Projection display system with varying light source

• US 8,061,854 B2
• Filed: 09/04/2008
• Issued: 11/22/2011
• Est. Priority Date: 11/01/2003
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite), Olympus Corporation
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Nishino, Hirokazu, Shirai, Akira, Ishii, Fusao, Horikawa, Yoshiaki
• Primary Examiner(s): Epps; Georgia Y
• Assistant Examiner(s): Cruz; Magda
• Application Number:
  US12/231,768
• Publication Number:
  US 20090091713A1
• Time in Patent Office: 1,174 Days
• Field of Search: 353/85, 353/98, 353/31, 353/99, 353/94, 359/850, 345/84, 348/771, 349/30
• US Class Current: 353/85
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2310/0218 with collection of electrodes in groups for n-dimensional addressing
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0237 Switching ON and OFF the backlight within one frame
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2330/028 Generation of voltages supplied to electrode drivers in a matrix display other than LCD
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833

Abstract

The present invention provides a projection apparatus, comprising: a light source; at least one spatial light modulator for modulating illumination light from the light source by a plurality of pixel elements by using different modulation states; 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 has a function of receiving data corresponding to the control signal generated by the spatial light modulator control unit, controlling a parameter of an emission pulse of the illumination light emitted from the light source, and thereby adjusting an emission intensity of the illumination light.

Claims

1. A projection apparatus, comprising:

a light source;

at least one spatial light modulator comprises a plurality of pixel elements controllable to operate in different modulation states for modulating an illumination light projected from the light source;

a light source control unit controls and modulates the light source; and

a spatial light modulator control unit receives and applies an input image signal for generating a control signal for driving the spatial light modulator, wherein the light source control unit further having a video image analysis unit for receiving and analyzing the control signal generated by the spatial light modulator control unit for applying video image analysis results for controlling the illumination light emitted from the light source for adjusting an emission intensity of the illumination light to change between a bright image and a dark image or adjusting a ratio between primary colors.

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

the light source control unit applies the control signal to adjust a pulse frequency of the light source.

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

the light source control unit applies the control signal to adjust a pulse width of the light source.

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

the light source control unit applies the control signal to adjust a pulse intensity of the light source.

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

the light source control unit applies the control signal to adjust a driving current for driving the light source.

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

the light source control unit controls an emission pulse of the light source for each frame or for each sub-frame.

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

the spatial light modulator control unit applies the input image signal for generating and transmitting the control signal to the light source control unit.

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

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

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

the spatial light modulator further comprises a digital micromirror device including a plurality of movable mirrors each corresponding to and modulating the illumination light for displaying an image pixel.

10. The projection apparatus according to claim 9, wherein:

the spatial light modulator control unit controls each of the movable mirrors to operate in an ON state for reflecting the illumination light to the projection optical system to operate in an OFF state for reflecting the illumination light away from the projection optical system, and to operate in an oscillation state for oscillating the movable mirrors between the ON state and the OFF state.

11. The projection apparatus according to claim 10, wherein:

the light source control unit controls the illumination light emitted from the light source when the light modulator control unit controls the movable mirrors to operate in the ON state or the oscillation state.

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

the light source control unit controls light source to project the illumination light during a period when the control signal generated by the spatial light modulator control unit drives the spatial light modulator.

13. 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 and analyzes data corresponding to the control signal for controlling the illumination light emitted from the light source for adjusting the emission intensity of the illumination light to change between a bright image and a dark image or adjusting the ratio between primary colors according to the control signal.

14. A projection apparatus, comprising:

light sources comprising at least a red (R) light, a green (G) light, and a blue (B) light;

at least one spatial light modulator for modulating illumination light from the light sources by a plurality of pixel elements by using different modulation states;

at least one spatial light modulator comprises a plurality of pixel elements controllable to operate in different modulation states for modulating an illumination light projected from the light sources;

a light source control unit controls and modulates the light source; and

a spatial light modulator control unit receives and applies an input image signal for generating a control signal for driving the spatial light modulator, wherein the light source control unit further having a video image analysis unit receiving and analyzing the control signal generated by the spatial light modulator control unit for controlling the illumination light emitted from the light sources for applying video image analysis results for adjusting a ration of the emission intensities of the illumination light of the respective red, green and blue (R/G/B) colors.

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

the light source control unit controls the emission pulse for the light source of each of the R/G/B colors in sync with the control signal generated by the spatial light modulator control unit.

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

the light source control unit applies the control signal to adjust a pulse frequency of the light source.

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

the light source control unit applies the control signal to adjust a pulse width of the light source.

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

the light source control unit applies the control signal to adjust a pulse intensity of the light source.

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

the light source further comprises a light emitting diode (LED) or a laser device.

20. A projection apparatus, comprising:

at least a light source for projecting an illumination light of different colors;

a light source control device for controlling the light source;

at least one micromirror device comprises a plurality of mirror elements for reflecting the illumination light projected from the light source;

a micromirror device control device receives and applies an input image signal for generating a control signal for controlling the micromirror device; and

a projection optical system for projecting, to a screen, the illumination light deflected by the micromirror device, wherein the light source control device having a video image analysis unit for receiving and analyzing the control signal generated by the spatial light modulator control unit for applying video image analysis results for controlling the illumination light emitted from the light source to adjust an emission intensity of the illumination light to change between a bright image and a dark image or adjusting a ratio between primary colors.

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

the micromirror device control device controls each of the mirror elements to operate in an ON state for reflecting the illumination light to the projection optical system to operate in an OFF state for reflecting the illumination light away from the projection optical system and to operate in an intermediate state for oscillating the mirror elements oscillate between the ON state and the OFF state.

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

the light source further comprises a light emitting diode (LED) or a laser device.

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

the light source control device further receives and analyzes a control signal generated by the spatial light modulator control unit for adjusting an area size ratio of pulses multiplied by two of the light source control device to control the emission intensity of the illumination light projected from the light source.

24. A projection apparatus comprising:

at least a light source for projecting an illumination light of different colors;

a light source control device for controlling the light source;

at least one micromirror device comprises a plurality of mirror elements for reflecting the illumination light projected from the light source;

a micromirror device control device for controlling the micromirror device; and

a projection optical system for projecting, to a screen, the illumination light deflected by the micromirror device, wherein the light source control device adjusts an emission intensity of the illumination light depending on a brightness during a display period of one frame for each of said colors and a combination of a brightness in the ON state and the intermediate state for each of said colors during the display period of one frame.

25. A projection apparatus comprising:

at least a light source for projecting an illumination light of different colors;

a light source control device for controlling the light source;

at least one spatial light modulator comprises a plurality of modulating elements for modulating the illumination light projected from the light source;

a spatial light modulator control device for controlling the spatial light modulator; and

a projection optical system for projecting, to a screen, the illumination light deflected by the spatial light modulator wherein the light source control device adjusts an emission intensity of the illumination light by adjusting an area size of a pulse of the light source control device to control the emission intensity of the illumination light projected from the light source.