Display with micro-LED front light

• US 10,133,426 B2
• Filed: 09/09/2015
• Issued: 11/20/2018
• Est. Priority Date: 06/18/2015
• Status: Active Grant

• Current Assignee: X Display Company Technology Limited (Sensinnovat BVBA)
• Original Assignee: X-Celeprint Limited
• Inventors: Den Boer, Willem, Cok, Ronald S.
• Primary Examiner(s): Balaoing, Ariel
• Application Number:
  US14/849,242
• Publication Number:
  US 20170068362A1
• Time in Patent Office: 1,168 Days
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/133601 for spatial active dimming
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133616 Front illuminating devices
• CPC Class Codes: G02F 2201/50 Protective arrangements
• CPC Class Codes: G02F 2203/02 reflective
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 33/60 : Reflective elements
• CPC Class Codes: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A reflective display includes an array of reflective pixels in or beneath a display viewing area for viewing electronically displayed information. A layer is located on or over the display viewing area through which the display viewing area is viewed and a plurality of micro-LEDs is located on the layer in the display viewing area and arranged to emit light toward the display viewing area. A plurality of conductors is located on the layer and the conductors are electrically connected to the micro-LEDs. A controller is connected to the conductors to control the micro-LEDs to emit light illuminating the display viewing area.

Claims

1. A reflective display, comprising:

an array of reflective pixels in or beneath a reflective display viewing area for electronically displaying information to be viewed, wherein each reflective pixel in the array of reflective pixels is a reflective element that controllably absorbs or reflects light and the array of reflective pixels is operable to form an image under control of a display controller;

a layer located on or over the reflective display viewing area, the layer comprising;

a plurality of micro-LEDs positioned in or on the layer within the x-y boundaries of the reflective display viewing area and oriented to emit light toward the reflective display viewing area; and

a plurality of conductors positioned on or in the layer and electrically connected to the plurality of micro-LEDs; and

a controller connected to the plurality of conductors to control the plurality of micro-LEDs to emit light illuminating the reflective display viewing area.

2. The reflective display of claim 1, wherein the layer is a display cover or substrate.

3. The reflective display of claim 1, wherein the plurality of micro-LEDs have an emitting face and are positioned on or in the layer such that there is a gap between the emitting face of the plurality of micro-LEDs and the surface of the reflective display viewing area.

4. The reflective display of claim 1, wherein the micro-LEDs in the plurality of micro-LEDs are inorganic micro-LEDs.

5. The reflective display of claim 1, wherein one or more of the plurality of micro-LEDs emits white light.

6. The reflective display of claim 1, wherein the plurality of micro-LEDs comprises red micro-LEDs that emit red light, green micro-LEDs that emit green light, and blue micro-LEDs that emit blue light.

7. The reflective display of claim 6, wherein the red micro-LEDs are located adjacent to green micro-LEDs, adjacent to blue micro-LEDs, or adjacent to both green and blue micro-LEDs.

8. The reflective display of claim 6, wherein the plurality of micro-LEDs is disposed in rows comprising red, green, and blue micro-LEDs and the micro-LEDs in adjacent rows are spatially offset or the colors of micro-LEDs in adjacent rows are spatially offset.

9. The reflective display of claim 6, wherein the plurality of micro-LEDs is disposed in two or more groups each comprising one red, one green, and one blue micro-LED and wherein the distance between the micro-LEDs within a group is less than the distance between the groups of micro-LEDs.

10. The reflective display of claim 1, wherein the layer has a first side adjacent to the reflective display viewing area and a second side opposite the first side, and the reflective display comprises a touch sensor comprising a pattern of electrodes formed on the first side, on the second side, or on both the first side and the second side.

11. The reflective display of claim 10, wherein the controller comprises a control circuit that provides electrical power to the plurality of conductors to emit light from the plurality of micro-LEDs and separately provides signals to the electrodes of the pattern of electrodes to detect touches on or near the layer or the reflective display.

12. The reflective display of claim 11, wherein the pattern of electrodes comprises an array of electrodes electrically separate from the plurality of conductors, wherein at least one of (i) the plurality of conductors and (ii) the plurality of micro-LEDs are disposed between the two of the plurality of electrodes.

13. The reflective display of claim 12, wherein the touch sensor comprises a pattern of electrodes on the first side and on the second side and the electrodes pattern of electrodes on the first side forms an array of electrically separate first electrodes extending in a first direction and the electrodes of the pattern of electrodes on the second side forms an array of electrically separate second electrodes extending in a second direction, wherein the second direction is different from the first direction.

14. The reflective display of claim 10, wherein the controller comprises a control circuit that provides electrical power to the plurality of conductors to emit light from the plurality of micro-LEDs during a first time period and provides signals to the pattern of electrodes to detect touches during a second time period different from the first time period.

15. The reflective display of claim 10, wherein the pattern of electrodes comprises the plurality of conductors, the pattern of electrodes are formed in an array of parallel electrodes, and each of the plurality of micro-LEDs is connected to a pair of adjacent electrodes.

16. The reflective display of claim 10, wherein the pattern of electrodes comprises the plurality of conductors, the pattern of electrodes forms an array of electrically separate first electrodes extending in a first direction and an array of electrically separate second electrodes extending in a second direction that is different from the first direction, and each micro-LED is connected to a first electrode and a second electrode.

17. The reflective display of claim 1, comprising an array of touch controller chiplets distributed over the display area each electrically connected to one or more electrically separate electrodes to detect touches on or adjacent to the one or more electrodes.

21. The reflective display of claim 1, wherein the layer is a transparent layer.

22. The reflective display of claim 21, wherein the transparent layer has a transparency greater than or equal to 50% for visible light.

23. The reflective display of claim 1, comprising the display controller.

24. The reflective display of claim 23, wherein the controller is the display controller.

25. The reflective display of claim 23, wherein the controller comprises a control circuit that controls the micro-LEDs responsive to the image displayed on the reflective display to provide front light dimming.

18. A method of operating a reflective display, comprising:

providing the reflective display, wherein the reflective display comprises;

an array of reflective pixels in or beneath a reflective display viewing area for electronically displaying information to be viewed, wherein each reflective pixel in the array of reflective pixels is a reflective element that controllably absorbs or reflects light and the array of reflective pixels is operable to form an image under control of a display controller;

a layer located on or over the reflective display viewing area, the layer comprising;

a plurality of micro-LEDs positioned in or on the layer within the x-y boundaries of the reflective display viewing area and oriented to emit light toward the reflective display viewing area; and

a plurality of conductors positioned on or in the layer and electrically connected to the plurality of micro-LEDs;

a controller connected to the conductors to control the plurality of micro-LEDs to emit light illuminating the reflective display viewing area; and

an array of electrodes electrically separate from the plurality of conductors;

controlling, by the controller, the plurality of micro-LEDs to emit light and the array of electrodes to detect a touch.

19. The method of claim 18, wherein the controller controls the plurality of micro-LEDs to emit light at the same time as a touch is detected.

20. The method of claim 18, wherein the controller controls the plurality of micro-LEDs to emit light during a first time period and detects a touch with the array of electrodes during a second time period different from the first time period.

26. The method of claim 18, wherein the reflective display comprises the display controller.