SYSTEM AND METHOD FOR A MEMS DEVICE

• US 20100245980A1
• Filed: 06/10/2010
• Published: 09/30/2010
• Est. Priority Date: 11/05/1996
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Miles, Mark W.
• Granted Patent: US 7,929,197 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
• CPC Class Codes: G09G 2300/0857 Static memory circuit, e.g. flip-flop
• CPC Class Codes: G09G 2300/088 using a non-linear two-terminal element
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2085 Special arrangements for addressing the individual elements of the matrix, other than by driving respective rows and columns in combination
• CPC Class Codes: G09G 3/3466 based on interferometric effect

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.

Claims

1-53. -53. (canceled)

54. A device for modulating light comprising:

a first layer comprising a first non-metallic reflective surface and a second layer comprising a second non-metallic reflective surface, the first layer and the second layer defining a cavity therebetween, the first layer being movable relative to the second layer along substantially an entire direction of motion of the first layer within the cavity; and

a control circuit configured to apply a continuously variable voltage to cause a continuous movement of the first layer,

wherein at least one of the first reflective surface and the second reflective surface comprises a broad band minor configured to operate across a visible range.

55. The device of claim 54, wherein the continuous movement of at least one of the first and second layer corresponds to a variation of a dimension of the cavity.

56. The device of claim 54, wherein the relative movement of the first and second layers is controllable by controlling the applied continuously variable voltage.

57. The device of claim 54, wherein the relative movement between the first and second layers provides a continuous frequency selection capability within an operational range.

58. The device of claim 57, wherein the operational range comprises a range of voltages.

59. The device of claim 57, wherein the operational range comprises a range of frequencies.

60. The device of claim 54, wherein the dimension of the cavity comprises a spatial distance between the first and second layer.

61. The device of claim 54, wherein the other one of the first and second layers comprises a narrow band reflective surface.

62. The device of claim 54, wherein both of the first and second layers comprise broadband mirrors.

63. The device of claim 54, wherein the movable one of the layers is under tensile stress.

64. A device for modulating light comprising:

a first layer and a second layer that define a cavity therebetween, the first layer being movable relative to the second layer;

a control circuit configured to apply a continuously variable voltage to cause a continuous movement of at least one of the first and second layer; and

a third layer coupled to the first layer, the third layer being configured to limit deformation of the first layer during said continuous movement of the first layer.

65. The device of claim 64, wherein the third layer is configured to maintain a substantially parallel orientation between the first and second layers.

66. A method for driving a device for modulating light, the method comprising:

continuously varying a voltage between a first layer and a second layer of the device;

causing a continuous variation in a dimension of a cavity formed by the first and second layer, the variation in the dimension in response to the continuously varying voltage; and

limiting deformation of the first layer with a third layer during said continuous movement of the first layer.

67. The method of claim 66, wherein the third layer is configured to maintain a substantially parallel orientation between the first and second layers.