Image projecting device and method

• US 20040239880A1
• Filed: 07/19/2004
• Published: 12/02/2004
• Est. Priority Date: 07/06/2001
• Status: Active Grant

• Current Assignee: Explay Ltd.
• Original Assignee: Explay Ltd.
• Inventors: Pomerantz, Itzhak, Zalevsky, Zeev, Kapellner, Yuval, Sabo, Eran, Kapellner, Sharon
• Granted Patent: US 7,128,420 B2
• Time in Patent Office: Days
• US Class Current: 353/20
• CPC Class Codes: H04N 5/7416 involving the use of a spatial light modulator, e.g. a light valve, controlled by a video signal
• 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 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20

Abstract

An image projecting device and method are presented. The device comprises a light source system operable to produce a light beam to impinge onto an active surface of a spatial light modulator (SLM) unit formed by an SLM pixel arrangement; and a magnification optics accommodated at the output side of the SLM unit. The light beam impinging onto the SLM pixel arrangement has a predetermined cross section corresponding to the size of said active surface. The SLM unit comprises first and second lens'"'"' arrays at opposite sides of the pixel arrangement, such that each lens in the first array and a respective opposite lens in the second array are associated with a corresponding one of the SLM pixels

Claims

1-38. -38. Cancel.

39. An image projecting device (1) comprising a spatial light modulating (SLM) pixel arrangement (5) defining an active surface;

first and second lens'"'"' arrays (10, 14) at opposite sides of said SLM pixel arrangement (5), such that each lens in the first array and a respective opposite lens in the second array are associated with a corresponding one of the pixels;

a light source system (LSS) operable to produce an incident light beam of a predetermined cross section corresponding to the size of said active surface; and

a magnification optics (22) accommodated at the output side of the SLM pixel arrangement;

the device being characterized in that;

said first and second lens'"'"' arrays are integral with said SLM pixel arrangement being located at opposite surfaces of the SLM pixel arrangement, and forming together with the SLM pixel arrangement a common SLM unit (12), each of said first and second lens'"'"' arrays being spaced from the respective surface of the pixel arrangement a predetermined small distance up to a physical contact,

said first and second lens'"'"' arrays are implemented in polymer spacers (P1, P2), respectively, at opposite surfaces of said SLM pixel arrangement.

40. The device according to claim 39, wherein the SLM pixel arrangement has a pixel pitch substantially not exceeding 50 μ

m.

41. The device according to claim 39, wherein the distance between the lens array and the respective surface of the SLM pixel arrangement substantially does not exceed 50 μ

m.

42. The device according to claim 39, wherein the SLM pixel arrangement comprises light modulating material defining said active surface.

43. The device according to claim 39, wherein the incident light impinging on to the SLM unit is specifically polarized, the device comprising a polarizer unit accommodated at the output side of the SLM pixel arrangement and having a preferred orientation of a plane of polarization so as to be either substantially the same as of the incident light beam or a 90-degree rotated with respect to that of the incident light beam.

44. The device according to claim 43, wherein the light source system includes a high-ratio polarized light source for generating the polarized incident light.

45. The device according to claim 43, comprising an input polarizer at the input side of the SLM pixel arrangement.

46. The device according to claim 39, wherein the light source system comprises an optical arrangement operable to provide substantially uniform intensity distribution within the cross-section of the incident light beam.

47. The device according to claim 46, wherein said optical arrangement includes a diffractive element operable to modify the beam intensity distribution to produce the substantially uniform intensity distribution of the beam within its cross-section.

48. The device according to claim 39 wherein the light source system includes a beam expander affecting the cross section of a light beam generated by the light source to provide the cross section of the beam substantially of the size of the active surface of the SLM unit.

49. The device according to claim 39, wherein the light source system includes a light source generating a light beam of the cross section substantially of the size of the active surface of the SLM unit.

50. The device according to claim 39, comprising an image processor system operable to carry out at least one of the following:

(i) applying digital processing to data indicative of an image to be projected so as to avoid or at least significantly reduce the speckles associated effects in the projected image;

(ii) processing data indicative of the projected image to correct for non-uniformities in the light intensity; and

(iii) analyzing data indicative of the environmental condition to adjust at least one of the intensity and color mixture of the incident light beam.

51. The device according to claim 50, comprising an image recorder operable to generate the data indicative of the projected image and transmit said data to the image processor system.

52. The device according to claim 50, comprising an environment sensor operable to generate the data indicative of the environment condition and transmit said data to the image processor system.

53. The device according to claim 39, comprising a modulation driver responsive to an imaging signal representative of an image to be projected, to generate modulation signals to the SLM pixel arrangement.

54. The device according to claim 53, wherein said modulation driver is connectable to the image processor system to receive therefrom said imaging signal.

55. The device according to claim 39, comprising a time modulator associated with said SLM pixel arrangement and operable to apply time modulation to different light components of the light source system.

56. The device according to claim 55, wherein said different light components are different color components.

57. The device according to claim 56, wherein said different color components are formed by a combination of highly polarized and non-polarized light.

58. The device according to claim 57, wherein the light source system includes at least one laser source for generating polarized light, and at least one light emitting diode for generating non-polarized light.

59. The device according to claim 39, wherein the light source system generates spatially separated different-color light components, the device comprising additional SLM pixel arrangements, each arrangement being associated with the corresponding one of the color light components.

60. The device according to claim 39, comprising a rotating mirror accommodated in front of a projecting surface, the device thereby enabling creation of a stereoscopic image.

61. The device according to claim 43, wherein said polarizer unit is constituted by the surface of wearable glasses capable of imitating a three-dimensional image.

62. A projecting system comprising at least two projecting devices, each constructed according to claim 39.

63. The system according to claim 62, comprising a control unit connectable to each of the projecting devices and operable to enable creation of a large combined image on a projecting surface formed by images created by the projecting devices.

64. The system according to claim 63, wherein said projecting surface is concave.

66. The device according to claim 40, wherein the distance between the lens array and the respective surface of the SLM pixel arrangement substantially does not exceed 50 μ

m.

67. A method for projecting an image comprising:

(i) providing a spatial light modulator (SLM) unit (12) composed of an SLM pixel arrangement (5) defining an active surface, and first and second lens'"'"' arrays (10, 14) at opposite sides of the SLM pixel arrangement, each of said first and second lens'"'"' arrays being spaced from the respective surface of said SLM pixel arrangement a predetermined small distance up to a physical contact with said surface, said lens'"'"' arrays being implemented in polymer spacers (P1 , P2), respectively, at the opposite surfaces of the SLM pixel arrangement, each lens in the first array and a respective opposite lens in the second array are associated with a corresponding one of the pixels; and

(ii) creating an incident light beam having a predetermined cross section corresponding to a size of said active surface defined by the SLM pixel arrangement;

(iii) passing said light through the SLM unit and concurrently operating the SLM pixel arrangement with an imaging signal representative of an image to be projected to thereby produce modulated light;

(iv) passing the modulated light emerging from the SLM unit through a magnifying optics (22) to be projected onto a projecting surface.

68. The method according to claim 67, wherein the SLM pixel arrangement has a pixel pitch substantially not exceeding 50 μ

m.

69. The method according to claim 67 surface of the SLM pixel arrangement substantially does not exceed 50 μ

m.

70. The method according to claim 67, comprising providing specific polarization of the incident light beam propagating towards the SLM pixel arrangement, and passing the modulated light, propagating towards the projecting surface, through a polarizer having a preferred orientation of a plane of polarization either substantially the same as that of the incident light beam or a 90-degree rotated with respect to that of the incident light beam.

71. The method according to claim 70, comprising passing the randomly polarized light beam generated by a light source through a polarizer accommodated at the input side of the SLM pixel arrangement.

72. The method according to claim 70, wherein the incident light beam is created by a high-ratio polarization light source.

73. The method according to claim 67, wherein the incident light beam is created by a light source emitting a light beam with a cross section substantially of the size of the active surface of the SLM pixel arrangement.

74. The method according to claim 67, wherein the creation of incident light beam comprises passage of a light beam emitted by a light source through a beam shaping optics to thereby produce the incident light beam of the predetermined cross section.

75. The method according to claim 67, comprising processing said imaging signal prior to operating thereby the SLM pixel arrangement, to apply digital jittering and gray level processing of pixels, thereby enabling reduction of speckles'"'"' effects in the projected image.

76. The method according to claim 67, comprising obtaining data indicative of the projected image, analyzing said data and processing said imaging signal prior to operating thereby the SLM pixel arrangement, to thereby provide substantially uniform intensity within the projected image.

77. The method according to claim 67, comprising obtaining data indicative of an environment condition, analyzing said data, and processing said imaging signal prior to operating thereby the SLM pixel arrangement, to thereby adjust at least one of the intensity and color mixture of the modulated light forming the projected image.

78. The method according to claim 68, wherein the distance between the lens array and the respective surface of the SLM pixel arrangement substantially does not exceed 50 μ

m.

79. The method according to claim 68, comprising providing specific polarization of the incident light beam propagating towards the SLM pixel arrangement, and passing the modulated light, propagating towards the projecting surface, through a polarizer having a preferred orientation of a plane of polarization either substantially the same as that of the incident light beam or a 90-degree rotated with respect to that of the incident light beam.

80. The method according to claim 79, comprising passing the randomly polarized light beam generated by a light source through a polarizer accommodated at the input side of the SLM pixel arrangement.

81. The method according to claim 79, wherein the incident light beam is created by a high-ratio polarization light source.