlarged without limiting the weight. However, the LCD has a high light loss due to a polarizing plate, and a thin film transistor for driving the LCD is formed for each pixel, so that there is a limit in increasing the aperture ratio (light transmission area).

Accordingly, a projection type image display apparatus using Actuated Mirror Arrays (hereinafter referred to as AMA) has been developed by Aura, USA.

1 is a schematic diagram of the conventional projection type image display apparatus, which includes a light source l for emitting light, an optical separation means 5 for separating the light into red, green and blue lights, and the separated color light. An optical path adjusting means (7) for reflecting each, a light quantity adjusting means (9) for adjusting the amount of each reflected light, a scanning mirror (13) for synthesizing and scanning the respective lights with the adjusted light amount and a screen; Lenses 15 for paralleling and projecting the linearly scanned light onto a screen

(17).

In the projection image display apparatus, the light source 1 emits light of high intensity that passes through the first balance lens 3 and forms a parallel light beam. The parallel luminous flux is separated into red, green and blue light through the optical separation means 5.

Each of the separated lights is reflected by the light path adjusting means 7 so that a desired amount of light passes through the light amount adjusting means 9, respectively. Each light passing through the gap of the light amount adjusting means 9 is synthesized by the scanning mirror l3 and line-scanned to the screen (not shown) through the second balance lens 15 and the projection lens 17. scanning).

2 is a cross-sectional view of the basic unit 20 of the optical path control means (7).

The basic unit 20 includes a substrate 21, deformation parts 22, 23, and a mirror 19. The substrate 21 is an insulator that supports the deformation parts 22 and 23 to be formed. The deformation parts 22 and 23 are made of a piezoelectric material polarized in one direction, and external electrodes 27 and 29 are formed on both sides thereof. In addition, a thin plate-shaped internal electrode 25 is formed between the deformable parts 22 and 23. Mirrors 19 reflecting the light separated from the light separating means 5 to the light amount adjusting means 9 are formed on the upper parts of the deformable parts 22 and 23.

When the voltage is applied to the internal electrodes 25 and the external electrodes 27 and 29 in the basic unit 20, the deformation parts 22 and 23 are deformed. That is, the deformable parts 22 and 23 contract in a right angle direction where a direction of an electric field generated when a voltage is applied contracts in a polarization direction, and a right angle direction where a direction of an electric field is opposite to a polarization direction To expand. The mirror 19 has an inclination according to the change of the deformable parts 22 and 23. Therefore, the light path of each light separated by the light separating means 5 changes according to the inclination of the mirror 19, thereby changing the amount of light passing through the light amount adjusting means 9.

However, the conventional projection type image display device described above has a problem that the volume is increased by the optical separation means for separating the light into three colors of light and the optical system is complicated. In addition, the light separation means has to be accurately aligned in order to inject all of the separated three colors of light into the mirror of the optical path control means has a difficult manufacturing process.

Accordingly, it is an object of the present invention to provide a projection type image display apparatus with a simple optical system.

Another object of the present invention is to provide a projection type image display device having an easy manufacturing process.

In order to achieve the above object, the present invention provides a light source for emitting light, light modulating means for separating and reflecting the light into red, green, and blue light, respectively, and adjusting the amount of light for each of the separated and reflected light. Means, a scanning mirror for synthesizing each light whose light quantity is adjusted and scanning a linear, and lenses for paralleling and projecting the linearly scanned light onto a screen.

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

3 is a schematic diagram of a projection image display apparatus according to an embodiment of the present invention. The projection image display apparatus includes a light source 31 for emitting light, a light modulator 37 for separating and reflecting the light into red, green, and blue light, and adjusting the amount of each of the separated and reflected light. Light amount adjusting means 39, a scanning mirror 43 for synthesizing and linearly scanning each light whose light amount is adjusted, and lenses 45 for paralleling and projecting the linearly scanned light onto a screen. And (47).

In the projection image display device, the light source 31 emits light of high intensity that passes through the first balance lens 33 to form a parallel light beam.

The light modulation means 37 includes color filters for separating the high luminance light into red, green and blue light, mirrors for reflecting each of the light separated into red, green and blue, and attaching the mirrors. Actuators to be tilted. The mirrors and actuators are arranged in parallel with three mirror arrays and three actuator arrays so as to correspond to the three colors of light separated by the color filters. The mirror arrays are for linearly reflecting each light separated by the color filters and at least one mirror is arranged in series. The actuator arrays are also located on top of an electrically insulated substrate in which the same number of actuators as the mirrors are in series. One actuator, one mirror, and one color filter in the above form the basic unit 65 of the light modulation means 37. The actuators are made of piezoelectric materials that are polarized in one direction, and when an electric field is generated in these actuators, a portion of the electric field that contracts with the polarization direction contracts in a right angle, and an opposite portion of the actuator is in a right angle. Is inflated. Therefore, the respective mirrors are inclined according to the deformation of the actuators to change and reflect the optical path of each light separated by the color filters.

The light quantity adjusting means 39 is composed of a non-reflective surface 41 having a plurality of gaps 40. The gaps 40 consist of a plurality of pinholes or a plurality of knife-edged slit. The light amount adjusting means 39 adjusts and passes the amount of light whose light path is adjusted by the light modulating means 37. That is, the amount of light passed through the optical paths of the respective light reflected by the light modulating means 37 is matched with the plurality of gaps 40.

The scanning mirror 43 combines the light passing through the gaps 40 of the light amount adjusting means 39 to line scan, and the second balance lens 45 and the projection lens 47 are synthesized. The pre-injected light is paralleled and projected onto a screen (not shown).

4 is a cross-sectional view of the basic unit 65 of the light modulating means 37. As shown in FIG.

The basic unit 65 includes an actuator 50, a mirror 61, and a color filter 63. The actuators 50 have first and second deformable portions 52 and 53, internal electrodes 55, and first and second external electrodes 57 and 59, respectively, having an “L” shape. It is arranged in a mirror image, the inner electrode 55 of the thin plate is formed between the first and second deformable portions 52, 53, and is formed on the outer surface of the first and second deformable portions 52, 53. First and second external electrodes 57 and 59 are formed.

In addition, the first and second deformable parts 52 and 53 may be formed of piezoelectric ceramics, and may be formed in a direction opposite to or opposite to the second external electrode 59 from the first external electrode 57. It is polarized perpendicularly to the internal electrode 55. The first and second external electrodes 57 and 59 are common ground, and the internal electrode 55 is configured to apply a voltage of '+' or '-'.

Mirrors 61 are formed on the first and second deformation parts 52 and 53. The upper surface of the mirror 61 must be flat to reflect light. In addition, a color filter 63 is formed on the upper surface of the mirror 6l. The color filter 63 is an organic filter coated with a dyed polymer. The organic filter is made of a dyed polymer, for example, by applying dichromate gelatin to the upper surface of the mirror 61 and dyeing with any one of red, green and blue dyes. The color filter 63 passes only one of red, green, and blue light. Therefore, the basic unit 65 of the light modulation means 37 separates only one of red, green and blue light by the color filter 63 at the balanced light beam passing through the first balance lens 33. The reflection is reflected by the mirror 61.

Therefore, since the present invention separates each color light by the color filters formed in the light modulating means and reflects the light by the mirrors, it is possible to miniaturize the product because of its small size and simple optical system. In addition, there is an easy advantage in the manufacturing process since it does not require accurate alignment for injecting each color light into all the mirrors of the light modulation means.

Claims (3)

A light source for emitting light, light modulation means for separating and reflecting the light into red, green, and blue light, respectively, light amount adjusting means for adjusting the separated and reflected light amounts, and each of the light amounts being adjusted And a scanning mirror for synthesizing and linearly scanning light, and lenses for parallelly projecting the linearly scanned light and projecting the light onto a screen. The optical modulator of claim 1, further comprising: deformation parts formed of a substrate and piezoelectric material and displaced according to an applied voltage; A mirror formed on the deformation parts to reflect light; And a color filter formed on the mirror and separately passing any one of red, green, and blue light in parallel light flux. The projection type image display apparatus according to claim 2, wherein the color filter is an organic filter.