High brightness digital display system

• US 6,392,717 B1
• Filed: 05/27/1998
• Issued: 05/21/2002
• Est. Priority Date: 05/30/1997
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Kunzman, Adam
• Primary Examiner(s): Miller, John W.
• Assistant Examiner(s): Yenke, Brian P.
• Application Number:
  US09/085,889
• Time in Patent Office: 1,455 Days
• Field of Search: H04/N.947, H04/N.964, H04/N.912, 348/68, 348/69, 348/70, 348/655, 348/742, 348/743, 348/771, 348/744, 348/758, 348/759, 345/85, 345/88, 345/150, 345/151
• US Class Current: 348/744
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A display system using red, green, blue, and white light. The system derives data for the white portion of a color wheel or a white device from the red, green and blue data. The white portion of the color wheel is controlled as if it were another primary color on the wheel. Errors are prevented by a correction applied if the unfiltered light from the source has a different color temperature than the white light produced using the red, green and blue segments of the color wheel, or the devices for those colors. Analysis is performed on the data to determine if white light is necessary to be added to each frame of data.

Claims

1. A color display system in which image data is converted into red, green and blue data prior to display, and displayed on a display system having at least one spatial light modulator, comprising:

a) a processing element which derives white image data from said red, green and blue data;

b) a source of red, green, blue and white light operable to impinge light on the spatial light modulator;

c) a system controller for controlling the timing of the red, green, blue, and white data onto the spatial light modulator, such that the appropriate data for each color is present when that color light is striking the spatial light modulator; and

d) a nonvolatile memory for storing correction data which corrects for differences between the white image data and the light from the source, allowing the display system to add brightness to the display system and preventing artifacts.

2. The system of claim 1, wherein the source of light comprises one white light source and a color wheel with red, green, blue and clear segments;

and wherein the nonvolatile memory is also for storing a sequence start delay value that is communicated to the system controller so that the timing of the data is controlled to coincide with a selected point on the color wheel.

3. The system of claim 2, wherein the clear segment is clear glass.

4. The system of claim 2, wherein the clear segment has a dichroic filter applied to tint the white light.

5. The system of claim 1, wherein the source of light comprises a pulsating lamp.

6. The system of claim 1, wherein the source of light comprises solid state light sources producing red, green, blue and white light.

7. The system of claim 6, wherein the light sources are solid state.

8. The system of claim 1, wherein a filter is used for white light.

9. The system of claim 1, wherein no filter is used for white light.