IP Library Granted Patent US 11,532,796
Granted Patent B2
US 11,532,796 · App. 17/014,574 · Granted Dec 20, 2022

Display device including flexible substrate, polarizing plate, and warpage suppressing member

Inventors: Makoto Noda (Tokyo, JP); Hiroki Kato (Tokyo, JP)
Assignee: JOLED INC.
H01L51/0097G09F9/301H01L51/5281
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Quick Facts
Patent No.
US 11,532,796
App. No.
17/014,574
Granted
Dec 20, 2022
Kind
B2
Abstract

A display device includes a flexible substrate, a display device layer, a polarizing plate, and a warpage suppressing member. The flexible substrate has a front surface on a front surface side and a back surface on a back surface side. The display device layer is provided on the front surface side of the flexible substrate and includes a self-luminescent element. The polarizing plate is opposed to the flexible substrate across the display device layer and has a predetermined dimensional change characteristic corresponding to environmental change. The warpage suppressing member is provided on the back surface side of the flexible substrate and has a dimensional change characteristic of the same tendency as the dimensional change characteristic of the polarizing plate. The warpage suppressing member is configured to cancel at least a portion of warping stress of the polarizing plate to be applied to the flexible substrate.

Claims (40)

1. A display device, comprising:

a flexible substrate having a front surface on a front surface side and a back surface on a back surface side;

a display device layer provided on the front surface side of the flexible substrate and including a self-luminescent element;

a polarizing plate opposed to the flexible substrate across the display device layer and having a predetermined dimensional change characteristic; and

a warpage suppressing member provided on the back surface side of the flexible substrate and having a dimensional change characteristic of swelling or shrinkage in a same direction of swelling or shrinkage of the dimensional change characteristic of the polarizing plate corresponding to temperature change, the warpage suppressing member being configured to cancel at least a portion of warping stress of the polarizing plate to be applied to the flexible substrate,

wherein the warpage suppressing member has a configuration different from a configuration of the polarizing plate, and

the warpage suppressing member includes at least one of polyethylene terephthalate, polystyrene, polypropylene, cycloolefin polymer, cyclic olefin copolymer, polyethersulfone, or polycarbonate.

2. The display device according to claim 1 ,

wherein the polarizing plate includes a polarizer, and

the warpage suppressing member includes a material that is same as a material included in the polarizer.

3. The display device according to claim 1 ,

wherein the dimensional change characteristic corresponds to temperature change, and

wherein the dimensional change characteristic corresponding to temperature change of the warpage suppressing member exhibits the same tendency as the dimensional change characteristic corresponding to temperature change of the polarizing plate.

4. The display device according to claim 1 ,

wherein the warpage suppressing member has a thickness of greater than 10 times a thickness of the polarizer and equal to or less than 30 times the thickness of the polarizer.

5. The display device according to claim 1 ,

wherein the polarizing plate includes an organic material.

6. The display device according to claim 1 ,

wherein the self-luminescent element comprises an organic electroluminescent element.

7. The display device according to claim 1 ,

wherein the warpage suppressing member comprises a polyethylene terephthalate (PET) monolayer sheet.

8. The display device according to claim 1 ,

wherein the warpage suppressing member includes a polyethylene terephthalate (PET) film having a thickness of 180 μm to 540 μm.

9. The display device according to claim 8 ,

wherein the PET film on the warpage suppressing member exhibits dimension change rates, such that a dimensional change rate in the MD direction is larger than a dimensional change rate in the TD direction.

10. The display device according to claim 2 ,

wherein the MD direction of the warpage suppressing member and the MD direction of the polarizer are disposed to be parallel to each other.

11. The display device according to claim 1 ,

wherein a reinforcing member is provided between the substrate and the warpage suppressing member.

12. The display device according to claim 11 ,

wherein the reinforcing member comprises polyethylene terephthalate (PET) or stainless steel.

13. The display device according to claim 11 ,

wherein a heat equalizing member is provided between the reinforcing member and the warpage suppressing member.

14. A display device, comprising:

a flexible substrate having a front surface on a front surface side and a back surface on a back surface side;

a display device layer provided on the front surface side of the flexible substrate and including a self-luminescent element;

a polarizing plate opposed to the flexible substrate across the display device layer and having a predetermined dimensional change characteristic; and

a warpage suppressing member provided on the back surface side of the flexible substrate and having a dimensional change characteristic of swelling or shrinkage in a same direction of swelling or shrinkage of the dimensional change characteristic of the polarizing plate corresponding to temperature change, the warpage suppressing member being configured to cancel at least a portion of warping stress of the polarizing plate to be applied to the flexible substrate,

wherein the warpage suppressing member does not include a retardation layer or a polarizer; and

the warpage suppressing member includes at least one of polyethylene terephthalate, polystyrene, polypropylene, cycloolefin polymer, cyclic olefin copolymer, polyethersulfone, or polycarbonate.

Assignments (5)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 18, 2025
From: JDI DESIGN AND DEVELOPMENT G.K.
To: MAGNOLIA BLUE CORPORATION
Reel/Frame 072039/0656 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 31, 2024
From: JOLED, INC.
To: JDI DESIGN AND DEVELOPMENT G.K.
Reel/Frame 066382/0619 →
CORRECTION BY AFFIDAVIT FILED AGAINST REEL/FRAME 063396/0671 Recorded Jun 12, 2023
From: JOLED, INC.
To: JOLED, INC.
Reel/Frame 064067/0723 →
SECURITY INTEREST Recorded Apr 20, 2023
From: JOLED, INC.
To: INCJ, LTD.
Reel/Frame 063396/0671 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 8, 2020
From: NODA, MAKOTO; KATO, HIROKI
To: JOLED INC.
Reel/Frame 053715/0107 →