Systems and methods of actuating MEMS display elements

• US 7,545,550 B2
• Filed: 09/16/2005
• Issued: 06/09/2009
• Est. Priority Date: 09/27/2004
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Gally, Brian J., Cummings, William J.
• Primary Examiner(s): Stultz; Jessica T
• Application Number:
  US11/228,118
• Publication Number:
  US 20060066560A1
• Time in Patent Office: 1,362 Days
• Field of Search: 359/245, 359/578, 345/108
• US Class Current: 359/245
• 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 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2320/0204 Compensation of DC component across the pixels in flat panels
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

Apparatus and methods of actuating MEMS display elements are disclosed. The disclosed embodiments can be incorporated into other drive schemes for MEMS display elements. In one embodiment, an apparatus for controlling a MEMS display element to display a frame of video data, said MEMS display element comprising a portion of an array of MEMS display elements, includes an array controller configured to assert a potential difference on said MEMS display element during a first portion of a frame display write process to place the MEMS display element in a first display state, and to assert a potential difference on said MEMS display element during a second portion of the frame display write process to place the MEMS display element in a second display state to display the frame of the video data, where the first display state is different from the second display state. In another embodiment, an array controller asserts a large potential difference across a MEMS display element to affect charge build up and an offset voltage level. In another embodiment, an array controller asserts a series of pulses to rapidly switch the MEMS display element between states to overcome adverse conditions that may affect the operation of the MEMS display element.

Claims

1. A display apparatus, comprising:

an array comprising a plurality of MEMS display elements; and

an array controller connected to said array, said array controller configured to write a frame of data to the array in a two-portion write operation by applying

a first potential to each of said MEMS display elements during a first portion of a frame data write operation, said first potential corresponding to a first display state for each of said MEMS display elements that is opposite of a second display state, the first display state of each of said MEMS display elements being based on the second display state of each respective MEMS display element, and

a second potential to each of said MEMS display elements during a second portion of the frame data write operation, said second potential corresponding to the second display state, the second display state being opposite the first display state for each of said MEMS display elements, the second display state displaying the frame of data on the array after the write operation is completed.

2. The apparatus of claim 1, wherein said MEMS display elements comprise one or more interferometric modulators.

3. The apparatus of claim 1, wherein for each of said MEMS display elements, if said first display state is relaxed then said second display state is actuated.

4. The apparatus of claim 1, wherein for each of said MEMS display elements, if said first display state is actuated then said second display state is relaxed.

5. The apparatus of claim 1, wherein said array controller is further configured to assert a voltage bias on column electrodes of said MEMS display elements to display said data, and further configured to assert row voltage pulses comprising two portions on the row electrodes of said MEMS display elements, wherein said first portion of said row voltage pulses is asserted during said first portion of said frame data write operation and places said MEMS display elements in said first display state, and said second portion of said row voltage pulses is asserted during said second portion of said frame data write operation and places said MEMS display elements in said second display state.

6. The apparatus of claim 1, further comprising:

a display comprising said array;

a processor that is in electrical communication with said display, said processor being configured to process said frame of data; and

a memory device in electrical communication with said processor.

7. The apparatus of claim 6, further comprising:

a first controller configured to send at least one signal to said display; and

a second controller configured to send at least a portion of said frame of data to said first controller.

8. The apparatus of claim 6, further comprising an image source module configured to send said frame of data to said processor.

9. The apparatus of claim 8, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

10. A display apparatus, comprising:

means for modulating light to display a frame of data; and

means for performing a two-portion write operation to display the frame of data on the light modulating means, said write operation comprising

applying a first potential to the light modulating means during a first portion of a frame data write operation to place the light modulating means in a first display state, the first display state being based on a second display state and opposite the second display state; and

applying a second potential to the light modulating means during a second portion of the frame data write operation to place the light modulating means in the second display state, the second different display state being opposite the first display state for each of the light modulating means,

wherein the frame of data is displayed when the light modulating means are in the second display state.

11. The apparatus of claim 10, wherein said light modulating means comprises one or more MEMS display elements.

12. The apparatus of claim 10, wherein said applying a first potential means comprises an array controller.

13. The apparatus of claim 10, wherein said applying a second potential means comprises an array controller.