PROJECTOR

• US 20070273849A1
• Filed: 03/07/2007
• Published: 11/29/2007
• Est. Priority Date: 04/04/2006
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Takeda, Takashi
• Application Number:
  US11/683,083
• Publication Number:
  US 20070273849A1
• Time in Patent Office: Days
• US Class Current: 353/122
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G02B 5/0242 by means of dispersed particles
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G03B 21/005 Projectors using an electronic spatial light modulator but not peculiar thereto
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10
• CPC Class Codes: H04N 9/3111 for displaying the colours sequentially, e.g. by using sequentially activated light sources sequential projection in colour photography G03B33/08
• CPC Class Codes: H04N 9/3132 using one-dimensional electronic spatial light modulators
• CPC Class Codes: H04N 9/3152 for shaping the light beam beam shaping per se G02B27/09
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

A projector includes: an image forming unit that forms an image using light emitted from a solid-state light source; a diffusion unit which is provided at focal positions of light components of the image formed by the image forming unit and diffuses the light; and a projection optical system that projects the light emitted from the diffusion unit.

Claims

1. A projector comprising:

an image forming unit that forms an image using light emitted from a solid-state light source;

a diffusion unit which is provided at focal positions of light components of the image formed by the image forming unit and diffuses the light; and

a projection optical system that projects the light emitted from the diffusion unit.

2. The projector according to claim 1,

wherein the diffusion unit randomly changes the phase of light incident according to the position of the diffusion unit.

3. The projector according to claim 2,

wherein the diffusion unit includes a member whose thickness in an optical axis direction and/or refractive index is randomly distributed in a two-dimensional direction substantially perpendicular to the optical axis direction.

4. The projector according to claim 1,

wherein the diffusion unit diffuses light by means of diffraction.

5. The projector according to claim 1,

wherein the diffusion unit rotates on an optical axis.

6. The projector according to claim 1,

wherein the diffusion unit is vibrated.

7. The projector according to claim 1,

wherein the diffusion unit includes:

a dispersion layer that has a fluid and charged particles dispersed in the fluid; and

electrodes that apply a voltage to the dispersion layer.

8. The projector according to claim 1,

wherein the diffusion unit includes a polymer dispersed liquid crystal member composed of a polymer material and liquid crystal molecules dispersed in the polymer material, and

the state of the polymer dispersed liquid crystal member is repeatedly changed between a first state in which light emitted from the polymer dispersed liquid crystal member is diffused and a second state in which the diffusion of light is smaller than that in the first state by varying the alignment of the liquid crystal molecules.

9. The projector according to claim 1,

wherein the size of the image formed on the diffusion unit is smaller than the size of an image projected by the projection optical system.

10. The projector according to claim 1,

wherein the image forming unit includes a spatial light modulator that modulates the light emitted from the solid-state light source in response to an image signal, and

the projector further includes an imaging optical system that focuses the light components modulated by the spatial light modulator on the diffusion unit.

11. The projector according to claim 10,

wherein the imaging optical system includes a telecentric optical system.

12. The projector according to claim 10,

wherein tie imaging optical system forms an image having a size that is 0.2 to 10 times the size of the spatial light modulator on the diffusion unit.

13. The projector according to claim 10,

wherein an F number of the imaging optical system is larger than an F number of the projection optical system.

14. The projector according to claim 10,

wherein the spatial light modulator is a liquid-crystal spatial light modulator.

15. When projector according to claim 10,

wherein the spatial light modulator includes a minute mirror array device.

16. The projector according to claim 1,

wherein the image forming unit includes a light scanning device that scans the diffusion unit with the light emitted from the solid-state light source to form an image.

17. The projector according to claim 16,

wherein the light scanning device includes:

a light beam shaping unit that shapes the light emitted from the solid-state light source into a linear light beam having a longitudinal direction as a first direction;

a spatial light modulator that modulates the linear light beam in response to an image signal; and

a scanning unit that scans the diffusion unit In a second direction substantially perpendicular to the first direction with the linear light beam emitted from the spatial light modulator.

18. The projector according to claim 16,

wherein the light scanning device includes a scanning unit that scans the diffusion unit in a first direction and a second direction substantially perpendicular to the first direction with the light emitted from the solid-state light source.

19. The projector according to claim 1,

wherein the solid-state light source is a laser light source.