US 12,248,167 B2
Illumination device
Makoto Hasegawa, Tokyo (JP); Nobuyuki Suzuki, Tokyo (JP); and Masafumi Okada, Tokyo (JP)
Assigned to JAPAN DISPLAY INC., Tokyo (JP)
Filed by Japan Display Inc., Tokyo (JP)
Filed on Apr. 10, 2024, as Appl. No. 18/631,044.
Application 18/631,044 is a continuation of application No. PCT/JP2022/036700, filed on Sep. 30, 2022.
Claims priority of application No. 2021-166817 (JP), filed on Oct. 11, 2021.
Prior Publication US 2024/0255691 A1, Aug. 1, 2024
Int. Cl. F21V 8/00 (2006.01)
CPC G02B 6/0076 (2013.01) [G02B 6/0025 (2013.01); G02B 6/0053 (2013.01); G02B 6/0068 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An illumination device comprising:
a first illumination element comprising a first light guide, a plurality of first light source elements provided on a first side surface of the first light guide, and a plurality of second light source elements provided on a second side surface on an opposite side to the first side surface;
a second illumination element comprising a second light guide, a plurality of third light source elements provided on a third side surface of the second light guide, and a plurality of fourth light source elements provided on a fourth side surface on an opposite side to the third side surface; and
a prism sheet provided between the first illumination elements and the second illumination elements, wherein
the first light guide includes a plurality of first projecting portions on a first main surface and a plurality of second projecting portions on a second main surface on an opposite side to the first main surface,
the prism sheet includes a plurality of third projecting portions on a third main surface opposing the first light guide and a fourth main surface opposing the second light guide,
the second light guide includes a plurality of fourth projecting portions provided in a first area of a fifth main surface opposing the prism sheet, a plurality of fifth projecting portions provided in a second area of the fifth main surface, and a plurality of sixth projecting portions on a sixth main surface opposing the fifth main surface,
cross-sectional shapes of the fourth projecting portions and the fifth projecting portions are scalene triangles, and
the fourth projecting portions and the fifth projecting portions are arranged in respective positions line-symmetrical position with respect to each other in plan view.