# US 12,120,902 B2 · Foldable display device

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- Number: US 12,120,902 B2
- Document ID: US12120902B2
- Status: Granted
- Kind: B2
- Application number: 18/119,445
- Filed: 2023-03-09
- Published: 2023-07-06
- Granted: 2024-10-15
- Earliest claimed: 2018-05-15
- Assignees: Samsung Display Co., Ltd.
- Applicants: Samsung Display Co., Ltd.
- Inventors: Myoung Seo Park
- Web page: https://patentgrep.com/patent/US12120902B2

## CPC

- H10K 77/111: {Flexible substrates}
- G02F 1/133305: {Flexible substrates, e.g. plastics, organic film}
- H05K 5/03: Covers
- H10K 59/8731: {multilayered coatings having a repetitive structure, e.g. having multiple organic-inorganic bilayers}
- H10K 2102/311: {Flexible OLED}
- Y02E 10/549: Organic PV cells
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES
- 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
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A foldable display device includes a flexible display module having an electroluminescent unit, a flexible functional module on the flexible display, the flexible functional module having at least one function selected from the group of polarization, a color filtering, color conversion, a touch sensing, and biometric information recognition, and a flexible window module on the flexible functional module. A side surface of the flexible display module, a side surface of the flexible functional module, and a side surface of the flexible window module may be located on a first plane at a first side portion. An inner angle formed by an upper surface of the flexible window module emitting light and the first plane may be an acute angle at the first side portion.

## Claims

### Claim 1

A foldable display device, comprising:
a flexible window module having a light transparency and serving as a protection structure,
a flexible functional module located under or below the flexible window module, the flexible functional module having at least one function selected from the group of color conversion, color filtering, touch sensing, biometric information recognition, and allowing a portion of light to selectively advance through;
a flexible display module located under or below the flexible functional module, the flexible display module comprising an electroluminescent unit, wherein
at a first side portion of the foldable display device, a side surface portion of the flexible window module, a side surface portion of the flexible functional module, and a side surface portion of the flexible display module are located substantially on a first etching plane,
at the first side portion of the foldable display device, an inner angle formed by an upper surface of the flexible window module and the first etching plane is an acute angle, the first side portion of the foldable display device having a first sidewall shape,
the foldable display device has a second side portion having a second sidewall shape substantially different from the first sidewall shape of the first side portion of the foldable display device, the second side portion of the foldable display device being located in a non-foldable region of the foldable display device,
the foldable display device has a third side portion having a third side wall shape substantially different from the first and second sidewall shapes of the first and second side portions of the foldable display device, the third side portion of the foldable display device being located in the non-foldable region,
the first side portion of the foldable display device continues to the second side portion of the foldable display device in plan view, and
the second side portion of the foldable display device is located between the first and third side portions of the foldable display device in plan view.

### Claim 2 (depends on 1)

The foldable display device of claim 1, wherein the first side portion of the foldable display device includes a side portion of a foldable region of the foldable display device.

### Claim 3 (depends on 1)

The foldable display device of claim 1, wherein
the flexible display module includes a lower inorganic encapsulation structure and an upper encapsulation structure which has a lower surface comprising only at least one inorganic material,
the flexible display module includes an inorganic-inorganic contact closed loop at which the lower surface of the upper encapsulation structure contacts the lower inorganic encapsulation structure,
the electroluminescent unit is located between the lower inorganic encapsulation structure and the upper encapsulation structure,
the electroluminescent unit is surrounded by the inorganic-inorganic contact closed loop in plan view, and
the inorganic-inorganic contact closed loop is spaced apart from the side surface portion of the flexible display module.

### Claim 4 (depends on 1)

The foldable display device of claim 1, further comprising:
a cushion module located under or below the flexible display module, wherein
at the first side portion of the foldable display device, a side surface portion of the cushion module is located substantially on a second plane located inside the first etching plane.

### Claim 5 (depends on 1)

The foldable display device of claim 1, wherein
at the third side portion of the foldable display device, the flexible display module includes a bent portion.

### Claim 6 (depends on 5)

The foldable display device of claim 5, wherein, at the third side portion of the foldable display device, an outermost portion of the bent portion is aligned to be located just under a side surface portion of the flexible window module.

### Claim 7 (depends on 1)

The foldable display device of claim 1, further comprising:
a cushion module under the flexible display module, wherein
at the second side portion of the foldable display device, a side surface portion of the flexible display module is located substantially on a third plane,
at the second side portion of the foldable display device, a side surface portion of the flexible window module is located substantially on a fourth plane located outside the third plane, and
at the second side portion of the foldable display device, a side surface portion of the cushion module is located substantially on a sixth plane located inside the third plane.

### Claim 8 (depends on 1)

The foldable display device of claim 1, wherein
at the second side portion of the foldable display device, a side surface portion of the flexible display module is located substantially on a third plane,
at the second side portion of the foldable display device, a side surface portion of the flexible window module is located substantially on a fourth plane located outside the third plane, and
at the third side portion of the foldable display device, the flexible display module includes a bent portion.

### Claim 9 (depends on 8)

The foldable display device of claim 8, wherein, at the third side portion of the foldable display device, an outermost portion of the bent portion is aligned to be located just under a side surface portion of the flexible window module.

### Claim 10 (depends on 8)

The foldable display device of claim 8, wherein the second side portion of the foldable display device is located between the first side portion of the foldable display device and the third side portion of the foldable display device.

### Claim 11 (depends on 1)

The foldable display device of claim 1, wherein the allowing the portion of light to selectively advance through is performed by a polarization layer.

### Claim 12

A foldable display device, comprising:
a first non-foldable region comprising a first outer side extending to have a first length in a first direction and an inner side located to be substantially opposite to the first outer side and extending in the first direction;
a second non-foldable region comprising an outer side extending to have a second length substantially larger than the first length in the first direction and an inner side located to be substantially opposite to the outer side and extending in the first direction;
a foldable region extending in the first direction between the inner side of the first non-foldable region and the inner side of the second non-foldable region; and
a bent region extending from the outer side of the second non-foldable region, comprising a pad portion of the foldable display device, and having a third length substantially smaller than the second length in the first direction, wherein
the first non-foldable region further includes a second outer side and a third outer side,
the second outer side is located to be substantially opposite to the inner side of the first non-foldable region and extends in the first direction to have a fourth length substantially smaller than the second length, and
the third outer side extends in a second direction substantially different from the first direction to connect the first outer side and the second outer side.

### Claim 13 (depends on 12)

The foldable display device of claim 12, wherein the third length is about 50% to about 95% of the second length.

### Claim 14

A foldable display device, comprising:
an upper member including at least one selected from the group of:
a flexible display module having a first side portion having a first side surface and a second side portion having a second side surface, the first side surface having substantially different profile from the second side surface, the first side portion having a substantially larger length than the second side portion in plan view, the flexible display module comprising an electroluminescent unit,
a flexible functional module having a third side portion having a third side surface and a fourth side portion having a fourth side surface, the third side surface having substantially different profile from the fourth side surface, the third side portion having a substantially larger length than the fourth side portion in plan view, the flexible functional module having at least one function selected from the group of biometric information recognition, allowing a portion of light to selectively advance through, color filtering, color conversion, and touch sensing, and
a flexible window module having a fifth side portion having a fifth side surface and a sixth side portion having a sixth side surface, the fifth side surface having a substantially different profile from the sixth side surface, the fifth side portion having a substantially larger length than the sixth side portion in plan view, the flexible window module having a light transparency and serving as a protection structure; and
a cushion module located under or below the upper member, the cushion module serving as an impact absorbing structure, wherein
the foldable display device has a first side portion having a first sidewall shape,
the foldable display device has a second side portion having a second sidewall shape substantially different from the first sidewall shape of the first side portion of the foldable display device, the second side portion of the foldable display device being located in a non-foldable region of the foldable display device,
the foldable display device has a third side portion having a third side wall shape substantially different from the first and second sidewall shapes of the first and second side portions of the foldable display device, the third side portion of the foldable display device being located in the non-foldable region,
the first side portion of the foldable display device continues to the second side portion of the foldable display device in plan view, and
the second side portion of the foldable display device is located between the first and third side portions of the foldable display device in plan view.

### Claim 15 (depends on 14)

The foldable display device of claim 14, wherein
the upper member includes the flexible window module, the flexible functional module, and the flexible display module,
the flexible functional module is located under or below the flexible window module,
the flexible display module is located under or below the flexible functional module, and
the first side surface of the flexible display module, the third side surface of the flexible functional module, and the fifth side surface of the flexible window module are a same etching surface.

### Claim 16 (depends on 15)

The foldable display device of claim 15, wherein
the flexible display module includes a lower inorganic encapsulation structure and an upper encapsulation structure comprising a lower surface comprising only at least one inorganic material,
the flexible display module includes an inorganic-inorganic contact closed loop at which the lower surface of the upper encapsulation structure contacts the lower inorganic encapsulation structure,
the electroluminescent unit is located between the lower inorganic encapsulation structure and the upper encapsulation structure,
the electroluminescent unit is surrounded by the inorganic-inorganic contact closed loop in plan view, and
the inorganic-inorganic contact closed loop is spaced apart from the first and second side surface of the flexible display module.

### Claim 17 (depends on 15)

The foldable display device of claim 15, wherein the same etching surface is formed using a laser having a pulse width substantially shorter than about 1 nanosecond.

### Claim 18 (depends on 15)

The foldable display device of claim 15, wherein
the same etching surface is formed by a laser, and
an advancing direction of the laser is tilted at about 0.1 to about 5 degrees, in a direction from a center of the flexible window module toward a side portion of the flexible window module, with respect to an emission direction of light vertically emitted from an upper surface of the flexible window module.

### Claim 19 (depends on 14)

The foldable display device of claim 14, wherein the allowing the portion of light to selectively advance through is performed by a polarization layer.

### Claim 20

A foldable display device, comprising:
a flexible window module having a light transparency and serving as a protection structure,
a flexible functional module located under or below the flexible window module, the flexible functional module having at least one function selected from the group of color conversion, color filtering, touch sensing, biometric information recognition, and allowing a portion of light to selectively advance through; and
a flexible display module located under or below the flexible functional module, the flexible display module comprising an electroluminescent unit, wherein
at a first side portion of the foldable display device, a side surface portion of the flexible window module, a side surface portion of the flexible functional module, and a side surface portion of the flexible display module are located substantially on a first etching plane,
at the first side portion of the foldable display device, an inner angle formed by an upper surface of the flexible window module and the first etching plane is an acute angle,
the foldable display device has a second side portion substantially different from the first side portion of the foldable display device and located in a non-foldable region of the foldable display device,
at the second side portion of the foldable display device, a side surface portion of the flexible display module is located substantially on a third plane,
at the second side portion of the foldable display device, a side surface portion of the flexible window module is located substantially on a fourth plane located outside the third plane, and
at the second side portion of the foldable display device, a side surface portion of the flexible functional module is located substantially on a fifth plane located inside the third plane.

### Claim 21 (depends on 20)

The foldable display device of claim 20, wherein the first side portion of the foldable display device includes a side portion of a foldable region of the foldable display device.

### Claim 22 (depends on 20)

The foldable display device of claim 20, wherein
the flexible display module includes a lower inorganic encapsulation structure and an upper encapsulation structure which has a lower surface comprising only at least one inorganic material,
the flexible display module includes an inorganic-inorganic contact closed loop at which the lower surface of the upper encapsulation structure contacts the lower inorganic encapsulation structure,
the electroluminescent unit is located between the lower inorganic encapsulation structure and the upper encapsulation structure,
the electroluminescent unit is surrounded by the inorganic-inorganic contact closed loop in plan view, and
the inorganic-inorganic contact closed loop is spaced apart from the side surface portion of the flexible display module.

### Claim 23 (depends on 20)

The foldable display device of claim 20, further comprising:
a cushion module located under or below the flexible display module, wherein
at the first side portion of the foldable display device, a side surface portion of the cushion module is located substantially on a second plane located inside the first etching plane.

### Claim 24 (depends on 20)

The foldable display device of claim 20, wherein
the foldable display device has a third side portion substantially different from the first side portion of the foldable display device and located in the non-foldable region, and
at the third side portion of the foldable display device, the flexible display module includes a bent portion.

### Claim 25 (depends on 24)

The foldable display device of claim 24, wherein, at the third side portion of the foldable display device, an outermost portion of the bent portion is aligned to be located just under a side surface portion of the flexible window module.

### Claim 26 (depends on 20)

The foldable display device of claim 20, further comprising:
a cushion module under the flexible display module, wherein
at the second side portion of the foldable display device, a side surface portion of the cushion module is located substantially on a sixth plane located inside the third plane.

### Claim 27 (depends on 20)

The foldable display device of claim 20, wherein
the foldable display device has a third side portion substantially different from the first and second side portions of the foldable display device and located in the non-foldable region of the foldable display device, and
at the third side portion of the foldable display device, the flexible display module includes a bent portion.

### Claim 28 (depends on 27)

The foldable display device of claim 27, wherein, at the third side portion of the foldable display device, an outermost portion of the bent portion is aligned to be located just under a side surface portion of the flexible window module.

### Claim 29 (depends on 27)

The foldable display device of claim 27, wherein the second side portion of the foldable display device is located between the first side portion of the foldable display device and the third side portion of the foldable display device.

### Claim 30 (depends on 20)

The foldable display device of claim 20, wherein the allowing the portion of light to selectively advance through is performed by a polarization layer.

### Claim 31

A foldable display device, comprising:
a flexible window module having a light transparency and serving as a protection structure,
a flexible functional module located under or below the flexible window module, the flexible functional module having at least one function selected from the group of color conversion, color filtering, touch sensing, biometric information recognition, and allowing a portion of light to selectively advance through; and
a flexible display module located under or below the flexible functional module, the flexible display module comprising an electroluminescent unit, wherein
at a first side portion of the foldable display device, a side surface portion of the flexible window module, a side surface portion of the flexible functional module, and a side surface portion of the flexible display module are located substantially on a first etching plane,
at the first side portion of the foldable display device, an inner angle formed by an upper surface of the flexible window module and the first etching plane is an acute angle,
the foldable display device further comprises a lower layer located under or below the flexible display module, and
at the first side portion of the foldable display device, a side surface portion of the lower layer is substantially non-parallel to, non-overlapping with, and spaced apart from the first etching plane.

### Claim 32 (depends on 31)

The foldable display device of claim 31, wherein the side surface portion of the lower layer is substantially perpendicular to a display surface of the flexible display module.

### Claim 33

A foldable display device, comprising:
an upper member including at least one selected from the group of:
a flexible display module having a first side portion having a first side surface and a second side portion having a second side surface, the first side surface having substantially different profile from the second side surface, the first side portion having a substantially larger length than the second side portion in plan view, the flexible display module comprising an electroluminescent unit,
a flexible functional module having a third side portion having a third side surface and a fourth side portion having a fourth side surface, the third side surface having substantially different profile from the fourth side surface, the third side portion having a substantially larger length than the fourth side portion in plan view, the flexible functional module having at least one function selected from the group of biometric information recognition, allowing a portion of light to selectively advance through, color filtering, color conversion, and touch sensing, and
a flexible window module having a fifth side portion having a fifth side surface and a sixth side portion having a sixth side surface, the fifth side surface having a substantially different profile from the sixth side surface, the fifth side portion having a substantially larger length than the sixth side portion in plan view, the flexible window module having a light transparency and serving as a protection structure; and
a cushion module located under or below the upper member, the cushion module serving as an impact absorbing structure, wherein
the cushion module comprises a cushion side surface that is substantially non-parallel to, non-overlapping with, and spaced apart from any one of the first side surface, the third side surface and the fifth side surface.

### Claim 34 (depends on 33)

The foldable display device of claim 33, wherein the first side surface, the third surface, and the fifth side surface are substantially on a same etching plane.

### Claim 35 (depends on 33)

The foldable display device of claim 33, wherein the cushion side surface is substantially perpendicular to an upper surface of the upper member.