US-12625520-B2 - Display device

US12625520B2US 12625520 B2US12625520 B2US 12625520B2US-12625520-B2

Abstract

A display device is provided. A display device including folding areas, the display device includes a display panel, a first protection member disposed on the display panel, a second protection member disposed on the first protection member, a first adhesive member disposed between the display panel and the first protection member, and a second adhesive member disposed between the first protection member and the second protection member and having an elastic modulus equal to or smaller than an elastic modulus of the first adhesive member.

Inventors

Jeoung Sub LEE
Ji Eun NAM
Joo Hyeon Lee
Heon Jung SHIN
Tae Hyeog Jung

Assignees

SAMSUNG DISPLAY CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20211014
Priority Date: 20210119

Claims (19)

1 . A display device comprising folding areas, the display device comprising: a display panel; a first protection member disposed on the display panel; a second protection member disposed on the first protection member; a first adhesive member disposed between the display panel and the first protection member; and a second adhesive member disposed between the first protection member and the second protection member and having an elastic modulus smaller than an elastic modulus of the first adhesive member, wherein a thickness of the first adhesive member is smaller than a thickness of the second adhesive member of which modulus is smaller than the modulus of the first adhesive member.
2 . The display device of claim 1 , wherein the elastic modulus of the first adhesive member and the elastic modulus of the second adhesive member are measured by dynamic mechanical analysis.
3 . The display device of claim 2 , wherein the elastic modulus of the first adhesive member is greater than 0 kPa and less than 150 kPa at −20° C., and wherein the elastic modulus of the second adhesive member is greater than 0 kPa and less than 100 kPa at −20° C.
4 . The display device of claim 1 , wherein the first protection member has a first thickness, and wherein the second protection member has a second thickness different from the first thickness.
5 . The display device of claim 1 , wherein the folding areas may include a first folding area extended in a first direction and a second folding area extended in the first direction, wherein the first folding area and the second folding area are separated from each other in a second direction different from the first direction, and wherein the display device is folded inward along on the first folding area and folded outward along on the second folding area.
6 . The display device of claim 5 , further comprising: a first non-folding area disposed at one side of the first folding area in the second direction; a second non-folding area disposed between the first folding area and the second folding area; and a third non-folding area disposed at an opposite side of the second folding area in the second direction.
7 . The display device of claim 6 , further comprising: a display area for displaying images; and a non-display area disposed outside the display area, wherein the display area and the non-display area are disposed across the first folding area, the second folding area, the first non-folding area, the second non-folding area and the third non-folding area.
8 . The display device of claim 7 , further comprising a first heat dissipation member and a second heat dissipation member under the display panel, wherein the first heat dissipation member is disposed at the first non-folding area and the second heat dissipation member is disposed at the second non-folding area and is separated from the first heat dissipation member.
9 . The display device of claim 1 , wherein a storage modulus of the second protection member increases with a frequency of an external impact applied to the second protection member.
10 . The display device of claim 9 , wherein the storage modulus of the second protection member according to the frequency increases more when the frequency of the second protection member is greater than 1 Hz than when the frequency of the second protection member is less than 1 Hz.
11 . The display device of claim 10 , wherein the storage modulus of the second protection member is in a range of from 6 GPa to 1,000 GPa when the frequency is 1 Hz, and is in a range of from 8 GPa to 1,000 GPa when the frequency is 30,000 Hz, and wherein the storage modulus of the second protection member is measured by dynamic mechanical analysis (DMA).
12 . The display device of claim 9 , wherein the second protection member includes at least one selected from the group consisting of: polyethylene terephthalate (PET), tri-acetyl cellulose (TAC), transparent polyimide and aramid.
13 . The display device of claim 1 , wherein a storage modulus of the first protection member lies in a range of from 1,000 MPa to 2,000 MPa at −20° C. and in a range of from 100 MPa to 2,000 MPa at 85° C.
14 . A display device comprising a first folding area and a second folding area spaced apart from each other and extended in a first direction, the display device comprising: a display panel; a first protection member disposed on the display panel; a second protection member disposed on the first protection member and having a storage modulus increasing with a frequency of an external impact applied to the second protection member; a first adhesive member disposed between the display panel and the first protection member; and a second adhesive member disposed between the first protection member and the second protection member, wherein the display device is folded inward along the first folding area and folded outward along the second folding area, wherein an elastic modulus of the second adhesive member is smaller than an elastic modulus of the first adhesive member, and wherein a thickness of the first adhesive member is greater than a thickness of the second adhesive member of which modulus is smaller than the modulus of the first adhesive member.
15 . The display device of claim 14 , wherein the storage modulus of the second protection member according to the frequency increases more when the frequency of the second protection member is greater than 1 Hz than when the frequency of the second protection member is less than 1 Hz.
16 . The display device of claim 15 , wherein the storage modulus of the second protection member is in a range of from 6 GPa to 1,000 GPa when the frequency is 1 Hz, and is in a range of from 8 GPa to 1,000 GPa when the frequency is 30,000 Hz, and wherein the storage modulus of the second protection member is measured by dynamic mechanical analysis (DMA).
17 . The display device of claim 14 , wherein the second protection member includes at least one selected from the group consisting of: polyethylene terephthalate (PET), tri-acetyl cellulous (TAC), transparent polyimide and aramid.
18 . The display device of claim 14 , wherein the storage modulus of the first protection member lies in a range of from 1,000 MPa to 2,000 MPa at −20° C. and in a range of from 100 MPa to 2,000 MPa at 85° C.
19 . A display device comprising a first folding area and a second folding area spaced apart from each other and extended in a first direction, the display device comprising: a display panel; a first protection member disposed on the display panel; a second protection member disposed on the first protection member; a first adhesive member disposed between the display panel and the first protection member; and a second adhesive member disposed between the first protection member and the second protection member, wherein a storage modulus of the first protection member lies in a range of from 1,000 MPa to 2,000 MPa at −20° C., and in a range of from 100 MPa to 2,000 MPa at 85° C., wherein an elastic modulus of the second adhesive member is smaller than an elastic modulus of the first adhesive member, and wherein a thickness of the first adhesive member is greater than a thickness of the second adhesive member of which modulus is smaller than the modulus of the first adhesive member.

Description

This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2021-0007586 filed on Jan. 19, 2021 in the Korean Intellectual Property Office, the contents of which in its entirety are herein incorporated by reference. BACKGROUND 1. Field of the Disclosure The present disclosure relates to a display device. 2. Description of the Related Art As the information-oriented society evolves, various demands for display devices are ever increasing. For example, display devices are being employed by a variety of electronic devices such as smart phones, digital cameras, laptop computers, navigation devices, and smart televisions. Recently, a foldable display device is getting a lot of attention. A foldable display device has the advantages of both a smart phone and a tablet PC because it is easy to carry and may have a wide screen. A protective film for such a foldable display device is desirable to have high durability in order to protect the elements in the display device, and to have high flexibility for smooth folding. SUMMARY Aspects of the present disclosure provide a display device including a protective film that has impact resistance as well as flexibility. It should be noted that objects of the present disclosure are not limited to the above-mentioned object; and other objects of the present disclosure will be apparent to those skilled in the art from the following descriptions. An embodiment of a display device including folding areas, the display device includes a display panel, a first protection member disposed on the display panel, a second protection member disposed on the first protection member, a first adhesive member disposed between the display panel and the first protection member, and a second adhesive member disposed between the first protection member and the second protection member and having an elastic modulus equal to or smaller than an elastic modulus of the first adhesive member. An embodiment of a display device including a first folding area and a second folding area spaced apart from each other and extended in a first direction, the display device includes a display panel, a first protection member disposed on the display panel, a second protection member disposed on the first protection member and having a storage modulus increasing with a frequency of an external impact applied to the second protection member, a first adhesive member disposed between the display panel and the first protection member, and a second adhesive member disposed between the first protection member and the second protection member, wherein the display device is folded inward along the first folding area and folded outward along the second folding area. An embodiment of a display device including a first folding area and a second folding area spaced apart from each other and extended in a first direction, the display device includes a display panel, a first protection member disposed on the display panel, a second protection member disposed on the first protection member, a first adhesive member disposed between the display panel and the first protection member, and a second adhesive member disposed between the first protection member and the second protection member, wherein a storage modulus of the first protection member lies in a range of from 1,000 MPa to 2,000 MPa at −20° C., and in a range of from 100 MPa to 2,000 MPa at 85° C. According to an embodiment of the present disclosure, a protective film of a display device may have impact resistance as well as flexibility. It should be noted that effects of the present disclosure are not limited to those described above and other effects of the present disclosure will be apparent to those skilled in the art from the following descriptions. BRIEF DESCRIPTION OF THE DRAWINGS The above and other aspects and features of the present disclosure will become more apparent by describing in detail embodiments thereof with reference to the attached drawings, in which: FIG. 1 is a perspective view of a display device according to an embodiment of the present disclosure when it is unfolded. FIG. 2 is a perspective view of the display device according to the embodiment of the present disclosure when it is folded. FIG. 3 is a cross-sectional view of a display device according to an embodiment of the present disclosure when the display device is unfolded. FIG. 4 is an enlarged view of area A of FIG. 3. FIG. 5 is a cross-sectional view of a display device according to an embodiment when the display device is folded inward at the first folding area. FIG. 6 is an enlarged view of area B of FIG. 5. FIG. 7 is a cross-sectional view of the display device according to the embodiment when the display device is folded outward at the second folding area. FIG. 8 is a graph showing a relationship between the modulus of the second protection member and external impact according to an embodiment. FIG. 9 is a cross-sectional view of a display panel according