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

Claim 8:
9. 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; and
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,
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,
each of the plurality of first prisms includes a third inclined surface having an inclination rising from a first light source side in the first direction in the first prism sheet toward a side opposite the first light source, and includes a fourth inclined surface having an inclination rising from the side opposite the first light source in the first direction in the first prism sheet toward the first light source side,
each of the plurality of second prisms includes a fifth inclined surface having an inclination rising from a first light source side in the first direction in the second prism sheet toward a side opposite the first light source, and includes a sixth inclined surface having an inclination rising from the side opposite the first light source in the first direction in the second prism sheet toward the first light source side, and
an angle formed by the fifth inclined surface in the second prism with respect to the first direction is smaller than an angle formed by the third inclined surface in the first prism with respect to the first direction.