Method and device for modulating light with optical compensation

• US 20060274400A1
• Filed: 05/12/2006
• Published: 12/07/2006
• Est. Priority Date: 11/06/1995
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Miles, Mark W.
• Granted Patent: US 7,907,319 B2
• Time in Patent Office: Days
• US Class Current: 359/291
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26

Abstract

An interferometric modulator (Imod) cavity has a reflector and an induced absorber. A direct view reflective flat panel display may include an array of the modulators. Adjacent spacers of different thicknesses are fabricated on a substrate by a lift-off technique used to pattern the spacers which are deposited separately, each deposition providing a different thickness of spacer. Or a patterned photoresist may be used to allow for an etching process to selectively etch back the thickness of a spacer which was deposited in a single deposition. A full-color static graphical image may be formed of combined patterns of interferometric modulator cavities. Each cavity includes a reflector, and an induced absorber, the induced absorber including a spacer having a thickness that defines a color associated with the cavity.

Claims

1-45. -45. (canceled)

46. A display device, comprising:

a substrate;

a reflector located below said substrate; and

an optical compensation material located above said substrate.

47. The display device of claim 46, wherein the optical compensation material is used to mitigate or eliminate a shift in color with respect to viewing angle.

48. The display device of claim 47, wherein the optical compensation material comprises at least one film selected from a group consisting of:

a film with holographic properties and a film with micro-optics.

49. The display device of claim 46, wherein the optical compensation material comprises a light source.

50. The display device of claim 49, wherein the light source comprises at least one material selected from the group consisting of:

an organic emitter and a micro-optic array.

51. A display device, comprising:

a light-absorbing material;

a substrate located above said light-absorbing material; and

a reflector located below said light-absorbing material.

52. The display device of claim 51, wherein the light-absorbing material is configured to attenuate light incident upon the light-absorbing material from the substrate or the reflector.

53. The display device of claim 51 . wherein the light-absorbing material comprises a high loss film.

54. The display device of claim 53, wherein the high loss film comprises at least one material from the group consisting of:

a metal, a semiconductor, and a combination of a metal and a semiconductor.

55. The display device of claim 51, further comprising an optical compensation material located above said substrate.

56. The display device of claim 55, wherein the optical compensation material is used to mitigate or eliminate a shift in color with respect to viewing angle.

57. The display device of claim 55, wherein the optical compensation material is used to provide supplemental frontlighting.

58. The display device of claim 55, wherein the optical compensation material comprises at least one layer selected from a group consisting of:

a layer with specific refractive indices, a layer with holographic properties, a layer with micro-optics, a layer with patterned organic emitters, and a layer with a micro-optic array.

59. A display device, comprising:

a reflector; and

a light-absorbing material placed between the reflector and a medium from which light is incident, the light-absorbing material being configured to attenuate light incident upon it, and having radiation admittance characteristics that substantially match the admittance of the reflector to the admittance of said medium.

60. The display device of claim 59, wherein the light-absorbing material comprises an absorber disposed between two matching layers.

61. The display device of claim 60, wherein at least one of the matching layers comprises at least one film selected from the group consisting of:

a metal film, a dielectric film, a semiconducting film, and a combination of at least two of a metal film, a dielectric film and a semiconducting film.

62. The display device of claim 60, wherein the absorber comprises a film selected from the group consisting of:

a metal film, a semiconducting film, and a combination film comprising a metal and a semiconducting material.

63. The display device of claim 59, further comprising an optical compensation material located on the other side of the medium from the reflector, wherein the optical compensation material comprises at least one layer selected from a group consisting of:

a layer with holographic properties, a layer with micro-optics, a layer with patterned organic emitters, and a layer with a micro-optic array.

64. A display device configured to display a color image, said display device comprising patterns of image elements, the elements of each of the patterns comprising interferometric cavities sharing a common fixed cavity thickness that defines a color associated with the pattern, the patterns together configured to produce said color image.

65. The display device of claim 64, wherein the color image is a static color image.

66. The display device of claim 64, wherein each pattern of image elements comprises at least one interferometric cavity, the at least one interferometric cavity comprising a reflector and a light absorbing material located above the reflector, wherein the cavity thickness of the at least one interferometric cavity is the space between the reflector and the light absorbing material.

67. A method of manufacturing a display device, the method comprising:

forming a reflective layer; and

forming a layer of absorbing material; and

providing a substrate layer; and

wherein the layer of absorbing material is located between the substrate layer and the reflective layer.

68. The method of claim 67, wherein forming a layer of absorbing material comprises forming an absorber and forming two matching layers, wherein the absorber is located between the two matching layers.

69. The method of claim 68, wherein the absorber comprises a metal, a semiconductor or a combination of a metal and a semiconductor, and at least one of the matching layers comprises at least one film selected from the group consisting of:

a metal film, a dielectric film, a semiconducting film, and a combination of at least two of a metal film, a dielectric film and a semiconducting film.

70. A method of manufacturing a display device, the method comprising:

forming a reflective layer;

providing a substrate layer; and

forming an optical compensation layer, wherein the substrate layer is located between the optical compensation layer and the layer of absorbing material.

71. The display device of claim 70, wherein the optical compensation material comprises at least one layer selected from a group consisting of:

a layer with holographic properties, a layer with micro-optics, a layer with patterned organic emitters, and a layer with a micro-optic array.

72. The display device of claim 70, further comprising forming a layer of absorbing material, wherein the layer of absorbing material is located between the reflective layer and the substrate layer.

73. The method of claim 72, wherein forming a layer of absorbing material comprises forming an absorber and forming two matching layers, wherein the absorber is located between the two matching layers.

74. A display device comprising:

a reflector;

a medium from which light is incident; and

a light absorbing material located between the reflector and the medium,

wherein the reflector is configurable in a first position such that the light absorbing material substantially matches the admittance of the reflector to the admittance of the medium, and wherein the reflector is configurable in a second position such that the light absorbing material does not match the admittance of the reflector to the admittance of the medium.

75. The display device of claim 74, wherein the light absorbing material further comprises an absorber layer and a first matching layer, wherein the absorber layer absorbs light and the first matching layer at least partially matches the admittance of the reflector to the admittance of the medium.

76. The display device of claim 75, wherein the light absorbing material further comprises a second matching layer that at least partially matches the admittance of the reflector to the admittance of the medium.

77. The display device of claim 76, wherein the absorber layer is disposed between the first and second matching layers.

78. The display device of claim 74, wherein the reflector is positioned closer to the light absorbing material in the first position than in the second position.

79. The display device of claim 74, wherein the display device reflects substantially non-visible light when the reflector is in the first position.

80. The display device of claim 75, wherein the at least one matching layer comprises at least one film selected from the group consisting of:

a metal film, a dielectric film, a semiconducting film, and a combination of at least two of a metal film, a dielectric film and a semiconducting film.

81. The display device of claim 75, wherein the absorber layer comprises a film selected from the group consisting of:

a metal film, a semiconducting film, and a combination film comprising a metal and a semiconducting material.