DMD Architecture to improve horizontal resolution

• US 6,232,936 B1
• Filed: 03/31/1995
• Issued: 05/15/2001
• Est. Priority Date: 12/03/1993
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Sampsell, Jeffrey B., Gove, Robert J.
• Primary Examiner(s): Mengistu, Amare
• Application Number:
  US08/415,101
• Time in Patent Office: 2,237 Days
• Field of Search: 345/85, 345/108, 346/160, 359/230, 430/321, 348/750, 348/755, 340/815.04
• US Class Current: 345/85
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A method and device for increasing the effective horizontal resolution of a display device. One embodiment forms a cardinal array of digital micromirror elements by staggering alternate rows in an array. According to a second embodiment, an ordinal pixel array 57, is converted to a cardinal pixel array, by grouping SLM elements 59, 61, 63, and 65 into a pixel block 58. All of the elements in a pixel block are controlled in unison such that the pixel block acts like a single pixel. Rows of pixel blocks 67 and 69 are offset to provide the effect of a cardinal array of pixels without the decrease in efficiency sometimes associated with cardinal pixel arrays.

Claims

1. A method for controlling an orthogonal array of spatial light modulator elements, the method comprising the steps of:

a. grouping said orthogonal spatial light modulator elements into sub-arrays in horizontal rows such that one said sub-array is horizontally between two adjacent sub-arrays in each adjacent row; and

b. controlling each of said modulator elements in said sub-array such that said modulator elements operate in unison.

2. The method of claim 1 wherein said controlling step comprises individually addressing each element in said sub-array.

3. The method of claim 1 wherein said controlling step comprises addressing each element in said sub-array simultaneously.

4. The method of claim 1 wherein said grouping step comprises forming sub-arrays having a predominately square form factor.

5. The method of claim 1 wherein said grouping step comprises forming sub-arrays consisting of four modulator elements arranged in a 2×

2 matrix.

6. The method of claim 1 wherein said spatial light modulator elements are digital micromirror devices.

7. The method of claim 1 wherein said spatial light modulator elements are torsion beam digital micromirror devices.

8. A spatial light modulator comprising:

a. an orthogonal array of spatial light modulator elements; and

b. a control circuit for controlling said elements, said control circuit causing sub-arrays of said elements to operate in unison, said sub-arrays arranged in staggered horizontal rows wherein each sub-array is located horizontally between two adjacent sub-arrays in each adjacent row.

9. The modulator of claim 8 wherein said sub-arrays have a predominately square form factor.

10. The modulator of claim 8 wherein said sub-arrays consist of four modulator elements arranged in a 2×

2 matrix.

11. The modulator of claim 8 wherein said elements are digital micromirror devices.

12. The modulator of claim 8 wherein said elements are torsion beam digital micromirror devices.

13. The modulator of claim 8 wherein two or more of said control circuits are fabricated for each sub-array.

14. A digital micromirror device comprising:

an orthogonal array of digital micromirror elements, each of said elements comprising a deflectable mirror suspended over an address electrode, said address electrode for receiving a bias voltage, said bias voltage for causing said deflectable mirror element to deflect toward said address electrode;

said elements grouped into sub-arrays comprised of at least two elements, wherein said address electrodes within each sub-array are electrically connected such that said bias voltage causes all deflectable mirror elements within a sub-array to deflect equally; and

said array comprised of at least three staggered horizonal rows of said sub-arrays wherein each said sub-array is located horizontally between two adjacent sub-arrays in an adjacent row.

15. The device of claim 14 wherein said digital micromirror elements are torsion beam digital micromirror elements.

16. A digital micromirror device according to claim 14, further comprising:

at least two controlling circuits, each of the controlling circuits alternatively operable for applying a voltage bias signal to the address electrodes associated with each of the digital micromirror elements sub-arrays.

17. A video display system comprising:

a light source for generating a beam of light;

a decoder for downconverting an input composite video signal and outputting an analog baseband video signal;

an analog to digital converter for sampling said analog baseband video signal and outputting a digital representation of said analog baseband video signal;

a video formatter for receiving said digital representation and outputting digital display data; and

a digital micromirror device receiving said digital display data and said beam of light, the digital micromirror device generating an image bearing beam of light dependent on said digital display data, wherein said digital micromirror device comprises an orthogonal array of digital micromirror elements and a control circuit for controlling said elements, said control circuit causing sub-arrays of said elements to operate in unison, said sub-arrays arranged in staggered horizontal rows wherein each sub-array is located horizontally between two adjacent sub-arrays in an adjacent row.

18. The display system of claim 17 wherein said video formatter comprises a video processor and a DMD formatter, said video processor receiving said digital representation of said analog baseband video signal and outputting an altered digital video signal, said DMD formatter for receiving said altered digital video signal and outputting said digital display data.

19. The display system of claim 17 further comprising a frame memory for storing said digital display data from said video formatter before said digital display data is displayed by said digital micromirror device.

20. The display system of claim 17 wherein said digital micromirror device is a torsion beam digital micromirror device.