Micro-electromechanical microshutter array

• US 8,077,372 B2
• Filed: 01/21/2010
• Issued: 12/13/2011
• Est. Priority Date: 10/11/2007
• Status: Active Grant

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Inventors: Border, John N., Erhardt, Herbert J., Lee, J. Kelly, Kowarz, Marek W., Boysel, Robert M.
• Primary Examiner(s): Martinez, Joseph P
• Application Number:
  US12/690,975
• Publication Number:
  US 20100118176A1
• Time in Patent Office: 691 Days
• Field of Search: 359/224.1, 359/290, 359/292
• US Class Current: 359/224.1
• CPC Class Codes: B81B 2201/045 Optical switches
• CPC Class Codes: B81B 7/04 Networks or arrays of similar microstructural devices
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A microshutter array has a frame having a light transmissive portion. Linear microshutter elements extend across the light transmissive portion and in parallel to each other. Each microshutter element has a flat blade extended in a length direction and first and second torsion arms extending outwards from each side of the blade in the length direction, the blade extending across the light transmissive portion. There is at least one electrode associated with each linear microshutter element and extended in the length direction parallel to the microshutter element.

Claims

1. A microshutter array comprising a frame having a single opening that includes a light transmissive portion that spans one or more lines of pixel elements;

a plurality of linear microshutter elements extending across at least one line of pixel elements included in the light transmissive portion, wherein each linear microshutter element comprises a blade extended in a length direction across the light transmissive portion and first and second torsion arms extending outwards from each side of the blade in the length direction and supported by the frame; and

at least one electrode associated with each linear microshutter element.

2. The microshutter array of claim 1, wherein the light transmissive portion is a transparent material.

3. The microshutter array of claim 2, wherein the at least one electrode associated with each linear microshutter element is formed with the transparent material.

4. The microshutter array of claim 3, wherein the at least one electrode associated with each linear microshutter element extends at least partially across the length direction of the light transmissive portion.

5. The microshutter array of claim 1, wherein the light transmissive portion is hollow.

6. The microshutter array of claim 1, wherein the frame is silicon or quartz.

7. The microshutter array of claim 1, wherein the blade allows light transmission through the light transmissive portion in an unactuated position and blocks light transmission when actuated.

8. The microshutter array of claim 1 further comprising a voltage source switchably connected to the at least one electrode.

9. The microshutter array of claim 1, wherein the at least one electrode is transparent.

10. The microshutter array of claim 1, wherein each linear microshutter element is individually actuable.

11. The microshutter array of claim 1, wherein at least a portion of the at least one electrode lies in a plane that is orthogonal relative to the path of light transmitted through the array.

12. The microshutter array of claim 1, wherein the microshutter element is formed from a material taken from the group consisting of silicon, gold, copper, aluminum, and nickel.

13. The microshutter array of claim 1, wherein the at least one electrode has a raised portion nearest its associated linear microshutter element.

14. The microshutter array of claim 1, wherein the at least one electrode is formed on the surface of the frame that faces the plurality of linear microshutter elements.

15. The microshutter array of claim 1, wherein each microshutter element is at the same electrical potential.

16. The microshutter array of claim 1 being formed onto a single substrate.

17. The microshutter array of claim 1, wherein lenslets are used to direct light between the microshutter elements.

18. A method for forming an image of a scene comprising:

directing light to a sensor having an array of pixel elements arranged in lines; and

exposing one or more lines of pixel elements in the array of pixel elements to the light by actuating one or more linear microshutter elements, wherein a plurality of linear microshutter elements are disposed between the light and the sensor and the plurality of linear microshutter elements span a light transmissive portion of a single opening, and wherein each linear microshutter element spans one or more lines of pixel elements and comprises a blade extended in a length direction across the light transmissive portion.

19. The method of claim 18 further comprising:

resetting the pixel elements in at least one line to begin an exposure;

actuating a first group of one or more linear microshutter elements during a first time period; and

actuating a second group of one or more linear microshutter elements during a second time period.

20. The method of claim 19, wherein actuating the first and second group further comprises providing similar exposure time periods for different lines of pixels.

21. The method of claim 19, wherein actuating the first and second group further comprises providing different exposure time periods for different lines of pixels.

22. The method of claim 19, wherein actuating the first and second group further comprises selecting exposure times for different lines of pixels based on aspects of the scene being imaged.

23. The method of claim 19 further comprising interlacing the first group and the second group of linear microshutter elements.

24. The method of claim 19, wherein actuating the first group comprises actuating a single linear microshutter element.

25. The method of claim 19, wherein actuating the second group comprises actuating a single linear microshutter element.

26. An imaging module, comprising:

an imaging sensor comprising an array of pixels arranged in lines; and

a microshutter array positioned over the array of pixels, wherein the microshutter array comprises;

a frame having a single opening that includes a light transmissive portion extending across one or more lines of pixels;

a plurality of linear microshutter elements extending across at least one line of pixels in the light transmissive portion, wherein each microshutter element comprises a blade extended in a length direction across the light transmissive portion and first and second torsion arms extending outwards from each side of the blade in the length direction and supported by the frame; and

at least one electrode associated with each linear microshutter element.

27. The imaging module of claim 26, wherein the at least one electrode associated with each linear microshutter element is extended in the length direction parallel to the microshutter element.