KR970003462B1 - Optical amount regulator - Google Patents

Abstract

A light quantity controller is disclosed. The light quantity controller comprises a number of reflection members(31) reflecting a light reflected from a light way controller(5); a number of shielding layers(37), attached to the reflection members(31), for shielding the light which is not reflected by the reflection members(31); and a frame(33) for supporting the reflection members(31) attaching the shielding layers(37).

Description

Fader

1 is a schematic view of a general projection image display device

2 is a perspective view of a conventional light amount regulator.

3 is a perspective view of a light quantity controller according to one embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: light source 2: optical separator

3: parallel lens 5: optical path controller

7: substrate 8: mirror surface

9: actuator 21, 31: reflecting rod

23, 33: frame 25, 35: gap

37: shield plate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light amount controller for a projection image display device, and more particularly, to a light amount controller that can improve brightness contrast by minimizing light transmission in a minimum light amount state.

Image display apparatus The image display apparatus is classified into a direct image display apparatus and a projection image display apparatus according to the display method. Direct image display device CRT (Cothod Ray Tube), etc. These CRT image display devices have good image quality but have problems such as increase in weight and thickness as the screen is enlarged and expensive, and thus have limitations in providing a large screen. have.

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 an LCD has a high light loss due to a flat 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 device using Actuated Mirror Arrays (hereinafter referred to as AMA) has been developed by Aura, USA.

The projection image display device is divided into 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 transmits an array of M × N pixels by transmitting M × N beams. Branches represent images.

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

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

The light source 1 emits white light of high brightness.

The optical splitter 2 consists of a rotating color wheel and sequentially separates the primary luminous fluxes of red, green or blue from the white light. The color wheel 2 is separated so that color filters transmitting 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 regulator 13, and the primary luminous fluxes are again dispersed and paralleled by the parallel lens 3.

The optical path controller 5 is composed of actuators 9 and mirrors 8 of an M × N array in a drive engine 7 for 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 amount controller 13 reflects the primary light beams separated and condensed into three primary colors to the optical path controller 5, and adjusts the amount of the second light beams reflected and adjusted by the optical path controller 5. Pass it toward the screen (19). In the above, the light amount regulator 13 is configured to pass the second luminous flux about 50% in the state in which the driving voltage is not applied to the optical path regulator 5, that is, the image signal is not applied.

The screen 19 sequentially projects the second light beam that will pass through the light amount controller 13 through the projection lens 18 to represent an image.

In the conventional optical system configured as described above, the light emitted from the light source 1 is separated through the optical splitter 2, and the separated primary luminous fluxes are reflected on the reflecting surface 15 of the light quantity controller 13. The light is reflected by the parallel lens 3 and is incident on the optical path controller 5 in a state parallel to the optical axis. At this time, the incident angle is made of the optical path controller 5 and 90 °. The light beams (secondary light beams) reflected back by the mirror 8 adjusted according to a predetermined signal are collected through the parallel lens 3 (called a condenser lens when the second light beam passes), and the light amount controller After passing through the gap 17 in (13), the projection lens 18 projects the image on the screen.

2 is a perspective view of a conventional light amount controller 13.

The light quantity controller 13 is composed of reflection rods 21 having a predetermined reflection angle and a frame 23 on which the reflection rods 21 can be installed. The reflection rods 21 are formed of right triangular pillars, and the surfaces formed at right angles are mounted on the frame 23, and the inclined surfaces reflect the first luminous flux to the optical path controller 5. In addition, the gaps 35 between the reflecting rods 21 pass through the second luminous flux reflected by the optical path controller 5 and connected by the parallel lens 3. The secondary light flux passing through the gaps 25 is controlled by the reflection rods 21. That is, the path of the light corresponding to each pixel of the second luminous flux reflected by the optical path controller 5 is adjusted, and the light corresponding to each pixel whose path is adjusted is respectively applied to the reflection rods 21. The amount passing through the gaps 25 is adjusted according to the degree of reflection. When the second light beam is shielded on the inclined surfaces of the reflecting rods 21 in the minimum light amount state, an image having a high brightness contrast can be obtained.

However, the above-described conventional light amount regulator has a problem that the secondary light flux is not blocked by the reflecting rod but the amount of light passes through the gaps even in the minimum excess state due to the aberration and alignment error of the parallel lens, thereby reducing the brightness contrast of the image. There was this.

Accordingly, an object of the present invention is to provide a light amount controller capable of improving the brightness contrast of the screen by minimizing the amount of light passing between the gaps in the minimum excess state.

The light quantity controller according to the present invention for achieving the above object is a reflection rod for reflecting the first luminous flux separated into red, green and blue to the optical path controller, and the second luminous flux reflected by the optical path controller, and A plurality of shielding layers attached to one or more surfaces perpendicular to the reflective rods to narrow the gap between the reflective rods to further block a predetermined amount not blocked by the reflective rods, and the reflective rods to which the shielding layers are attached. The poem has a frame.

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

3 is a perspective view of a light quantity controller 13 according to a preferred embodiment of the present invention.

The light amount controller 13 is composed of reflecting rods 31, a frame 33 and shielding plates 37.

The reflection rods 31 are formed of right triangular pillars, and the inclined surfaces reflect the first luminous flux to the optical path controller 5 so that the surfaces formed at right angles are mounted on the frame 33.

The shield plates 37 are attached to one surface of the reflective rod 31 which is perpendicular to the parallel lens. The shield plates 37 are intended to reduce the width of the gaps 35 between the reflective bars 31 and block a part of the light that is not blocked by the reflective bars 31. Accordingly, the shield plates 37 are wider than one surface of the reflective rod 31 attached thereto, or are exposed only to the upper or lower side of the pseudo rod 31.

The frame 33 mounts the reflective rods 31 to which the shield plates 37 are attached, and thus gaps 35 are formed between the shield plates 37 to allow the second light beam to pass therethrough.

The above-described light amount controller 13 reflects the optical path controller 5 through the parallel lens 3 to the first light beam incident by the inclined surface of the reflection rod 31, and the second light beam reflected by the optical path controller 5. The amount of light is adjusted by passing the light beam through the gaps 35. That is, the path of the light corresponding to each pixel is controlled by the optical path controller 5, and the light amount is adjusted according to the degree that the light whose light path is adjusted passes through the gap 35. In this case, the shield plates 37 block the amount of light passing through the gap 35. Therefore, the amount of light passing through the gaps 35 is shielded by the light shielding plates 37 which are not blocked by the reflecting rods 31 by the aberration and alignment error of the parallel lens 3 in the minimum light amount state. Minimize.

As described above, the present invention attaches a shielding plate to the reflection rod so as to be perpendicular to the parallel lens, thereby minimizing the amount of light passing through the gaps by aberration and error alignment of the parallel lens in the minimum light amount state.

Therefore, the present invention has the advantage of improving the brightness contrast of the image by minimizing the amount of light passing through the gaps in the minimum light amount state.

As described above, the present invention has been described and illustrated with reference to a preferred embodiment, but it will be apparent to those skilled in the art that the present invention may be modified without departing from the spirit and scope of the present invention.

Claims (3)

Reflecting rods that are separated into red, green, and blue light beams are reflected to the optical path controller, and are attached to reflecting rods that block the secondary light beams reflected by the optical path controller, and one surface perpendicular to the reflective rods. And a shielding layer for narrowing a gap between the reflecting bars to further block a predetermined amount of light not blocked by the reflecting bars, and a frame passing through the reflecting bars to which the shielding layers are attached. The light quantity adjuster of claim 1, wherein the shielding layers are larger in widths than the attached surfaces of the reflecting rods. The light quantity controller of claim 1, wherein the shielding layers expose only the upper or lower portions of the attached surfaces of the reflective rods.