Synchronous control system for light source and spatial light modulator employed in projection apparatus

• US 8,157,389 B2
• Filed: 10/01/2008
• Issued: 04/17/2012
• Est. Priority Date: 11/01/2003
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite)
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Maeda, Yoshihiro, Nishino, Hirokazu, Shirai, Akira, Ishii, Fusao
• Primary Examiner(s): Ko, Tony
• Assistant Examiner(s): Cruz, Magda
• Application Number:
  US12/286,800
• Publication Number:
  US 20090033808A1
• Time in Patent Office: 1,294 Days
• Field of Search: 353/85, 353/31, 353/98, 359/292, 359/291, 348/771, 348/536, 348/735, 257/89, 345/84
• US Class Current: 353/85
• CPC Class Codes: G02B 27/141 using dichroic mirrors
• CPC Class Codes: G03B 21/2053 Intensity control of illuminating light controlled by video signal processing H04N5/74 or H04N9/31
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: G03B 33/12 using beam-splitting or beam-combining systems, e.g. dichroic mirrors
• CPC Class Codes: H04N 2005/745 Control circuits therefor
• CPC Class Codes: H04N 5/7458 the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]
• CPC Class Codes: H04N 7/012 Conversion between an interlaced and a progressive signal for graphics images G09G2310/0229
• 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 9/3155 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 display apparatus, comprising: an a light source for emitting illumination light for transmitting along illumination light path; a display device includes a plurality of pixels for modulating the illumination light for reflecting the illumination light along a projection light path after said illumination light is modulated by said display device; light path change actuator for changing the projection light paths; and a control circuit for controlling the light source, wherein the control circuit controls the light source in response to changes of the projection light path.

Claims

1. A display apparatus, comprising:

a light source for emitting an illumination light;

a display device includes a plurality of pixels for modulating and projecting the illumination light along a projection light path for displaying an image comprising said plurality of pixels;

a light wobbling device for slightly changing the locations of the pixels of the image projected through the projection light path; and

a control circuit for controlling the light source corresponding to changes made by the light wobbling device.

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

the control circuit controls the light source during a period synchronized with the changes made by the light wobbling device.

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

the control circuit decreases the quantity of the illumination light projected from the light source or turns it off the light source in synchronous with the changes made by light wobbling device.

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

the control circuit changes colors of the illumination light projected from the light source in synchronous with the changes made by light wobbling device.

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

the control circuit changes emission periods of the illumination light projected from the light source in synchronous with the changes made by light wobbling device.

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

the light source comprises a plurality of sub-light sources, wherein the control circuit changes the numbers of the sub-light sources for changing an intensity of the illumination light in synchronous with the changes made by light wobbling device.

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

the light wobbling device slightly changes the locations of the pixels of a predetermined set of pixel(s) of the image projected through the projection light path.

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

the light path change actuator changes the projection positions of the pixel corresponding to a predetermined color.

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

the light wobbling device slightly changes the locations of the pixels of a predetermined column of pixels of the image projected through the projection light path.

10. The display apparatus according to claim 1, wherein:

the light wobbling device slightly changes the locations of the pixels by a distance no more than an approximate pitch of the pixels.

11. The display apparatus according to claim 1, wherein:

the light wobbling device slightly changes the locations of the pixels periodically at a frequency higher than or equal to 120 Hz.

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

the display device comprising a mirror device having a plurality of mirror elements each is controllable for modulation and reflecting the illumination light in a controlled direction.

13. The display apparatus according to claim 1, wherein:

the light wobbling device further comprising a wobbling actuator for wobbling the display device.

14. The display apparatus according to claim 1, wherein:

the light wobbling device further comprises an actuator to shift a mirror surface of the display device for slightly changing the locations of the pixels of the image projected through the projection light path.

15. The display apparatus according to claim 1, wherein:

the light wobbling device further comprising an actuator to change a polarization of a polarization element of the display device for slightly changing the locations of the pixels of the image projected through the projection light path.

16. The display apparatus according to claim 1, wherein:

the light source is further controllable to emit the illumination light as a plurality of pulsed emissions within a display frame period.

17. A display apparatus, comprising:

a light source for emitting an illumination light;

a display device comprising a plurality of pixels, for modulating the illumination light in accordance with a video image signal for projecting a projection light reflected from the display device along a projection light path;

a light wobbling device for slightly changing an optical axis of the projection light; and

a light source control circuit controls and adjusts the light source during a period corresponding to changes made by the light wobbling device.

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

the display device receives and applies a wobbling control signal different from the video image signal during a period when the light wobbling device changes the optical axis of the projection light.

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

the display device receives and applies a wobbling control signal to operate in an OFF state during a period when the light wobbling device changes the optical axis of the projection light.

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

the light source control circuit controls and adjusts the light source in synchronization with the changes made by the light wobbling device.

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

the display device comprising a mirror device having a number of pixels equal to a half of a video image pixels according to the video image signal for projecting and displaying an image.

22. The display apparatus according to claim 17, wherein:

the display device comprising a mirror device for modulating and reflecting the illumination light to an ON direction, an OFF direction and an intermediate direction between said ON and OFF directions.

23. A projection apparatus, comprising:

a laser or light emitting diode (LED) light source emitting an illumination light;

a light source control circuit for controlling an intensity of the illumination light of the light source or the emission timing of the light source;

a video image signal generated at a frequency of 120 Hz or higher per frame;

a mirror device comprising a plurality of mirror elements wherein each of said mirror elements controlled in accordance with the video image signal to deflect and modulate the illumination light to an ON direction and an OFF direction; and

a screen for projecting the reflected light when the mirror element is in an ON state, wherein the light source is controlled to emit a reduced amount of illumination light during a period when the plurality of mirror elements is deflected in the same direction between two consecutive display frames.

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

the light source control circuit control the light source to change colors of the illumination light in a sub-frame having a frequency of 360 Hz or higher within the display frame.

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

the mirror elements are controlled by the video image signal having a display frame period with a frequency of 240 Hz or higher.