Flexible display device and method for detecting bending state thereof

Patent metadata

Field	Value
Publication number	US-10614757-B2
Application number	US-201615770526-A
Country	US
Kind code	B2
Filing date	Nov 25, 2016
Priority date	Dec 2, 2015
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

An organic EL panel 10 is a bendable display panel including a plurality of pixel circuits 60 each having a light emitting element and a drive element. A data line drive circuit 15 performs, by driving data lines, an operation of writing a voltage to a control terminal of the drive element and an operation of measuring a current flowing through the drive element for the pixel circuits 60 selected by a scanning line drive circuit 14. A bending detection unit 90 detects a bending state of the organic EL panel 10 based on a measurement result of the current flowing through the drive element. A correction unit 80 corrects a video signal VS1 based on the detected bending state. With this, the bending state of a screen is detected and a change in brightness or color when the screen is bent is prevented.

First claim

The invention claimed is:

1. A flexible display device comprising:
a bendable display panel including a plurality of scanning lines, a plurality of data lines, and a plurality of pixel circuits each including a light emitting element and a drive element;
a scanning line drive circuit that selects the plurality of pixel circuits by driving the plurality of scanning lines;
a data line drive circuit that performs, by driving the plurality of data lines, an operation of writing a voltage to a control terminal of the drive element, and an operation of measuring a current flowing through the drive element for each of the plurality of pixel circuits selected by the scanning line drive circuit;
bending detection circuitry that detects a bending state of the display panel based on a measurement result of the current flowing through the drive element; and
correction circuitry that corrects a video signal based on the bending state detected by the bending detection circuitry to compensate for a change of an amount of the current flowing through the drive element, the change caused by bending, wherein
the data line drive circuit applies, to the plurality of data lines, voltages based on the video signal corrected by the correction circuitry,
the correction circuitry obtains a first characteristic being an electrical characteristic of the drive element and a second characteristic being an electrical characteristic of the light emitting element, and
the bending detection circuitry estimates, based on the second characteristic, a third characteristic being the electrical characteristic of the drive element when the display panel is not bent, and detects the bending state of the display panel by comparing the first characteristic and the third characteristic.

2. The flexible display device according to claim 1 , wherein
the plurality of pixel circuits are either display pixel circuits or measurement pixel circuits, and
at least one of the display pixel circuits and at least one of the measurement pixel circuits are connected to a same scanning line of the plurality of scanning lines.

3. The flexible display device according to claim 1 , wherein
the plurality of pixel circuits are either display pixel circuits or measurement pixel circuits, and
at least one of the display pixel circuits and at least one of the measurement pixel circuits are connected to a same data line of the plurality of data lines.

4. The flexible display device according to claim 1 , wherein, among the plurality of pixel circuits, an arrangement of measurement pixel circuits is different from an arrangement of display pixel circuits.

5. The flexible display device according to claim 4 , wherein an arrangement interval of the measurement pixel circuits is different from an arrangement interval of the display pixel circuits.

6. The flexible display device according to claim 1 , wherein, among the plurality of pixel circuits, display pixel circuits and measurement pixel circuits are arranged inside a display area in a mixed manner.

7. The flexible display device according to claim 1 , wherein
a display area of the flexible display device has a rectangular shape, and
measurement pixel circuits included in the plurality of pixel circuits are arranged along two adjacent sides of the display area.

8. The flexible display device according to claim 1 , wherein one of the first to the third electrical characteristics of the drive element in a measurement pixel circuit is different from a corresponding one of the first to the third electrical characteristics of the drive element in a display pixel circuit.

9. A flexible display device comprising:
a bendable display panel including a plurality of scanning lines, a plurality of data lines, and a plurality of pixel circuits each including a light emitting element and a drive element;
a scanning line drive circuit that selects the plurality of pixel circuits by driving the plurality of scanning lines;
a data line drive circuit that performs, by driving the plurality of data lines, an operation of writing a voltage to a control terminal of the drive element and an operation of measuring a current flowing through the drive element for each of the plurality of pixel circuits selected by the scanning line drive circuit;
bending detection circuitry that detects a bending state of the display panel based on a measurement result of the current flowing through the drive element; and
correction circuitry that corrects a video signal based on the bending state detected by the bending detection circuitry, wherein
the data line drive circuit applies, to the plurality of data lines, voltages based on the video signal corrected by the correction circuitry, and
the correction circuitry corrects the video signal corresponding to a bent portion, to a non-display level.

10. The flexible display device according to claim 9 , wherein
the plurality of pixel circuits are either display pixel circuits or measurement pixel circuits, and
at least one of the display pixel circuits and at least one of the measurement pixel circuits are connected to a same scanning line of the plurality of scanning lines.

11. The flexible display device according to claim 9 , wherein
the plurality of pixel circuits are either display pixel circuits or measurement pixel circuits, and
at least one of the display pixel circuits and at least one of the measurement pixel circuits are connected to a same data line of the plurality of data lines.

12. The flexible display device according to claim 9 , wherein, among the plurality of pixel circuits, an arrangement of measurement pixel circuits is different from an arrangement of display pixel circuits.

13. The flexible display device according to claim 12 , wherein an arrangement interval of the measurement pixel circuits is different from an arrangement interval of the display pixel circuits.

14. The flexible display device according to claim 9 , wherein, among the plurality of pixel circuits, display pixel circuits and measurement pixel circuits are arranged inside a display area in a mixed manner.

15. The flexible display device according to claim 9 , wherein
a display area of the flexible display device has a rectangular shape, and
measurement pixel circuits of the plurality of pixel circuits are arranged along two adjacent sides of the display area.

16. The flexible display device according to claim 9 , wherein an electrical characteristic of the drive element in a measurement pixel circuit of the plurality of pixel circuits is different from an electrical characteristic of the drive element in a display pixel circuit of the plurality of pixel circuits.

Assignees

• Sharp Kk

Inventors

• Takizawa Kazuo
• Kishi Noritaka
• Gotoh Naoko
• Uchida Hideki
• Kikuchi Katsuhiro

Classifications

• G09G2320/0233

  Improving the luminance or brightness uniformity across the screen · CPC title

• G09G2320/0295

  by monitoring each display pixel · CPC title

• G09G2320/0693

  Calibration of display systems · CPC title

• G09G2380/02

  Flexible displays · CPC title

• G09G3/3233 Primary

  with pixel circuitry controlling the current through the light-emitting element · CPC title