Apparatus and method of dual-mode display

• US 8,023,169 B2
• Filed: 01/25/2010
• Issued: 09/20/2011
• Est. Priority Date: 03/28/2008
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Lan, Je-Hsiung
• Primary Examiner(s): Spector; David N
• Application Number:
  US12/693,346
• Publication Number:
  US 20100123706A1
• Time in Patent Office: 603 Days
• Field of Search: 257/431, 345/84, 345/85, 345/102, 359/260, 359/292, 359/297, 359/578, 362/97.1
• US Class Current: 359/260
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G09G 2300/046 with an emissive area and a light-modulating area combined in one pixel
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0866 by means of changes in the pixel supply voltage
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

One embodiment includes display comprising a light modulator configured to display a portion of an image such as a reflective light modulator, a light emitter configured to display the portion of the image and a circuit configured to selectively provide signals to at least one of the light modulator and the light emitter indicative of the portion of the image. In one such embodiment, an active matrix provides a simple, efficient drive for such devices. Other embodiments methods of making and driving such devices.

Claims

1. A method of operating a display, the method comprising:

applying a voltage difference across a first display element based on a first voltage level indicative of a portion of an image; and

selectively applying a current indicative of the portion of the image across a second display element based at least partly on the first voltage level and based at least partly on a second voltage level,

wherein the voltage difference is applied so that the first display element substantially absorbs incident light when the current is below a specified level and reflects light when the current exceeds the specified level.

2. The method of claim 1, further comprising:

receiving data indicative of ambient lighting; and

determining the first voltage level and the second voltage level at least partly on the data.

3. The method of claim 1, wherein the first display element comprises an interferometric modulator.

4. The method of claim 1, wherein the applying comprises applying a voltage difference between a first electrode of the first display element and second electrode of the first display element.

5. The method of claim 1, wherein the second display element comprises a light emitting diode.

6. The method of claim 5, wherein the light emitting diode comprises an organic light emitting diode.

7. A display, comprising:

a reflective display element configured to display a portion of an image;

an emissive display element configured to display the portion of the image; and

a circuit configured to selectively provide signals indicative of the portion of the image to at least one of the reflective display element and the emissive display element.

8. The display of claim 7, wherein the reflective display element is configured to substantially absorb incident light when a current provided by the circuit is below a specified level and configured to reflect light when the current exceeds the specified level.

9. The display of claim 7, wherein the reflective display element is configured to reflectively output light indicative of the portion of the image and wherein the emissive display element is configured to emit light indicative of the portion of the image.

10. The display of claim 7, wherein the reflective display element is configured to output light from the device when the emissive display element is configured to substantially absorb incident light.

11. The display of claim 7, wherein the portion of the image comprises a pixel.

12. The display of claim 7, wherein the reflective display element comprises an reflective interferometric light modulator and the emissive display element comprises a light emitting diode.

13. The display of claim 7, wherein the portion of the image comprises a pixel.

14. The display of claim 7, further comprising:

a processor that is configured to communicate with the circuit, the processor being configured to process image data; and

a memory device that is configured to communicate with the processor.

15. The apparatus of claim 14, further comprising an input device configured to receive input data and to communicate the input data to the processor.

16. The apparatus of claim 14, further comprising a driver circuit configured to send at least one signal to the circuit.

17. The apparatus of claim 16, further comprising a controller configured to send at least a portion of the image data to the driver circuit.

18. The apparatus of claim 14, further comprising an image source module configured to send the image data to the processor.

19. The apparatus of claim 18, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

20. A method of operating a display, the method comprising:

applying a voltage difference across a first display element based on a first voltage level indicative of a portion of an image; and

selectively applying a current across a second display element based at least partly on the first voltage level and based at least partly on a second voltage level,

wherein the voltage difference is applied so that the first display element substantially absorbs incident light when the current is below a specified level and reflects light when the current exceeds the specified level.

21. The method of claim 20, further comprising:

receiving data indicative of ambient lighting; and

determining the first voltage level and the second voltage level at least partly on the data.

22. A display, comprising:

at least one reflective display element configured to display a pixel of an image;

at least one emissive display element configured to display the pixel, wherein each of the reflective display element and the emissive display element are configured to selectively display the pixel based on ambient lighting conditions.

23. The display of claim 22, wherein the reflective display element is configured to substantially absorb incident light when the emissive display element is configured to emit light with an output level below a specified output level and configured to reflect light when the output level of the emissive display element exceeds the specified output level.

24. The display of claim 22, wherein the reflective display element comprises an reflective interferometric light modulator and the emissive display element comprises a light emitting diode.

25. The display of claim 22, further comprising a circuit configured to selectively provide signals indicative of the pixel to at least one of the reflective display element and the emissive display element based on ambient lighting conditions.

26. The display of claim 25, wherein the reflective display element is configured to substantially absorb incident light when a current provided by the circuit is below a specified level and configured to reflect light when the current exceeds the specified level.

27. The display of claim 25, wherein the first display element comprises a first electrode and a second electrode, wherein the reflective display element is configured to reflect light based on the voltage difference provided by the circuit and applied between the first and second electrode.

28. The display of claim 25, wherein the circuit comprises an active matrix element.