US 12,013,610 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 Apr. 26, 2023, as Appl. No. 18/307,059.
Application 18/307,059 is a continuation of application No. 17/829,425, filed on Jun. 1, 2022, granted, now 11,668,976.
Application 17/829,425 is a continuation of application No. 17/220,503, filed on Apr. 1, 2021, granted, now 11,378,841, issued on Jul. 5, 2022.
Claims priority of application No. 2020-067778 (JP), filed on Apr. 3, 2020.
Prior Publication US 2023/0266619 A1, Aug. 24, 2023
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 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 the third side surface; and
a plurality of light source elements facing the first side surface of the light guide plate and arranging along a first direction, wherein
an emission surface of the light source element is disposed in a second direction which crosses the first direction,
the light guide plate has a plurality of upper protrusions on the first main surface and a plurality of protrusions on the second main surface,
the upper protrusions are arranged along the first direction and extended along the second direction,
a cross-sectional shape of the upper protrusions have an apex angle between 55 and 65 degrees, inclusive,
each of the plurality of protrusions is extended along the first direction and arranged along the second direction,
each of the plurality of protrusions has ridge extending from the third side surface to the fourth side surface,
a cross-sectional shape of each protrusions has a base angle between 1 and 3 degrees, inclusive, and
a prism sheet disposes to be opposed to the first main surface.