Illumination device and projector

• US 20080088914A1
• Filed: 09/27/2007
• Published: 04/17/2008
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Toyooka, Takashi
• Granted Patent: US 7,866,830 B2
• Time in Patent Office: Days
• US Class Current: 359/315
• 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 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

An illumination device includes: a light source section emitting coherent light; and a phase modulation section onto which the coherent light emitted from the light source section is incident, modulating the phase of the coherent light, forming a phase modulation pattern, varying the phase of the coherent light while generating a diffracted light in accordance with the phase modulation pattern, thereby scanning the light onto at least a part of a region of a projection surface.

Claims

1. An illumination device comprising:

a light source section emitting coherent light; and

a phase modulation section onto which the coherent light emitted from the light source section is incident, modulating the phase of the coherent light, forming a phase modulation pattern, varying the phase of the coherent light while generating a diffracted light in accordance with the phase modulation pattern, thereby scanning the light onto at least a part of a region of a projection surface.

2. The illumination device according to claim 1, wherein

the phase modulation section includes a liquid crystal element.

3. The illumination device according to claim 2, wherein

the liquid crystal element is an electrically controlled birefringence mode liquid crystal element.

4. The illumination device according to claim 1, wherein

the light source section emits the coherent light in accordance with the phase modulation section.

5. A projector comprising:

the illumination device according to claim 1, and

a spatial light modulation device including the projection surface and modulating the light which has been emitted from the illumination device and which is incident onto the projection surface in accordance with an image signal.

6. The projector according to claim 5, wherein

the illumination device includes the phase modulation section modulating the phase of the coherent light emitted from the light source section and leading the coherent light to be incident onto the projection surface, wherein

the phase modulation section varies the phase of the coherent light while generating the diffracted light in accordance with the phase modulation pattern, and scans the light onto a region of the projection surface, the region being determined based on the image signal.

7. The projector according to claim 5, wherein

the projection surface includes a plurality of unit regions set thereon, and the spatial light modulation device includes a region of a pixel, and wherein

the illumination device leads the light to be incident onto each unit region of the projection surface, and the unit region is smaller than the projection surface and is greater than the region of the pixel in the spatial light modulation device.

8. The projector according to claim 5, wherein

the phase modulation section varies the phase of the coherent light in accordance with a control signal generated based on a signal different from the image signal.

9. The projector according to claim 5, wherein

the phase modulation section scans the light while synchronizing the writing of a visual data to the spatial light modulation device.