Projectors and operation thereof

• US 20070188720A1
• Filed: 02/13/2006
• Published: 08/16/2007
• Est. Priority Date: 02/13/2006
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Govyadinov, Alexander, Lerner, Scott, Kelly, Conor
• Granted Patent: US 7,530,696 B2
• Time in Patent Office: Days
• US Class Current: 353/121
• CPC Class Codes: G03B 21/005 Projectors using an electronic spatial light modulator but not peculiar thereto
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: H04N 5/7458 the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]
• CPC Class Codes: H04N 9/3108 by using a single electronic spatial light modulator

Abstract

At least first and second narrowband beams of light, respectively of different wavelengths, are concurrently directed onto a modulator respectively at first and second angles of incidence.

Claims

1. A method of operating a projector, comprising:

concurrently directing at least first and second narrowband beams of light, respectively of different wavelengths, onto a modulator respectively at first and second angles of incidence.

2. The method of claim 1, wherein the first and second angles of incidence are selected so that a single size of a gap between total and partial reflectors of the modulator produces substantially the same reflective or absorptive state for the first and second beams.

3. The method of claim 2 further comprises directing at least a third beam of light onto the modulator at a third angle of incidence concurrently with the first and second beams of light, the at least third beam of light having a wavelength different than the wavelengths of the at least first and second beams of light, wherein the third angle of incidence is selected so that the single size of the gap produces substantially the same reflective or absorptive state for the at least third beam as for the first and second beams.

4. The method of claim 1, wherein the at least first and second beams of light have the same order within the gap.

5. The method of claim 1, wherein the at least first and second beams of light have different orders within the gap.

6. The method of claim 1 further comprises converging reflections of the at least first and second beams from the modulator.

7. The method of claim 1 further comprises shaping the at least first and second beams of light before directing them onto the modulator.

8. The method of claim 1, wherein the at least first and second beams of light respectively at the first and second angles of incidence are telecentric beams of light.

9. The method of claim 1 further comprises selecting a size of a gap between total and partial reflectors of the modulator to produce substantially the same reflective state for the at least first and second beams.

10. The method of claim 9 further comprises selecting another size of the gap between total and partial reflectors to produce substantially the same absorptive state for the at least first and second beams.

11. A projector, comprising:

means for concurrently directing incoming first and second beams of light, respectively of different wavelengths, onto a modulator respectively at first and second angles of incidence; and

means for selecting a gap size between total and partial reflectors of the modulator to produce substantially the same reflective or absorptive state for the first and second beams.

12. The projector of claim 11 further comprises means for directing a third beam of light onto the modulator at a third angle of incidence concurrently with the first and second beams of light, the third beam of light having a wavelength different than the wavelengths of the first and second beams of light, wherein the gap size between the total and partial reflectors is further selected to produce substantially the same reflective or absorptive state for the third beam as for the first and second beams.

13. A projector, comprising:

a light source configured to direct first and second beams of light, respectively at different wavelengths, onto a modulator at respectively first and second angles of incidence the modulator comprising;

a partial reflector;

a total reflector; and

a selectively adjustable gap interposed between the partial and total reflectors;

wherein the first and second angles of incidence are selected so that a selected first size of the gap produces substantially the same reflective state for the first and second beams and a selected second size of the gap produces substantially the same absorptive state for the first and second beams.

14. The projector of claim 13, wherein light source is further configured to direct a third beam of light, at a different wavelength than the wavelengths of the first and second beams, onto the modulator at a third angle of incidence.

15. The projector of claim 14, wherein the third angle of incidence is selected so that the selected first and second sizes of the gap respectively produce substantially the same reflective state for the third beam as for the first and second beams and substantially the same absorptive state for the third beam as for the first and second beams.

16. The projector of claim 13 further comprises shaping optics interposed between the light source and the modulator.

17. The projector of claim 16 further comprises a field lens interposed between the shaping optics and the modulator.

18. The projector of claim 13, wherein the light source comprises first and second lasers or first and second light-emitting diodes for respectively producing the first and second beams of light.

19. The projector of claim 13 further comprises converging optics interposed between the modulator and projection optics of the projector.

20. The projector of claim 19, wherein the converging optics are integrated in the modulator.