Area array modulation and lead reduction in interferometric modulators

• US 7,782,525 B2
• Filed: 02/06/2009
• Issued: 08/24/2010
• Est. Priority Date: 12/09/2003
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Chui, Clarence, Kothari, Manish, Sampsell, Jeffrey Brian
• Primary Examiner(s): Choi; William C
• Application Number:
  US12/367,422
• Publication Number:
  US 20090135464A1
• Time in Patent Office: 564 Days
• Field of Search: 359/247, 359/290, 359/291, 359/302
• US Class Current: 359/291
• 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 2300/06 Passive matrix structure, i.e. with direct application of both column and row voltages to the light emitting or modulating elements, other than LCD or OLED
• CPC Class Codes: G09G 2310/0267 Details of drivers for scan electrodes, other than drivers for liquid crystal, plasma or OLED displays
• CPC Class Codes: G09G 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

A light modulator is arranged as an array of rows and columns of interferometric display elements. Each element is divided into sub-rows of sub-elements. Array connection lines transmit operating signals to the display elements, with one connection line corresponding to one row of display elements in the array. Sub-array connection lines electrically connect to each array connection line. Switches transmit the operating signals from each array connection line to the sub-rows to effect gray scale modulation.

Claims

1. A display device comprising:

an array comprising rows and columns of interferometric display elements, each element being divided into sub-rows of one or more sub-elements;

array connection lines to transmit operating signals to the display elements, wherein one connection line corresponds to one row of display elements in the array; and

switches to transmit the operating signals from each array connection line to a selected one of the sub-rows.

2. The device of claim 1, wherein said one or more sub-elements further comprise a sub-element in each row for red, green and blue.

3. The device of claim 1, wherein said array connection lines further comprise three column connection lines, one each for red, green and blue sub-elements in each element.

4. The device of claim 1, wherein the switches further comprise micro-electromechanical switches.

5. The device of claim 1, wherein the switches further comprise switches of a similar configuration as the sub-elements.

6. The device of claim 1, wherein the switches further comprise the sub-elements such that when a selected sub-element is deflected, the selected sub element causes the operating signal from the array connection line to transfer from the selected sub-element to an adjacent sub-element.

7. The device of claim 1, wherein the switches further comprise semiconductor transistor switches.

8. The device of claim 1, wherein the number of sub-rows is pre-determined depending upon a desired bit-depth for the display device.

9. The device of claim 1, wherein each sub-row further comprises a number of sub-columns.

10. The device of claim 9, wherein the number of sub-columns is pre-determined depending upon a desired number of colors for the display.

11. The device of claim 1, wherein each sub-element comprises an interferometric modulator.

12. The device of claim 11, wherein each interferometric modulator comprises a cavity defined by a fixed layer deposited on the substrate and a movable layer connected to the substrate, wherein light incident to the interferometric modulator is interferometrically modulated by the first and second layer.

13. A method of controlling a display device, comprising:

generating an operating signal for setting the state of a plurality of interferometric display elements arranged in an array defining rows and columns, each element being divided into sub-rows of one or more sub-elements; and

switching said operating signal to a selected one of the sub-rows of sub-elements, wherein said switching comprises providing a control signal to control the state of at least one switch.

14. The method of claim 13, wherein said switching comprises controlling the state of at least one microelectromechanical switch.

15. A display device comprising:

an array of interferometric display elements arranged in rows and columns, each element comprising a number of sub-elements; and

an array connection line corresponding to each row of display elements, wherein each array connection line is electrically connected to a sub-element in each display element,

wherein at least one sub-element is configured to selectively form an electrical connection connecting said array connection line to at least one other sub-element.

16. The display device of claim 15, wherein the number of sub-elements is pre-determined by a desired bit depth.

17. The display device of claim 15, wherein each element is approximately the same size.

18. The display device of claim 15, wherein each element comprises a predetermined number of sub-elements cascades, and the predetermined number of cascades corresponds to the number of colors in the element.

19. The display device of claim 15, wherein the sub-elements of each element are connected to form one or more sub-element cascades, the device further comprises addressing circuitry to provide an addressing pulse to each sub-element cascade, wherein a number of sub-elements in the cascade that become active depends upon a length of the addressing pulse.

20. The display device of claim 15, wherein each element comprises at least one sub-element cascade for each of a desired color comprising a predetermined number of sub-elements.

21. A display device comprising:

an array comprising rows and columns of interferometric display elements, each element being divided into sub-rows of one or more sub-elements;

means for transmitting an operating signal to a row of the display elements; and

means for switching said operating signal to a selected one of the sub-rows, wherein the means for switching said operating signal to a selected one of the sub-rows comprises switches to transmit the operating signal to a selected one of the sub-rows.

22. The display device of claim 21, wherein the means for transmitting an operating signal to a row of the display elements comprises a connection line transmitting an operating signal to a row of the display elements.

23. A display device comprising:

an array comprising rows and columns of interferometric display elements, each element being divided into sub-rows of one or more sub-elements;

means for transmitting an operating signal to a row of the display elements, wherein at least one of said sub-elements is configured to selectively transmit said operating signal to at least one other sub-element.

24. The display device of claim 23, wherein the means for transmitting an operating signal to a row of the display elements comprises a connection line transmitting an operating signal to a row of the display elements.