FLEXIBLE DISPLAY DEVICE

• US 20170060283A1
• Filed: 08/24/2016
• Published: 03/02/2017
• Est. Priority Date: 08/26/2015
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: SOHN, Min-Ho, KANG, Sung-Jin, KWON, Su-Jin, CHOI, Yong-Kyun
• Granted Patent: US 10,564,744 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04102 Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G09G 2380/02 Flexible displays

Abstract

Disclosed herein is a flexible display device having a bending sensor mounted in a layer that is tensioned or a layer that is compressed in order to increase the magnitude of voltage output from the bending sensor. The flexible display device includes at least two bending sensors mounted in a layer that is tensioned and/or a layer that is compressed when the flexible display device, including a plurality of layers, is bent.

Claims

1. A flexible display device comprising:

first and second bend sensors positioned in at least one of a first layer that is tensioned and a second layer that is compressed when the flexible display device is bent.

2. The flexible display device according to claim 1, wherein the first bend sensor is positioned in the first layer, and the second bend sensor is positioned in the second layer.

3. The flexible display device according to claim 2, further comprising:

a bridge circuit including;

a first branch, in which the first bend sensor and a first resistor are coupled to each other in series, the first branch including a first output terminal positioned between the first bend sensor and the first resistor, and

a second branch, in which the second bend sensor and a second resistor are coupled to each other in series, the second branch including a second output terminal positioned between the second bend sensor and the second resistor, the first and second branches being coupled to a power source in parallel with respect to each other.

4. The flexible display device according to claim 2, further comprising:

a bridge circuit including;

a first branch, in which the first and second bend sensors are coupled to each other in series, the first branch including a first output terminal positioned between the first and second bend sensors, and

a second branch, in which a first resistor and a second resistor are coupled to each other in series, the second branch including a second output terminal positioned between the first and second resistors, the first and second branches being coupled to a power source in parallel with respect to each other.

5. The flexible display device according to claim 2, further comprising:

a bridge circuit including;

a first branch, in which first and second resistors are coupled to each other in series, the first branch including a first output terminal positioned between the first and second resistors, and

a second branch, in which the first and second bend sensors are coupled to each other in series, the second branch including a second output terminal positioned between the first and second bend sensors, the first and second branches being coupled to a power source in parallel with respect to each other.

6. The flexible display device according to claim 1, wherein the first and second bend sensors are positioned in the first layer that is tensioned when the flexible display device is bent.

7. The flexible display device according to claim 6, further comprising:

a bridge circuit including;

a first branch, in which the first bend sensor and a first resistor are coupled to each other in series, the first branch including a first output terminal positioned between the first bend sensor and the first resistor, and

a second branch, in which the second bend sensor and a second resistor are coupled to each other in series, the first and second branches being coupled to a power source in parallel with respect to each other, the first bend sensor being coupled between the first output terminal and a first power source terminal, the second bend sensor being coupled between the second output terminal and a second power source terminal.

8. The flexible display device according to claim 1, wherein the first and second bend sensors are positioned in the second layer that is compressed when the flexible display device is bent.

9. The flexible display device according to claim 8, further comprising:

a bridge circuit including;

a first branch, in which the first bend sensor and a first resistor are coupled to each other in series, the first branch including a first output terminal positioned between the first bend sensor and the first resistor, and

a second branch, in which the second bend sensor and a second resistor are coupled to each other in series, the first and second branches being coupled to a power source in parallel with respect to each other, the first bend sensor being coupled between the first output terminal and a first power source terminal, the second bend sensor being coupled between the second output terminal and a second power source terminal.

10. The flexible display device according to claim 1, further comprising:

third and fourth bend sensors, wherein the first and second bend sensors are positioned in the first layer that is tensioned when the flexible display device is bent, and the third and fourth bend sensors are positioned in the second layer that is compressed when the flexible display device is bent.

11. The flexible display device according to claim 10, further comprising:

a bridge circuit including;

a first branch, in which the first and third bend sensors are coupled to each other in series, the first branch including a first output terminal positioned between the first and third bend sensors, and

a second branch, in which the second and fourth bend sensors are coupled to each other in series, the first and second branches being coupled to a power source in parallel with respect to each other.

12. A flexible display device, comprising:

a first layer;

a second layer on the first layer;

a first bend sensor formed in the first layer;

a second bend sensor formed in the second layer;

a bridge circuit including first and second branches coupled to a power source in parallel with respect to each other, the first and second branches including respective first and second output terminals, the first and second bend sensors being provided in at least one of the first and second branches; and

an amplifier having a first input terminal coupled to the first output terminal of the bridge circuit, and a second input terminal coupled to the second output terminal of the bridge circuit, the amplifier being configured to amplify a voltage difference between the first and second output terminals of the bridge circuit in response to bending the flexible display device.

13. The display device of claim 12, further comprising:

an analog-to-digital converter coupled to an output of the amplifier and configured to receive an amplified signal provided at the amplifier output; and

a microprocessor coupled to an output of the analog-to-digital converter.

14. The display device of claim 12, wherein the first layer is tensioned and the second layer is compressed in response to bending the flexible display device in a first direction, and the first layer is compressed and the second layer is tensioned in response to bending the flexible display device in a second direction opposite the first direction.

15. The display device of claim 12, wherein the first layer includes one of a pixel array layer and a touch sensor layer, and the second layer includes the other of the pixel array layer and the touch sensor layer.

16. The display device of claim 12, wherein the first branch includes a first resistor coupled in series to the first bend sensor, the first output terminal being positioned between the first bend sensor and the first resistor, and the second branch includes a second resistor coupled in series to the second bend sensor, the second output terminal being positioned between the second bend sensor and the second resistor.

17. The display device of claim 12, wherein the first branch includes the first bend sensor coupled in series to the second bend sensor, the first output terminal being positioned between the first and second bend sensors, and the second branch includes a first resistor coupled in series to a second resistor, the second output terminal being positioned between the first and second bend resistors.

18. The display device of claim 12, further comprising:

a third bend sensor formed in the first layer; and

a fourth bend sensor formed in the second layer,

wherein the first branch includes the first bend sensor coupled in series to the second bend sensor, the first output terminal being positioned between the first and second bend sensors, and the second branch includes the third bend sensor coupled in series to the fourth bend sensor, the second output terminal being positioned between the third and fourth bend sensors.

19. A method, comprising:

forming a first bend sensor in a first layer of a flexible display device;

forming a second bend sensor in a second layer of a flexible display device, the second layer being positioned on the first layer; and

forming a bridge circuit including first and second branches, the first and second branches including respective first and second output terminals, the first and second bend sensors being provided in at least one of the first and second branches,

wherein the first layer is tensioned and the second layer is compressed in response to bending the flexible display device in a first direction, and the first layer is compressed and the second layer is tensioned in response to bending the flexible display device in a second direction opposite the first direction.

20. The method of claim 19, wherein forming the bridge circuit includes:

forming the first branch by coupling a first resistor in series to the first bend sensor, the first output terminal being positioned between the first bend sensor and the first resistor; and

forming the second branch by coupling a second resistor in series to the second bend sensor, the second output terminal being positioned between the second bend sensor and the second resistor.

21. The method of claim 19, wherein forming the bridge circuit includes:

forming the first branch by coupling the first bend sensor in series to the second bend sensor, the first output terminal being positioned between the first and second bend sensors; and

forming the second branch by coupling a first resistor in series to a second resistor, the second output terminal being positioned between the first and second bend resistors.

22. The method of claim 19, further comprising:

forming a third bend sensor in the first layer of the flexible display device; and

forming a fourth bend sensor in the second layer of the flexible display device,

wherein forming the bridge circuit includes;

forming the first branch by coupling the first bend sensor in series to the second bend sensor, the first output terminal being positioned between the first and second bend sensors; and

forming the second branch by coupling the third bend sensor in series to the fourth bend sensor, the second output terminal being positioned between the third and fourth bend sensors.