Patent ID: 11892675
Assignee: JAPAN DISPLAY INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G | IPC F

Claim 0:
1. An illumination device comprising:
a light guide including:
a first side surface,
a second side surface opposed to the first side surface in a first direction,
a main surface, and
an opposing surface opposed to the main surface in a second direction intersecting the first direction;

a light source that is opposed to the first side surface and emits light to the first side surface;
a reflective layer provided on the second side surface;
a first prism provided on the opposing surface; and
a second prism provided on a side closer to the second side surface in the first direction than the first prism on the opposing surface, wherein
the light guide has a thickness in the second direction increasing from the first side surface toward the second side surface in the first direction,
the opposing surface includes
a first slope,
a second slope located on a side closer to the second side surface than the first slope in the first direction,
a third slope located on a side closer to the second side surface than the second slope in the first direction,
a fourth slope located on a side closer to the second side surface than the third slope in the first direction,
a first plane that connects the first slope and the second slope and is parallel to the main surface, and
a second plane that connects the third slope and the fourth slope and is parallel to the main surface,

the first prism and the second prism have cross-sectional shapes being formed in a triangle shape protruding to an opposite side of the opposing surface in the second direction,
the first prism is disposed on the first plane,
the second prism is disposed on the second plane,
a first height of the first prism in the second direction is smaller than a second height of the second prism in the second direction, and
a sum of the first height, a third height of the first slope in the second direction, and a fourth height of the second slope in the second direction is larger than a sum of the second height, a fifth height of the third slope in the second direction, and a sixth height of the fourth slope in the second direction.