KR970009466B1 - Projector type image display apparatus - Google Patents

Abstract

A projection display apparatus which traces red, green, and blue lights divided from a white light by color filters, respectively is disclosed. The apparatus includes means for dividing 35 whith light radiated from a light source 31 into red, green, and blue of lights; means 38 for reflecting the red, green, and blue lights via second optical pathlengths to be irradiated to a plurality of picture elements; and means 61 for controlling each intensity of the red, green, and blue lights. The light dividing means 35 includes a plurality of color-selecting mirrors dividing the white light into the red, green, and blue lights by selectively reflecting or permeating the white light. The reflecting means 38 includes a plurality of optical pathlength controllers, each of which reflects the red, green, and blue lights via the second optical pathlengths to be irradiated to the plurality of picture elements.

Description

Projection type image display device

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

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

* Explanation of symbols for main parts of the drawings

30: projection image display device 31: light source

33: parallel lens 35: optical separation means

36,37: first and second color discriminating mirror 38: optical path control device

39,45,53: 1st, 2nd, 3rd actuator array pattern 61: Overload regulating device

69: screen

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection image display apparatus, and more particularly, to a projection image display apparatus that separates white light from red, green, and blue light beams and adjusts paths by color-dividing glasses.

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 such a CRT image display device 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 a large screen liquid crystal display (hereinafter referred to as an LCD), and such a large screen LCD can be thinned to reduce weight. However, the LCD has a high light loss due to the 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 image display apparatus using Actuated Mirror Arrays (hereinafter referred to as AMA) has been developed by Aura, United States.

The projection image display apparatus is classified into using one-dimensional AMA and two-dimensional AMA. The one-dimensional AMA has mirror surfaces arranged in an M × 1 array, and the two-dimensional AMA has mirror surfaces arranged in an M × N array. Therefore, a projection image display device using a one-dimensional AMA pre-scans M × 1 beams using a scanning mirror, and a projection image display device using a two-dimensional AMA projects M × N beams to produce an array of M × N pixels. Branches represent images.

1 is a schematic diagram of the conventional projection type image display apparatus 20. As shown in FIG.

The projection image display apparatus 20 includes a light source 1, a light separation means 2, an optical path adjusting means 5, a light amount adjusting means 13 and a screen 19.

The light source 1 emits white light of high brightness. The light separating means (2) consists of a rotating color wheel (color wheel) and sequentially separates the primary luminous flux of red, green or blue from the white light. The color wheel 2 is separated so that color filters which transmit any one of red, green or blue light have the same area, and rotate in an integer multiple of a field or frame of an image signal. Each of the primary luminous fluxes is focused and reflected by the reflecting surface 15 of the light quantity adjusting means 13, and the reflected primary luminous fluxes are dispersed again and are paralleled by the parallel lens 3.

The optical path adjusting means (5) consists of a plurality of actuators 9 and mirrors (8) of an M × N array on a substrate (7) and a plurality of primary beams paralleled by the parallel lenses (3). Reflects with secondary beams. The secondary light beams for each of the primary light beams are light paths adjusted by the inclination of the mirrors 8. In addition, the second luminous fluxes are focused again by the parallel lens 3.

The light quantity adjusting means 13 consists of a reflective surface 15 having one or more gaps 17. The reflecting surface 15 reflects the primary light beams separated into three primary colors and focused by the scattered light again. In addition, the gaps 17 adjust and pass the amount of the second luminous flux focused by the parallel lens 3. The gaps 17 pass about 50% of each of the second luminous fluxes in the state in which the driving voltage is not applied to the optical path adjusting means 5, that is, in the absence of an image signal. To this end, the optical path adjusting means 5 is not in parallel with the parallel lens 3 and is inclined at a predetermined angle Δθ.

The screen 19 displays an image by synthesizing the second luminous fluxes for each of the adjusted primary luminous fluxes which are sequentially projected to the front surface through the projection lens 18.

In the above-described conventional projection type image display apparatus, white light having high luminance emitted from a light source is sequentially separated and reflected at red, green, and blue light speeds by a color wheel and an optical path adjusting means, and sequentially through a light amount adjusting means and a projection lens. Projected on the screen to implement the image.

However, in the above-described projection type image display apparatus, white light is sequentially incident on the filters by rotation of a color wheel composed of red, green, and blue filters, which are optical separation means, so that only light beams of colors corresponding to the filters pass. Since the light beams are separated and reflected or transmitted through the remaining colors, the amount of light projected on the screen is reduced, thereby lowering luminance. In addition, as the color wheel is rotated, the light is separated into two color filters at the same time, thereby reducing the color purity of the luminous flux.

Accordingly, it is an object of the present invention to provide a projection type image display apparatus capable of improving the brightness of an image.

Another object of the present invention is to provide a projection type image display apparatus capable of increasing the color purity of separated light beams.

In the projection type image display apparatus according to the present invention for achieving the above objects, the high luminance white light emitted from a light source is separated into red, green, and blue primary luminous fluxes by optical separation means, and the separated primary luminous fluxes are optical paths. A projection type image display apparatus comprising a screen in which light paths whose paths of light corresponding to a plurality of pixels are adjusted by adjustment means are reflected, and a light amount of these secondary light beams is adjusted and projected to display a predetermined image. Means for reflecting the primary light beam having any one of red, green and blue color light from the white light simultaneously emitted from the light source, and a first dichroic mirror for passing the other two color lights; A second dichroic mirror that reflects a primary light beam having any one of two color lights and passes the primary light beam having one other color Thus, the white light emitted simultaneously from the light source is all separated into primary luminous fluxes of red, green and blue, and the optical path adjusting means includes first, second and third actuator arrays to which the primary primary luminous fluxes are respectively input. It consists of panels, and the red, green and blue secondary luminous fluxes respectively separated from the light separating means reflect the red, green and blue secondary luminous fluxes whose respective paths of light corresponding to the pixels are adjusted.

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

2 is a schematic diagram of a projection image display apparatus 30 according to an embodiment of the present invention.

The projection image display device 30 includes a light source 31, a parallel lens 33, a light separation means 35, an optical path adjusting means 38, a light amount adjusting means 61, and a screen 69.

The light source 31 reflects high brightness white light. The reflected white light is focused and reflected by the reflecting surface 63 of the light amount adjusting means 61 to be parallel by the parallel lens 33.

The optical separation means 35 separates the white light into luminous fluxes of red, green and blue. The light separating means 35 consists of first and second dichoic mirrors 36 and 37 which separate white light into light velocities having respective colors.

That is, if the first and second dichroic mirrors 36 and 37 separate light beams having red and green colors, respectively, the red light beam is reflected from the white light incident from the first dichroic mirror 36 and the remaining light beams are separated. Is transmitted through the second dichroic mirror 37 to reflect the light beam of green and the light beam of blue. Therefore, the first and second dichroic mirrors 36 and 37 reflect or transmit the incident white light into primary, luminous fluxes of red, green and blue.

The optical path control means 38 reflects the primary beams on the engines 40, 47, 55 respectively to the secondary beams whose paths of light are adjusted in correspondence with the pixels. The first, second, and third actuators in which M × N pieces are mounted on the actuators 41, 49, and 57, respectively, for the 59 and the mirrors 43, 51, and 59 to have mirrors. Array panels 39, 45, and 53. Actuators 41, 49, 57 and mirrors 43, 51, 59 of the first, second and third actuator panels 39, 45, 53 correspond to pixels. The first incident light beams separated from the first and second dichroic mirrors 36 and 37 reflect secondary beams of which light paths are controlled by the mirrors of the mirrors 43, 51 and 59. Let's do it. Each of the secondary beams is focused again through a parallel lens 33 which is reflected along the path of incidence of the primary beams. Secondary light beams on which light passing simultaneously through the parallel lens 33 is reflected must be simultaneously focused on the parallel lens 33. Therefore, the first, second and third actuator array panels 39, 45 and 53 are each provided with the same distance traveled along the respective optical paths of light incident from the light source to the first dichroic mirror 36, respectively. Each is located.

The light quantity adjusting means 61 consists of a reflecting surface 63 having one or more gaps 65. The reflecting surface 63 reflects the white light radiated from the light source and converged to the parallel lens 33 to be dispersed, and the gaps 65 pass through adjusting the amount of light of the secondary beams focused again by the parallel lens 33. Let's do it. In the above gaps 65, the second optical speed is achieved without driving the actuators 41, 49, 57 of the first, second, and third actuator array panels 39, 45, 53. Pass them around 50%. To this end, the first, second and third actuator array panels 39, 45 and 53 are not perpendicular to the incident primary luminous fluxes and are formed at 90 ° ± Δθ (Δθ is a predetermined fine angle). Is installed.

The screen 69 passes through the gaps 65 through the projection lens 67 to simultaneously project the secondary beams of which the amount of light is adjusted to display a desired image.

As described above, the projection image display apparatus according to the present invention reflects or transmits white light by the first and second color-dividing mirrors so as not to be mixed into the primary luminous fluxes of red, green, and blue, and to separate them. The second and third actuator array panels are positioned such that the light incident on the first dichroic mirror travels the same distance along the optical path.

Therefore, the present invention has the advantage that the light efficiency is increased by improving the light efficiency because the light is reflected or transmitted through the white light is separated into the primary luminous flux of red, green and blue. In addition, the first and second dichroic mirrors have an advantage of improving color purity of the separated light because the first and second dichroic mirrors prevent color mixing of the primary light beams during light separation.

Although the present invention has been described and illustrated with reference to the preferred embodiments as described above, it will be apparent to those skilled in the art that modifications may be made without departing from the spirit and scope of the invention.

Claims (4)

Light separating means for separating the high brightness white light emitted from the light source into the primary luminous fluxes of red, green and blue, and reflecting the separated primary luminous fluxes into secondary optical paths whose paths are adjusted to correspond to the plurality of pixels. And a light path adjusting means for adjusting and projecting light amounts of the secondary light beams, and a screen for displaying a predetermined image with the secondary light beams, wherein the light separation means comprises: the light source; Is composed of a plurality of color selection mirrors that are selectively reflected and transmitted from the white light simultaneously emitted from and separated into primary luminous fluxes of red, green, and blue, and the optical path control means receives the separated primary luminous fluxes respectively. And a plurality of reflective optical path control devices for reflecting the secondary beams whose paths are adjusted to correspond to the respective pixels. The first separation mirror according to claim 1, wherein the optical separation means reflects the primary light beam having any one of red, green and blue color light from the white light, and passes the remaining two colors of light. And a second dichroic mirror for reflecting a primary light beam having any one of the remaining two color lights and passing the primary light beam having the other one. The first actuator array of claim 2, wherein the reflective optical path control device receives a primary beam of light reflected by the first color discriminating mirror and reflects the secondary beams whose paths are adjusted to correspond to each pixel. A panel, a second actuator array panel that receives the primary light beam reflected by the second dichroic mirror and reflects the secondary light fluxes adjusted to correspond to the pixels, and transmits the light by the second dichroic mirror And a second actuator array panel which receives the first primary light beam and reflects the secondary light beams whose paths are adjusted to correspond to the respective pixels. The method of claim 3, wherein the first, second and third actuator array panels are respectively positioned where light incident from the light source to the first dichroic mirror is moved by the same distance along each light path. Projection type image display device.