US 11,668,976 B2
Light emitting device and illumination device
Masafumi Okada, Tokyo (JP); Nobuyuki Suzuki, Tokyo (JP); and Makoto Hasegawa, Tokyo (JP)
Assigned to Japan Display Inc., Tokyo (JP)
Filed by Japan Display Inc., Tokyo (JP)
Filed on Jun. 1, 2022, as Appl. No. 17/829,425.
Application 17/829,425 is a continuation of application No. 17/220,503, filed on Apr. 1, 2021, granted, now 11,378,841.
Claims priority of application No. JP2020-067778 (JP), filed on Apr. 3, 2020.
Prior Publication US 2022/0291546 A1, Sep. 15, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G02F 1/13357 (2006.01); G02F 1/1335 (2006.01)
CPC G02F 1/133603 (2013.01) [G02F 1/133526 (2013.01); G02F 1/133607 (2021.01)] 6 Claims
OG exemplary drawing
 
1. A light emitting device comprising:
a light guide plate having a first main surface, a second main surface, a first side surface, a second side surface opposite to the first side surface, a third side surface adjacent to the first side surface and the second side surface and a fourth side surface opposite to the third side surface; and
a light source element disposed on the first side surface of the light guide plate, wherein
the light guide plate has a first protrusion part on the first main surface and a second protrusion part on the second main surface,
a plurality of the first protrusion parts are arranged along a first direction and extended along a second direction which crosses the first direction,
the first protrusion part has a first ridge extending from the first side surface to the second side surface,
a plurality of the second protrusion parts are arranged along the second direction and extended along the first direction,
the second protrusion part has a second ridge extending from the third side surface to the fourth side surface,
a cross-sectional shape of each of the first protrusion parts has an apex angle between 55 and 65 degrees, inclusive,
a cross-sectional shape of each of the second protrusion parts has a base angle between 1 and 3 degrees, inclusive,
an emission surface of the light source element is disposed in the second direction, and
a reflection sheet disposes to be opposed to the second main surface of the light guide plate.