Method and device for modulating light

• US 7,379,227 B2
• Filed: 02/11/2005
• Issued: 05/27/2008
• Est. Priority Date: 05/05/1994
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Miles, Mark W.
• Primary Examiner(s): Lester; Evelyn A.
• Application Number:
  US11/056,571
• Publication Number:
  US 20050244949A1
• Time in Patent Office: 1,201 Days
• Field of Search: 359290-292, 359/295, 359/298, 359/223, 359/224
• US Class Current: 359/290
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• 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: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/085 the reflecting means being moved or deformed by electromagnetic means
• CPC Class Codes: G02B 26/0858 the reflecting means being moved or deformed by piezoelectric means
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 6/12 of the integrated circuit kind electric integrated circuits H01L27/00
• CPC Class Codes: G02F 1/13725 based on guest-host interaction G02F1/13762, G02F1/13737, take precedence
• CPC Class Codes: G02F 1/169 based on orientable non-spherical particles having a common optical characteristic, e.g. suspended particles of reflective metal flakes
• CPC Class Codes: G02F 1/216 using liquid crystals, e.g. liquid crystal Fabry-Perot filters
• CPC Class Codes: G02F 2203/03 scattering
• CPC Class Codes: G06F 3/1431 using a single graphics controller
• CPC Class Codes: G06F 3/1446 display composed of modules, e.g. video walls
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0452 : Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 3/001 : using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/2014 : by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/2074 : using sub-pixels
• CPC Class Codes: G09G 3/2077 : by a combination of two or more gradation control methods
• CPC Class Codes: G09G 3/3466 : based on interferometric effect
• CPC Class Codes: G09G 5/02 : characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: H01Q 9/26 : with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength resonant loop antennas H01Q7/00

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 elements are made by forming a sandwich of two layers and a sacrificial layer between them and removing the sacrificial layer.”

Claims

1. A device for modulating light comprising:

a light modulating element comprising an interferometric light modulating cavity, and a charge coupled but not voltage coupled device configured to shift a packet of charge to the light modulating element,

wherein the modulating element is configured to modulate light in response to, at least in part, the shifted charge, and

wherein the light modulating element comprises at least a first wall and a second wall defining the cavity, at least one of the walls being movable relative to the other, and

wherein the first wall and the second wall are substantially parallel at a plurality of different relative positions of the first wall and the second wall.

2. The device of claim 1 wherein the charging element comprises a charge storing component.

3. The device of claim 1 wherein the charging element comprises a charge coupled device.

4. The device of claim 1 wherein the shifted packet of charge controls the degree of relative motion of the first wall to the second wall.

5. The device of claim 4 wherein the device is configured to modulate light in response to a relative movement between at least two walls.

6. The device of claim 1 wherein the shifted packet of charge controls the degree of deformity of the first wall.

7. The device of claim 1 wherein the shifted packet of charge controls the dimension of the cavity.

8. The device of claim 1 wherein at least one of the walls is movable relative to the other wall in response to the shifted packet of charge from said charging element.

9. A device for modulating light comprising:

a light modulating element comprising a first wall and a second wall defining an interferometric cavity, wherein at least one of the walls is movable relative to the other; and

a charge coupled but not voltage coupled device configured to shift a packet of charge to the light modulating element, wherein the shifted charge controls that relative movement of the walls

wherein the first wall and the second wall are substantially parallel at a plurality of different relative positions of the first wall and the second wall.

10. The device of claim 9 wherein the charging element comprises a charge storing component.

11. A light modulating device for displaying at least a portion of an image, the device comprising:

a light modulating element comprising a first surface and a second surface defining a cavity there between, at least one of the first surface and the second surface being at least partially reflective, wherein at least one of the first surface and the second surface is moveable relative to the other, and wherein the first surface and second surface are substantially parallel at a plurality of different relative positions of the relative movement, and wherein light is modulated in response to optical interference within said cavity, and wherein said optical interference is dependent, at least in part, on a distance between the first and second surfaces; and

a charge coupled but not voltage coupled device configured to shift packets of charge to the light modulating element, wherein said distance is altered in response to said shift of charge.

12. The device of claim 11, wherein the charge coupled device comprises a capacitive component.

13. A light modulating device, the device comprising:

a row of light modulating pixels comprising selectively light reflective and light absorbing structures defining an interferometric cavity, wherein each light modulating pixel comprises at least a first wall and a second wall at least one of the walls being movable relative to the other, and

a pixel scanner comprising a charge coupled but not voltage coupled device configured to shift charge along the row of light modulation elements,

wherein the first wall and the second wall are substantially parallel at a plurality of different relative positions of the first wall and the second wall.

14. The device of claim 13 wherein the charge coupled device comprises a charge storing component.

15. A light modulating device comprising:

an array of light modulating pixels comprising selectively light reflective and light absorbing structures defining an interferometric cavity, wherein each light modulating pixel comprises at least a first wall and a second wall at least one of the walls being movable relative to the other, and

charge coupled devices configured to shift packets of charge along rows of pixels of the array of light modulating pixels.