Projector

• US 20060158617A1
• Filed: 01/20/2005
• Published: 07/20/2006
• Est. Priority Date: 01/20/2005
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Hu, Deqing, Snyder, Terrill D., Pinard, Daniel T.
• Granted Patent: US 7,503,658 B2
• Time in Patent Office: Days
• US Class Current: 353/84
• CPC Class Codes: G03B 21/10 Projectors with built-in or built-on screen
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: G03B 33/08 Sequential recording or projection G03B33/02, G03B33/04, G03B33/06 take precedence
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386

Abstract

An apparatus projects at least one color of light which is attenuated.

Claims

1. An apparatus comprising:

a projector configured to sequentially project colors of light;

a light sensitive device; and

a filter configured to attenuate at least one of the colors before a portion of the light impinges upon the light sensitive device.

2. The apparatus of claim 1 further comprising a screen configured to be illuminated by the colors.

3. The apparatus of claim 2 further comprising a light source configured to project light towards the screen.

4. The apparatus of claim 3, wherein the light source and the light sensitive device are on a common side of the screen.

5. The apparatus of claim 3, wherein the screen is between the light source and the light sensitive device.

6. The apparatus of claim 3, wherein the light source, the screen and the light sensitive device are arranged such that the light sensitive device receives light from the light source after it has been reflected off of a surface upon the screen.

7. The apparatus of claim 2, wherein the screen is substantially horizontal.

8. The apparatus of claim 2, wherein the screen is configured to scatter light.

9. The apparatus of claim 1, wherein the filter is configured to filter out a plurality of the colors.

10. The apparatus of claim 1, wherein the filter is configured to filter out each of the colors.

11. The apparatus of claim 1, wherein the light sensitive device is configured to receive light during projection of said one of the colors and not during projection of a remainder of the colors.

12. The apparatus of claim 11, wherein the light sensitive device includes a shutter configured to permit the light sensitive device to receive light during projection of said one of the colors and not during projection of the remainder of the colors.

13. The apparatus of claim 12, wherein the filter comprises a wavelength filter.

14. The apparatus of claim 13 further comprising a light source strobed to the shutter.

15. The apparatus of claim 1, wherein the filter includes a color wheel comprised of colored segments.

16. The apparatus of claim 1, wherein the projector includes a first color wheel and wherein the filter includes a second color wheel.

17. The apparatus of claim 16, wherein the second color wheel is synchronized with the first color wheel to filter the colors projected by the projector.

18. The apparatus of claim 16 further comprising a synchronizer coupled between the first color wheel and the second color wheel.

19. The apparatus of claim 1, wherein the light sensitive device includes a camera.

20. The apparatus of claim 1 further comprising a processor in communication with the light sensitive device, wherein the processor is configured to detect and compare first signals from the light sensitive device at a first time to second signals from the light sensitive device at a second time.

21. The apparatus of claim 1 further comprising:

a screen configured to be illuminated by the colors;

a light source configured to project light towards the screen; and

a processor in communication with the light sensitive device,

wherein the processor is configured to detect and compare first signals from the light sensitive device based upon reflected light from the light source at a first time to second signals from the light sensitive device based upon the reflected light from the light source at a second time.

22. The apparatus of claim 21, wherein the first signals from the light sensitive device are based upon the reflected light of the light source reflected from multiple first and second surfaces of first and second objects located at first and second positions, respectively, adjacent the screen and wherein the second signals from the light sensitive device are based upon the reflected light of the light source reflected from the first and second surfaces at third and fourth different positions, respectively.

23. The apparatus of claim 1 further comprising:

a screen configured to be illuminated by the colors;

a light source configured to project light towards the screen; and

a processor in communication with the light sensitive device,

wherein the processor is configured to detect and compare signals from the light sensitive device based upon the light from the light source that is passed through the screen without being blocked at a first time to second signals from the light sensitive device based upon the light from the light source that is passed through the screen without being blocked at a second time.

24. The apparatus of claim 1 further comprising:

a controller in communication with the light sensitive device and the projector, wherein the controller is configured to generate control signals actuating the light sensitive device during projection of said one of the colors.

25. The apparatus of claim 1 further comprising:

a screen configured to be illuminated by the colors; and

a first object configured to rest upon the screen.

26. The apparatus of claim 25, further comprising a second object configured to rest upon the screen.

27. The apparatus of claim 25, wherein the first object includes a light source.

28. The apparatus of claim 1 further comprising:

an object including a light emitter configured to emit a focused beam of light at the light sensitive device.

29. The apparatus of claim 1, wherein the light sensitive device is configured to sense shadows resulting from blocked ambient light.

30. An apparatus comprising:

a means for sequentially projecting light in a series of colors;

a means for sensing light; and

a means for preventing light from the projection means from being sensed by the sensor means.

31. The apparatus of claim 30 further comprising:

a light source; and

a means for receiving light from the light source and for receiving light from the projection means.

32. The apparatus of claim 31, wherein the means for sensing is configured to sense light from the light source which is reflected from an object adjacent the means for receiving light.

33. The apparatus of claim 31, wherein the means for sensing is configured to sense light from the light source passing by an object adjacent the means for receiving light.

34. A method comprising:

projecting a first light of at least one color towards a screen;

projecting a second light towards the screen;

attenuating the first light; and

sensing the second light.

35. The method of claim 34, wherein the projecting the first light includes projecting light in a sequential series of colors.

36. The method of claim 35, wherein the projecting the first light includes directing light through a first rotating color wheel.

37. The method of claim 36 further comprising synchronously rotating a second color wheel with the first color wheel.

38. The method of claim 34, wherein the attenuating the first light includes filtering out the at least one color of the first light.

39. The method of claim 34 further comprising reflecting the second light off an object on the screen prior to being sensed.

40. The method of claim 34 further comprising transmitting the second light past an object on the screen prior to the second light being sensed.

41. The method of claim 34, wherein the second light is emitted by an object adjacent the screen.

42. The method of claim 34, wherein the second light is emitted by a handheld object spaced from the screen.

43. The method of claim 34, wherein sensing the second light includes sensing the second light at a first time to produce a first signal and sensing the second light at a second time to produce a second signal and wherein the method further includes comparing the first signal and the second signal.

44. The method of claim 34 further comprising:

positioning a first surface and a second surface adjacent the screen at first and second positions, respectively, while the first light forms a first image on the screen, wherein sensing the second light includes sensing the second light after it has been reflected off of the first surface at the first position and off of the second surface at the second position to create a first signal;

repositioning the first surface to a third position adjacent the screen while the first light forms a second image on the screen, wherein sensing the second light further includes sensing the second light after the second light has been reflected off of the first surface at the third position to produce a second signal; and

comparing the first signal and the second signal.

45. The method of claim 44, wherein the projecting a first light includes projecting light in a sequential series of colors, wherein the second light is sensed only during projection of one of the colors and wherein only said one of the colors of the first light is attenuated.

46. The method of claim 45, wherein the second light is sensed with a light sensitive device and wherein the method further includes blocking the light sensitive device from the first light during projection of the one color.

47. The method of claim 46, wherein projecting the first light includes directing light through a rotating color wheel and wherein blocking the light sensitive device includes synchronizing a shutter proximate the light sensitive device with a rotation of the color wheel.

48. The method of claim 44, wherein the projecting a first light includes projecting light in a sequential series of colors, wherein each of the colors is prevented from being sensed.

49. The method of claim 34 further comprising:

positioning a first surface and a second surface adjacent the screen at first and second positions, respectively, while the first light forms a first image on the screen, wherein sensing the second light includes sensing the second light after it has passed the first surface at the first position and past the second surface at the second position to create a first signal;

repositioning the first surface to a third position adjacent the screen while the first light forms a second image on the screen, wherein sensing the second light further includes sensing the second light after the second light has passed the first surface at the third position to produce a second signal; and

comparing the first signal and the second signal.

50. A computer-readable medium comprising:

stored instructions to attenuate a first light projected towards a screen; and

stored instructions to sense a second light projected towards a screen.

51. The computer-readable medium of claim 50 further comprising:

stored instructions to compare the second light sensed at a first time with the second light sensed at a second time.

52. The computer-readable medium of claim 50 further comprising:

stored instructions to synchronize rotation of a first color wheel through which the first light is projected with rotation of a second color filter wheel.

53. The computer-readable medium of claim 50 further comprising:

stored instructions to synchronize the positioning of a color filter relative to a light sensitive device with respect to a color wheel through which the first light passes.

54. A system comprising:

a screen;

a projector configured to sequentially project colors of light towards the screen;

a light sensitive device; and

a filter configured to attenuate at least one of the colors before a portion of the light impinges upon the light sensitive device.

55. The system of claim 54, wherein the projector includes a first color wheel and wherein the filter comprises a second color wheel.

56. The system of claim 55 including a synchronizer configured to synchronize rotation of the first color wheel and the second color wheel.

57. The system of claim 54 further comprising a controller configured to compare signals from the light sensitive device at a first time with signals from the light sensitive device at a second time.