ILLUMINATION DEVICE, LIGHT GUIDE OF ILLUMINATION DEVICE AND DISPLAY DEVICE COMPRISING ILLUMINATION DEVICE
According to one embodiment, an illumination device includes a light guide including an emission surface and an incident surface, the incident surface including an uneven pattern with a convex portion having a height of 0.01 to 0.4 mm, and a light emitting element provided to oppose the incident surface and adhered to the uneven pattern by an adhesive.
1 . An illumination device comprising:
a light guide including an emission surface and an incident surface, the incident surface including an uneven pattern with a convex portion having a height of 0.01 to 0.4 mm; and
a light emitting element provided to oppose the incident surface and adhered to the uneven pattern by an adhesive.
2 . The illumination device of claim 1 , wherein
the uneven pattern includes a plurality of convex portions and a plurality of concave portions each extending in a first direction, and the plurality of convex portions and plurality of concave portions are alternately aligned in a second direction intersecting the first direction.
3 . The illumination device of claim 2 , wherein
an alignment pitch of the plurality of convex portions in the second direction is set to 0.05 to 0.3 mm.
4 . The illumination device of claim 1 , wherein
each of the convex portions has a triangular, semi-elliptical, semi-circular, or trapezoidal cross-sectional shape.
5 . The illumination device of claim 1 , wherein
the light emitting element includes a light emitting surface opposing the uneven pattern, and the light emitting surface is adhered to the uneven pattern by the adhesive.
6 . The illumination device of claim 5 , wherein
the adhesive is a transparent resin adhesive having a refractive index lower than or equal to a refractive index of the light guide and further 1.4 or higher and having a haze of 5% or less.
7 . The illumination device of claim 2 , wherein
the incident surface is formed into a rectangular shape with a pair of long sides and a pair of short sides, and
the first direction is a direction parallel to the short sides and the second direction is a direction parallel to the long sides.
8 . The illumination device of claim 2 , wherein
the incident surface is formed into a rectangular shape with a pair of long sides and a pair of short sides, and
the first direction is a direction parallel to the long sides and the second direction is a direction parallel to the short sides.
9 . The illumination device of claim 2 , wherein
the incident surface is formed into a rectangular shape with a pair of long sides and a pair of short sides, and
the first direction is a direction inclined by an angle less than 90 degrees with respect to a direction parallel to the long sides, and the second direction is a direction orthogonal to the first direction.
10 . The illumination device of claim 2 , wherein
the incident surface is formed into a rectangular shape with a pair of long sides and a pair of short sides, and
the uneven pattern is provided over a region of substantially an entire length of the incident surface in a direction parallel to the long sides.
11 . The illumination device of claim 2 , wherein
the incident surface is formed into a rectangular shape with a pair of long sides and a pair of short sides, and
the uneven pattern is provided dividedly at a plurality of locations on the incident surface at intervals in a direction parallel to the long sides.
12 . The illumination device of claim 10 , wherein
the uneven pattern is provided in a region of ⅘ or greater of a length of the short sides in a direction parallel to the short sides.
13 . The illumination device of claim 11 , wherein
the unevenness pattern is provided in a region of ⅘ or greater of a length of the short sides in a direction parallel to the short sides.
14 . A display device comprising:
a display panel; and
an illumination device provided to oppose the display panel, and
the illumination device comprising a light guide including an emission surface opposing the display panel and an incident surface, the incident surface including an uneven pattern with a convex portion having a height of 0.01 to 0.4 mm, and a light emitting element provided to oppose the incident surface and adhered to the uneven pattern by an adhesive.
15 . A light guide of an illumination device, comprising:
an emission surface and an incident surface; and
an uneven pattern provided on the incident surface, including a convex portion having height of 0.01 to 0.4 mm.