KR100425336B1 - Laser image projector for projecting to multi-screen - Google Patents

Abstract

PURPOSE: A laser image projection apparatus for multi-surface projection is provided to project an image on a plurality of large screens. CONSTITUTION: An optical source(100) outputs a laser beam with white light. An optical splitting unit(250) splits the laser beam into beams of single color light with the first to third wavelengths. An optical modulating unit(600) modulates the beams of the single color light provided from the optical splitting unit(250) into optical signals using a color signal separated from a certain image signal. An optical synthesizing unit(650) synthesizes the single color lights modulated by the optical modulating unit(600) as one beam. An optical scanning device including a vertical scanning unit(700) and a horizontal scanning unit(800) scans the synthesized beam in a vertical direction and a horizontal direction to form an image. A multi-surface projection optical system separates the image formed in the optical scanning device by the first to nth reflective mirrors, and changes an optical path. The multi-surface projection optical system adjusts the number of screens and the horizontal resolution of the image lighted on the screens according to a rotation speed and the number of rotation surfaces of a mirror used when the horizontal scan is performed in the optical scanning device. A plurality of screens(900) correspond to the image lighted on a plurality of screens formed by the multi-surface projection optical system.

Description

Laser image projector for multi-sided projection {{Laser image projector for projecting to multi-screen}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser image projection apparatus for multi-sided projection. Specifically, a laser is used as a light source, and the light from the light source is modulated by an acoustic-optic modulator (AOM) according to an image signal, thereby scanning the scanner. The present invention relates to a laser image projection apparatus for projection when projecting image information onto a plurality of screens.

The typical representative image display means is a flat panel display element such as a cathode ray tube or a liquid crystal display element of a television receiver. However, a cathode ray tube or a liquid crystal display element is more difficult to manufacture as a large screen, and the resolution is lowered and there is a limit to practical use. Therefore, in order to realize a large screen, a method of enlarging an image displayed on a cathode ray tube or a liquid crystal display with a lens and projecting it on a screen is used.

In this image projection method, three cathode ray tubes and three lenses are independently used for color images to project red, green, and blue monochrome images superimposed on the screen (USP 4,942,525) and three cathode ray tubes, respectively. There is a method of synthesizing monochromatic images of and projecting it onto a screen with one lens (USP 4,842,394).

As described above, in the conventional cathode ray tube or the liquid crystal display device, which is used to display an image on a large screen, the image display method of the image display on the screen is not clear by simply enlarging and projecting the displayed image with a lens. There is a problem that the output of the light source is limited due to the possibility of being damaged due to the temperature characteristics of the display means, especially the optical system, and the luminance is low.

In addition, a conventional image projection apparatus such as a cathode ray tube or a liquid crystal display element has only a case of projecting an image on one screen with one projection apparatus. In view of the increasing demand for outdoor advertising using large screens, the fact that it is impossible to implement images on multiple screens from the same image projection device is a barrier to obtaining effective advertising effects. Can be. Moreover, in the case where the image is projected only by the lens, the image quality worsens when the image is projected on the multiple side.

The present invention was devised to improve the above problems, and if the image quality is clear and high brightness can be displayed on a large screen, in particular, if the image projection apparatus for projecting a plurality of large screen The purpose is to provide.

1 is a schematic block diagram of a laser image projection apparatus for a multi-sided projection according to the present invention,

FIG. 2 is a schematic layout view of an optical system of the laser image projection apparatus for the multi-sided projection of FIG. 1,

3 is a schematic configuration diagram of a multi-sided projection optical system.

In order to achieve the above object, a multi-layer laser image projection apparatus according to the present invention includes a light source for outputting a beam of white light; Light separating means for separating the beam of white light into beams of monochromatic light having first, second and third wavelengths, respectively; Light modulation means for modulating the beams of the monochromatic light according to color signals, respectively; Light synthesizing means for synthesizing the monochromatic lights modulated by the light modulating means into one beam; Optical scanning means for scanning the synthesized beam of modulated monochromatic light to form an image; A projection optical system for changing a light path so that a plurality of images formed by the light scanning means are illuminated; And a plurality of screens respectively corresponding to the plurality of reflected images.

In the present invention, the optical separation means, the first dichroic mirror reflects at least 99% of the monochromatic light of the first wavelength in the beam of white light and passes at least 95% of the monochromatic light of the second and third wavelengths; And a second dichroic mirror which reflects at least 99% of the monochromatic light of the second wavelength and passes at least 95% of the monochromatic light of the third wavelength. And a high reflection mirror for reflecting at least 99% of the monochromatic light of the third wavelength, wherein the optical modulation means includes three optical acoustic modulators to modulate the beams of the monochromatic light of the first, second and third wavelengths, respectively. The light synthesizing means may include: a third dichroic mirror configured to pass a beam of monochromatic light of the first wavelength and reflect beams of the monochromatic light of the second and third wavelengths; And a fourth dichroic mirror which reflects the monochromatic light of the second wavelength and passes the monochromatic light of the third wavelength. And a high reflection mirror reflecting the monochromatic light of the third wavelength, wherein the light synthesizing means comprises a plurality of reflecting mirrors.

Hereinafter, a multi-layer laser image projection apparatus according to the present invention will be described with reference to the drawings.

The multi-layer laser image projection apparatus according to the present invention makes it possible to express clearer image quality by scanning modulated light onto a screen without forming an image by a primary image display means, and also by using a high output light source, The present invention can be greatly improved, and image display means such as a conventional cathode ray tube or a liquid crystal display element are not required, and an image can be projected on a multi-screen screen.

1 is a schematic block diagram of a multi-layer laser image projection apparatus according to the present invention. As shown, the multi-layer laser image projection apparatus according to the present invention in the optical system 200, the optical system 200 for condensing the white light emitted from the light source 100, the white light emitted from the light source 100 in the form of a beam An optical splitter 250 for separating the incident white laser beam into red, green and blue monochromatic beams, an image signal generator 300 for providing a predetermined image signal, and an image provided from the image signal generator A synchronization signal separation unit 350 for separating horizontal and vertical synchronization signals from the signal, a color signal separation decoder 400 for separating color signals from an image signal provided from the image signal generator 300, and a color signal separation decoder 400 A high frequency signal amplifier 500 for amplifying a color signal separated from the signal, and modulating the beam incident from the optical system 200 using an image signal (color signal) provided from the high frequency amplifier 500 The optical modulator 600, the optical combiner 650 for synthesizing the modulated red, green, and blue monochromatic light beams, and the horizontal and vertical sync signals provided by the synchronization signal separator 350, respectively. The vertical scanning unit 700 and the horizontal scanning unit 800 for scanning the synthesized laser beam from the combining unit 650 in the vertical and horizontal directions are provided by the vertical scanning unit 700 and the horizontal scanning unit 800. A multi-faceted projection optical system 850, and a plurality of screens 900a and 900b, are made up of reflectors for causing the modulated laser beam to be projected onto a multi-screen screen.

An embodiment of a multi-layer laser image projection apparatus configured as described above is shown in FIG. 2. The light source 100 is composed of a white light laser that generates white light. In particular, the main wavelengths of the white light laser beam emitted from the light source are 488 nm, 514 nm and 647 nm, respectively. On the optical path of the light source 100, the size of the high reflection mirror 21 for changing the path of the laser beam generated by the light source 100, the collimating lens 22 for making the laser beam parallel light, and the size of the parallel beam An optical system 200 composed of telescopic lens systems 23 and 24 for reducing is disposed. The telescope lens systems 23 and 24 have a long focal length at the front end and a short focal length at the rear end. The laser beam having a constant divergence angle becomes a parallel beam passing through the collimating lens 22 of the optical system 200, and the size of the beam reduced by the magnification ratio of two lenses forming the telescope lens while passing through the telescope lens system. Will have Here, reducing the size of the beam is to allow optical modulation to be performed at maximum efficiency while installing an optoacoustic modulator in a limited space.

The optical splitter 250 separates the laser beam of white light incident from the telescope lens systems 23 and 24 of the optical system 200 into red, green, and blue monochromatic light. The light splitter 250 includes two dichroic mirrors 67a and 68a and one high reflection mirror 69a. A dichroic mirror 67a reflects blue light by 99% or more, and transmits light of the remaining wavelengths by 95% or more. Similarly, the dichroic mirror 68a reflects 99% or more of green light and transmits 95% or more of red light. The high reflection mirror 69a reflects the transmitted red light and enters the optoacoustic modulator 63. In particular, the dichroic mirror is used to greatly improve the transmittance and reflectance for the main wavelengths of the light source 100, 488nm, 514nm, 647nm.

The thickness of the beam incident through the optical splitter 250 to the optical modulators 61, 62, and 63 should be 200 m, which is a distance between the focusing lenses 64a, 65a, and 66a, respectively. It is possible by installing in front of the (61, 62, 63). The distance between the focusing lenses 64a, 65a, 66a and the optical modulators 61, 62, 63 is determined according to the beam size incident on the focusing lenses 64a, 65a, 66a. The smaller the beam size, the smaller the distance between the focusing lenses 64a, 65a, 66a and the optical modulators 61, 62, 63 for obtaining the 200um beam waist diameter in the optical modulators 61, 62, 63. . However, reducing the beam size too small increases the light output per unit area, which is difficult because the lenses or mirrors are damaged. Therefore, the appropriate size of the beam diameter must be determined.

The optical modulator 600 is provided by the light source 100 according to a color signal (amplified by the high frequency amplifier 500) separated by the color separation decoder 400 from the image signal provided by the image signal generator 300. Three photoacoustic modulators (AOM) 61, 62, which modulate the red, green, and blue monochromatic light beams separated by the white light beam through the optical system 200 and the optical separation unit 250 into a monochromatic light signal, respectively. 63).

The light combiner 650 combines the beams of monochromatic light modulated by the photoacoustic modulators 61, 62, and 63 into optical signals into one to form an image signal in the form of beams of various colors. The light combiner 650 is configured to change the paths of the dichroic mirrors 67b and 68b and the separated monochromatic light, which are installed to synthesize the monochromatic beams into the beam-shaped image signal for projecting onto the screen 900. It is composed of a reflecting mirror 69b.

The vertical scan unit 700 includes a galvanometer, and the horizontal scan unit 800 includes a polygonal mirror.

The multi-sided projection laser image projection apparatus operates as follows.

First, the white light emitted from the light source 100 is reflected by the high reflection mirror 21 to become a laser beam in the form of parallel light in the collimating lens 22. The laser beam passes through the telescope lens system 23 and 24, and then passes through the dichroic mirrors 67a and 68a, and is separated into blue, green, and red light in order to enter the optoacoustic modulators 61, 62, and 63. do. That is, blue light is reflected by the dichroic mirror 67a by 99% or more and is incident on the optoacoustic modulator 61, and light of the remaining wavelength is transmitted by 95% or more. Similarly, green light is reflected by the dichroic mirror 68a or more by 99% or more and enters the optoacoustic modulator 62, and red light is transmitted by 95% or more. The transmitted red light is reflected by the high reflection mirror 69a and is incident on the photoacoustic modulator 63. Here, when the dichroic mirror is installed, considering that the main wavelengths of the white light laser, which is a single light source used in the multi-layer projection laser image projection apparatus of the present invention, are 488 nm, 514 nm, and 647 nm, the transmittance and reflectance of these main wavelengths are greatly increased. Try to improve. As such, by improving the transmittance and reflectance of the main wavelengths of the white light laser beam, the color realization ability can be greatly improved.

Monochromatic light incident to the photoacoustic modulator 63 is modulated according to the image signal provided from the image signal generator 300 (exactly, the image signal provided from the image signal generator 300 is a color signal separation decoder 400). The color signals of blue, green, and red light are separated, and the separated color signals are amplified by the high frequency amplifier 500. The monochromatic lights are modulated according to the amplified color signals. Therefore, the image information in pixel units is carried on the modulated monochromatic light. Here, the focusing lenses 64a, 65a, and 66a having appropriate focal lengths disposed in front of the optoacoustic modulators 61, 62, and 63 are for maximizing the light efficiency of the optoacoustic modulators 61, 62, and 63. Lenses 64b, 65b and 66b, which have the same focal length as the focusing lens, located at the rear ends of the optoacoustic modulators 61, 62 and 63, are in the state before the laser beams of the photomodulated monochromatic light are incident again to the focusing lens. To restore the size of the laser beam in the form of parallel light.

The light modulated blue, green, and red monochromatic light are combined into one beam by the dichroic mirrors 67b and 68b and the high reflection mirror 69b constituting the light combiner 650. Green light is reflected by the dichroic mirror 68b, red light is transmitted, blue light is transmitted by the dichroic mirror 67b, and red and green light is reflected. However, in some cases, the design of the dichroic mirror may be changed, and the order of separation of blue, green, and red light may be changed.

The light containing the image information synthesized by the light combining unit 650 is vertically scanned by the vertical scanning unit 700 and horizontally scanned by the horizontal scanning unit 800 to display an image on the plurality of screens 900a and 900b. Will be concluded. That is, in the modulated composite light, the scanning path is changed in the vertical direction by the galvanometer of the vertical scanning unit 700, and the scanning path is changed in the horizontal direction by the polygonal mirror of the horizontal scanning unit 800. An image is constituted, and each of the configured images is projected to the respective screens 900a and 900b by the multiple projection optical system 850.

3 is a schematic configuration diagram of a multi-sided projection optical system used in a multi-layered laser image projection apparatus according to the present invention. As shown, the multi-sided projection optical system 850 includes a plurality of (four pairs) first and second reflectors to project modulated light scanned from the horizontal scanning unit 800 onto a plurality of (four) screens. . When the speed of the polygonal mirror which is the horizontal scanning unit 800 is reduced to 1/2 or the number of rotating planes is reduced by half, two images having 525/2 horizontal scanning lines can be configured. By reducing the speed of the polygon mirror to half and reducing the number of rotating planes in half, four images with 525/4 horizontal scanning lines are formed. If each image is separated by using an optical system composed of a reflector and directed to the screen to be projected, the same multiple images can be obtained from one projection device. The reflector is generally composed of a pair of primary reflector and secondary reflector, and separates each composed image and serves to illuminate the screen at a desired position. Therefore, the arrangement of the reflectors is changed according to the position of each screen, and in some cases, reflectors such as 3rd and 4th order may be required.

In addition, relay lens systems 31 and 32 are provided between the galvanometer of the vertical scanning unit 700 and the polygonal mirror of the horizontal scanning unit 800. The galvanometer of the vertical scanning unit 700 vibrates up and down at a speed synchronized by the vertical synchronizing signal separated from the horizontal / vertical synchronizing signal separating unit 350, and the polygonal mirror of the horizontal scanning unit 800 is horizontal. It is rotated at a high speed by the horizontal synchronizing signal separated from the vertical synchronizing signal separation unit 350. That is, the optically modulated beam has the scanning path changed in the vertical direction by the galvanometer 700, and the scanning path is changed in the horizontal direction by the polygonal mirror 800, so that the front surface of the screen 900 is changed. Is injected. The relay lens systems 31 and 32 between the galvanometer 700 and the polygonal mirror 800 collect light so that the vertically scanned laser beam is incident into the effective area of the polygonal mirror surface, which is a horizontal scanning surface. . The relay lens systems 31 and 32 are composed of two lenses having the same focal length, and are spaced apart by the sum of the focal lengths.

In addition, the front edge of the screen 900 side of the polygonal mirror 800 has a f ?? The lens system 34 is provided. f ?? The lens system 34 serves to correct the shape and size of the beam formed on the screen to be the same for the entire area of the screen. In addition, it adjusts the divergence angle of the beam to be scanned to the screen to adjust the size of the beam required on the screen. That is, even if the screen 900 is moved back and forth, it serves to adjust the image of the screen is always maintained naturally.

As described above, the multi-layer laser image projection apparatus according to the present invention uses a laser having a wavelength that is advantageous for realizing natural colors as a light source, and includes a dichroic mirror and a multi-sided projection optical system that can completely separate it. It is possible to project a large image of high definition and high resolution close to natural colors onto a plurality of large screens. Therefore, when the demand for outdoor advertisement using a large image is greatly increased, it is a great advantage in terms of advertisement that the same image can be implemented on multiple screens by one image projection apparatus. In particular, the laser image projection apparatus for multi-sided projection can adjust the projection optical system, that is, the arrangement of the reflector, to display the same image by using various walls of a city building as a screen, so that an excellent advertisement effect can be obtained.

Claims (13)

A light source for outputting a laser beam of white light; Optical separation means for separating the laser beam of white light into beams of monochromatic light having first, second and third wavelengths, respectively; Optical modulation means for modulating the first, second and third wavelength monochromatic beams provided from the optical separation means into optical signals using color signals separated from a predetermined video signal, respectively; Light synthesizing means for synthesizing the monochromatic lights modulated by the light modulating means into one beam; Optical scanning means for scanning the synthesized beam of the modulated monochromatic light in a vertical direction and a horizontal direction to form an image; 1 to n (where n is 2 or more), which is composed of a plurality of reflecting mirrors in pairs, and the image formed by the light scanning means is separated into the 1 to nth reflecting mirror and then the light is reflected on the plurality of screens. A multi-sided projection optical system configured to change the path and adjust the number of the screen and the horizontal resolution of the image projected on the screen according to the rotational speed of the mirror and the number of the rotating surfaces used for the horizontal scanning in the optical scanning means; And And a plurality of screens respectively corresponding to images projected on the plurality of screens formed by the multi-sided projection optical system. The method of claim 1, The optical separation means, A first dichroic mirror which reflects at least 99% of the monochromatic light of the first wavelength and passes at least 95% of the monochromatic light of the second and third wavelengths in the beam of white light; And And a second dichroic mirror which reflects at least 99% of the monochromatic light of the second wavelength and passes at least 95% of the monochromatic light of the third wavelength. The method of claim 2, And said optical separation means further comprises a high reflection mirror for reflecting at least 99% of said monochromatic light of said third wavelength. The method of claim 1, And said optical modulating means comprises three optical acoustic modulators for modulating the beams of monochromatic light of the first, second and third wavelengths, respectively. The method of claim 1, The light synthesizing means, A third dichroic mirror for passing the beam of monochromatic light of the first wavelength and reflecting the beams of monochromatic light of the second and third wavelengths; And And a fourth dichroic mirror for reflecting the monochromatic light of the second wavelength and allowing the monochromatic light of the third wavelength to pass therethrough. The method of claim 5, And the light synthesizing means further comprises a high reflection mirror for reflecting the monochromatic light of the third wavelength. The method of claim 1, The optical scanning means, Vertical scanning means for scanning the composite beam output from the light combining means in a vertical direction; And And horizontal scanning means for scanning the composite beam output from the vertical scanning means in a horizontal direction. The method of claim 7, wherein And the vertical scanning means comprises a galvanometer. The method of claim 7, wherein And said horizontal scanning means comprises a polygonal mirror. The method of claim 7, wherein And a relay lens for adjusting the vertically scanned composite beam to enter the effective area of the horizontal scanning means on the optical path between the vertical scanning means and the horizontal scanning means. Device. The method of claim 7, wherein And an f | H lens system for correcting a composite beam scanned to said screen on an optical path between said horizontal scanning means and said screen. The method of claim 1, Multi-layered projection laser image further comprises an optical system for making a laser beam of the white light emitted from the light source in a parallel beam on the optical path between the light source and the light separation means, and adjusts the thickness of the parallel beam Projection device. The method of claim 12, The optical system, A collimating lens for converting the laser beam of the white light into parallel light; And And a telescope lens system that adjusts the thickness of the parallel light.