System and method for color-specific sequence scaling for sequential color systems

• US 20080084369A1
• Filed: 10/10/2006
• Published: 04/10/2008
• Est. Priority Date: 10/10/2006
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Dickinson, Larry D.
• Granted Patent: US 8,493,288 B2
• Time in Patent Office: Days
• US Class Current: 345/84
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2320/062 Adjustment of illumination source parameters
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

System and method for adjusting the color segment durations for colors in a color sequence in sequential color display systems. A preferred embodiment comprises receiving a desired color sequence to display, computing a scaling factor for each color in the desired color sequence based on a reference color sequence, and sequentially displaying the colors in the desired color sequence. The reference color sequence used in computing the scaling factors specifies a duration for each color in the reference color sequence, while the desired color sequence specifies a desired duration for each color in the desired color sequence. The use of a single reference color sequence to create a large number of color sequences can save a significant amount of storage space and can allow for the storage of reference color sequences to meet varying chromatic properties due to changes in the display system, user settings, and operating environment.

Claims

1. A method for displaying a color sequence, the method comprising:

receiving a desired color sequence to display;

computing a scaling factor for each color in the desired color sequence based on a reference color sequence, wherein the reference color sequence specifies a reference duration for each color in the reference color sequence and wherein the desired color sequence specifies a desired duration for each color in the desired color sequence; and

sequentially displaying each color in the desired color sequence based on the computed scaling factor for each respective color.

2. The method of claim 1, wherein the scaling factor for a color specifies a ratio between the reference duration of the color in the reference color sequence and the desired duration of the color in the desired color sequence.

3. The method of claim 2, wherein the displaying comprises sequentially displaying each color in the desired color sequence for a display duration substantially equal to the scaling factor for the color being displayed multiplied by the desired duration for the color being displayed.

4. The method of claim 1 further comprising, prior to the computing, adjusting the desired color sequence in response to a determination that the desired color sequence is an invalid color sequence.

5. The method of claim 4, wherein the adjusting comprises modifying the desired duration for at least one of the colors in the desired color sequence.

6. The method of claim 5, wherein, after the adjusting, a sum of the desired duration of all colors in the desired color sequence is less than or equal to a color cycle time.

7. The method of claim 1, wherein the reference color sequence is selected based upon chromatic characteristics of a display system displaying the desired color sequence.

8. The method of claim 7, wherein the reference color sequence is also selected based upon desired chromatic characteristics of an image displayed using the desired color sequence.

9. The method of claim 1, wherein the reference color sequence is selected based upon an operating environment of a display system displaying the desired color sequence.

10. A method for displaying an image, the method comprising:

receiving a desired color sequence for use in illuminating a spatial light modulator;

computing a clock drop factor for each color in the desired color sequence, wherein a clock drop factor for each respective color is based on a reference duration for the respective color in a reference color sequence and a desired duration for the respective color in the desired color sequence;

sequentially displaying each color in the desired color sequence, wherein a display duration of each color is controlled by applying the respective clock drop factor to the reference duration for the respective color in the reference color sequence; and

setting a state of each light modulator in the spatial light modulator using image data corresponding to the respective color being displayed.

11. The method of claim 10, wherein a reference clock is used to time the reference duration of a color in the reference color sequence, and wherein each clock drop factor specifies an associated number of reference clock cycles between a skipping of a reference clock cycle.

12. The method of claim 11, wherein each clock drop factor specifies the associated number of reference clock cycles between a skipping of multiple reference clock cycles.

13. A display system comprising:

a light source;

an array of light modulators optically coupled to the light source, the array of light modulators configured to modulate light from the light source based upon image data to produce images on a display plane;

a memory storing reference color sequences, wherein each reference color sequence contains data for generating light with specific chromatic properties under a set of display system conditions;

a controller coupled to the array of light modulators, to the memory, and to the light source, the controller comprising

a sequence controller coupled to the array of light modulators, the sequence controller configured to control modulation of the array of light modulators and to specify desired color sequences used to illuminate the array of light modulators; and

a light controller coupled to the sequence controller, to the memory, and to the light source, the light controller configured to issue commands to the light source to produce light corresponding to the desired color sequences from the sequence controller, wherein the commands issued by the light controller are based on a selected reference color sequence that is selected based on a set of display system conditions or specified chromatic properties.

14. The display system of claim 13, wherein the image data being displayed is based on the color of the light produced by the light source.

15. The display system of claim 13 further comprising an optoelectrical converter electrically coupled to the controller and optically coupled to the light source, the optoelectrical converter configured to produce electrical signals from samples of light produced by the light source, wherein the electrical signals provide chromatic information to the sequence controller, and the sequence controller selects one of the reference color sequences based on the chromatic information.

16. The display system of claim 15, wherein the electrical signals further provide chromatic information to the light controller, and the light controller adjusts commands to the light source to match the light from the light source to the desired color sequences from the sequence controller.

17. The display system of claim 13, wherein the light controller is configured to compute a clock drop factor for each color in the desired color sequence provided by the sequence controller.

18. The display system of claim 17, wherein each reference color sequence specifies a respective reference duration for each color in a color sequence, and wherein the light controller comprises a timer enable circuit configured to scale the respective reference duration for each color into a respective duration for the corresponding color specified by the sequence controller.

19. The display system of claim 13, wherein the array of light modulators is a spatial light modulator.

20. The display system of claim 19, wherein the spatial light modulator is a digital micromirror device (DMD).