# US 12,216,353 B2 · Flexible display apparatus

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- Number: US 12,216,353 B2
- Document ID: US12216353B2
- Status: Granted
- Kind: B2
- Application number: 18/136,396
- Filed: 2023-04-19
- Published: 2023-08-17
- Granted: 2025-02-04
- Earliest claimed: 2016-11-28
- Assignees: Samsung Display Co., Ltd.
- Applicants: Samsung Display Co., LTD.
- Inventors: Heeyoung Lee; Eunmi Seo
- Web page: https://patentgrep.com/patent/US12216353B2

## CPC

- G02B 5/3033: {in the form of a thin sheet or foil, e.g. Polaroid}
- G02F 1/133528: {Polarisers}
- G02F 1/133305: {Flexible substrates, e.g. plastics, organic film}
- G02F 1/13363: Birefringent elements, e.g. for optical compensation
- H10K 59/8791: {Arrangements for improving contrast, e.g. preventing reflection of ambient light}
- G02B 5/3016: {involving passive liquid crystal elements (optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528)}
- G02B 5/3083: {Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001)}
- G02F 1/133541: {Circular polarisers}
- G02F 2202/28: Adhesive materials or arrangements
- H10K 50/86: Arrangements for improving contrast, e.g. preventing reflection of ambient light
- H10K 59/40: OLEDs integrated with touch screens
- H10K 77/111: {Flexible substrates}
- H10K 2102/311: {Flexible OLED}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES

## Abstract

A flexible display apparatus including a bending area and a non-bending area. The flexible display apparatus further includes a display panel and a polarizing structure disposed on the display panel. The polarizing structure includes a λ/4 phase retardation layer, a linear polarizer disposed on the λ/4 phase retardation layer, and a first adhesive structure disposed between the λ/4 phase retardation layer and the linear polarizer. The linear polarizer includes a stretched polymer film. The first adhesive structure is an adhesive layer with a glass transition temperature that is greater than or equal to 40° C. and less than or equal to 150° C. Accordingly, deformation of the λ/4 phase retardation layer may be prevented or reduced when the flexible display apparatus is folded or bent, thereby improving display quality.

## Claims

### Claim 1

A flexible display apparatus comprising:
a display panel; and
a polarizing structure disposed on the display panel,
wherein the polarizing structure comprises:
a λ/4 phase retardation layer;
a linear polarizer disposed on the λ/4 phase retardation layer;
a first adhesive structure disposed between the λ/4 phase retardation layer and the linear polarizer;
a λ/2 phase retardation layer disposed between the λ/4 phase retardation layer and the linear polarizer; and
a second adhesive structure disposed between the λ/2 phase retardation layer and the linear polarizer,
wherein, in a plan view, an angle between an absorption axis or a transmission axis of the linear polarizer and a bending axis of the flexible display apparatus is 45 degrees±30 degrees, and
wherein a glass transition temperature of the first adhesive structure is greater than a glass transition temperature of the second adhesive structure, and
the first adhesive structure is an adhesive layer having the glass transition temperature greater than or equal to 40° C. and less than or equal to 150° C.; and
the second adhesive structure is an adhesive layer having the glass transition temperature greater than or equal to −35° C. and less than or equal to 0° C.

### Claim 2 (depends on 1)

The flexible display apparatus of claim 1, wherein:
the first adhesive structure is disposed between the λ/4 phase retardation layer and the λ/2 phase retardation layer; and
the second adhesive structure is directly contact with the linear polarizer.

### Claim 3 (depends on 1)

The flexible display apparatus of claim 1, wherein a thickness of the second adhesive structure is greater than a thickness of the first adhesive structure.

### Claim 4 (depends on 1)

The flexible display apparatus of claim 1, wherein a thickness of the first adhesive structure and a thickness of the second adhesive structure is less than or equal to 5 μm, respectively.

### Claim 5 (depends on 1)

The flexible display apparatus of claim 1, wherein:
a thickness of the λ/4 phase retardation layer and a thickness of the λ/2 phase retardation layer is greater than or equal to 0.5 μm and less than or equal to 2 μm, respectively; and
a total thickness, including the λ/4 phase retardation layer, the first adhesive structure, the λ/2 phase retardation layer, and the second adhesive structure, is greater than or equal to 1.2 μm and less than or equal to 14 μm.

### Claim 6 (depends on 1)

The flexible display apparatus of claim 1, wherein:
the first adhesive structure comprises an ultraviolet curable adhesive; and
the second adhesive structure comprises a pressure sensitive adhesive.

### Claim 7 (depends on 1)

The flexible display apparatus of claim 1, wherein, in a plan view:
an angle between an absorption axis or a transmission axis of the linear polarizer and a first optical axis of λ/4 phase retardation layer is 75 degrees±30 degrees; and
an angle between the absorption axis or the transmission axis and a second optical axis of the λ/2 phase retardation layer is 15 degrees±13 degrees.

### Claim 8 (depends on 1)

The flexible display apparatus of claim 1, wherein, in a plan view, an angle between a first optical axis of the λ/4 phase retardation layer and a second optical axis of the λ/2 phase retardation layer is 60 degrees±30 degrees.