Patent ID: 11966071
Assignee: SHARP DISPLAY TECHNOLOGY CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G | IPC F

Claim 10:
11. An illumination device comprising:
a first sheet including a first light entering main surface being one main surface disposed along a first direction, a first light emission main surface being another main surface along the first direction, two first light blocking portions disposed at an interval in the first direction, and a first light-transmitting portion disposed between the two first light blocking portions;
a second sheet including a second light entering main surface being one main surface disposed along the first direction and configured to face the first light emission main surface, a second light emission main surface being another main surface along the first direction, and a first lens disposed on the second light entering main surface or the second light emission main surface;
a third sheet including a third light entering main surface being one main surface disposed along the first direction and configured to face the second light emission main surface, a third light emission main surface being another main surface along the first direction, two second light blocking portions disposed at an interval in the first direction, and a second light-transmitting portion disposed between the two second light blocking portions;
a first light source;
a first light guide plate aligned along the first direction with respect to the first light source;
a first prism sheet disposed on a light emission side with respect to the first light guide plate, the first prism sheet including a plurality of first prisms disposed side by side along the first direction and configured to extend along a second direction orthogonal to both of the first direction and a normal direction of a main surface of the first light guide plate;
a second prism sheet disposed on a light emission side with respect to the first prism sheet, the second prism sheet including a plurality of second prisms disposed side by side along the first direction and configured to extend along the second direction;
a second light source; and
a second light guide plate aligned along the first direction with respect to the second light source,
wherein the first lens includes a first inclined surface having an inclination rising from an end side in the first direction in the second sheet toward a central side,
the third sheet has a ratio acquired by dividing a width of the second light-transmitting portion by a height of the second light-transmitting portion greater than a ratio acquired by dividing a width of the first light-transmitting portion by a height of the first light-transmitting portion,
the first light guide plate includes at least a part of an outer circumferential end face as a first light entering end face facing the first light source, and further includes one main surface as a fourth light emission main surface configured to emit light,
the second prism sheet includes a main surface on the light emission side facing the first light entering main surface of the first sheet,
the second light guide plate includes:
at least a part of an outer circumferential end face as a second light entering end face facing the second light source,

one main surface as a fifth light emission main surface configured to emit light, and
another main surface as an opposite main surface facing the third light emission main surface and being provided with a second lens, and

the second lens includes a seventh inclined surface having an inclination rising from a side opposite the second light source in the first direction in the second light guide plate toward a second light source side.