Light source device and distance measuring device
AssigneeCanon Kabushiki Kaisha
InventorsTakako Suga, Takeshi Uchida
Life of this patent
Estimating the term…
Abstract
The disclosed light source device includes a light emitting element including a first reflector, a second reflector, and a resonator spacer portion provided between the first reflector and the second reflector and including an active layer, and emits a first light as a laser beam and a second light as a spontaneous emission light, a light receiving element that determines an amount of the second light, and a determination unit that determines a timing at which the first light oscillates based on a decrease in the amount of the second light determined by the light receiving element.
Claims17
A light source device comprising:
- a light emitting element including a first reflector, a second reflector, and a resonator spacer portion provided between the first reflector and the second reflector and including an active layer, and emitting a first light as a laser beam and second light as a spontaneous emission light;
- a light receiving element configured to determine a light amount of the second light;
- and
- a determination unit configured to determine a timing at which the first light oscillates based on a decrease in an amount of the second light determined by the light receiving element,
- wherein assuming that a distance between a light emitting portion of the second light of the light emitting element and a light receiving unit of the light receiving element is L, a total amount of the second light emitted from the light emitting element is P, an area of the light receiving unit is S, a sensitivity of the light receiving unit is Q, and a dark current of the light emitting element is Da, a following relationship is satisfied:
- P×(S/4πL2)×Q>Da.
Dependencies are inferred from the claim text.