Search

US-12619282-B2 - Rollable display apparatus

US12619282B2US 12619282 B2US12619282 B2US 12619282B2US-12619282-B2

Abstract

A rollable display apparatus including a display panel having a threshold curvature radius; a roller, having a curvature radius equal to or larger than the threshold curvature radius, attached to one side of the display panel and configured to allow the display panel to be rolled-up; and a curved surface member, spaced apart from the roller, having a curvature radius equal to or larger than the threshold curvature radius in an area in contact with the display panel, configured to bend the display panel in a direction opposite to a direction in which the display panel is rolled by the roller.

Inventors

  • NhoHoon MYOUNG

Assignees

  • LG DISPLAY CO., LTD.

Dates

Publication Date
20260505
Application Date
20220308
Priority Date
20180921

Claims (10)

  1. 1 . A flexible organic light emitting diode display apparatus comprising: a display panel having a display area where a plurality of pixels are disposed and a non-display area which is a periphery area of the display area, each of the plurality of pixels having bottom emission type electroluminescence element including a first electrode, an electroluminescence layer on the first electrode, and a second electrode on the electroluminescence layer, a driving unit disposed in the non-display area and having a gate driver configured to supply a scan signal and a data driver configured to supply a video signal, a first roller fixed to one side of the display panel; a second roller disposed on an upper side; and a housing including a cavity, the display panel, the first roller, and the second roller are disposed in the cavity of the housing, wherein the housing includes a first edge of the housing and a second edge of the housing that is opposite the first edge of the housing and spaced apart from the first edge of the housing such that an opening is formed between an end of the first edge of the housing and an end of the second edge of the housing, and wherein the display panel moving through the opening includes a first side and a second side opposite to the first side, wherein each of a curvature radius of the first edge of the housing which is in contact with the first side and a curvature radius of the second edge of the housing which is in contact with the second side is equal to or larger than a threshold curvature radius of the display panel, wherein the first edge of the housing is in direct contact with the first side and the second edge of the housing is in direct contact with the second side that is opposite the first side while the first edge of the housing is in direct contact with the first side as the display panel extends out of the housing through the opening or extends into the housing through the opening, and wherein all regions of the first edge of the housing that are in direct contact with the first side and all regions of the second edge of the housing that are in direct contact with the second side are curved surfaces opposing and symmetrical to each other.
  2. 2 . The flexible organic light emitting diode display apparatus of claim 1 , wherein the display panel is configured to have the threshold curvature radius, the display panel is configured to be rolled with a curvature equal to or larger than the threshold curvature radius without being damaged; wherein the first roller is configured to roll-up the display panel, the first roller having a curvature radius equal to or larger than the threshold curvature radius; and wherein the second roller has a curvature radius equal to or larger than the threshold curvature radius.
  3. 3 . The flexible organic light emitting diode display apparatus of claim 1 , wherein a sheet resistance of a surface of at least one of the first roller, the second roller, and the housing is less than or equal to a specific value so as to reduce a static electricity generated by friction of at least one of the first roller, the second roller, and the housing in contact with the display panel.
  4. 4 . The flexible organic light emitting diode display apparatus of claim 1 , wherein the housing is electrically grounded.
  5. 5 . The flexible organic light emitting diode display apparatus of claim 1 , wherein the display panel is electrically grounded.
  6. 6 . The flexible organic light emitting diode display apparatus of claim 1 , wherein the first roller is electrically grounded.
  7. 7 . The flexible organic light emitting diode display apparatus of claim 1 , wherein the first side of the display panel is in contact with a surface of the first roller, and the second side of the display panel is in contact with a surface of the second roller.
  8. 8 . The flexible organic light emitting diode display apparatus of claim 1 , wherein the display panel is configured to extend out of the housing through the opening along a first direction or extending into the housing through the opening along the first direction, wherein the second roller is configured to move between a first position and a second position along a second direction that is different from the first direction such that a first distance in the second direction is between the second roller and the display panel at the first position and a second distance in the second direction is between the second roller and the display panel at the second position where the second distance is different from the first distance, wherein the second roller is in contact with the display panel when the second roller is in the first position, and wherein the second roller is not in contact with the display panel when the second roller is in the second position.
  9. 9 . The flexible organic light emitting diode display apparatus of claim 1 , wherein the driving unit is embedded in the first roller.
  10. 10 . The flexible organic light emitting diode display apparatus of claim 1 , wherein a cross sectional of the first roller is circle, and wherein a cross sectional of the second roller is circle.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation application under 35 U.S.C. § 120 of U.S. patent application Ser. No. 16/571,039 filed on Sep. 13, 2019, which claims priority under 35 U.S.C. § 119 (a) from Republic of Korea Patent Application No. 10-2018-0113687 filed on Sep. 21, 2018, all of which are incorporated by reference herein in its entirety. TECHNICAL FIELD The present disclosure relates to a rollable display apparatus, and more particularly to a rollable display apparatus with improved reliability. BACKGROUND A display apparatus can receive an image signal and display an image. A flexible display apparatus refers to a display apparatus having flexible characteristics. The flexible display apparatus may be a curved display apparatus that is bent to a specific shape, a foldable display apparatus that can be folded to specific axes, and a rollable display apparatus that can be curled to a specific radius of curvature. The display apparatus can be implemented with an electroluminescence element such as a micro light emitting diode (Micro LED), an organic light emitting diode (OLED), a quantum-dot light emitting diode (QLED), and the like. Among the flexible display apparatus, the rollable display apparatus generally stores a flexible display panel in the housing. When the rollable display apparatus is stored while being rolled into the housing, excessive stress, cracks, or stamping may occur in a part of the display panel of the rollable display apparatus, resulting in defects or reliability problems. SUMMARY Disclosed are various structures capable of restoring the deformation of the display panel of the rollable display apparatus to be stored by being rolled-up and not applying excessive stress to the display panel. For example, a curvature radius of the contact area of the display panel corresponding to the structures for restoring the deformation of the display panel affects the reliability of the display panel. Thus, the disclosed embodiments take into consideration the radius of curvature of structures contacting the display panel. Moreover, friction may occur due to contact between the display panel and structures for restoring deformation of the display panel, and static electricity may be generated on the display panel. Further, undesired foreign matter may adhere to the surface of the display panel due to static electricity, so that when the display panel is rolled-up, damage to the display panel may occur due to foreign matter. Accordingly, an object of the present disclosure is to provide a rollable display apparatus in which the above-mentioned problems are improved. Accordingly, an object of the present disclosure is to provide a rollable display apparatus with improved reliability of display panel of the rollable display apparatus. Accordingly, an object of the present disclosure is to provide a rollable display apparatus comprising a structure that can restore the deformation of the display panel and guide the display panel not being bent below the threshold curvature radius. Accordingly, an object of the present disclosure is to provide a rollable display apparatus that can restore the deformation of the display panel of the rollable display apparatus and can reduce the generation of static electricity. The objects of the present disclosure are not limited to the above-mentioned objects, and the other objects of the present disclosure can be clearly understood by those skilled in the art from the following description. According to the embodiments of the present disclosure, a rollable display apparatus may include a display panel having a threshold curvature radius; a roller, having a curvature radius equal to or larger than the threshold curvature radius, attached to one side of the display panel and configured to allow the display panel to be rolled-up in a first direction; and a curved surface member, spaced apart from the roller, having a curvature radius equal to or larger than the threshold curvature radius in an area in contact with the display panel, configured to bend the display panel in a second direction opposite to the first direction in which the display panel is rolled by the roller. The display panel is configured to be rolled with a curvature equal to or larger than the threshold curvature radius without being damaged. The roller may be electrically grounded and configured to discharge static electricity of the display panel. The curved surface member may be electrically grounded and configured to discharge static electricity generated on the display panel. A surface of at least one of the roller, the curved surface member, and the display panel may have a sheet resistance capable of reducing static electricity. At least one among the roller, the curved surface member, and the display panel may comprise at least one material among a conductive carbon material, a nanometal, and a conductive polymer. The sheet resistance at a surface of the d