Partially curved or foldable display device including recess grooves and manufacturing method therefor

1 . A display device in which a first folding area, a first non-folding area on one side of the first folding area, and a second non-folding area on the other side of the first folding area are defined, the display device comprising:

a first substrate;

a second substrate disposed on the first substrate;

a liquid crystal layer disposed between the first substrate and the second substrate;

an upper polarization member disposed on one surface of the second substrate and spaced apart from the liquid crystal layer with the second substrate interposed therebetween;

a driving connection film attached to the first substrate; and

a driving circuit board attached to the driving connection film,

wherein the second substrate has a first thickness, which is partially slimmed, in the first folding area,

the second substrate has a second thickness, which is greater than the first thickness and corresponds to an original thickness of a flat display element without being slimmed, in each of the non-folding areas,

the upper polarization member is disposed over the first non-folding area, the folding area and the second non-folding area,

a first gap distance between one surface of the second substrate and the upper polarization member in the first folding area is greater than a second gap distance between one surface of the second substrate and the upper polarization member in each of the non-folding areas, and

the display device is configured to be folded in the first folding area, and is configured to be unfolded in each of the non-folding areas, and

wherein the second substrate includes a single upper recess groove recessed toward the first substrate in the first folding area, and

wherein the first substrate includes a single lower recess groove recessed toward the second substrate in the first folding area, and

wherein the single upper recess groove completely overlaps the single lower recess groove in a thickness direction of the first substrate, and

wherein the single upper recess groove and the single lower recess groove are not located in the non-folding areas, and

wherein the driving connection film is not disposed in the first folding area, but the first non-folding area and the second non-folding area.

2 . The display device of claim 1 , wherein the first folding area includes a curved shape, and each of the non-folding areas includes a linear shape, and a width of the first folding area is smaller than that of each of the non-folding areas.

3 . The display device of claim 1 , one surface of the second substrate and the upper polarization member are spaced apart from each other with the upper recess groove interposed therebetween.

4 . The display device of claim 3 , further comprising a first reinforcing filling pattern disposed in the upper recess groove and disposed between one surface of the second substrate and the upper polarization member, wherein the first reinforcing filling pattern is directly in contact with one surface of the second substrate.

5 . The display device of claim 4 , wherein a surface of the first reinforcing filling pattern is positioned on the same plane as one surface of the second substrate in each of the non-folding areas.

6 . The display device of claim 4 , wherein the first reinforcement filling pattern includes an organic material, an inorganic material, or a composite material of an organic material and an inorganic material, the second substrate includes glass, a difference in a refractive index between the first reinforcing filling pattern and the second substrate is within 0.3, and the first reinforcing filling pattern has light transmittance of 70% or more with respect to a visible light wavelength range.

7 . The display device of claim 4 , wherein the first reinforcing filling pattern includes a light shielding material.

8 . The display device of claim 4 , further comprising a lower polarization member disposed on one surface of the first substrate and spaced apart from the liquid crystal layer with the first substrate interposed therebetween, wherein the first substrate has a third thickness, which is partially slimmed, in the first folding area, and in each of the non-folding areas, the first substrate has a fourth thinness that is greater than the third thickness and corresponds to an original thickness of a flat display element without being slimmed.

9 . The display device of claim 8 , wherein the lower polarization member is disposed over the first non-folding area, the first folding area and the second non-folding area, and a third gap distance between one surface of the first substrate and the lower polarization member in the first folding area is greater than a fourth gap distance between one surface of the first substrate and the lower polarization member in each of the non-folding areas.

10 . The display device of claim 9 , one surface of the first substrate and the lower polarization member are spaced apart from each other with the lower recess groove interposed therebetween, the display device further comprising a second reinforcing filling pattern disposed between one surface of the first substrate and the lower polarization member, wherein the second reinforcement filling pattern is directly in contact with one surface of the first substrate.

11 . The display device of claim 10 , wherein the first substrate has a thickness greater than that of the second substrate, and a recess depth of the lower recess groove is greater than that of the upper recess groove.

12 . The display device of claim 10 , wherein the first substrate has the same thickness as that of the second substrate, and a recess depth of the lower recess groove and a recess depth of the upper recess groove are different from each other.

13 . The display device of claim 10 , wherein the first substrate has a thickness greater than that of the second substrate, and a recess depth of the lower recess groove and a recess depth of the upper recess groove are the same as each other.

14 . The display device of claim 10 , further comprising:

a third non-folding area spaced apart from the first folding area with the second non-folding area interposed therebetween; and

a second folding area spaced apart from the first folding area with the third non-folding area interposed therebetween.

15 . The display device of claim 14 , wherein the second substrate further includes an upper recess groove recessed toward the first substrate in the second folding area, one surface of the second substrate and the upper polarization member are spaced apart from each other with the upper recess groove of the second substrate of the second folding area, which is interposed therebetween, and the first reinforcement filling pattern is further disposed in the upper recess groove of the second substrate of the second folding area.

16 . The display device of claim 15 , wherein the first substrate further includes a lower recess groove recessed toward the second substrate in the second folding area, one surface of the first substrate and the lower polarization member are spaced apart from each other with the lower recess groove of the first substrate of the second folding area, which is interposed therebetween, and the second reinforcement filling pattern is further disposed in the lower recess groove of the first substrate of the second folding area.