Alignment for display having multiple spatial light modulators

• US 5,729,245 A
• Filed: 03/14/1995
• Issued: 03/17/1998
• Est. Priority Date: 03/21/1994
• Status: Expired due to Fees

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Marshall, Stephen W., Gove, Robert J., Meyer, Richard C., Sextro, Gary L.
• Primary Examiner(s): WU, XIAO MIN
• Application Number:
  US08/403,532
• Time in Patent Office: 1,099 Days
• Field of Search: 345/88, 345/100, 345/98, 345/84, 345/190, 345/185, 345/4, 345/5, 345/6, 345/54, 348/806, 348/189, 348/190, 348/745, 348/755, 348/770, 348/771, 359/53, 349/33
• US Class Current: 345/84
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 5/346 for systems having a bit-mapped display memory
• CPC Class Codes: H04N 9/30 using solid-state colour display devices

Abstract

A method and structure for a display system having multiple spatial light modulators (SLMs) (16), each of which contributes an image of one color that is perceived by the viewer as a combined image. The SLMs (16) have more rows and columns of pixel elements (42) than rows or columns of pixel data to be displayed. A window of "active" pixel elements (42) can be shifted up and down or right and left by selecting which pixel elements (42) are to receive data. The addressing circuit (31, 31a, 35, 35a) of each SLM 16 can be controlled so as to accomplish this shifting.

Claims

1. A spatial light modulator for use in a display system that combines images from multiple spatial light modulators to generate a display image, comprising:

an array of pixel elements, wherein said array has more pixel elements per row than are to be displayed as said display image;

an array of memory cells for storing data representing a voltage to be applied to said pixel elements;

an input register operable to receive a display row of data for said display image, and deliver said display row of data for said display image to a selected row of said array of memory cells, said input register having an output tap for delivering data down a column line for each column of said memory cells;

a row decoder for providing a row enable signal to said selected row of said array of memory cells; and

an alignment control unit having means for controlling which of said column lines shall deliver said display row to said array of memory cells thereby determining horizontal position of said display row, wherein which of said column lines shall deliver said display row is determined by the comparison between said display image and an image created by at least one other spatially separate SLM.

2. The spatial light modulator of claim 1, wherein said alignment control unit controls said output taps.

3. The spatial light modulator of claim 1, further comprising a parallel latch interposed between said input register and said memory cell array, for storing said display row, each bit position of said parallel latch in data communication with one of said column lines, and wherein said alignment control unit controls the output of said parallel latch.

4. The spatial light modulator of claim 1, wherein said pixel element array has more rows than are to be displayed as said display image, and wherein said alignment control unit further has means for controlling which of said row select lines shall deliver display rows of said display image to said memory cells.

5. A video display system for generating an image from pixel data and having multiple, spatially separate spatial light modulators for generating a combined image on an image plane, comprising:

a processing system for processing said pixel data;

a display memory in data communication with said processing system for storing processing pixel data; and

at least two spatially separate spatial light modulators in data communication with said display memory, each having an array of pixel elements, individually addressable, wherein said array has more pixel elements per row than are to be displayed as said display image;

an array of memory cells for storing data representing a voltage to be applied to said pixel elements;

an input register operable to receive a row of data for said display image, and deliver said row of data to a selected row of said memory cells, said input register having an output tap for each of said pixel elements;

a row decoder for providing a row enable signal to said selected row of said array of memory cells; and

an alignment control unit having means for controlling which of said output taps of said input register shall deliver said row of data to said array of memory cells thereby determining horizontal position of said display row, wherein which of said output taps is selected based upon a comparison between said display images of said at least two spatially separate spatial light modulators.

6. The display system of claim 5, wherein said system has three of said spatial light modulators, for receiving data representing different colors and for displaying differently colored images.

7. The display system of claim 5, wherein said alignment control unit controls said output taps.

8. The display system of claim 5, wherein said comprising a parallel latch interposed between said input register and said memory cell array, for storing said display row, each bit position of said parallel latch in data communication with one of said column lines, and wherein said alignment control unit controls the output of said parallel latch.

9. The display system claim 5, wherein said pixel element array has more rows than are to be displayed as said display image, and wherein said alignment control unit further has means for controlling which of said row select lines shall deliver display rows of said display image to said memory cells.

10. The video display system of claim 5, wherein said system receives an analog RGB signal, further comprising an analog-to-digital converter for each color of said RGB signal, and a delay unit for delaying the operation of each said analog-to-digital converter.

11. The video display system of claim 5, further comprising a digital filter for delaying RGB data for a time interval of less than one sample period.

12. The video display system of claim 5, further comprising a digital filter for delaying RGB data for a time interval of less than one line period.