Direct-view MEMS display devices and methods for generating images thereon

• US 20070205969A1
• Filed: 12/19/2006
• Published: 09/06/2007
• Est. Priority Date: 02/23/2005
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Lewis, Stephen, Gandhi, Jignesh, McAllister, Abraham, Hagood, Nesbitt, Malzbender, Rainer
• Application Number:
  US11/643,042
• Publication Number:
  US 20070205969A1
• Time in Patent Office: Days
• US Class Current: 345/84
• CPC Class Codes: G02B 26/004 based on a displacement or a deformation of a fluid
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• 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: G09G 5/06 using colour palettes, e.g. look-up tables
• CPC Class Codes: G09G 5/363 Graphics controllers
• CPC Class Codes: G09G 5/393 Arrangements for updating the contents of the bit-mapped memory

Abstract

A direct-view display includes an array of MEMS light modulators and a control matrix formed on a transparent substrate, where each light modulator can be driven into at least two states, and a controller for controlling the states of each light modulator in the array. The control matrix transmits data and actuation voltages to the array. The controller includes an input, a processor, a memory, and an output. The input receives image data encoding an image frame for display. The processor derives a plurality of sub-frame data sets from the image data, where each sub-frame data set indicates desired states of light modulators in multiple rows and multiple columns of the array. The memory stores the plurality of sub-frame data sets. The output outputs the plurality of sub-frame data sets according to an output sequence to drive light modulators into the states indicated in the sub-frame data sets.

Claims

1. A direct-view display comprising:

a transparent substrate;

an array of MEMS light modulators formed on the transparent substrate, wherein each of the light modulators can be driven into at least two states;

a control matrix formed on the transparent substrate for transmitting data and actuation voltages to the array; and

a controller for controlling the states of each of the light modulators in the array including;

an input for receiving image data encoding an image frame for display on the direct-view display,

a processor for deriving a plurality of sub-frame data sets from the image data, wherein each sub-frame data set indicates desired states of light modulators in multiple rows and multiple columns of the array;

a memory for storing the plurality of sub-frame data sets; and

an output for outputting the plurality of sub-frame data sets according to an output sequence to drive light modulators into the states indicated in the sub-frame data sets.

2. The direct-view display of claim 1, wherein the output sequence includes a plurality of events;

and wherein the controller stores different time values associated with events corresponding to at least two sub-frame data sets.

3. The direct-view display of claim 2, wherein the time values are selected to prevent illumination of the array while the modulators change states.

4. The direct-view display of claim 3, comprising a plurality of lamps, wherein the memory stores time values associated with lamp illumination events included in the output sequence.

5. The direct-view display of claim 3, comprising a plurality of lamps, wherein the memory stores time values associated with lamp extinguishing events included in the output sequence.

6. The direct-view display of claim 2, wherein the output sequence includes addressing events, and the memory stores time values associated with the addressing events.

7. The direct-view display of claim 2, wherein the time values correlate to a brightness of a sub-frame image resulting from an outputting of a sub-frame data set of the plurality of sub-frame data sets.

8. The direct-view display of claim 1, wherein the plurality of sub-frame data sets includes distinct sub-frame data sets for at least two of at least three color components of the image frame.

9. The direct-view display of claim 1, wherein the plurality of sub-frame data sets includes distinct sub-frame data sets for four color components of the image frame.

10. The direct-view display of claim 9, wherein the four color components consist of red, green, blue, and white.

11. The direct-view display of claim 1, wherein the output sequence is stored at least in part in memory.

12. The direct-view display of claim 11, comprising a plurality of lamps, wherein the output sequence includes a lamp illumination sequence.

13. The direct-view display of claim 12, wherein the lamp illumination sequence includes data corresponding to the intensity with which lamps are illuminated in association with sub-frame data sets output in the output sequence.

14. The direct-view display of claim 12, wherein the lamp illumination sequence includes data correlated to the length of time lamps are illuminated for sub-frame data sets output in the output sequence.

15. The direct-view display of claim 14, wherein the length of time that a lamp is illuminated for each sub-frame data set in the lamp illumination sequence is less than or equal to 4 milliseconds.

16. The direct-view display of claim 1, wherein the deriving the plurality of sub-frame data sets includes:

decomposing the image frame into a plurality of sub-frame images; and

assigning a weight to each sub-frame image of the plurality of sub-frame images.

17. The direct-view display of claim 16, wherein the processor assigns the weight according to a coding scheme.

18. The direct-view display of claim 16, wherein the controller causes a sub-frame image to be illuminated for a length of time proportional to the weight assigned to the sub-frame image.

19. The direct-view display of claim 16, wherein the controller causes a sub-frame image to be illuminated with an illumination intensity proportional to the weight assigned to the sub-frame image.

20. The direct-view display of claim 17, wherein the coding scheme is a binary coding scheme, the sub-frame data sets are bitplanes, and each color component of the image frame is decomposed into at least a most significant sub-frame image and a next most significant sub-frame image.

21. The direct-view display of claim 20, wherein the most-significant sub-frame image contributes to a displayed image frame twice as much as the next most significant sub-frame image.

22. The direct-view display of claim 20, wherein the output sequence includes outputting the bitplane corresponding to the most significant sub-image of at least one color component of the image frame at two distinct times.

23. The direct-view display of claim 22, wherein according to the output sequence, the two distinct times at which the bitplane corresponding to the most significant sub-frame image are output are separated by no more than 25 milliseconds.

24. The direct-view display of claim 22, wherein according to the output sequence, the length of time between a first time the bitplane corresponding to the most significant sub-frame image of a color component of the image frame is output and a second time the bitplane corresponding to the most significant sub-frame image of the color component is output is within 10% of the length of time between the second time the bitplane corresponding to the most significant sub-frame image of the color component is output and a subsequent time at which a sub-frame image corresponding to a most significant sub-frame image of the color component is output.

25. The direct-view display of claim 1, wherein the output sequence includes:

outputting at least one sub-frame data set corresponding to a first color component of the image frame before outputting at least one sub-frame data set corresponding to a second color component of the image frame, and

outputting at least one sub-frame data set corresponding to the first color component of the image frame after outputting at least one sub-frame data set corresponding to the second color component of the image frame.

26. The direct-view display of claim 1, wherein lamps of at least two different colors are illuminated to display a single sub-frame image corresponding to a single sub-frame data set.

27. The direct-view display of claim 26, wherein a lamp of one of the at least two colors is illuminated with a substantially greater intensity than the others of the at least two colors.

28. The direct-view display of claim 11, comprising a data link to an external processor for receiving changes to the output sequence.

29. The direct-view display of claim 1, comprising a memory for storing a plurality of alternative output sequences.

30. The direct-view display of claim 29, comprising an output sequence switching module for switching between the output sequence and the plurality of alternative output sequences.

31. The direct-view display of claim 30, wherein the output sequence switching module is responsive to instructions received from a second processor, external to the controller, included in the device in which the direct-view display is incorporated.

32. The direct-view display of claim 30, comprising a user interface, wherein the output sequence switching module is responsive to the user interface.

33. The direct-view display of claim 32, wherein the user interface is a manual switch.

34. The direct-view display of claim 30, wherein the output sequence switching module is responsive to the processor.

35. The direct-view display of claim 1, comprising a sequence parameter calculation module for deriving changes to the output sequence.

36. The direct-view display of claim 35, wherein the sequence parameter calculation module derives changes to the output sequence based on characteristics of a received image frame.

37. The direct-view display of claim 35, wherein the sequence parameter calculation module derives changes to timing values stored in relation to events included in the output sequence.

38. The direct-view display of claim 35, comprising a plurality of lamps, wherein the sequence parameter calculation module derives changes to lamp intensity values stored in relation to lamp illumination events included in the output sequence.

39. The direct-view display of claim 35, wherein the sequence parameter calculation module derives changes to sub-frame data sets based on characteristics of a received image frame.

40. The direct-view display of claim 1, wherein the array of light modulators comprises a plurality of independently actuatable banks of light modulators.

41. The direct-view display of claim 40, wherein the control matrix comprises a plurality of global actuation interconnects, each global actuation interconnect corresponding to a respective bank of light modulators.

42. The direct-view display of claim 40, wherein the plurality of banks are located adjacent one another in the array.

43. The direct-view display of claim 40, wherein each bank of light modulator comprises a plurality of rows in the array, and the banks are interwoven with one another in the array.

44. The direct-view display of claim 40, wherein the display of a sub-frame image corresponding to a particular significance and color component in one of the banks is no more than 25 ms from a subsequent display of a sub-frame image corresponding to the significance value and color component and is no more than 25 ms after a prior display of a sub-frame image corresponding to the significance and color component in the other of the banks.

45. The direct-view display of claim 1, wherein the light modulators comprise shutters.

46. The direct-view display of claim 45, wherein the shutters selectively reflect light.

47. The direct-view display of claim 45, wherein the shutters selectively allow low light to pass through corresponding apertures.

48. The direct-view display of claim 45, wherein the shutters are driven transverse to the substrate.

49. The direct-view display of claim 1, wherein the light modulators are reflective light modulators.

50. The direct-view display of claim 1, wherein the light modulators selectively allow the passage of light towards a viewer.

51. The direct-view display of claim 1, comprising a light guide positioned proximate the array of light modulators.

52. The direct-view display of claim 1, wherein the output sequence includes a plurality of global actuation events.

53. The direct-view display of claim 52, comprising a global actuation interconnect coupled to the array of light modulators for causing light modulators in multiple rows and multiple columns of the array of light modulators to actuate substantially simultaneously.

54. The direct-view display of claim 1, wherein the control matrix comprises, for each light modulator, a transistor and a capacitor.

55. A direct-view display comprising:

a transparent substrate;

an array of MEMS light modulators formed on the transparent substrate, wherein each of the light modulators can be driven into at least two states;

a control matrix formed on the transparent substrate for transmitting data and actuation voltages to the array;

lamps of at least three colors; and

a controller for;

controlling the states of each of the light modulators in the array;

controlling the illumination of lamps to illuminate the array of light modulators with lamps of at least two colors at the same time to form a portion of an image.

56. The direct-view display of claim 55, wherein at least one of the colors illuminating the array of light modulators is of greater intensity than the other colors.

57. A method for displaying an image frame on a direct-view display comprising:

receiving image data encoding the image frame;

deriving a plurality of sub-frame data sets from the image data, wherein each sub-frame data set indicates desired states of MEMS light modulators in multiple rows and multiple columns of a light modulator array formed on a transparent substrate;

storing the plurality of sub-frame data sets in a memory; and

outputting the plurality of sub-frame data sets according to an output sequence to drive the MEMS light modulators into the desired states indicated in each sub-frame data set, wherein the outputting comprises transmitting data and actuation voltages to the light modulator array via a control matrix formed on the transparent substrate.

58. The method of claim 57, comprising storing different time values associated with events corresponding to at least two sub-frame data sets, wherein the output sequence includes the events.

59. The method of claim 58, wherein the time values are selected to prevent illumination of the light modulator array while the MEMS light modulators change states.

60. The method of claim 59, comprising illuminating at least one of a plurality of lamps according to lamp illumination events included in the output sequence, wherein the time values are associated with the lamp illumination events.

61. The method of claim 59, comprising extinguishing at least one of a plurality of lamps according to lamp extinguishing events included in the output sequence, wherein the time values are associated with the lamp extinguishing events.

62. The method of claim 58, wherein the output sequence includes addressing events;

and the memory stores time values associated with the addressing events.

63. The method of claim 58, wherein the time values correlate to a brightness of a sub-frame image resulting from the outputting of a sub-frame data set of the plurality of sub-frame data sets.

64. The method of claim 57, wherein the plurality of sub-frame data sets includes distinct sub-frame data sets for at least two of at least three color components of the image frame.

65. The method of claim 57, wherein the plurality of sub-frame data sets includes distinct sub-frame data sets for four color components of the image frame.

66. The method of claim 65, wherein the four color components consist of red, green, blue, and white.

67. The method of claim 57, wherein the output sequence is stored at least in part in memory.

68. The method of claim 67, wherein the output sequence includes a lamp illumination sequence corresponding to a plurality of lamps.

69. The method of claim 68, wherein the lamp illumination sequence includes data corresponding to the intensity with which lamps are illuminated in association with sub-frame data sets output in the output sequence.

70. The method of claim 68, wherein the lamp illumination sequence includes data corresponding to the length of time lamps are illuminated for sub-frame data sets output in the output sequence.

71. The method of claim 70, wherein the length of time that a lamp is illuminated for each sub-frame data set in the lamp illumination sequence is less than or equal to 4 milliseconds.

72. The method of claim 57, wherein the deriving the plurality of sub-frame data sets includes:

decomposing the image frame into a plurality of sub-frame images, and

assigning a weight to each sub-frame image of the plurality of sub-frame images.

73. The method of claim 72, wherein the assigning the weight occurs according to a coding scheme.

74. The method of claim 72, comprising illuminating a sub-frame image for a length of time proportional to the weight assigned to the sub-frame image.

75. The method of claim 72, comprising illuminating a sub-frame image with an illumination intensity proportional to the weight assigned to the sub-frame image.

76. The method of claim 73, wherein the coding scheme is a binary coding scheme, the sub-frame data sets are bitplanes, and each color component of the image frame is decomposed into at least a most significant sub-frame image and a next most significant sub-frame image.

77. The method of claim 76, wherein the most-significant sub-frame image contributes to a displayed image frame twice as much as the next most significant sub-frame image.

78. The method of claim 76, wherein the outputting the plurality of sub-frame data sets includes outputting a bitplane corresponding to the most significant sub-frame image of at least one color component of the image frame at two distinct times.

79. The method of claim 78, wherein according to the output sequence, the two distinct times at which the bitplane corresponding to the most significant sub-frame image are output are separated by no more than 25 milliseconds.

80. The method of claim 78, wherein according to the output sequence, the length of time between a first time the bitplane corresponding to the most significant sub-frame image of a color component of the image frame is output and a second time the bitplane corresponding to the most significant sub-frame image of the color component is output is within 10% of the length of time between the second time the bitplane corresponding to the most significant sub-frame image of the color component is output and a subsequent time at which a sub-frame image corresponding to a most significant sub-frame image of the color component is output.

81. The method of claim 57, wherein the outputting the plurality of sub-frame data sets includes:

outputting at least one sub-frame data set corresponding to a first color component of the image frame before outputting at least one sub-frame data set corresponding to a second color component of the image frame, and

outputting at least one sub-frame data set corresponding to the first color component of the image frame after outputting at least one sub-frame data set corresponding to the second color component of the image frame.

82. The method of claim 57, wherein lamps of at least two different colors are illuminated to display a single sub-frame image corresponding to a single sub-frame data set.

83. The method of claim 82, wherein a lamp of one of the at least two colors is illuminated at a substantially greater intensity than the others of the at least two colors.

84. The method of claim 67, comprising receiving changes to the output sequence via a data link to an external processor.

85. The method of claim 57, comprising storing a plurality of alternative output sequences in a memory.

86. The method of claim 85, comprising switching between the output sequence and the plurality of alternative output sequences via an output sequence switching module.

87. The method of claim 86, comprising receiving instructions from an external processor to which the output sequence switching module is responsive.

88. The method of claim 86, comprising receiving instructions from a user interface to which the output sequence switching module is responsive.

89. The method of claim 88, wherein the user interface is a manual switch.

90. The method of claim 86, wherein the deriving a plurality of sub-frame data sets is performed by an image processing module;

and the output sequence switching module is responsive to an image processing module.

91. The method of claim 57, comprising deriving changes to the output sequence via a sequence parameter calculation module.

92. The method of claim 91, wherein the sequence parameter calculation module derives changes to the output sequence based on characteristics of a received image frame.

93. The method of claim 91, wherein the sequence parameter calculation module derives changes to timing values stored in relation to events included in the output sequence.

94. The method of claim 91, comprising a plurality of lamps, wherein the sequence parameter calculation module derives changes to lamp intensity values stored in relation to lamp illumination events included in the output sequence.

95. The method of claim 91, wherein the sequence parameter calculation module derives changes to sub-frame data sets based on characteristics of a received image frame.

96. The method of claim 57, wherein the light modulator array comprises a plurality of banks of light modulators, each bank capable of being independently actuated.

97. The method of claim 96, wherein the control matrix comprises a plurality of global actuation interconnects, each global actuation interconnect corresponding to a respective bank of light modulators.

98. The method of claim 96, wherein banks of the plurality of banks are located adjacent one another in the light modulator array.

99. The method of claim 96, wherein each bank of the plurality of banks comprises a plurality of rows in the light modulator array;

and banks of the plurality of banks are interwoven with one another in the light modulator array.

100. The method of claim 96, wherein the display of a sub-frame image corresponding to a particular significance and color component in one of the banks is no more than 25 ms from a subsequent display of a sub-frame image corresponding to the significance value and color component and is no more than 25 ms after a prior display of a sub-frame image corresponding to the significance and color component in the other of the banks.

101. The method of claim 57, wherein the MEMS light modulators comprise shutters.

102. The method of claim 101, wherein the shutters selectively reflect light.

103. The method of claim 101, wherein the shutters selectively allow low light to pass through corresponding apertures.

104. The method of claim 101, comprising driving the shutters transverse to the substrate.

105. The method of claim 57, wherein the MEMS light modulators are reflective light modulators.

106. The method of claim 57, wherein the MEMS light modulators selectively allow the passage of light towards a viewer.

107. The method of claim 57, comprising guiding light via a light guide positioned proximate the light modulator array.

108. The method of claim 57, wherein the output sequence includes a plurality of global actuation events.

109. The method of claim 108, comprising actuating substantially simultaneously MEMS light modulators in multiple rows and multiple columns of the light modulator array via a global actuation interconnect coupled to the light modulator array.

110. The method of claim 57, wherein the control matrix comprises, for each MEMS light modulator, a transistor and a capacitor.

111. A method for displaying an image on a direct-view display comprising:

controlling states of MEMS light modulators in a light modulator array formed on a transparent substrate, wherein each of the MEMS light modulators can be driven into at least two states;

transmitting data and actuation voltages to the light modulator array via a control matrix formed on the transparent substrate; and

controlling the illumination of lamps of at least three colors to illuminate the light modulator array with lamps of at least two colors at the same time to form a portion of the image.

112. The method of claim 111, wherein at least one of the colors illuminating the array of light modulators is of greater intensity than the other colors.

113. A direct-view display comprising:

a transparent substrate;

an array of MEMS light modulators formed on the transparent substrate, wherein each of the light modulators can be driven into at least two states;

a control matrix formed on the transparent substrate for transmitting data and actuation voltages to the array; and

a controller for;

controlling the states of each of the light modulators in the array;

controlling the illumination of lamps of at least four colors to display an image.

114. The direct-view display of claim 113, wherein the lamps include at least a red lamp, a green lamp, a blue lamp, and a white lamp.

115. The direct-view display of claim 113, wherein the lamps include at least a red lamp, a green lamp, a blue lamp, and a yellow lamp.

116. The direct-view display of claim 113, comprising a processor for translating three color image data into four color image data.

117. A method for displaying an image on a direct-view display comprising:

controlling states of MEMS light modulators in a light modulator array formed on a transparent substrate, wherein each of the MEMS light modulators can be driven into at least two states;

transmitting data and actuation voltages to the light modulator array via a control matrix formed on the transparent substrate; and

controlling the illumination of lamps of at least four colors to display the image.

118. The method of claim 117, wherein the lamps include at least a red lamp, a green lamp, a blue lamp, and a white lamp.

119. The method of claim 117, wherein the lamps include at least a red lamp, a green lamp, a blue lamp, and a yellow lamp.

120. The method of claim 117, comprising translating three color image data into four color image data.