Display Device Including Ultrasonic Fingerprint Sensor

• US 20200134278A1
• Filed: 09/06/2019
• Published: 04/30/2020
• Est. Priority Date: 10/29/2018
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: LEE, Youngsoo, GONG, NamYong, LEE, NamSeok, KIM, Jinyeol, CHOI, SungPil, MIN, HyunJun
• Granted Patent: US 11,080,502 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1652 the display being flexible, e.g. mimicking a sheet of paper, or rollable
• CPC Class Codes: G06F 1/1684 Constructional details or arrangements related to integrated I/O peripherals not covered by groups G06F1/1635 - G06F1/1675
• CPC Class Codes: G06F 1/203 for portable computers, e.g. for laptops
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: H05K 1/0278 Rigid circuit boards or rigid supports of circuit boards locally made bendable, e.g. by removal or replacement of material
• CPC Class Codes: H05K 7/20454 with a conformable or flexible structure compensating for irregularities, e.g. cushion bags, thermal paste
• CPC Class Codes: H05K 9/0054 specially adapted for display applications

Abstract

A display device includes a flexible display panel, an ultrasonic fingerprint sensor which is disposed below a rear surface of an active area of the flexible display panel and has a first thickness and a first width, a cushion structure which is disposed below the rear surface of the flexible display panel, surrounds the periphery of the ultrasonic fingerprint sensor, and has a second thickness larger than the first thickness, and a circuit board which is electrically connected to the ultrasonic fingerprint sensor and has a second width larger than the first width.

Claims

1. A display device comprising:

a flexible display panel including an active area for emitting light;

an ultrasonic fingerprint sensor disposed below the active area of the flexible display panel, the ultrasonic fingerprint sensor spaced apart from a rear surface of the flexible display panel in a first direction;

a cushion structure disposed below the flexible display panel, and disposed adjacent the ultrasonic fingerprint sensor in a second direction different from the first direction; and

a circuit board electrically connected to the ultrasonic fingerprint sensor.

2. The display device of claim 1, wherein the flexible display panel has a first thickness along the first direction and a first width along the second direction, wherein the circuit board has a second width along the second direction larger than the first width.

3. The display device of claim 1,

wherein an area of the circuit board is larger than an area of the ultrasonic fingerprint sensor, and wherein the circuit board is disposed below at least a part of the cushion structure.

4. The display device of claim 1,

wherein the ultrasonic fingerprint sensor is mounted to the circuit board such that the ultrasonic fingerprint sensor does not directly contact the flexible display panel.

5. The display device of claim 1, further comprising:

an adhesive layer disposed between the ultrasonic fingerprint sensor and the flexible display panel.

6. The display device of claim 5,

wherein a thickness of the thermosetting adhesive layer along the first direction is 3 μ

m or more.

7. The display device of claim 1,

wherein the ultrasonic fingerprint sensor is spaced apart from at least a part of the cushion structure in the second direction to create a separation space between the ultrasonic fingerprint sensor and the part of the cushion structure.

8. The display device of claim 7,

wherein at least another part of the cushion structure is disposed on a top surface of the ultrasonic fingerprint sensor and covers the separation space.

9. The display device of claim 8,

wherein the cushion structure includes a black layer disposed between the flexible display panel and the ultrasonic fingerprint sensor, and wherein at least a part of the black layer covers the separation space.

10. The display device of claim 7,

wherein the circuit board is disposed below the ultrasonic fingerprint sensor, and covers the separation space from a rear surface of the ultrasonic fingerprint sensor.

11. The display device of claim 7,

wherein the cushion structure includes a shock absorbing layer, and wherein at least a part of the shock absorbing layer is spaced apart from the ultrasonic fingerprint sensor.

12. The display device of claim 11,

wherein the cushion structure further includes an adhesive layer disposed on the shock absorbing layer,

wherein the adhesive layer overlaps with the shock absorbing layer and is disposed on the ultrasonic fingerprint sensor to adhere to the ultrasonic fingerprint sensor.

13. The display device of claim 1,

wherein the cushion structure includes a heat dissipation layer, and wherein the heat dissipation layer contacts with the circuit board.

14. The display device of claim 13,

wherein the heat dissipation layer is electrically connected to at least a part of the circuit board.

15. The display device of claim 13,

wherein the heat dissipation layer is electrically grounded.

16. The display device of claim 1, further comprising:

a shielding layer disposed between the ultrasonic fingerprint sensor and the flexible display panel, the shielding layer formed of metal and configured to block interference between a signal generated from the flexible display panel and a signal generated from the ultrasonic fingerprint sensor.

17. The display device of claim 16, wherein the cushion structure includes a heat dissipation layer, and

wherein the shielding layer is electrically connected to the heat dissipation layer.

18. A display device comprising:

a flexible display panel including an active area for emitting light;

an ultrasonic fingerprint sensor disposed below the active area of the flexible display panel;

a cushion structure disposed below the flexible display panel in a first direction, and disposed adjacent the ultrasonic fingerprint sensor in a second direction different from the first direction; and

a circuit board electrically connected to the ultrasonic fingerprint sensor.

19. The display device of claim 18,

wherein the cushion structure is formed with an opening area, and wherein the ultrasonic fingerprint sensor is disposed within the opening area of the cushion structure.

20. The display device of claim 18,

wherein the circuit board is disposed below the ultrasonic fingerprint sensor and configured to cover the opening area from a rear surface of the ultrasonic fingerprint sensor.