Systems and methods for MEMS light modulator arrays with reduced acoustic emission

• US 9,291,813 B2
• Filed: 12/20/2011
• Issued: 03/22/2016
• Est. Priority Date: 12/20/2010
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Steyn, Jasper Lodewyk, Gandhi, Jignesh
• Primary Examiner(s): Sharifi-Tafreshi, Koosha
• Application Number:
  US13/330,924
• Publication Number:
  US 20120154455A1
• Time in Patent Office: 1,554 Days
• Field of Search: 345/55, 345/84, 345/109, 345/690, 359/290, 359/230, 359/298, 359/233, 359/291, 359/292
• US Class Current: 1/1
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/04 by periodically varying the intensity of light, e.g. using choppers shutters, diaphragms for cameras G03B9/00; devices for eliminating or reducing the effect of flicker in projection systems G03B21/40
• CPC Class Codes: G09G 2300/0456 with a reflective area and a transmissive area combined in one pixel, such as in transflectance pixels
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0857 Static memory circuit, e.g. flip-flop
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3433 using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

Systems and methods for a display having an array of pixels, a substrate, and a control matrix formed on the substrate are described. The array of pixels includes mechanical light modulators that can be referred to as micro-electro-mechanical or MEMS light modulators. The MEMS light modulators may be shutter-based light modulators, and an array of apertures may be formed on the substrate corresponding spatially to the shutters in the array of shutter-based light modulators. Each modulator is configured to be driven from a-light-blocking state to a-light-transmissive state through a movement direction. The array of light modulators are arranged to reduce the correlations in movement directions of neighboring pixels, thereby reducing the amplitude of acoustic emissions from the display.

Claims

1. A display comprising:

a substrate;

an array of apertures formed on the substrate; and

an array of MEMS light modulators spaced away from the array of apertures, the array of MEMS light modulators comprising;

a first group of MEMS light modulators capable of being driven from a light blocking state to a light-transmissive state through movement in a first direction substantially along a first axis, the first group comprising a plurality of first linear arrangements of MEMS light modulators, and

a second group of MEMS light modulators capable of being driven from a light blocking state to a light-transmissive state through movement in a second direction substantially along a second axis

oriented by one of about 45 degrees, about 60 degrees, or about 90 degrees relative to the first axis, the second group comprising a plurality of second linear arrangements of MEMS light modulators interdigitated with the first linear arrangements.

2. The display of claim 1, wherein the second linear arrangements interdigitated with the first linear arrangements are defined by alternating groups of rows of the first and second groups of MEMS light modulators.

3. The display of claim 2, wherein a spatial period of alternation between the alternating groups of rows of MEMS light modulators is less than about the thickness of the substrate.

4. The display of claim 1, wherein the second linear arrangements interdigitated with the first linear arrangements are defined by alternating groups of columns of the first and second groups of light modulators.

5. The display of claim 4, wherein a spatial period of alternation between the alternating groups of columns of MEMS light modulators is less than about the thickness of the substrate.

6. The display of claim 1, wherein the second linear arrangements interdigitated with the first linear arrangements are defined by alternating clusters of the first and second groups of light modulators, wherein each cluster comprises at least one light modulator.

7. The display of claim 1, wherein each MEMS light modulator in the array includes a shutter.

8. The display of claim 1, wherein the first and second group of MEMS light modulators include a third state which partially allows light to pass through a corresponding aperture.

9. The display of claim 1, further including a controller including a driver chip and a controller matrix for transmitting data and actuation voltages to the array of MEMS light modulators.

10. The display of claim 9, wherein the controller matrix is capable of actuating the first group of MEMS light modulators in the first direction and the second group of light modulators in the second direction in response to a control signal to move the light modulators from the light-blocking state to the light-transmissive state.

11. The display of claim 9, wherein the controller stores in memory which of the first and second directions of movement is appropriate to achieve the light-transmissive state for each MEMS light modulator in the array.

12. The display of claim 1, wherein the substrate is a transparent substrate.

31. The display of claim 11, wherein the control matrix is configured with wiring layouts for actuating the two groups in substantially different directions.

32. The display of claim 11, wherein the controller stores in memory a map of the first and second groups of light modulators in the array and their associated direction of movement to achieve an active state.

13. A method for manufacturing a display, comprising:

forming an array of apertures on a substrate,

forming a first group of MEMS light modulators on the substrate spaced away from the array of apertures such that the light modulators in the first group of MEMS light modulators are capable of actuating from a light-blocking state to a light-transmissive state through movement in a first direction substantially along a first axis, the first group comprising a plurality of first linear arrangements of MEMS light modulators,

forming a second group of MEMS light modulators on the substrate spaced away from the array of apertures such that the light modulators in the second group of MEMS light modulators are capable of actuating from a light-blocking state to a light-transmissive state through movement in a second direction substantially along a second axis

oriented by one of about 45 degrees, about 60 degrees, and about 90 degrees relative to the first axis, the second group comprising a plurality of second linear arrangements of MEMS light modulators interdigitated with the first linear arrangements.

14. The method of claim 13, wherein the second linear arrangements interdigitated with the first linear arrangements are defined by alternating groups of rows of the first and second groups of MEMS light modulators.

15. The method of claim 14, wherein a spatial period of alternation between the alternating groups of MEMS light modulators is less than about the thickness of the substrate.

16. The method of claim 13, wherein the second linear arrangements interdigitated with the first linear arrangements are defined by alternating groups of columns of the first and second groups of MEMS light modulators.

17. The method of claim 16, wherein a spatial period of alternation between the alternating groups of MEMS light modulators is less than about the thickness of the substrate.

18. The method of claim 13, wherein the second linear arrangements interdigitated with the first linear arrangements are defined by alternating clusters of the first and second group of MEMS light modulators, wherein each cluster comprises at least one light modulator.

19. The method of claim 13, further comprising forming a control matrix onto the substrate for transmitting data and actuation voltages to the array of MEMS light modulators and electrically coupling a controller to the control matrix, the controller including a memory for storing which of the first and second directions of movement is appropriate to achieve the light-transmissive state for each MEMS light modulator in the array.

20. The method of claim 13, wherein the substrate is a transparent substrate.

21. A system for modulating light to form an image on a display including an array of apertures on a substrate and an array of MEMS light modulators spaced away from the array of apertures, comprising:

means for actuating a first group of MEMS light modulators in the array of MEMS light modulators from a light-blocking state to a light-transmissive state by initiating movement of the MEMS light modulators in a first direction substantially along a first axis, the first group comprising a plurality of first linear arrangements of MEMS light modulators, and

means for actuating a second group of MEMS light modulators in the array of MEMS light modulators from a light-blocking state to a light-transmissive state by initiating movement of the MEMS light modulators in a second direction substantially along a second axis

orientated oriented by one of about 45 degrees, about 60 degrees, and about 90 degrees relative to the first axis, the second group comprising a plurality of second linear arrangements of MEMS light modulators interdigitated with the first linear arrangements.

22. The system of claim 21, further comprising means for determining which of the first and second directions of movement is appropriate to achieve the light-transmissive state for each MEMS light modulator in the array and means for transmitting data and actuation voltages to the array of MEMS light modulators.

23. The system of claim 21, wherein the substrate is a transparent substrate.

24. The system of claim 21, wherein the second linear arrangements interdigitated with the first linear arrangements are defined by alternating groups of rows of the first and second groups of MEMS light modulators.

25. The system of claim 24, wherein a spatial period of alternation between the alternating groups of columns of MEMS light modulators is less than about the thickness of the substrate.

26. The system of claim 21, further including a controller including a driver chip and a controller matrix for transmitting data and actuation voltages to the array of MEMS light modulators.

27. The system of claim 26, wherein the controller stores in memory which of the first and second directions of movement is appropriate to achieve the light-transmissive state for each MEMS light modulator in the array.

28. The system of claim 27, wherein the control matrix is configured with wiring layouts for actuating the two groups in substantially different directions.

29. The system of claim 27, wherein the controller stores in memory a map of the first and second groups of light modulators in the array and their associated direction of movement to achieve an active state.

30. The system of claim 29, wherein the controller processes pixel data prior to sending the pixel data to the control matrix to determine the proper direction of movement for each pixel.

33. The display of claim 27, wherein the controller processes pixel data prior to sending the pixel data to the control matrix to determine the proper direction of movement for each pixel.