Enhanced resolution for digital micro-mirror displays

• US 5,490,009 A
• Filed: 10/31/1994
• Issued: 02/06/1996
• Est. Priority Date: 10/31/1994
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Nelson, William E., Venkateswar, Vadlamannati
• Primary Examiner(s): Ben, Loha
• Application Number:
  US08/332,023
• Time in Patent Office: 463 Days
• Field of Search: 359/213, 359/223, 359/224, 359/226, 359/230, 359/291, 359/317, 359/292, 359/846, 359/847, 359/255, 359/259, 348/203, 348/755, 348/770, 348/771
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: H04N 5/7458 the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]

Abstract

A display system (20) that uses multiple SLMs (25) to enhance horizontal or vertical resolution, or both. For example, to approximate a two-fold increase in horizontal resolution, the input data is sampled at a doubled rate, and each SLM (25) receives every other sample. Each SLM (25) generates an image, and the two images are partially superposed with a horizontal offset and simultaneously displayed. The resulting output image has a perceived resolution that approximates that of an image generated by an SLM with twice as many pixels per row.

Claims

1. A method of enhancing the horizontal resolution of a spatial light modulator (SLM)-based display system, comprising the steps of:

receiving sampled image data to a number, n, of SLMs, such that every nth SLM receives data representing every nth sample;

focusing said SLMs to an image plane, such that each of said SLMs generate a sub-image wherein said sub-images are partially superposed with a horizontal offset from each other; and

simultaneously displaying said sub-images to form an image.

2. The method of claim 1, wherein said steps are performed with two SLMs for approximating a two-fold increase in horizontal resolution.

3. The method of claim 1, wherein said SLMs are digital micro-mirror devices.

4. The method of claim 1, wherein said focussing step is performed with offsets of approximately 1/n the center-to-center horizontal spacing of the pixel elements of said SLMs.

5. The method of claim 1, wherein said SLMs have pixel elements that are substantially square.

6. A method of enhancing the vertical resolution of a spatial light modulator (SLM)-based display system, comprising the steps of:

receiving rows of image data to a number, n, of SLMs, such that every nth SLM receives data representing every nth row of samples;

focusing said SLMs to an image plane, such that each of said SLMs generate a sub-image wherein said sub-images are partially superposed with a vertical offset from each other; and

simultaneously displaying said sub-images to form an image.

7. The method of claim 6, wherein said steps are performed with two SLMs for approximating a two-fold increase in vertical resolution.

8. The method of claim 6, wherein said SLMs are digital micro-mirror devices.

9. The method of claim 6, wherein said focussing step is performed with offsets of approximately 1/n the center-to-center vertical spacing of the pixel elements of said SLMs.

10. The method of claim 6, wherein said SLMs have pixel elements that are substantially square.