SENSOR-BASED FEEDBACK FOR DISPLAY APPARATUS

• US 20100188443A1
• Filed: 01/18/2008
• Published: 07/29/2010
• Est. Priority Date: 01/19/2007
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Gandhi, Jignesh, Lewis, Stephen R., McAllister, Abraham, Fijol, John J.
• Application Number:
  US12/523,863
• Publication Number:
  US 20100188443A1
• Time in Patent Office: Days
• US Class Current: 345/691
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0237 Switching ON and OFF the backlight within one frame
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2340/0428 Gradation resolution change
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

The invention relates to methods and apparatus for feedback control of image and color quality in a direct-view MEMS display apparatus. The display apparatus includes a lamp capable of providing light, a sensor capable of detecting information indicative of characteristics of light provided by the lamp and outputting a sensor signal based at least partially on the information, and control circuitry for controlling illumination of the lamp based at least partially on the sensor signal.

Claims

1. A field sequential color display apparatus comprising:

a plurality of lamps, each capable of providing light of a different color,

a sensor capable of detecting information indicative of characteristics of light provided by each of the lamps and outputting a sensor signal based on the information, and

control circuitry for controlling illumination of each of the lamps, comprising

timing circuitry for controlling a length of time to illuminate each of the plurality of lamps and for outputting timing signals indicative thereof, and

lamp driver circuitry capable of outputting power to illuminate the plurality lamps based on the sensor signal and the timing signals.

2. The field sequential color display apparatus of claim 1, wherein the sensor includes a photosensor capable of measuring light intensity.

3. The field sequential color display apparatus of claim 2, wherein the photosensor is capable of measuring light intensity of ambient light and the sensor signal is based at least partially on the light intensity of the ambient light.

4. The field sequential color display apparatus of claim 1, comprising a second sensor capable of detecting second information indicative of characteristics of ambient light.

5. The field sequential color display apparatus of claim 1, wherein the sensor includes a thermal sensor capable of measuring temperature and the control circuitry includes a memory storing data that corresponds to a plurality of temperatures.

6. The field sequential color display apparatus of claim 1, wherein the timing circuitry determines the lengths of time to illuminate each of the plurality of lamps according to a time-division gray scale process.

7. The field sequential color display apparatus of claim 6, wherein the lamp driver circuitry adjusts the amplitude of the power output to illuminate at least one of the lamps based on the sensor signal.

8. The field sequential color display apparatus of claim 7, wherein the lamp driver adjusts the amplitude of the power output to illuminate the at least one lamp by adjusting a current level supplied to the at least one lamp.

9. The field sequential color display apparatus of claim 7, wherein the lamp driver adjusts the amplitude of the power output to illuminate the at least one lamp by adjusting a voltage level supplied to the at least one lamp.

10. The field sequential color display apparatus of claim 1, wherein the timing circuitry determines the lengths of time to illuminate each of the plurality of lamps according to a time-division gray scale process and the sensor signal.

11. The field sequential color display apparatus of claim 1, wherein the timing circuitry determines the lengths of time to illuminate each of the plurality of lamps according to an analog gray scale process and the sensor signal.

12. The field sequential color display apparatus of claim 1, wherein the sensor includes exactly one photosensor for measuring light intensity levels from each of the plurality of lamps.

13. The field sequential color display apparatus of claim 1, wherein in response to the sensor signal, the control circuitry adjusts a number of digital bit levels used to display an image.

14. The field sequential color display apparatus of claim 1, comprising a plurality of MEMS light modulators for modulating the light provided by the plurality of lamps.

15. The field sequential color display apparatus of claim 14, wherein the plurality of MEMS light modulators comprise shutter-based light modulators.

16. The field sequential color display apparatus of claim 14, wherein the timing circuitry is configured to control actuation of the plurality of MEMS light modulators.

17. The field sequential color display apparatus of claim 14, wherein the plurality of the MEMS light modulators and the sensor are formed on a common substrate.

18. A direct-view MEMS display apparatus comprising

a lamp capable of providing light,

a sensor capable of detecting information indicative of characteristics of light provided by the lamp and outputting a sensor signal based at least partially on the information, and

control circuitry for controlling illumination of the lamp based at least partially on the sensor signal.

19. The direct-view MEMS display apparatus of claim 18, comprising a plurality of MEMS light modulators for modulating the light provided by the lamp.

20. The field sequential color display apparatus of claim 19, wherein the plurality of MEMS light modulators comprise shutter-based light modulators.

21. The field sequential color display apparatus of claim 19, comprising timing circuitry configured for controlling actuation of the plurality of MEMS light modulators.

22. The field sequential color display apparatus of claim 19, comprising timing circuitry configured for controlling lengths of time the lamp is illuminated.

23. The field sequential color display apparatus of claim 19, comprising timing circuitry configured for controlling actuation of the plurality of MEMS light modulators and the lengths of time the lamp is illuminated.

24. The field sequential color display apparatus of claim 19, wherein the plurality of the MEMS light modulators and the sensor are formed on a common substrate.