Method and device for multi-color interferometric modulation

• US 7,826,120 B2
• Filed: 08/20/2007
• Issued: 11/02/2010
• Est. Priority Date: 05/05/1994
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Miles, Mark W.
• Primary Examiner(s): Mack; Ricky L
• Assistant Examiner(s): Thomas; Brandi N
• Application Number:
  US11/841,752
• Publication Number:
  US 20080037093A1
• Time in Patent Office: 1,170 Days
• Field of Search: 359/237, 359/290, 359/291, 359/292
• US Class Current: 359/237
• 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 26/00 Optical devices or arrangements for the control of light using movable or deformable optical elements control of light by modification of the optical properties of the media of the elements involved therein G02F1/00
• 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 26/007 the movable or deformable optical element controlling the colour, i.e. a spectral characteristic, of the light
• 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 5/284 of etalon type comprising a resonant cavity other than a thin solid film, e.g. gas, air, solid plates etalons for fibre optic multiplexing G02B6/29358; etalons for spectral measurement G01J3/26
• 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 1/216 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 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. An array of light modulators, comprising:

at least three modulators arranged so as to form one resulting picture element;

each modulator comprising a mirror suspended over a cavity by supports, the supports formed such that each modulator corresponding to each color assumes a quiescent state corresponding to a cavity with a different dimension.

7. The array of claim 1, wherein each of the modulators are located on a single layer.

8. The array of claim 1, wherein at least two of the modulators are located on separate layers.

9. The array of claim 1, wherein a first modulator corresponds to a first primary color, a second modulator corresponds to a second primary color, and a third modulator corresponds to a third primary color.

10. The array of claim 1, wherein the dimension comprises a height of the cavity.

2. An array of light modulators, comprising:

a first modulator, said first modulator comprising a reflective element suspended over a first cavity by supports, wherein the first modulator assumes a quiescent state corresponding to a first color based on, at least in part, a first dimension of the first cavity;

a second modulator, said second, modulator comprising a reflective element suspended over a second cavity by supports, wherein the supports are formed such that the second modulator assumes a quiescent state corresponding to a second color based on, at least in part, a second dimension of the second cavity; and

a third modulator, said third modulator comprising a reflective element suspended over a second cavity by supports, wherein the supports are formed such that the third modulator assumes a quiescent state corresponding to a third color based on, at least in part, a third dimension of the third cavity.

3. The array of claim 2, wherein each of the modulators are located on a single layer.

4. The array of claim 2, wherein at least two of the modulators are located on separate layers.

5. The array of claim 2, wherein the colors correspond to primary colors.

6. The array of claim 2, wherein the dimension comprises the height of the cavity.

11. An array of light modulators, comprising:

first means for modulating light, wherein said first means comprises a first cavity with a first dimension and wherein said first means is associated with a first color based on, at least in part, the first dimension;

second means for modulating light, wherein said second means comprises a second cavity with a second dimension and wherein said second means is associated with a second color based on, at least in part, the second dimension; and

third means for modulating light, wherein said third means comprises a third cavity with a third dimension and wherein said third means is associated with a third color based on, at least in part, the third dimension.

12. The array of claim 11, wherein each of the first light modulating means, the second light modulating means, and the third light modulating means are located on a single layer.

13. The array of claim 11, wherein at least two of the first light modulating means, the second light modulating means, and the third light modulating means are located on separate layers.

14. The array of claim 11, wherein the colors correspond to primary colors.

15. The array of claim 11, wherein at least one of the first dimension, the second dimension, and the third dimension comprises a height.