APPARATUS AND METHOD OF DUAL-MODE DISPLAY

• US 20100123706A1
• Filed: 01/25/2010
• Published: 05/20/2010
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Lan, Je-Hsiung
• Granted Patent: US 8,023,169 B2
• Time in Patent Office: Days
• US Class Current: 345/211
• 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 device for outputting light, the device comprising:

a first display element configured to output light based on a voltage difference applied to the first display element;

a second display element configured to output light based on a current applied to the second display element; and

a circuit configured to supply the current to the second display element and to supply the voltage difference to the first display element based on a first voltage level indicative of a portion of an image, wherein the circuit is further configured to selectively supply the current based on a second voltage level indicative of the portion of the image.

2. The device of claim 1, wherein the first display element comprises an interferometric modulator configured to reflectively output light.

3. The device of claim 2, wherein the first display element is configured to substantially absorb incident light when the current is below a specified level and configured to reflect light when the current exceeds the specified level.

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

5. The device of claim 4, wherein the light emitting diode comprises an organic light emitting diode.

6. The device of claim 1, wherein the circuit comprises an active matrix element.

7. The device of claim 1, wherein the first display element comprises a first electrode and a second electrode, wherein the output light is based on the voltage difference applied between the first and second electrode.

8. The device of claim 7, wherein the circuit comprises:

a capacitor connected in parallel to the first display element.

9. The device of claim 8, wherein the circuit further comprises:

a transistor having a gate connected to a first electrode of the capacitor, wherein the transistor is configured to provide the current to the second display element from an source of the transistor.

10. The device of claim 9, wherein the gate of the transistor is further connected to a first electrode of the first display element, wherein the first electrode of the capacitor, the first electrode of the first display element, and the gate of the transistor are configured to receive the first voltage level indicative of the portion of the image, and wherein a second electrode of the first display element, a second electrode of the capacitor, and a drain of the transistor are configured to receive the second voltage level.

11. The device of claim 1, further comprising:

a processor that is configured to communicate with the first and second display elements, the processor being configured to process image data; and

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

12. The apparatus of claim 11, further comprising a driver circuit configured to send at least one signal to the circuit.

13. The apparatus of claim 12, further comprising a controller configured to send at least a portion of the image data to the driver circuit.

14. The apparatus of claim 11, further comprising an image source module configured to send the image data to the processor.

15. The apparatus of claim 14, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

16. The apparatus of claim 11, further comprising an input device configured to receive input data and to communicate the input data to the processor.

29. The device of claim 1, wherein the first display element is configured to reflectively output light indicative of the portion of the image and wherein the second display element is configured to emit light indicative of the portion of the image.

30. The device of claim 29, wherein the second display element is configured to output light from the device when the display element is configured to substantially absorb incident light.

31. The device of claim 12, wherein the portion of the image comprises a pixel.

17. A device for outputting light, the device comprising:

means for outputting light based on a voltage difference applied to the first display element;

means for outputting light based on a current applied to the second display element;

means for supplying the current to the second display element and for supplying the voltage difference to the first display element based on a first voltage level indicative of a portion of an image, wherein the supplying means is further configured to selectively supply the current based on a second voltage level indicative of the portion of the image.

18. The device of claim 17, wherein the means for outputting light based on a voltage difference comprises an interferometric modulator configured to reflectively output light.

19. The device of claim 18, wherein the interferometric modulator is configured to substantially absorb incident light when the current is below a specified level and configured to reflect light when the current exceeds the specified level.

20. The device of claim 17, wherein the means for outputting light based on a current comprises a light emitting diode.

21. The device of claim 20, wherein the light emitting diode comprises an organic light emitting diode.

22. The device of claim 17, wherein the supplying means comprises an active matrix element.

23. The device of claim 17, wherein the means for outputting light based on a voltage difference comprises a first electrode and a second electrode, wherein the output light is based on the voltage difference applied between the first and second electrode.

24. The device of claim 23, wherein the supplying means comprises:

a capacitor connected in parallel to the first display element.

25. The device of claim 24, wherein the supplying means further comprises:

a transistor having a gate connected to a first electrode of the capacitor, wherein the transistor is configured to provide the current from an source of the transistor.

26. The device of claim 25, wherein the gate of the transistor is further connected to the first electrode of the means for outputting light based on the voltage difference, wherein the first electrode of the capacitor, the first electrode of the means for outputting light based on the voltage difference, and the gate of the transistor are configured to receive the first voltage level indicative of a portion of the image, and wherein the second electrode of the means for outputting light based on the voltage difference, a second electrode of the capacitor, and an source of the transistor are configured to receive the second voltage level.

27. 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.

28. The method of claim 27, 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.