Patent ID: 11880016
Assignee: NICHIA CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC F  G | IPC F

Claim 0:
1. A light emitting device comprising:
a plurality of light source parts each being configured to emit an irradiation light, the plurality of light source parts comprising at least one first light source part, at least one second light source part, and at least one third light source part; wherein
each of the at least one first light source part comprising a first light emitting element having a first light emitting surface and a first light-guiding member configured to guide light emitted from the first light emitting element;
each of the at least one second light source part comprising a second light emitting element having a second light emitting surface and a second light-guiding member configured to guide light emitted from the second light emitting element;
each of the least one third light source part comprising a third light emitting element having a third light emitting surface and a third light-guiding member configured to guide light emitted from the third light emitting element;
with respect to at least one second light source part, a center of a light-exiting surface of the second light-guiding member is positionally shifted from a center of an incident surface of the second light-guiding member;
each of the at least one first light-guiding member having a tapered shape narrowing toward the first light emitting element; and
each of the at least one second light-guiding member having a tapered shape narrowing toward the second light emitting element;
wherein the irradiation light emitted from the first light source part and the irradiation light emitted from the second light source part satisfy the condition (1):

θ≤α≤tan−1{2 tan(θ)}  (1)

wherein θ is an angle between an imaginary straight line connecting a position of center of a light-irradiation region on a light-irradiation surface of the irradiation light emitted from each one of the at least one first light source part and a center of the first light emitting surface of the first light source part, the light-irradiation surface being separate and spaced apart from the light emitting device, and the light-irradiation surface being a flat plane surface perpendicular to a first central axis of the first light-guiding member, and
an imaginary straight line connecting a position on the light-irradiation surface having an illuminance of at least one-half of an illuminance at center position of the corresponding one of the at least one first light source part and the center of the first light emitting surface of the first light source part, and
α is an angle between the imaginary straight line connecting the position of center of the light-irradiation region on the light-irradiation surface of the irradiation light emitted from the corresponding one of the at least one first light source part and the center of the first light emitting surface of the corresponding one of the at least one first light source part, and
an imaginary straight line connecting a position of center of a light-irradiation region on a light-irradiation surface of the irradiation light emitted from each one of the at least one second light source part and a center of the second light emitting surface of the second light source part,
wherein the second light emitting element of one of the at least one second light source part is positioned on a boundary of the corresponding second light-exiting surface of the corresponding second light-guiding member when viewed in a plan view, and
the third light emitting element of the at least one third light source part that is adjacent to the at least one second light source part, is positioned on a boundary of the corresponding third light-exiting surface of the corresponding third light-guiding member when viewed in the plan view.