Laser illuminated image producing system and method of using same

• US 5,700,076 A
• Filed: 08/18/1994
• Issued: 12/23/1997
• Est. Priority Date: 07/25/1994
• Status: Expired due to Fees

• Current Assignee: Proxima Corporation (Ask ASA)
• Original Assignee: Proxima Corporation (Ask ASA)
• Inventors: Hargis, David E., Assa, Shlomo, Kappel, David W., Minich, Arthur P.
• Primary Examiner(s): Dowling, William C.
• Application Number:
  US08/292,619
• Time in Patent Office: 1,223 Days
• Field of Search: 353/31, 353/33, 353/37, 353/98, 353/121, 353/122, 359/42, 359/48, 359/72, 359/212, 359/223, 348/771, 348/768, 345/9, 345/31, 345/85, 345/7, 345/1
• US Class Current: 353/31
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/0944 Diffractive optical elements, e.g. gratings, holograms gratings per se G02B5/18; holograms used as optical elements per se G02B5/32
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G02B 27/1033 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/1053 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/1086 operating by diffraction only
• CPC Class Codes: G02B 27/123 The splitting element being a lens or a system of lenses, including arrays and surfaces with refractive power
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G03B 21/005 Projectors using an electronic spatial light modulator but not peculiar thereto
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 33/08 Sequential recording or projection G03B33/02, G03B33/04, G03B33/06 take precedence
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

The laser illuminated image producing system includes in one form of the invention, a single light valve which not only serves to form an image, but also to increase the number of its colors. In another form of the invention, the lasers are sequenced at high input energy for short intervals of time to provide high average output luminosity at lower average energy costs.

Claims

1. An image producing system, comprising:

light source means including at least one laser device switchable between an on state and an off state for generating pulses of coherent projection light along an input optical path, wherein said coherent projection light is generated at a maximum luminosity level when said laser device is switched to said on state;

spatial light modulator means disposed in said input optical path for modulating said coherent projection light to produce output light representative of the image along an output optical path for facilitating the projection of the image onto a remote surface, wherein substantially all of said output light produced by said spatial light modulator means is projected onto said remote surface;

said spatial light modulator means includes a light valve for controlling the luminosity of said output light produced by said spatial light modulator means to facilitate reproducing the image with varying shades on said remote surface; and

wherein said light source means includes at least three laser devices, said laser devices including a red laser device, a green laser device, and a blue laser device which are each switched between their on and off states to generate sequential mono-colored pulses of coherent projection light for facilitating the reproduction of the image in full color.

2. An image producing system according to claim 1, wherein said light valve is reflective.

3. An image producing system according to claim 2, wherein said light valve is beam addressed.

4. An image producing system according to claim 3, wherein said light valve is a photoelectric liquid crystal device.

5. An image producing system according to claim 4, wherein said spatial light modulator means further includes a writing means to generate the image to be projected and a fiber optic plate disposed between said photoelectric liquid crystal device and said writing means to optically transfer the image from said writing means to said photoelectric liquid crystal device.

6. An image producing system according to claim 5, wherein said writing means includes a cathode ray tube device.

7. An image producing system according to claim 5, wherein said writing means includes a writing light source, and an active matrix liquid crystal device disposed between said writing light source and said fiber optic plate.

8. An image producing system according to claim 2, wherein said spatial light modulator means further includes a mirror device for reflecting modulated coherent projection light to direct it onto said output optical path as said output light.

9. An image producing system according to claim 8, wherein said light valve is a ferroelectric liquid crystal display device.

10. An image producing system according to claim 1, wherein said light valve is transmissive.

11. An image producing system according to claim 10, wherein said light valve is a ferroelectric liquid crystal display device.

12. An image producing system according to claim 1, further including an optical lens for facilitating the coordination of a cross-sectional area of said coherent projection light with a frontal surface area of said light valve to enable substantially all of said coherent projection light to impinge said frontal surface area.

13. An image producing system according to claim 12, wherein said spatial light modulator means further includes means for redirecting said coherent projection light toward said light valve to permit said coherent projection light to impinge said light valve at about a right angle.

14. An image producing system according to claim 13, wherein said redirecting means includes a polarizing beam splitter.

15. A method according to claim 14, further including using a spherical mirror for image relaying.

16. A method according to claim 14, further including using an emersed eggcrate dichroic mirror assembly to combine the laser lights.

17. A method of projecting an image, comprising:

generating pulses of coherent projection light along an input optical path with a light source means including at least one laser device selectively switchable between an on state and an off state, wherein said coherent projection light is generated at a maximum luminosity level when said laser device is switched to said on state;

modulating said coherent projection light with a spatial light modulator means disposed in said input optical path to produce output light representative of the image along an output optical path for facilitating the projection of the image onto a remote surface, wherein substantially all of said output light produced by said spatial light modulator means is projected onto said remote surface;

controlling the luminosity of said output light produced by said spatial light modulator means with a light valve to facilitate reproducing the image with varying shades on said remote surface; and

using a light source including at least three laser devices, said laser devices including a red laser device, a green laser device, and a blue laser device, and switching each of said laser devices between their on and off states to generate sequential mono-colored pulses of coherent projection light for facilitating the reproduction of the image in full color.

18. A system for producing a bright image comprising:

a plurality of lasers for generating a plurality of different colored laser lights;

means for controlling each one of the lasers individually and sequentially to cause them to be energized at a substantially peak ON output luminosity for a short ON period of time, thereby providing a high average output luminosity at a low average energy cost;

means for controlling each one of the lasers individually and sequentially to cause them to be activated and deactivated selectively during a portion only of a frame time interval between a near ON output luminosity for a long OFF period of time and said substantially peak ON output luminosity for said short ON period of time to enable the lasers to switch between OFF and ON in an efficient manner;

means for forming a bright image from the laser lights;

wherein said means for forming includes a deformable mirror device; and

an image relaying arrangement for the deformable mirror device to shorten effectively the optical path of the ON light reflected from the deformable mirror device.

19. A system according to claim 18, wherein said arrangement includes a spherical mirror for image relaying purposes.

20. A system according to claim 18, further including an emersed eggcrate dichroic mirror assembly to combine the laser lights.

21. A method of producing a bright image utilizing a plurality of different colored lasers, comprising:

generating a plurality of different colored laser lights;

controlling each one of the laser lights individually and sequentially to cause them to be energized at a substantially peak ON output luminosity for a short ON period of time, thereby providing a high average output luminosity at a low average energy cost;

controlling each one of the laser lights individually and sequentially to cause them to be activated and deactivated selectively during a portion only of a frame time interval between a near ON output luminosity for a long OFF period of time and said substantially peak ON output luminosity for said short ON period of time to enable the laser lights to switch between OFF and ON in an efficient manner;

forming a bright image from the laser lights;

wherein the image is formed by using a deformable mirror device; and

image relaying from the deformable mirror device to shorten effectively the optical path of the ON light reflected from the deformable mirror device.