Foldable display and driving method thereof

Patent metadata

Field	Value
Publication number	US-11100900-B2
Application number	US-202016886554-A
Country	US
Kind code	B2
Filing date	May 28, 2020
Priority date	Jun 12, 2019
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

A foldable display comprises a flexible display panel including a screen which displays an image; a measuring part configured to measure a folding angle of the flexible display panel; and an image processor configured to vary a size of the image displayed on the screen and a size of a black pattern displayed on the screen of the flexible display panel while the folding angle of the flexible display panel is varied.

First claim

What is claimed is:

1. A foldable display comprising:
a flexible display panel including a screen which displays an image;
a measuring part configured to measure a folding angle of the flexible display panel; and
an image processor configured to vary a size of the image displayed on the screen and a size of a black pattern displayed on the screen of the flexible display panel while the folding angle of the flexible display panel is varied,
a display panel driver configured to activate an entire screen of the flexible display panel to display the image on a maximum screen when the flexible display panel is in an unfolded state and activate a part of the screen when the flexible display panel is in a folded state to display the image on an activated screen and display the black pattern on a non-activated screen; and
a gate driver divided into two or more gate drivers and driving a screen without applying data voltages to pixels of the non-activated screen in the folded state of the foldable display,
while the flexible display panel is folding, the size of the black pattern on the screen gradually increases as the size of the image on the screen decreases, and
while the flexible display panel is unfolding, the size of the black pattern on the screen gradually decreases as the size of the image on the screen increases.

2. The foldable display of claim 1 , wherein the image processor gradually varies a size and a resolution of the image during a switching time between the unfolded state and the folded state of the flexible display panel.

3. The foldable display of claim 2 , wherein the image processor gradually decreases the resolution of the image and gradually enlarges the size of the black pattern while the unfolded state of the flexible display panel is switched to the folded state of the flexible display panel.

4. The foldable display of claim 2 , wherein the image processor gradually increases the resolution of the image and gradually reduces the size of the black pattern while the folded state of the flexible display panel is switched to the unfolded state of the flexible display panel.

5. The foldable display of claim 2 , wherein, the image processor shifts pixel data of the image in one direction and gradually varies the resolution of the image while the folding angle of the flexible display panel is varied.

6. The foldable display of claim 2 , wherein the image processor gradually varies a size of a fan-shaped area in which the black pattern is displayed and gradually varies a size of an activated area in which the image is displayed while the folding angle of the flexible display panel is varied.

7. A foldable display comprising:
a flexible display panel including a screen which displays an image;
a measuring part configured to measure a folding angle of the flexible display panel; and
an image processor configured to vary a size of the image displayed on the screen and a size of a black pattern displayed on the screen of the flexible display panel while the folding angle of the flexible display panel is varied,
while the flexible display panel is folding, the size of the black pattern on the screen gradually increases as the size of the image on the screen decreases, and
while the flexible display panel is unfolding, the size of the black pattern on the screen gradually decreases as the size of the image on the screen increases.

8. The foldable display of claim 7 , wherein the measuring part measures the folding angle of the flexible display panel based on a resistance value of a wiring line formed on the flexible display panel.

9. The foldable display of claim 7 , wherein the measuring part measures the folding angle of the flexible display panel based on resistance of a support element that supports the flexible display panel.

10. The foldable display of claim 7 , wherein the measuring part measures resistance of a folding boundary on the screen of which a curvature is varied according to the folding angle of the flexible display panel.

11. The foldable display of claim 7 , further comprising a display panel driver configured to activate an entire screen of the flexible display panel to display the image on a maximum screen when the flexible display panel is in an unfolded state and activate a part of the screen when the flexible display panel is in a folded state to display the image on an activated screen that is smaller than the maximum screen and display the black pattern on a non-activated screen.

12. The foldable display of claim 11 , wherein the image processor gradually varies a size and a resolution of the image during a switching time between the unfolded state and the folded state of the flexible display panel.

13. The foldable display of claim 12 , wherein the image processor gradually decreases the resolution of the image and gradually enlarges the size of the black pattern while the unfolded state of the flexible display panel is switched to the folded state of the flexible display panel.

14. The foldable display of claim 12 , wherein the image processor gradually increases the resolution of the image and gradually reduces the size of the black pattern while the folded state of the flexible display panel is switched to the unfolded state of the flexible display panel.

15. The foldable display of claim 12 , wherein, the image processor shifts pixel data of the image in one direction and gradually varies the resolution of the image while the folding angle of the flexible display panel is varied.

16. The foldable display of claim 12 , wherein the image processor gradually varies a size of a fan-shaped area in which the black pattern is displayed and gradually varies a size of an activated area in which the image is displayed while the folding angle of the flexible display panel is varied.

17. The foldable display of claim 11 , wherein the screen of the flexible display panel includes data lines to which data voltages are applied, gate lines which cross the data lines and to which gate signals are applied, and a plurality of pixels disposed in a form of a matrix,
wherein each of the pixels includes:
a light emitting element;
a drive element disposed between a pixel driving voltage and the light emitting element to supply a current to the light emitting element; and
a capacitor connected between a first power line to which the pixel driving voltage is applied and a first node to which an initialization voltage is applied, and
wherein the gate signal includes:
a scan signal synchronized with a data voltage of an input image in the activated screen and controlling a switching element connected to an anode of the light emitting element in the non-activated screen to supply an initialization signal, which suppresses light emission of the light emitting element, to the anode of the light emitting element; and
a light emission control signal which switches a current path of the light emitting element.

18. The foldable display of claim 17 , wherein the drive element includes a first electrode connected to the first node, a gate connected to a second node, and a second electrode connected to a third node,
wherein each of the pixels includes:
a first switching element turned on in response to a gate-on voltage pulse of an Nth scan signal (N being a natural number) to connect the second node to the third node;
a second switching element turned on in response to the gate-on voltage pulse of the Nth scan signal to connect the data line to the first node;
a third switching element turned on in response to a gate-on voltage of the lig

Assignees

• Lg Display Co Ltd

Inventors

• Park Myung Jong
• Oh Dae Seok
• Jung Jin Woo

Classifications

• G01B7/30

  for measuring angles or tapers; for testing the alignment of axes · CPC title

• G09G2300/0861

  with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes · CPC title

• G09G5/373 Primary

  for modifying the size of the graphic pattern · CPC title

• G09F9/301 Primary

  flexible foldable or roll-able electronic displays, e.g. thin LCD, OLED · CPC title

• G09G2310/0262

  The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes · CPC title