System and method for charge control in a MEMS device
First Claim
1. An electronic device for at least partially displaying a pixel of a displayable image comprising:
- a first reflector and a second reflector defining an optical cavity therebetween and selective of a visible wavelength at an intensity by optical interference; and
, a charge-controlling mechanism to allow optical properties of the optical cavity to be varied by controlling a predetermined amount of charge stored on the first and the second reflectors, without specifically controlling voltage between the first and the second reflectors, such that at least one of the visible wavelength and the intensity are variably selectable in correspondence with the pixel of the displayable image.
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0 Petitions
Accused Products
Abstract
Light in the visible spectrum is modulated using an array of modulation elements, and control circuitry connected to the array for controlling each of the modulation elements independently, each of the modulation elements having a surface which is caused to exhibit a predetermined impedance characteristic to particular frequencies of light. The amplitude of light delivered by each of the modulation elements is controlled independently by pulse code modulation. Each modulation element has a deformable portion held under tensile stress, and the control circuitry controls the deformation of the deformable portion. Each deformable element has a deformation mechanism and an optical portion, the deformation mechanism and the optical portion independently imparting to the element respectively a controlled deformation characteristic and a controlled modulation characteristic. The deformable modulation element may be a non-metal. The elements are made by forming a sandwich of two layers and a sacrificial layer between them, the sacrificial layer having a thickness related to the final cavity dimension, and using water or an oxygen based plasma to remove the sacrificial layer.
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Citations
123 Claims
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1. An electronic device for at least partially displaying a pixel of a displayable image comprising:
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a first reflector and a second reflector defining an optical cavity therebetween and selective of a visible wavelength at an intensity by optical interference; and
,a charge-controlling mechanism to allow optical properties of the optical cavity to be varied by controlling a predetermined amount of charge stored on the first and the second reflectors, without specifically controlling voltage between the first and the second reflectors, such that at least one of the visible wavelength and the intensity are variably selectable in correspondence with the pixel of the displayable image. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An electronic device for at least partially displaying a pixel of a displayable image comprising:
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a first reflector and a second reflector defining an optical cavity therebetween and selective of a visible wavelength at an intensity by optical interference; and
,means for controlling a predetermined amount of charge stored on the first and the second reflectors, without specifically controlling voltage between the first and the second reflectors, to vary optical properties of the optical cavity to variably select at least one of the visible wavelength and the intensity in correspondence with the pixel of the displayable image. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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23. A display device comprising:
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a plurality of electrically adjustable optical resonant cavities to correspondingly display a plurality of pixels of a displayable image by optical interference such that the plurality of cavities are digital, such that the plurality of cavities are divided into a plurality of cavity groups, each cavity group variably selecting a visible wavelength at an intensity corresponding to a color and an intensity of a corresponding pixel of the displayable image; and
at least one charge-controlling mechanism to allow optical properties of the optical resonant cavities to be varied by controlling a predetermined amount of charge stored over the cavities, without specifically controlling voltage over the cavities. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A method comprising:
for each pixel of a pixilated displayable image, controlling a predetermined amount of charge over one or more corresponding optical resonant cavities, without specifically controlling voltage over the cavities, to select a corresponding visible wavelength at a corresponding intensity by optical interference to display the pixel. - View Dependent Claims (34, 35, 36)
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37. An electronic device for at least partially displaying a pixel of a displayable image comprising:
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a first reflector, a second reflector, and a third reflector in between the first and the second reflectors defining an optical cavity inclusive of a first gap between the first reflector and the third reflector, and a second gap between the second reflector and the third reflector, the optical cavity selective of a visible wavelength at an intensity by optical interference; and
,a mechanism to allow optical properties of the optical cavity to be varied by controlling a predetermined amount of charge stored over the cavity, without specifically controlling voltage over the cavity, such that at least one of the visible wavelength and the intensity are variably selectable in correspondence with the pixel of the displayable image. - View Dependent Claims (38, 39, 40, 41)
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42. A charge control circuit, comprising:
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a switch circuit having an input node configured to receive a reference voltage at a selected voltage level and configured to respond to a charge signal to pre-charge said input node with a pulse charge at said selected voltage level; and
wherein said switch circuit further includes a single switch configured to respond to an enable signal having a variable capacitor with first and second plates and wherein said single switch is coupled to said MEM device to apply said selected voltage level across first and second plates of a variable capacitor of said MEM device for said duration to thereby cause said pulse charge to accumulate on said variable capacitor. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
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53. A micro-electromechanical cell, comprising:
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a micro-electromechanical (MEM) device having a variable capacitor formed by a first conductive plate and a second conductive plate separated by a variable gap distance; and
a switch circuit having an input node configured to receive a reference voltage at a selected voltage level and configured to respond to a charge signal to pre-charge said input node with a pulse charge at said selected voltage level; and
wherein said switch circuit further includes only a first switch coupled to said variable capacitor configured to respond to an enable signal having a duration shorter than a mechanical time constant of a MEM device and coupled to said MEM device to apply said selected voltage level across first and second plates for said duration to thereby cause said pulse charge to accumulate on said variable capacitor. - View Dependent Claims (54, 55, 56, 57, 58)
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59. micro-electromechanical system, comprising:
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an M-row by N-column array of a micro-electromechanical cells, wherein each cell includes a MEM device having a variable capacitor formed by a first conductive plate and a second conductive plate separated by a variable gap distance; and
a switch circuit having an input node configured to receive a reference voltage at a selected voltage level and configured to respond to a charge signal to pre-charge said input node with a pulse charge at said selected voltage level and wherein said switch circuit further comprises a single switch coupled to said variable capacitor and configured to respond to a enable signal having a duration shorter than a mechanical time constant of a MEM device and coupled to said MEM device to apply said selected voltage level across first and second plates of a variable capacitor of said MEM device for said duration to thereby cause said pulse charge to accumulate on said variable capacitor. - View Dependent Claims (60, 61, 62)
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63. charge control circuit, comprising:
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means for accumulating a charge;
means for transferring said charge to a variable capacitor;
means for reducing the capacitance of said means for transferring said charge; and
means for removing said charge from said variable capacitor.
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64. method of controlling a micro-electromechanical device having a variable capacitor, comprising:
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applying a voltage at a preselected voltage level to charge an input node;
providing an enable signal to a first switch to close said first switch for a duration less than the mechanical time constant of said micro-electromechanical device; and
applying said charge to said variable capacitor wherein said charge corresponds to a gap distance between first and second conductive plates of said variable capacitor and wherein said first switch is the only switch directly coupled to said variable capacitor. - View Dependent Claims (65, 66)
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67. charge control circuit, comprising:
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a switch circuit having an input node configured to receive a reference current at a selected current level and configured to respond to a charge signal to pre-charge said input node with a pulse current at said selected current level; and
wherein said switch circuit further comprises a first switch configured to respond to an enable signal having a duration shorter than a mechanical time constant of a micro-electromechanical device (MEM device) and coupled to said MEM device to apply said selected current level across first and second plates of a variable capacitor of said MEM device for said duration to thereby cause said pulse current to accumulate on said variable capacitor wherein the first switch is the only connected to said capacitor. - View Dependent Claims (68, 69, 70, 71, 72, 73, 74, 75)
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76. method of controlling a micro-electromechanical system (MEMS) device having a variable capacitor defining a variable gap distance, comprising:
applying a reference voltage having a selected voltage level across the MEMS device so as to cause a stored charge having a desired magnitude to accumulate on the variable capacitor, wherein the variable gap distance is a function of magnitude of the stored charge. - View Dependent Claims (77)
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78. method of controlling a MEMS actuator having a pair of plates with a gap therebetween supported by a spring mechanism having a mechanical time constant, comprising:
applying a isolatable voltage to the pair of plates to select a desired gap size by having a reference voltage applied then removing the reference voltage after a desired charge has been applied to the pair of plates. - View Dependent Claims (79)
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80. method of controlling a MEMS actuator having a first plate and a second plate with a restoring force applied to a gap therebetween, the second plate coupled to ground, comprising:
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switching a reference voltage across the first plate and ground;
accumulating a desired charge on the first plate and second plate; and
decoupling the reference voltage from the first plate. - View Dependent Claims (81)
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82. An electronic device for at least partially displaying a pixel of a displayable image comprising:
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a first reflector and a second reflector defining an optical cavity therebetween and selective of a visible wavelength at an intensity by optical interference; and
,a charge-controlling mechanism to allow optical properties of the optical cavity to be varied by controlling a predetermined amount of charge stored on the first and the second reflectors, such that at least one of the visible wavelength and the intensity are variably selectable in correspondence with the pixel of the displayable image. - View Dependent Claims (83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96)
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97. n electronic device for at least partially displaying a pixel of a displayable image comprising:
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a first reflector and a second reflector defining an optical cavity therebetween and selective of a visible wavelength at an intensity by optical interference; and
,means for controlling a predetermined amount of charge stored on the first and the second reflectors to vary optical properties of the optical cavity to variably select at least one of the visible wavelength and the intensity in correspondence with the pixel of the displayable image. - View Dependent Claims (98, 99, 100, 101, 102, 103)
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104. display device comprising:
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a plurality of electrically adjustable optical resonant cavities to correspondingly display a plurality of pixels of a displayable image by optical interference, wherein the plurality of cavities are digital, such that the plurality of cavities are divided into a plurality of cavity groups, each cavity group variably selecting a visible wavelength at an intensity corresponding to a color and an intensity of a corresponding pixel of the displayable image. - View Dependent Claims (105, 106, 107, 108, 109, 110, 111, 112, 113, 114)
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115. method comprising:
for each pixel of a pixilated displayable image, controlling a predetermined amount of charge over one or more corresponding optical resonant cavities to select a corresponding visible wavelength at a corresponding intensity by optical interference to display the pixel. - View Dependent Claims (116, 117, 118)
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119. n electronic device for at least partially displaying a pixel of a displayable image comprising:
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a first reflector, a second reflector, and a third reflector in-between the first and the second reflectors defining an optical cavity inclusive of a first gap between the first reflector and the third reflector, and a second gap between the second reflector and the third reflector, the optical cavity selective of a visible wavelength at an intensity by optical interference; and
,a mechanism to allow optical properties of the optical cavity, such that at least one of the visible wavelength and the intensity are variably selectable in correspondence with the pixel of the displayable image. - View Dependent Claims (120, 121, 122, 123)
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Specification