Intensity distribution of incident light flux

• US 7,646,527 B2
• Filed: 03/18/2007
• Issued: 01/12/2010
• Est. Priority Date: 11/01/2003
• Status: Expired due to Fees

• Current Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Maeda, Yoshihiro, Ichikawa, Hirotoshi, Arai, Kazuma, Ishii, Fusao
• Primary Examiner(s): Schwartz; Jordan M.
• Assistant Examiner(s): JONES, JAMES
• Application Number:
  US11/728,553
• Publication Number:
  US 20070171507A1
• Time in Patent Office: 1,031 Days
• Field of Search: 359/391, 359/395, 359/390, 359/291, 359/290
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 27/09 Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for adapting the beam shape of a laser diode G02B19/0052; adapting the beam shape of an LED G02B19/0061; coupling into light guides using intermediate optical elements G02B6/4204; beam shaping specially adapted for lasers H01S3/005
• CPC Class Codes: G03B 21/008 using micromirror devices
• 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 5/7458 the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time
• 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

Additional control flexibilities to generate more gray scales for an image display system is achieved by controlling the intensity distribution of the light projection from a light source to a deflecting mirror to further coordinate with the control of the intermediate states of the deflecting mirror. The control light source intensity distribution can provide incident light with wide varieties of intensity distributions including non-uniform, symmetrical and non-symmetrical, different distributions of polarizations, various cross sectional shapes of the incident lights and other combinations of all of the above variations. More stable and better control of gray scale control is also achieved by optimizing the intensity distributions of the incident light to produce the best visual effects of the image display.

Claims

1. A projection device receiving a light from a light source through an illumination optics for projecting to a deflecting type spatial light modulator having a plurality of micromirrors controlled to deflect to different deflection angles for projecting a predefined amount of light toward an optical pupil disposed on an image-display projection light path, wherein:

said light source or said illumination optics is configured to project an illumination light with a non-uniform intensity distribution within a range of an incident NA (numeric aperture) to the each mirror element,

a controller controls the micromirrors in a first control period, and a second control period to increase and decrease an intensity of light incident to said deflecting type spatial light modulator (SLM) in at least one of the first and the second control periods, or in one or more sub-control periods wherein at least one of the first and the second control periods is divided into two or more sub-control periods.

2. The projection device according to claim 1, further comprising

a removable light attenuation element disposed on a light path between said light source and said deflecting type SLM for adjusting the intensity of light incident to said deflecting type spatial light modulator (SLM) in synchronization with each of the control periods.

4. The projection device according to claim 1, wherein

said controller controls said first and second control periods in synchronization with a resonant frequency of the micromirrors for adjusting said light intensity incident to said deflecting type spatial light modulator (SLM).

5. The projection device according to claim 1, wherein

said controller controls said first and second control periods in synchronization with a minimum time unit for turning on said micromirrors for adjusting said light intensity incident to said deflecting type spatial light modulator (SLM).

6. The projection device according to claim 1, wherein

said controller turns off said illumination light when the mirror element deflects said illumination light away from said image display projection light path.

7. The projection device according to claim 1, wherein

said light source is modulated to project said illumination light with an intensity of two or more stages.

8. The projection device according to claim 1, wherein

said controller applies color sequential control process for sequentially displaying images of different colors within one frame time.

9. The projection device according to claim 1, wherein

the controller controls an intensity of said illumination light projected from said light source to said deflecting type spatial light modulator according to a scale of 1/n where n is an integer.

10. The projection device according to claim 1, wherein

an oscillation amplitude of the micromirrors is changed during the second control period.

11. The projection device according to claim 1, wherein

said light source is a laser light source or an LED light source.

3. A projection device receiving a light from a light source through an illumination optics for projecting to a spatial light modulator having a plurality of micromirrors controlled to deflect to different deflection angles for projecting a predefined amount of light toward an optical pupil disposed on a projection light path, wherein:

said light source or said illumination optics is configured to make an intensity distribution or an average light amount of illumination light non-uniform within a range of an incident NA to the each mirror element,

a controller to control the micromirrors to hold a particular deflection angle in a first control period, and controls the micromirrors to oscillate in a second control period,

an intensity of light incident to said deflecting type spatial light modulator is increased or decreased in at least one of the first and the second control periods, or in one or more sub-control periods when at least one of the first and the second control periods is divided into two or more sub-control periods; and

a polarizing element for adjusting a light transmitting therethrough for increasing or decreasing the intensity of light incident to said deflecting type spatial light modulator in synchronization with each of the control periods.

12. A projection device receiving a light from a light source through an illumination optics for projecting to a spatial light modulator having a plurality of micromirrors controlled to deflect to different deflection angles for projecting a predefined amount of light toward an optical pupil disposed on a projection light path, wherein:

said light source or said illumination optics is configured to make an intensity distribution or an average light amount of illumination light non-uniform within a range of an incident NA to the each mirror element,

a controller to control the micromirrors to hold a particular deflection angle in a first control period, and controls the micromirrors to oscillate in a second control period,

an intensity of light incident to said deflecting type spatial light modulator is increased or decreased in at least one of the first and the second control periods, or in one or more sub-control periods when at least one of the first and the second control periods is divided into two or more sub-control periods; and

;

said light source comprising an array of plurality of sub-light sources wherein each of the plurality of sub-light sources is controlled in the second control period, or in one or more sub-control periods in the second control period to emit an adjustable light intensity.

13. The projection device according to claim 12, wherein

the intensity of light is adjusted in synchronization with a resonant frequency of the micromirrors.

14. The projection device according to claim 12, wherein

the intensity of light is adjusted is the first control period, and also modulated in synchronization with a minimum time unit for turning on the micromirrors.

15. The projection device according to claim 12, wherein

illumination is turned off while a deflection direction of the mirror element is in a direction where illumination light is not deflected to said projection light path.

16. The projection device according to claim 12, wherein

said light source light is modulated to project a light with an intensity of two or more stages.

17. The projection device according to claim 12, wherein

said light source is a laser light source or an LED light source.

18. The projection device according to claim 12, wherein

the plurality of sub-light sources comprising sub-light sources of a same color or different colors.

19. The projection device according to claim 12, wherein:

said plurality of sub-light sources are controlled to project a light emission pattern.

20. The projection device according to claim 19, wherein

said plurality of sub-light sources are controlled to project a light emission pattern symmetrically or asymmetrically with an optical axis.

21. The projection device according to claim 19, wherein

said plurality of sub-light sources are controlled to project a light emission pattern during a display time period.

22. The projection device according to claim 19, wherein

said controller configuring a color image display by applying a color sequential method for sequentially displaying images of different colors within one frame time and controlling said plurality of sub-light sources in different sub-field for each of said colors.

23. The projection device according to claim 12, wherein

said light source further comprising a light source, and a light guiding member.

24. The projection device according to claim 23, wherein

the light guiding member further comprises a light synthesizer, or a light separator.

25. The projection device according to claim 12, wherein

said light source projecting a light having a cross sectional area equal to or smaller than 5 mm².

26. The projection device according to claim 12, wherein

said light source emits lights of two different primary colors.

27. A projection device receiving a light from a light source through an illumination optics for projecting to a spatial light modulator having a plurality of micromirrors controlled to oscillated to different deflection angles for projecting a predefined amount of light toward an optical pupil disposed on an image-display projection light path, wherein:

a controller to control the micromirrors to hold a particular deflection angle in a first control period, and controls the micromirrors to continuously oscillate within an oscillation angle around a central oscillation axis in a second control period to operate in an intermediate state for controlling and adjusting an intensity of light incident to said spatial light modulator for increasing or decreasing said light intensity according to said oscillation angle and said central axis of oscillation of said micromirrors in at least one of said first and second control periods or in one or more sub-control periods.

28. The projection device according to claim 27, wherein

said controller controls said first and second control periods in synchronization with a resonant frequency of the micromirrors for adjusting said light intensity.

29. The projection device according to claim 27, wherein

said controller controls said first and second control periods in synchronization with a minimum time unit for turning on said micromirrors for adjusting said light intensity.

30. The projection device according to claim 27, wherein

said controller turns off said illumination light when the mirror element deflects said illumination light away from said image display projection light path.

31. The projection device according to claim 27, wherein

said light source is modulated to project said illumination light with an intensity of two or more stages.

32. The projection device according to claim 27, wherein

said controller applies a color sequential control process for sequentially displaying images of different colors within one frame time.

33. The projection device according to claim 27, wherein

the controller controls said intensity of said illumination light incident from said light source to said deflecting type spatial light modulator for decreasing said illumination light to 1/n of the intensity wherein n is an integer or flexibly adjusting said intensity of said illumination light.

34. The projection device according to claim 27, wherein:

the controller adjusts the intensity of said illumination light incident from said light source to said deflecting type spatial light modulator; and

said controller further controls and adjusts an oscillation amplitude of said micromirrors.

35. The projection device according to claim 27, wherein

said light source further comprises a laser light source or an LED light source.

36. A projection device receiving a light from a light source through an illumination optics for projecting to a spatial light modulator having a plurality of micromirrors controlled to oscillated to different deflection angles for projecting a predefined amount of light toward an optical pupil disposed on a an image-display projection light path, wherein

a controller to control the micromirrors to hold a particular deflection angle in a first control period, and controls the micromirrors to continuously oscillate within an oscillation angle around a central oscillation axis in a second control period to operate in an intermediate state for controlling and adjusting an intensity of light incident to said spatial light modulator for increasing or decreasing said light intensity according to said oscillation angle and said central axis of oscillation of said micromirrors in at least one of said first and second control periods or in one or more sub-control periods;

and

said light source comprises a plurality of sub-light sources, and the intensity of light is increased or decreased depending on a change in a light emission amount, a light emission pattern, or the number of light emitting elements.

37. The projection device according to claim 36, wherein

a time period during which the intensity of light is changed is synchronous with a resonant frequency of the mirror element.

38. The projection device according to claim 36, wherein

illumination is turned off while a deflection direction of the mirror element is a direction where illumination light is not deflected to said projection light path.

39. The projection device according to claim 36, wherein

a time period during which the intensity of light is changed is the first control period, and the intensity is modulated in synchronization with a minimum time unit in which the mirror element is turned on.

40. The projection device according to claim 36, wherein

light source light is modulated to an intensity of two or more stages.

41. The projection device according to claim 36, wherein

said light source is a laser light source or an LED light source.

42. The projection device according to claim 36, wherein

the plurality of sub-light sources are composed of sub-light sources of a same color or different colors.

43. The projection device according to claim 36, wherein

a light emission pattern of the plurality of sub-light sources is switched.

44. The projection device according to claim 43, wherein

a light emission pattern of the plurality of sub-light sources is switched symmetrically or asymmetrically with an optical axis.

45. The projection device according to claim 43, wherein

a light emission pattern of the plurality of sub-light sources is switched during a display time period.

46. The projection device according to claim 43, wherein

said controller configuring a color image display by applying a color sequential method for sequentially displaying images of different colors within one frame time and controlling said plurality of sub-light sources in different sub-field for each of said colors.

47. The projection device according to claim 36, wherein

said light source is composed of a light source, and a light guiding member.

48. The projection device according to claim 47, wherein

the light guiding member comprises light synthesis means, or light separation means.

49. The projection device according to claim 36, wherein

a light emission area of said light source is equal to or smaller than 5 mm².

50. The projection device according to claim 36, wherein

said light source emits lights of two different primary colors.