PROJECTOR

• US 20100201894A1
• Filed: 05/20/2009
• Published: 08/12/2010
• Est. Priority Date: 05/21/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Kadowaki, Shinichi, Furuya, Hiroyuki, Itoh, Tatsuo, Nakayama, Kenji, Yamamoto, Kazuhisa
• Granted Patent: US 8,235,534 B2
• Time in Patent Office: Days
• US Class Current: 348/745
• CPC Class Codes: G03B 21/005 Projectors using an electronic spatial light modulator but not peculiar thereto
• CPC Class Codes: G09G 3/3433 using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38
• 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 9/3164 using multiple light sources
• CPC Class Codes: H04N 9/3173 wherein the projection device is specially adapted for enhanced portability
• CPC Class Codes: H04N 9/3185 Geometric adjustment, e.g. keystone or convergence optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A projector has: light source (1R, 1G, 1B); a light modulation unit (6) that modulates a light emitted from the light source based on image signals; a display control unit (41) that outputs the image signals including main cyclic image signals to the light modulation unit, and controls the display thereof; a projection unit (7) that projects the image based on the light modulated by the light modulation unit; and an imaging unit (40) that captures an image to be displayed based on the light projected from the projection unit, and the display control unit inserts a correction image signal for projecting a correction image, which is visually recognized as a uniform white or gray screen when time integration is performed, between the cyclic main image signals.

Claims

1-27. -27. (canceled)

28. A projector, comprising:

a light source;

a light modulation unit that modulates a light emitted from the light source based on image signals;

a display control unit that outputs the image signals including cyclic main image signals to the light modulation unit and controls the display thereof;

a projection unit that projects the light modulated by the light modulation unit; and

an imaging unit that captures an image based on the light projected from the projection unit,

the projector being characterized in that

the display control unit inserts a correction image signal for projecting a correction image, which is visually recognized as a uniform white or gray screen when time integration is performed, between the cyclic main image signals.

29. The projector according to claim 28, characterized in that

the imaging unit captures only the correction image in synchronization with a projection timing of the correction image.

30. The projector according to claim 29, characterized in that

the correction image comprises at least two images that cancel the difference of color or brightness in an image plane when time integration is performed.

31. The projector according to claim 28, characterized in that

the projection unit projects the correction image with white light.

32. The projector according to claim 28, characterized in that

the projection unit projects the correction image that includes at least a red image, green image and blue image.

33. The projector according to claim 28, characterized in that

the projection unit projects a correction image that includes at least two images having complementary colors.

34. The projector according to claim 28, characterized in that

the projection unit projects a correction image that cancels color or brightness of a projection target captured by the imaging unit during a non-projection period of a main image to be projected at a predetermined frequency, and that is visually recognized as uniform white or gray in a plane of the projection target when time integration is performed.

35. The projector according to claim 28, characterized in that

the correction image comprises at least two pattern images of which brightnesses are inverted from each other.

36. The projector according to claim 35, characterized in that

at least one of the pattern images has a lattice pattern.

37. The projector according to claim 28, further comprising:

a correction unit that corrects the main image signals based on the correction image captured by the imaging unit,

the projector being characterized in that the correction unit corrects distortion of the main image.

38. The projector according to claim 35, characterized in that

at least one of the pattern images is a two-dimensional code.

39. The projector according to claim 38, further comprising:

an analysis unit that extracts information from the two-dimensional code captured by the imaging portion.

40. The projector according to claim 28, characterized in that

the correction image is one or a plurality of uniform images.

41. The projector according to claim 40, further comprising:

a correction unit that corrects the main image signals based on the correction image captured by the imaging unit,

the projector being characterized in that the correction unit corrects a color of the main image.

42. The projector according to claim 28, characterized in that

the light source is an LED.

43. The projector according to claim 28, characterized in that

the light source is a laser.

44. The projector according to claim 28, characterized in that

the projection unit includes a projection lens that projects light modulated by the light modulation unit, and the imaging unit also uses the projection lens as an imaging lens.

45. The projector according to claim 44, characterized in that the projection unit comprises:

a polarized beam splitter that separates light according to polarization; and

a ¼

wavelength plate that is disposed between the polarized beam splitter and the projection lens and sets the phase difference between an outgoing path and returning path of the light that reciprocatingly transmits through the projection lens to π

/2.

46. The projector according to claim 28, characterized in that

a drive frequency of the main image is 180 Hz or more.

47. The projector according to claim 28, characterized in that

the light modulation unit is a spatial modulation element that spatially modulates light.

48. The projector according to claim 47, characterized in that

the spatial modulation element is a reflection type signal plate liquid crystal display element.

49. The projector according to claim 47, characterized in that

the spatial modulation element is a plurality of micro-mirrors that can change the angle.

50. The projector according to claim 28, characterized in that the light modulation unit comprises:

a scanning unit that performs light scanning two-dimensionally; and

an intensity modulation unit that can modulate an intensity of light that enters from the light source to the scanning unit.

51. The projector according to claim 28, further comprising:

a processing unit that computes prediction of a change in the projection target based on a plurality of the correction images captured in different frames by the imaging unit.

52. The projector according to claim 28, further comprising:

a signal transmission/reception unit that transmits/receives a synchronization signal that indicates a timing to project the correction image.

53. The projector according to claim 28, further comprising:

a switching unit that switches setting whether the correction image signal is inserted between the cyclic main image signals or not.

54. The projector according to claim 53, further comprising:

a motion sensor that detects motion of the projector,

the projector being characterized in that

the switching unit inserts the correction image signal when the motion sensor detects motion, and does not insert the correction image signal when the motion sensor does not detect motion.