Projection display system with varying light source

• US 20090231669A1
• Filed: 09/04/2008
• Published: 09/17/2009
• Est. Priority Date: 05/23/2005
• Status: Active Grant

• Current Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Nishino, Hirokazu, Shirai, Akira, Ishii, Fusao, Horikawa, Yoshiaki
• Granted Patent: US 7,826,128 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09G 3/2011 by amplitude modulation
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833
• CPC Class Codes: H04N 9/312 Driving therefor driving of electronic spatial light modulators in displays other than projection devices G09G3/34, G09G3/36; control of liquid crystal elements G02F1/133; control of micromechanical modulators G02B26/08
• CPC Class Codes: H04N 9/3155 for controlling the light source light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406

Abstract

The present invention provides a projection apparatus, comprising: a light source for emitting illumination light; at least one spatial light modulator with a plurality of movable mirrors corresponding to pixels to be displayed, for performing a modulation of the illumination light through operation of the movable mirrors; a light source control unit performing a modulation control of the light source; and a spatial light modulator control unit generating, from an input image signal, a control signal for driving the spatial light modulator, wherein: the light source control unit adjusts a pulse emission frequency of an emission pulse of the illumination light emitted from the light source while corresponding to an oscillation frequency of the movable mirrors.

Claims

1. A projection apparatus, comprising:

a light source for emitting illumination light;

at least one spatial light modulator with a plurality of movable mirrors corresponding to pixels to be displayed, for performing a modulation of the illumination light through operation of the movable mirrors;

a light source control unit performing a modulation control of the light source; and

a spatial light modulator control unit generating, from an input image signal, a control signal for driving the spatial light modulator, wherein;

the light source control unit adjusts a pulse emission frequency of an emission pulse of the illumination light emitted from the light source while corresponding to an oscillation frequency of the movable mirrors.

2. The projection apparatus according to claim 1, wherein:

the pulse emission frequency of the illumination light emitted from the light source is ten times the oscillation frequency of the movable mirrors or higher.

3. The projection apparatus according to claim 1, wherein:

the pulse emission frequency of the illumination light emitted from the light source is one-tenth the oscillation frequency of the movable mirrors or lower.

4. The projection apparatus according to claim 1, wherein:

the light source control unit drives the light source so as to change a pulse width of the emission pulse.

5. The projection apparatus according to claim 1, wherein:

the light source control unit drives the light source so as to change a pulse intensity of the emission pulse.

6. The projection apparatus according to claim 1, wherein:

the light source is a laser diode or a light emitting diode (LED).

7. The projection apparatus according to claim 1, wherein:

the movable mirrors have an ON state of reflecting, to a projection optical system, the illumination light emitted from the light source, an OFF state of reflecting the illumination light to a position that is offset from the projection optical system, and an oscillation state in which the movable mirrors oscillate between the ON state and the OFF state.

8. The projection apparatus according to claim 1, wherein:

the light source control unit performs a control so as to stop emission of the light source during a period other than a period during which the control signal generated by the spatial light modulator control unit drives the spatial light modulator.

9. The projection apparatus according to claim 1, comprising:

a plurality of the light sources respectively corresponding to at least red (R), green (G), and blue (B), wherein;

the light source control unit independently drives the light sources of R/G/B.

10. The projection apparatus according to claim 1, comprising:

the light sources of at least red (R) green (G), and blue (B), wherein;

the light source control unit performs a drive so that the spatial light modulator control unit adjusts an emission intensity of the illumination light for the light source of each of R/G/B synchronously with the control signal generated by the spatial light modulator control unit.

11. The projection apparatus according to claim 1, comprising:

a plurality of the spatial light modulators, wherein;

the spatial light modulator control unit generates the control signal for driving the plurality of spatial light modulators; and

the light source control unit receives the control signal for driving each of the spatial light modulators, and adjusts an emission intensity of the illumination light emitted from the light sources to the spatial light modulators.

12. A projection apparatus, wherein:

a light source for emitting illumination light;

at least one spatial light modulator with a plurality of movable mirrors corresponding to pixels to be displayed, for performing a modulation of the illumination light through operation of the movable mirrors;

a light source control unit performing a modulation control of the light source; and

a spatial light modulator control unit generating, from an input image signal, a control signal for driving the spatial light modulator, wherein;

the light source control unit controls a pulse emission frequency of an emission pulse of the illumination light emitted from the light source so that the pulse emission frequency is ten times an oscillation frequency of the movable mirrors or higher.

13. The projection apparatus according to claim 12, wherein:

the light source control unit drives the light source so as to change a pulse width of the emission pulse.

14. The projection apparatus according to claim 12, wherein:

the light source control unit drives the light source so as to change a pulse intensity of the emission pulse.

15. The projection apparatus according to claim 12, wherein:

the light source is a laser diode or a light emitting diode (LED).

16. The projection apparatus according to claim 12, wherein:

the movable mirrors have an ON state of reflecting, to a projection optical system, the illumination light emitted from the light source, an OFF state of reflecting the illumination light to a position that is offset from the projection optical system, and an oscillation state in which the movable mirrors oscillate between the ON state and the OFF state.

17. A projection apparatus, comprising:

a light source for emitting illumination light;

at least one spatial light modulator with a plurality of movable mirrors corresponding to pixels to be displayed, for performing a modulation of the illumination light through operation of the movable mirrors;

a light source control unit performing a modulation control of the light source; and

a spatial light modulator control unit generating, from an input image signal, a control signal for driving the spatial light modulator, wherein;

the light source control unit controls a pulse emission frequency of an emission pulse of the illumination light emitted from the light source so that the pulse emission frequency is one-tenth an oscillation frequency of the movable mirrors or lower.

18. The projection apparatus according to claim 17, wherein:

the light source control unit drives the light source so as to change a pulse width of the emission pulse.

19. The projection apparatus according to claim 17, wherein:

the light source control unit drives the light source so as to change a pulse intensity of the emission pulse.

20. The projection apparatus according to claim 17, wherein:

the light source is a laser diode or a light emitting diode (LED).

21. The projection apparatus according to claim 17, wherein:

the movable mirrors have an ON state of reflecting, to a projection optical system, the illumination light emitted from the light source, an OFF state of reflecting the illumination light to a position that is offset from the projection optical system, and an oscillation state in which the movable mirrors oscillate between the ON state and the OFF state.