OLED display having TFT integrated with photodetectors

Patent metadata

Field	Value
Publication number	US-11527587-B2
Application number	US-202016789359-A
Country	US
Kind code	B2
Filing date	Feb 12, 2020
Priority date	Jun 17, 2019
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

An electronic device includes a display screen that includes a cover glass, and a display illumination layer. The display illumination layer includes an array of light-emitting elements that forms an array of pixels of the display screen. The electronic device further includes a light source disposed adjacent the cover glass and configured to emit a light beam to be coupled into the cover glass. A portion of the light beam may be transmitted through the top surface of the cover glass to illuminate a hand of a user. The electronic device further includes an optical ID sensing module that includes an array of photodetectors disposed under the array of light-emitting elements and spatially distributed across the array of pixels of the display screen, and electronic circuitry coupled to the array of photodetectors and configured to capture a fingerprint image or a palmprint image of the hand.

First claim

What is claimed is:

1. An electronic device comprising:
a display screen comprising:
a cover glass having a top surface and a bottom surface; and
a display illumination layer disposed under the cover glass, the display illumination layer including an array of light-emitting elements that forms an array of pixels of the display screen, wherein the display illumination layer comprises an edge side;

a light source disposed adjacent the cover glass and at the edge side of the display illumination layer, the light source configured to emit a light beam to be coupled into the cover glass, a portion of the light beam being transmitted through the top surface of the cover glass to illuminate a hand of a user placed adjacent the top surface of the cover glass; and
an optical ID sensing module comprising:
an array of photodetectors disposed under the array of light-emitting elements and spatially distributed across the array of pixels of the display screen, the array of photodetectors configured to detect light reflected or scattered by the hand illuminated by the light source; and
electronic circuitry coupled to the array of photodetectors and configured to capture a fingerprint image or a palmprint image of the hand.

2. The electronic device of claim 1 , wherein the cover glass has an edge, the light source is disposed against the edge of the cover glass, and the light beam emitted by the light source is coupled into the cover glass through the edge of the cover glass.

3. The electronic device of claim 1 , wherein the light source is disposed under the bottom surface of the cover glass, and the light beam emitted by the light source is coupled into the cover glass through the bottom surface of the cover glass.

4. The electronic device of claim 3 , further comprising:
a dark coating applied to a border of the bottom surface of the cover glass;
wherein the light source is disposed under the dark coating, and is configured to emit the light beam in a first wavelength range; and
wherein the dark coating is at least partially transparent in the first wavelength range.

5. The electronic device of claim 4 , the first wavelength range includes a near infrared (NIR) wavelength range, or an ultraviolet (UV) wavelength range.

6. The electronic device of claim 1 , wherein the cover glass has a slanted surface at an edge thereof, and wherein the light source is disposed under the bottom surface of the cover glass adjacent the edge, the slanted surface configured to reflect the light beam emitted by the light source and coupled into the cover glass.

7. The electronic device of claim 6 , further comprising a high-reflection coating applied to the slanted surface of the cover glass.

8. The electronic device of claim 6 , wherein the slanted surface forms an angle with respect to the top surface of the cover glass, the angle ranging from about 100 degrees to about 175 degrees.

9. The electronic device of claim 6 , further comprising a dark coating applied to an area of the bottom surface of the cover glass that is adjacent the edge, the dark coating exposing the light source.

10. The electronic device of claim 1 , wherein the light source comprises a light-emitting diode (LED), a laser diode (LD), or a vertical-cavity surface-emitting lasers (VCSEL).

11. The electronic device of claim 1 , wherein the light source is configured to emit the light beam in a near infrared (NIR) wavelength range, an ultraviolet (UV) wavelength range, or a visible wavelength range.

12. The electronic device of claim 1 , wherein the array of light-emitting elements comprises a plurality of organic light-emitting diodes (OLEDs).

13. The electronic device of claim 1 , wherein the display screen further comprises a touch sensing layer disposed between the cover glass and the display illumination layer.

14. The electronic device of claim 1 , wherein the array of photodetectors and the array of light-emitting elements are formed in a common layer.

15. The electronic device of claim 1 , wherein the display illumination layer comprises a first layer and a second layer under the first layer, wherein the array of light-emitting elements is disposed in the first layer, the display illumination layer further comprises:
an array of thin film transistors (TFTs) disposed in the second layer, wherein the array of photodetectors is disposed in the second layer.

16. The electronic device of claim 1 , further comprising:
a processor communicatively coupled to the optical ID sensing module, the display screen, and the light source, the processor configured to:
detect a trigger event for operating the optical ID sensing module; and
in response to detecting the trigger event:
turn off the array of light-emitting elements in the display illumination layer;
turn on the light source; and
cause the optical ID sensing module to capture the fingerprint image or the palmprint image of the hand illuminated by the light source.

17. An electronic device comprising:
a display screen comprising:
a cover glass;
a transparent layer disposed under the cover glass, the transparent layer having an edge side; and
an array of light-emitting elements disposed under the transparent layer, the array of light-emitting elements forming an array of pixels of the display screen;

a light source disposed at the edge side of the transparent layer, the light source configured to emit a light beam to be coupled into the transparent layer through the edge side, a portion of the light beam being transmitted through the cover glass to illuminate a hand of a user placed adjacent the cover glass; and
an optical ID sensing module comprising:
an array of photodetectors disposed under the array of light-emitting elements and spatially distributed across the array of pixels of the display screen, the array of photodetectors configured to detect light reflected or scattered by the hand illuminated by the light source; and
electronic circuitry coupled to the array of photodetectors and configured to capture a fingerprint image or a palmprint image of the hand.

18. The electronic device of claim 17 , wherein the transparent layer comprises touch sensing circuitries.

19. The electronic device of claim 17 , wherein the array of light-emitting elements comprises a plurality of organic light-emitting diodes (OLEDs).

20. The electronic device of claim 17 , wherein the light source comprises a light-emitting diode (LED), a laser diode (LD), or a vertical-cavity surface-emitting lasers (VCSEL).

21. The electronic device of claim 17 , wherein the light source is configured to emit the light beam in a near infrared (NIR) wavelength range, an ultraviolet (UV) wavelength range, or a visible wavelength range.

22. The electronic device of claim 17 , wherein the display screen further comprises a dark coating applied to a back surface of the cover glass at a border of the display screen, and wherein the light source is disposed under the dark coating.

23. The electronic device of claim 17 , wherein the array of photodetectors and the array of light-emitting elements are formed in a common layer.

24. The electronic device of claim 17 , wherein:
the array of light-emitting elements is formed in a first layer; and
the array of photodetectors is formed in a second layer under the first layer.

25. The electronic device of claim 24 , wherein the second layer includes thin film transistors (TFTs) of the displ

Assignees

• Shenzhen Goodix Tech Co Ltd

Inventors

• He Yi
• Pi Bo

Classifications

• G06V40/1306

  non-optical, e.g. ultrasonic or capacitive sensing · CPC title

• G06V40/1318

  using electro-optical elements or layers, e.g. electroluminescent sensing · CPC title

• H01L27/3234 Primary

  Electricity · mapped topic

• G06F21/32 Primary

  using biometric data, e.g. fingerprints, iris scans or voiceprints · CPC title

• H01L27/323

  Electricity · mapped topic