KR970006985B1 - Projector type image displaying apparatus - Google Patents

Abstract

A light source emits high brightness white light. This light can be separated into each light flux, red, green, blue etc. That makes the first step light flux. The first step light flux is reflected by a mirror(38) and are converted into the secondary light flux that makes each picture element. And the secondary light flux is reflected by the light path adjusting devices(35). And the light volume is adjusted by an aperture. Thus, the secondary light flux of which light volume is adjusted by the aperture(47) are projected on the face of the picture thru the projecting lens(48) which represents the desired picture.

Description

Projection type image display device

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

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

31: light source 32: optical separation means

33: parallel lens 35: optical path control means

37 substrate 38 mirror surface

39: actuator 43: light amount adjusting means

45 reflection surface 48 projection lens

49: screen 50: image display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type image display apparatus, and in particular, mirror surfaces and actuators of an optical path adjusting means are arranged in M × N two-dimensions corresponding to pixels on a screen to project light beams on the front of the screen to implement an image. The present invention relates to a projection type 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 (Cathoe 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 a large-screen liquid crystal display (Liqiuid Crystal Display: hereinafter referred to as LCD), etc., such a large-screen LCD can be thinned to reduce the 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). Therefore, a projection type image display apparatus using Actuated Mirror Arrays (hereinafter referred to as AMA) has been developed by Aura, United States.

1 is a schematic diagram of the conventional projection type image display apparatus 20, which includes a light source 1 for emitting white light, optical separation means 5 for separating the white light into red, green and blue light beams, and A light path adjusting means (7) for adjusting the light path by reflecting each of the separated light beams, a light amount adjusting means (9) for adjusting the light quantity of each of the reflected light beams, and the respective light fluxes whose light amounts are adjusted A scanning mirror 13 for scanning linearly, and lenses 15 and 17 for paralleling and projecting the light beams scanned linearly onto the screen.

In the projection type image display device 20, the light source 1 emits high intensity white light that passes through the first balance lens 3 to form a parallel high beam.

The optical separation means 5 separates the parallel luminous flux into luminous fluxes of red, green and blue.

The optical path control means 7 comprises a mirror component 8 for reflecting the respective luminous fluxes separated into red, green and blue, and an actuator component 6 having a tilt by attaching the mirror component 8 to. do. The mirror component 8 and the actuator component 6 have three mirror arrays 8a, 8b, 8c and three actuator arrays 6a, 6b, 6c in parallel, respectively. Is placed. The three mirrors correspond to one pixel, and each of the mirror arrays 8a, 8b, and 8c includes the same number of mirrors as the number of pixels forming a horizontal line on the screen. . The actuator arrays 6a, 6b and 6c are also located on top of an electrically insulated substrate in series with the same number of actuators as the mirrors.

The actuators are made of a piezoelectric material polarized in one direction and are deformed when voltage is applied. Therefore, the respective mirrors are inclined according to the deformation of the actuators to reflect the light separated by the optical separation means 5 by changing the optical path.

The light quantity adjusting means 9 consists of a non-reflective surface 11 having a plurality of gaps 10. The gaps 10 consist of a plurality of pinholes or a plurality of knife-edged slit.

The light quantity adjusting means 9 adjusts and passes the amount of light beams whose light path is adjusted by the light path adjusting means 7. That is, the amount of light that passes through the optical paths of the respective luminous fluxes reflected by the optical path adjusting means 7 is matched with the plurality of gaps 10.

The scanning mirror 13 is composed of polygons whose respective surfaces are used as reflecting surfaces, and combines the beams passing through the gaps 10 of the light amount adjusting means 9 to horizontally scan the line and perform a second line balance. The lens 15 and the projection lens 17 project the synthesized and prescanned light beams in parallel to a screen (not shown).

The above-described image display apparatus has a mirror array corresponding to a pixel array composed of M pixels, and in order to represent an image having M × N pixels, N lines are formed by scanning mirrors to reflect light reflected from the mirror array. Inject to have.

However, the above-described conventional projection type image display apparatus has a problem in that the brightness of the image is reduced because the luminous flux pre-injected by the scanning mirror is reflected only once every N times on the pixels of the screens. In addition, there is a problem that it is difficult to implement an image by accurately scanning the light beam on the screen by the scanning mirror.

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 device which is easy to implement an image.

SUMMARY OF THE INVENTION In order to achieve the above objects, the present invention provides a projection type image display device that displays an image with M × N pixels. Separation means, light amount adjusting means for adjusting the light quantity of each of the second light beams with respect to each of the first light beams reflected correspondingly to the pixels, the first light beams in parallel and a second order A parallel lens for focusing the beams again; A means for adjusting the optical paths by installing a predetermined angle inclined with respect to the parallel lens and reflecting the first luminous fluxes M × N second luminous fluxes corresponding to the pixels from time to time; And a screen for displaying an image by sequentially receiving and summating secondary beams for each of the primary beams.

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

2 is a schematic diagram of a projection image display apparatus 50 according to the present invention.

The projection type image display apparatus 50 includes a light source 31, a light separating means 32, an optical path adjusting means 35, a light amount adjusting means 43, and a screen 49.

The light source 31 emits high brightness white light.

The optical separation means 32 sequentially separates red, green or blue primary luminous fluxes from the light. The optical separation means 32 is composed of a rotating color wheel. In addition, the optical separation means 32 including the color circle is formed such that color filters for transmitting any one of red, green, or blue light have the same area, and have an integer for a field or frame of an image signal. Rotate by boat Therefore,

The white light emitted from the light source 31 passes through the red, green or blue color filter region of the rotating color circle and is separated into primary luminous fluxes of red, green or blue. The respective luminous fluxes are focused and reflected by the reflecting surface 45 of the light quantity adjusting means 43, and the reflected primary luminous fluxes are dispersed again and are paralleled by the parallel lens 33.

The light separating means 32 may be composed of respective filters separating the luminous fluxes of red, green and blue from the white light.

In addition, the optical separation means 32 may be positioned between the parallel lens 33 and the optical path control means 35. In this case, the light separating means 32 may be formed of a micro color matrix corresponding to the mirrors 38, thereby simultaneously separating red, green, and blue light beams from white light.

The optical path control means 35 are located on the substrate 37 and mirrors 38 for reflecting the primary beams parallelized by the parallel lens 33 into a plurality of secondary beams, respectively. Actuators 39 include mirrors 38 that have a tilt. The mirrors 38 and actuators 39 are made of M × N two dimensions.

The actuators 39 are composed of first and second portions each having an internal electrode 40 to which a driving voltage is applied and having external electrodes 41 grounded. The first and second portions are formed in the inner portion. It is formed of a piezoelectric or electrostrictive ceramic perpendicular to the electrodes 40 and polarized in one direction. When an electric field is generated in the actuator 39 by applying respective driving voltages to the internal electrodes 40, the portion of the electric field that is in agreement with the direction of polarization contracts in the vertical direction, and the opposite portion is in the vertical direction. To expand. The contraction or expansion of the actuators 39 is proportional to the strength of the electric field, and the respective mirrors 38 are inclined according to the deformation of the actuator 39. Therefore, when reflecting the primary light beams incident in parallel through the parallel lens 33 by the respective mirrors 38, the paths of the secondary light beams corresponding to the respective pixels can be adjusted.

The parallel lens 33 connects the secondary light beams reflected by the mirrors 38. Although the actuator 39 has a bimorph type, the actuator 39 may be formed in a monomorph type or a unimorph type having no internal electrode.

The light quantity adjusting means 43 consists of a reflective surface 45 having one or more gaps 47.

The reflective surface 45 reflects red, green or blue primary luminous fluxes separated and focused on the optical separation means 32 to the parallel lens 33, and the reflected primary luminous fluxes are dispersed again. do.

The gaps 47 are made of pinholes or knife-edged silts, which are reflected by the optical path control means 35 and focused by a parallel lens 33. Adjust the amount of water. When the gaps 47 are adjusted to pass about 50% of the second luminous fluxes reflected without the driving voltage applied to the optical path control means 35, the mirror 38 is moved in both directions. By tilting, it is possible not to pass 100% or pass the reflected secondary light beams even at a small tilt.

In order to pass about 50% of the secondary beams reflected by the optical path adjusting means 35 without the driving voltage, the optical path adjusting means 35 is connected to the parallel lens 33. It is inclined with respect to a predetermined angle Δθ, for example, an angle of about 0.1 to 2.0 degrees. In addition, the secondary light beams focused by the parallel lens 33 are focused to pass through the gaps 47, and the passed secondary light beams are phase-inverted and dispersed.

The screen 49 is projected to the front through the projection lens 48, the secondary light flux of which the amount of light is adjusted through the gaps 47 to display a desired image. Secondary luminous fluxes of red, green, and blue are projected onto the screen 49. The secondary luminous fluxes of the three colors are adjusted and the amount of light corresponding to the respective pixels is synthesized to represent an image.

When the color wheel is used as the optical separation means 32, the secondary, luminous fluxes of red, green, and blue are projected on the screen 49 in an integer number of times with respect to the field or frame of the image signal.

As described above, the primary luminous flux of red, green, or blue separated from the white light by the rotating color wheel is arranged in two dimensions and reflected by M × N mirror surfaces equal to the number of pixels to correspond to each pixel. Since the paths of the secondary luminous fluxes are adjusted, the light quantity of the secondary luminous fluxes passing through the gaps of the luminous intensity control means is adjusted, and the secondary luminous fluxes are projected on the front of the screen to display an image.

Therefore, the present invention has the advantage that the brightness of the image is increased because the second, luminous fluxes of red, green and blue are projected on the front of the screen. In addition, since the amount of light of the second luminous flux corresponding to each pixel is adjusted and projected on the front of the screen, an accurate image can be easily realized.

The present invention is not limited to the above-described embodiments, and those skilled in the art can make various modifications within the scope of the present invention, and the red, green, and blue light can be directly emitted from the light source to the optical path control means.

Claims (6)

A projection type image display device for displaying an image with M x N pixels, comprising: a light source for emitting white light; Optical separation means for separating primary beams having a plurality of primary colors from the white light; Light amount adjusting means for adjusting an amount of light of each of the secondary light beams in which the respective primary light beams are reflected corresponding to the pixels; A parallel lens for paralleling the first luminous fluxes and focusing the second luminous fluxes again; An optical path adjusting means installed to be inclined at a predetermined angle with respect to the parallel lens and adjusting optical paths by reflecting paths differently to M × N secondary light beams corresponding to the pixels; And a screen displaying an image by sequentially receiving and combining secondary light beams for each of the primary light beams whose light amount is adjusted. The projection image display apparatus according to claim 1, wherein the optical separation means comprises a rotating color wheel that is evenly divided into regions capable of separating red, green, and blue light. The projection image display apparatus according to claim 1, wherein the optical path adjusting means includes M x N actuators and mirror surfaces, respectively. The projection type image display apparatus according to claim 1, wherein the light amount adjusting means includes a reflecting surface reflecting the primary light beams to the optical path adjusting means and gaps for adjusting and passing the light amount of each of the second light beams. The projection type image display apparatus according to claim 1, wherein the optical path adjusting means is inclined at an angle of about 0.1 to 2.0 degrees with the parallel lens. The projection type image display apparatus according to claim 1, further comprising a projection lens positioned between the light amount adjusting means and the screen to project the second light beams whose light amount is adjusted onto a screen.