Cover window, method of providing cover window, and display device including cover window
A cover window includes a glass including a folding portion and a non-folding portion, and a groove in the folding portion of the glass. The glass which is folded at the folding portion includes an inner surface that is compressed and an outer surface that is stretched, the groove filled with a multi-layered resin layer, a storage modulus of a layer of the multi-layered resin layer which is closest to the inner surface being largest, and elongation of a layer of the multi-layered resin layer which is closest to the outer surface being largest.
1 . A cover window comprising:
a glass facing a display panel, the glass including a folding portion and a non-folding portion;
a groove in the folding portion of the glass; and
a multi-layered resin layer which fills the groove, the multi-layered resin layer including a plurality of resin layers each directly contacting the glass within the groove,
wherein the glass which is folded at the folding portion includes:
an inner surface which is compressed,
an outer surface which is stretched, and
among the plurality of resin layers each directly contacting the glass within the groove:
each of the plurality of resin layers has a storage modulus and an elongation,
the storage modulus of a resin layer which is closest to the inner surface is largest,
the storage modulus of the resin layer which is closest to the inner surface is about 0.046 megapascal or less at 20 degrees Celsius, and
the elongation of a resin layer which is closest to the outer surface is largest.
2 . The cover window of claim 1 , wherein the groove is recessed in a direction from the outer surface of the glass toward the inner surface of the glass.
3 . The cover window of claim 2 , wherein the elongation of the resin layer which is closest to the outer surface is about 120% or more.
4 . The cover window of claim 1 , wherein among the plurality of resin layers each directly contacting the glass within the groove:
each of the plurality of resin layers further has a refractive index, and
a difference in refractive index between the plurality of resin layers is less than about 2%,
the glass has a refractive index, and
a difference in refractive index between the multi-layered resin layer and the glass is less than about 2%.
5 . The cover window of claim 1 , wherein the multi-layered resin layer and the glass each has a refractive index of about 1.48 to about 1.52.
6 . The cover window of claim 1 , wherein
the plurality of resin layers each directly contacting the glass within the groove includes a first layer and a second layer in order in a direction from the inner surface to the outer surface,
the first layer includes a resin including acrylate, and
the second layer includes a resin including silicone.
7 . The cover window of claim 1 , wherein
the plurality of resin layers each directly contacting the glass within the groove includes a first layer, a second layer, and a third layer in order in a direction from the inner surface to the outer surface,
the first layer includes a resin including acrylate,
the second layer includes a resin including acrylate or a resin including urethane, and
the third layer includes a resin including silicone.
8 . The cover window of claim 1 , wherein
the plurality of resin layers each directly contacting the glass within the groove includes a first layer, a second layer, a third layer, and a fourth layer in order in a direction from the inner surface to the outer surface,
the first layer includes a resin including acrylate,
the second layer and the third layer include a resin including acrylate or a resin including urethane, and
the fourth layer includes a resin including silicone.
9 . The cover window of claim 1 , wherein among the plurality of resin layers each directly contacting the glass within the groove:
each of the plurality of resin layers further has a thickness, and
a thickness difference between the plurality of resin layers is about 10% to about 300%.
10 . The cover window of claim 1 , wherein among the plurality of resin layers each directly contacting the glass within the groove:
each of the plurality of resin layers is formed from a material directly provided into the groove of the glass, the material having a viscosity,
the viscosity of the material which forms the resin layer which is closest to the inner surface is lowest, and
the viscosity of the material which forms the resin layer which is closest to the outer surface is highest.
11 . The cover window of claim 1 , wherein
the glass further includes a side surface which defines the groove, and
the side surface of the glass is inclined.
12 . The cover window of claim 1 , wherein
the glass further includes a side surface which defines the groove, and
the side surface of the glass is perpendicular to the inner surface.
13 . The cover window of claim 1 , wherein the glass further includes:
a thickness at the folding portion and at the non-folding portion,
the thickness of the glass at the non-folding portion is about 150 micrometers or more, and
the thickness of the glass corresponding to the groove is about 30 micrometers or less.
14 . The cover window of claim 1 , wherein
the cover window is foldable at the folding portion in a first direction, and
the groove extends along a second direction which crosses the first direction.
15 . A display device comprising:
a display panel; and
a cover window facing the display panel, the cover comprising:
a glass including a folding portion and a non-folding portion;
a groove in the folding portion of the glass; and
a multi-layered resin layer which fills the groove, the multi-layered resin layer including a plurality of resin layers each directly contacting the glass within the groove,
wherein the glass which is folded at the folding portion includes:
an inner surface which is compressed,
an outer surface which is stretched, and
among the plurality of resin layers each directly contacting the glass within the groove:
each of the plurality of resin layers has a storage modulus and an elongation,
the storage modulus of a resin layer which is closest to the inner surface is largest,
the storage modulus of the resin layer which is closest to the inner surface is about 0.046 megapascal or less at 20 degrees Celsius, and
the elongation of a resin layer which is closest to the outer surface is largest.