Projection apparatus and projection control apparatus

Patent metadata

Field	Value
Publication number	US-9829781-B2
Application number	US-201615151758-A
Country	US
Kind code	B2
Filing date	May 11, 2016
Priority date	Apr 28, 2011
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

A projection apparatus has an optical device configured to be capable of diffusing coherent light beams, an irradiation unit configured to irradiate the coherent light beams to the optical device so that the coherent light beams scan the optical device, a light modulator that is illuminated by coherent light beams incident on and diffused at respective points of the optical device from the irradiation unit, a projection optical system configured to project a modulated image generated by the light modulator onto a scattering plane, and an intermediate optical system provided between the optical device and the light modulator, configured to restrict an diffusion angle of coherent light beams diffused by the optical device.

First claim

The invention claimed is:

1. A illumination apparatus comprising:
an optical device configured to diffuse incident coherent light beams and change an incident direction of the coherent light beams to each position of an illumination zone with time;
an irradiation unit configured to irradiate the coherent light beams to the optical device while changing a propagation direction of the coherent light beams by changing angles of the coherent light beams with time so that the coherent light beams scan the optical device; and
an intermediate optical system provided between the optical device and the illumination zone, configured to restrict a diffusion angle of coherent light beams diffused by the optical device,
wherein, after the diffusion angle is restricted by the intermediate optical system, the coherent light beams diffused by the optical device are superimposed on one another to illuminate at least all the illumination zone, regardless of diffusion points on the optical device,
wherein the irradiation unit comprises:
a light source configured to emit coherent light beams; and
a mirror device configured to change a propagation direction of the coherent light beams emitted from the light source to make the coherent light beams scan the optical device.

2. The illumination apparatus of claim 1 , wherein the intermediate optical system is positioned so that a distance between the optical device and the intermediate optical system is equal to a focal length of the intermediate optical system.

3. The illumination apparatus of claim 1 , wherein the intermediate optical system is positioned so that a distance between the illumination zone and the intermediate optical system is equal to a focal length of the intermediate optical system.

4. The illumination apparatus of claim 1 , wherein the optical device is a hologram recording medium.

5. The illumination apparatus of claim 4 , wherein interference fringes of the hologram recording medium are formed so that a direction of main light beams of coherent light beams diffused by the hologram recording medium and having a diffusion angle restricted by the intermediate optical system is roughly parallel with a central axis of the illumination zone.

6. The illumination apparatus of claim 4 , wherein the hologram recording medium is a volume hologram.

7. The illumination apparatus of claim 4 , wherein the hologram recording medium is a computer generated hologram.

8. The illumination apparatus of claim 4 , wherein the hologram recording medium is a surface relief-type holographic diffuser.

9. The illumination apparatus of claim 1 , wherein the optical device is a microlens array comprising a plurality of lenses.

10. The illumination apparatus of claim 1 , further comprising a relay optical system provided between the intermediate optical system and the illumination zone, configured to form an image of an intermediate image created by coherent light beams having a diffusion angle restricted by the intermediate optical system on the illumination zone.

11. The illumination apparatus of claim 10 , further comprising an integrator rod provided between the intermediate optical system and the relay optical system.

Assignees

• Dainippon Printing Co Ltd

Inventors

• Kurashige Makio
• Taniguchi Yukio
• Ooyagi Yasuyuki

Classifications

• G02B27/48

  Laser speckle optics · CPC title

• G03B21/2033

  LED or laser light sources · CPC title

• G03H1/32

  Systems for obtaining speckle elimination · CPC title

• H04N9/3129

  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 title

• G03B21/208

  Homogenising, shaping of the illumination light · CPC title