Display device
A display device includes a display panel which is foldable with respect to at least one folding axis, a first adhesive layer disposed on the display panel, and a window disposed on the first adhesive layer. The first adhesive layer has a storage modulus of about 1.8 MPa to about 4.0 MPa at room temperature, and particularly at 30000 Hertz (Hz) when the window comprises a polymer film or at 50000 Hz when the window comprises a glass substrate.
1. A display device comprising:
a display panel which is foldable with respect to at least one folding axis;
a window disposed on the display panel; and
a first adhesive layer disposed between the display panel and the window, attached to the window, and including silicone-based resin, acrylic-based resin, or urethane-based resin,
wherein the window comprises one of a polymer film and a glass substrate,
wherein the first adhesive layer has a storage modulus of about 1.8 megapascals (MPa) to about 4.0 MPa at room temperature and 30000 Hertz (Hz) when the window comprises the polymer film,
wherein the first adhesive layer has the storage modulus of about 1.8 megapascals (MPa) to about 4.0 MPa at room temperature and 50000 Hz when the window comprises the glass substrate, and
the polymer film comprises at least one polymer resin selected from the group consisting of polybutylene terephthalate, polyvinyl chloride, polypropylene, polyamide, polyphenylene ether, polyoxymethylene, polysulfone, polyethyleneimine, polyether ether ketone, polyamide imide, and thermoplastic polyurethane.
2. The display device of claim 1 , wherein when the window comprises the glass substrate,
a loss factor (tan δ) of the first adhesive layer at 50000 Hz is about 1.6 or greater.
3. The display device of claim 1 , further comprising:
a polarizing film disposed between the first adhesive layer and the display panel; and
a second adhesive layer having a storage modulus of about 0.2 MPa or less at −20° C. and disposed between the polarizing film and the display panel at any frequency.
4. The display device of claim 3 , wherein when the window comprises the glass substrate,
the second adhesive layer has a storage modulus of about 1.8 MPa to about 4.0 MPa at 40000 Hz.
5. The display device of claim 3 , wherein when the window comprises the glass substrate,
a loss factor (tan δ) of the second adhesive layer at 40000 Hz is about 1.5 or greater.
6. The display device of claim 1 , wherein the first adhesive layer has a thickness of about 75 micrometers (μm) to about 150 μm.
7. The display device of claim 1 , wherein the window has a thickness being greater than about 0 μm and equal to or less than about 100 μm.
8. The display device of claim 1 , wherein the display panel and the window are foldable to have a radius of curvature of about 1 millimeters (mm) to about 5 mm with respect to the at least one folding axis.
9. The display device of claim 1 , the display device is a personal digital terminal, a tablet, a car navigation unit, a game console, or a wearable device.