ILLUMINATION DEVICE, PROJECTION APPARATUS AND PROJECTION-TYPE IMAGE DISPLAY APPARATUS

• US 20130170006A1
• Filed: 09/08/2011
• Published: 07/04/2013
• Est. Priority Date: 09/08/2010
• Status: Active Grant

• Current Assignee: Dai Nippon Printing Company Limited
• Original Assignee: Dai Nippon Printing Company Limited
• Inventors: Kurashige, Makio, Ishida, Kazutoshi, Takanokura, Tomoe, Ooyagi, Yasuyuki
• Granted Patent: US 9,454,014 B2
• Time in Patent Office: Days
• US Class Current: 359/15
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G02B 5/0252 using holographic or diffractive means
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity
• CPC Class Codes: G02F 2203/12 spatial light modulator
• CPC Class Codes: G02F 2203/24 beam steering
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: G03H 1/0005 Adaptation of holography to specific applications holographic optical element G02B5/32; holographic scanner G02B26/106; recognition using holographic mask G06V10/88; holographic memories G11B7/0065, G11C13/042
• CPC Class Codes: G03H 1/22 Processes or apparatus for obtaining an optical image from holograms G03H1/26 - G03H1/34 take precedence
• CPC Class Codes: G03H 1/2286 Particular reconstruction light G03H1/24 takes precedence; Beam properties
• CPC Class Codes: G03H 1/32 Systems for obtaining speckle elimination
• CPC Class Codes: G03H 2001/2271 RGB holobject
• CPC Class Codes: G03H 2001/2292 Using scanning means
• CPC Class Codes: G03H 2222/18 RGB trichrome light
• CPC Class Codes: G03H 2222/36 Scanning light beam
• 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

An illumination device has an optical device and an irradiation unit. The irradiation unit has a light source emitting a coherent light beam, and a scanning device capable of adjusting a reflection angle of the coherent light beam emitted from the light source. The light source has light sources emitting a plurality of coherent light beams having an identical wavelength range, the hologram recording medium has a recording area to be scanned with each of a plurality of coherent light beams reflected by the scanning device, and the recording area has an interference fringe that diffracts an incident coherent light beam. The optical device uses the plurality of coherent light beams diffracted by the interference fringe of the recording area so that each of the coherent light beams diffracted by the hologram recording medium is superimposed on at least one portion to reproduce the image of the reference member.

Claims

1. An illumination device comprising:

an optical device including a hologram recording medium on which an image of a scattering plate is recorded; and

an irradiation unit configured to irradiate a coherent light beam to the optical device so that the coherent light beam scans the hologram recording medium,

wherein the irradiation unit comprises;

a light source configured to emit a coherent light beam; and

a scanning device configured to be capable of adjusting a reflection angle of the coherent light beam emitted from the light source and to make a reflected coherent light beam scan on the hologram recording medium,

wherein the light source comprises a plurality of light sources configured to emit a plurality of coherent light beams having an identical wavelength range,

the hologram recording medium comprises a recording area to be scanned with each of a plurality of coherent light beams reflected by the scanning device, and

the recording area comprises an interference fringe that diffracts an incident coherent light beam,

wherein the optical device uses the plurality of coherent light beams diffracted by the interference fringe of the recording area so that each of the coherent light beams diffracted by the hologram recording medium is superimposed on a predetermined area to reproduce the image of the scattering plate.

2. The illumination device of claim 1, wherein the plurality of coherent light beams emitted from the plurality of light sources are emitted to an identical point on the scanning device.

3. The illumination device of claim 2, wherein a plurality of coherent light beams reflected at the identical point on the scanning device are incident on the hologram recording medium as diffused light beams.

4. The illumination device of claim 2, wherein the plurality of light sources emit a plurality of coherent light beams having the identical wavelength range in roughly parallel directions,

wherein the irradiation unit further comprises a converged-beam generator configured to irradiate the identical point of the scanning device with the plurality of coherent light beams emitted in the roughly parallel directions from the plurality of light sources.

5. The illumination device of claim 1, wherein the plurality of coherent light beams emitted from the plurality of light sources and incident on the scanning device are parallel beams.

6. The illumination device of claim 5, wherein the plurality of coherent light beams incident on the scanning device from the plurality of light sources in the roughly parallel directions are reflected by the scanning device and incident on the hologram recording medium as a diverging light.

7. The illumination device of claim 2 further comprising a parallel-beam generator configured to convert the coherent light beams reflected and diffused at the identical point on the scanning device into parallel beams to be incident on the hologram recording medium.

8. The illumination device of claim 1, wherein the light source comprises a laser array comprising the plurality of laser sources arranged adjacent to one another,

wherein each of a plurality of coherent light beams from the plurality of laser sources in the laser array scans on the recording area.

9. A projection apparatus comprising:

the illumination device of claim 1; and

a spatial light modulator that is provided at a location overlapped with the predetermined area reproducing the image of the scattering plate and illuminated by the illumination device.

10. The projection apparatus of claim 9 further comprising a projection optical system configured to project a modulated image generated in the spatial light modulator on a screen.

11. A projection apparatus comprising:

the illumination device of claim 1;

a spatial light modulator that is provided at a location overlapped with the predetermined area reproducing the image of the scattering Plate and illuminated by the illumination device; and

a projection optical system configured to project a modulated image generated in the spatial light modulator on a screen,

wherein the projection optical system is provided at a location on which zero-order light is not incident, the zero-order light being included among coherent light beams that are reflected by or pass through the hologram recording medium.

12. A projection-type image display apparatus comprising:

the projection apparatus of claim 10; and

a screen that projects a modulated image generated in the spatial light modulator.

13-17. -17. (canceled)