ELECTROLUMINESCENT DISPLAY DEVICE WITH OPTICALLY COMMUNICATING CHIPLETS

• US 20120212465A1
• Filed: 02/17/2011
• Published: 08/23/2012
• Est. Priority Date: 02/17/2011
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Inventors: WHITE, Christopher J., Cok, Ronald S., Hamer, John W., Arnold, Andrew
• Granted Patent: US 8,587,501 B2
• Time in Patent Office: Days
• US Class Current: 345/205
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2360/142 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 2360/148 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 2370/18 Use of optical transmission of display information
• CPC Class Codes: G09G 3/2085 Special arrangements for addressing the individual elements of the matrix, other than by driving respective rows and columns in combination
• CPC Class Codes: G09G 3/30 using electroluminescent panels
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/1446 in a repetitive configuration
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H10K 59/129 Chiplets

Abstract

An electroluminescent display includes a display substrate, a plurality of patterned first electrodes formed over the display substrate, one or more layers of light-emitting material formed over the plurality of first electrodes, at least one second electrode formed over the one or more layers of light-emitting material, and a plurality of chiplets. Each chiplet is electrically connected to a first electrode. Each chiplet further includes a light detector and a light emitter separate from the one-or-more layers of light-emitting material connected to the chiplet circuitry. The chiplet circuitry includes a modulating circuit for modulating light emitted by the light emitter and a demodulating circuit for demodulating light detected by the light detector so that light emitted by the light emitter of a first chiplet is received by the light detector of a second chiplet.

Claims

1. An electroluminescent display, comprising:

(a) a display substrate having a device side and a display area;

(b) a plurality of patterned first electrodes formed over the display substrate device side in the display area, one or more layers of light-emitting material formed over the plurality of first electrodes, and at least one second electrode formed over the one or more layers of light-emitting material, the first and second electrodes providing current to cause the light-emitting material to emit light in a light-emitting area within the display area;

(c) a plurality of chiplets, each chiplet having;

a chiplet substrate separate and independent from the display substrate located over, and adhered to, the device substrate device side in the display area;

one or more connection pads; and

a chiplet circuit formed in the chiplet, the chiplet circuit electrically connected to one or more connection pads and at least one connection pad electrically connected to a first electrode; and

(d) wherein each chiplet further includes a light detector and a light emitter separate from the one-or-more layers of light-emitting material connected to the chiplet circuitry arranged so that light emitted by the light emitter of a first chiplet is received by the light detector of a second chiplet and the chiplet circuitry includes a modulating circuit for modulating light emitted by the light emitter and a demodulating circuit for demodulating light detected by the light detector.

2. The electroluminescent display of claim 1, wherein the chiplet circuit includes circuitry for controlling current flow between the first and second electrodes.

3. The electroluminescent display of claim 1, further comprising at least one transparent layer extending over or around at least a portion of the chiplets and wherein the light emitter emits light into the transparent layer.

4. The electroluminescent display of claim 1, wherein the display substrate is transparent and wherein light emitted by the light emitter in at least one chiplet is transmitted or reflected by the display substrate. 5

5. The electroluminescent display of claim 1, further comprising a cover that reflects or transmits light emitted by the light emitter in at least one chiplet.

6. The electroluminescent display of claim 1, further comprising an optical waveguide structure that extends from the first chiplet to the second chiplet and transmits light emitted by the light emitter of the first chiplet into the waveguide structure.

7. The electroluminescent display of claim 6, further comprising a controller external to the display substrate, the controller including a controller optical light emitter that emits light into the display substrate or waveguide structure.

8. The electroluminescent display of claim 1, wherein the modulated light is modulated according to image information.

9. The electroluminescent display of claim 1, wherein the modulating circuit temporally modulates the light emitted by the light emitter.

10. A method of operating an electroluminescent display, comprising:

a) providing an electroluminescent display according to claim 1;

b) providing a display controller external to the electroluminescent display;

c) communicating information from the display controller to at least the first chiplet in the electroluminescent display;

d) optically communicating information from the first chiplet to the second chiplet in the electroluminescent display by modulating light emitted from the first chiplet light emitter and detecting and demodulating the modulated light using the second chiplet light detector; and

e) driving the first electrodes connected to each chiplet in accordance with the information to cause at least a portion of the light-emitting layer to emit light.

11. The method of claim 10, wherein the light emitted by the first chiplet light emitter is detected by all of the chiplet light detectors.

12. The method of claim 10, wherein the light emitted by the first chiplet light emitter is transmitted to only the light detector in the second chiplet.

13. The method of claim 10, wherein the light emitted by the first chiplet light emitter is transmitted through, or reflected from, the display substrate.

14. The method of claim 10, further including providing at least one transparent layer extending over or around at least a portion of the first and second chiplets and wherein light emitted by the first chiplet light emitter is transmitted into the transparent layer.

15. The method of claim 10, further including providing a cover adhered to the display substrate and wherein light emitted by the first chiplet is transmitted through, or reflected from, the cover.

16. The method of claim 10, further including providing a controller external to the display substrate that emits modulated light into the display substrate to communicate information to one or more chiplets.

17. The method of claim 10, wherein the modulated light emitted by the first chiplet is broadcast and detected by multiple other chiplets.

18. The method of claim 10, wherein the modulated light emitted by the first chiplet is detected by only one of the other chiplets.

19. The method of claim 10, wherein the light modulation is temporal modulation.