Area array modulation and lead reduction in interferometric modulators

• US 20050122560A1
• Filed: 12/09/2003
• Published: 06/09/2005
• Est. Priority Date: 12/09/2003
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Chui, Clarence, Kothari, Manish, Sampsell, Jeffrey Brian
• Granted Patent: US 7,161,728 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• 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 light modulator, comprising:

an array comprised of rows and columns of interferometric display elements, each element being divided into sub-rows of 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;

sub-array connection lines electrically connected to each array connection line; and

switches to transmit the operating signals from each array connection line to the sub-rows to effect gray scale modulation.

2. The light modulator of claim 1, multiple sub-elements further comprising a sub-element in each row for red, green and blue.

3. The light modulator of claim 1, column connection lines further comprising three column connection lines, one each for red, green and blue sub-elements in each element.

4. The light modulator of claim 1, the switches further comprising microelectromechancial switches.

5. The light modulator of claim 1, the switches further comprising switches of a similar configuration as the interferometric display elements.

6. The light modulator of claim 1, the switches further comprising 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 light modulator of claim 1, the switches further comprising semiconductor transistor switches.

8. A method of manufacturing an interferometric light modulator, the method comprising:

providing an array of interferometric display elements arranged in rows and columns, each display element comprising;

a predetermined number of sub-rows of sub-elements, wherein the predetermined number of sub-rows depends upon a desired bit-depth for a display; and

a predetermined number of sub-columns within each sub-row, wherein the predetermined number of sub-columns corresponds to a desired number of colors for the display;

arranging array connection lines for each row, such that each connection line corresponds to one row of the array; and

providing electrical connection between the array connection line for each row to one of the sub-rows of the corresponding row of the array.

9. The method of claim 8, arranging array connection lines for each row further comprising arranging array connection lines between the array and a driver device.

10. The method of claim 8, providing electrical connection between the array connection line further comprising providing connection to a set of microelectromechancial switches.

11. The method of claim 8, providing electrical connection between the array connection line further comprising providing connection to a set of semiconductor switches.

12. The method of claim 10, the microelectromechanical switches further comprising switches of a similar configuration as the interferometric display elements.

13. The method of claim 8, providing electrical connection further comprising deflecting a sub-element of a sub-row, thereby forming a connection between the sub-element and an adjacent sub-element.

14. A light modulator, comprising:

an array of interferometric display elements arranged in rows and columns, each element comprising a predetermined number of sub-elements, wherein the number of sub-elements is determined by a desired bit depth and each element is approximately the same size;

electrical connections between the sub-elements such that the electrical connection is forms a sub-element cascade; 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.

15. The light modulator of claim 14, the modulator further comprising a predetermined number of sub-element cascades within each display element, wherein the predetermined number is a desired number of colors.

16. The light modulator of claim 14, the modulator further comprising 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.

17. A method of manufacturing a light modulator, the method comprising:

providing an array of interferometric display elements arranged in rows and columns,

each element comprising at least one sub-element cascade of a predetermined number of sub-elements; and

electrically connecting a first element in each sub-element cascade in a row to a corresponding connection line for that row;

18. The method of claim 17, the method further comprising providing an array of interferometric elements having at least one sub-element cascade further comprises providing a sub-element cascade for each desired color.

19. The method of claim 17, the method further comprising electrically connecting the connection lines for each row to a driver device.

20. A light modulator, comprising:

an array of interferometric elements, each element comprising a pre-determined number of sub-elements, each of a different size corresponding to a different binary weight of display information, wherein the number of sub-elements depends upon a desired bit depth.

21. The light modulator of claim 20, the pre-determined number of sub-elements further comprising four sub-elements, a first sub-element of half-size, a second sub-element of quarter-size and third sub element of eighth-size and a fourth sub-element of sixteenth size.

22. The light modulator of claim 20, the light modulator further comprising a connection line for each of the sub-elements.

23. The light modulator of claim 20, the light modulator further comprising one connection line for each display element, and a set of switches electrically connected between the display element and the sub-elements, such that sub-elements needed to create a weighting of a pixel are activated in accordance with display information.

24. A method of manufacturing a light modulator, the method comprising:

providing an array of interferometric display elements;

forming sub-elements within each display element of a size approximately equal to one half a display element;

forming sub-elements as desired, each sub-element having a size approximately equal to half the size of a next largest element.

25. The method of claim 24, the method further comprising forming a connection line for each sub-element.

26. The method of claim 24, the method further comprising forming a connection line for each display element and providing multiplexing switches in electrical connection between the connection line and the sub-elements.

27. A method of operating a light modulator, comprising:

receiving a row selection signal for a row of display elements;

transmitting the row selection signal for a predetermined period of time to an array of sub-elements such that a predetermined number of sub-elements are activated.

28. A light modulator, comprising:

an array of elements having differing values of deflection versus time and deflection versus voltage; and

addressing lines to provide addressing pulses of varying voltage level and time to the array of elements such that different combinations of elements switch in a selectable manner, depending upon the voltage level and time duration of the addressing pulses.

29. The light modulator of claim 28, addressing lines arranged to provide one addressing for a row in the array of elements.

30. The light modulator of claim 28, the array of elements having differing mechanical structures to effect differing values of deflection versus time and deflection versus voltage.

31. The light modulator of claim 28, the array of elements having differing film thicknesses to effect differing values of deflection versus time and deflection versus voltage.