Light source apparatus, temperature detection method, and sensing module
A light source apparatus is provided with the emission section in which a plurality of vertical-cavity surface-emitting laser light-emitting elements is arrayed, the driving circuit section that causes the plurality of light-emitting elements of the emission section to emit light, the temperature detection section that includes a plurality of temperature sensors arranged to detect the temperature of the emission section, and a control section. The control section is configured to, during an emission target period when the light-emitting elements of the emission section are driven by the driving circuit section, correct a detection value from each of the plurality of temperature sensors by using a correction value set for each of the temperature sensors.
1. A light source apparatus, comprising:
an emission section comprising an array of a plurality of light-emitting elements;
a driving circuit section configured to drive the plurality of light-emitting elements of the emission section to emit light;
a temperature detection section including a plurality of temperature sensors to detect a temperature of the emission section, wherein each temperature sensor of the plurality of temperature sensors is configured to detect a temperature detection value that corresponds to the temperature; and
a control section configured to:
store, in a memory of the light source apparatus, a correction value for the temperature detection value of each temperature sensor of the plurality of temperature sensors; and
correct the temperature detection value from each temperature sensor of the plurality of temperature sensors based on the correction value stored for each temperature sensor of the plurality of temperature sensors in the memory,
wherein the correction is performed in an emission target period in which the plurality of light-emitting elements of the emission section is driven to emit the light by the driving circuit section.
2. The light source apparatus according to claim 1 , wherein
the correction value is an offset value that indicates a difference between a reference detection value and the temperature detection value from each of the plurality of temperature sensors.
3. The light source apparatus according to claim 1 , wherein the control section is further configured to compute the correction value based on the temperature detection value of each of the plurality of temperature sensors, and a reference detection value, and wherein the temperature detection value is detected in a non-emission period in which the driving circuit section is not configured to drive the plurality of light-emitting elements of the emission section to emit light.
4. The light source apparatus according to claim 2 , wherein
the temperature detection section includes a reference temperature sensor as an absolute thermometer, and
the reference detection value is a detection value from the reference temperature sensor.
5. The light source apparatus according to claim 2 , wherein
the reference detection value is an average of temperature detection values detected by the plurality of temperature sensors.
6. The light source apparatus according to claim 1 , wherein
the plurality of temperature sensors is underneath mesas where the plurality of light-emitting elements is present.
7. The light source apparatus according to claim 1 , wherein
the driving circuit section is configured to individually drive emission operation for each specific unit of the plurality of the light-emitting elements.
8. The light source apparatus according to claim 1 , wherein the control section is further configured to switch on a driving method of the emission section by the driving circuit section based on the corrected temperature detection value.
9. The light source apparatus according to claim 1 , wherein
the emission section is configured to emit the light in synchronization with a frame period of an image sensor configured to receive the light emitted by the emission section and reflected by a subject.
10. A temperature detection method for a light source apparatus that comprises
an emission section that includes an array of a plurality of light-emitting elements,
a driving circuit section configured to drive the plurality of light-emitting elements of the emission section to emit light, and
a temperature detection section including a plurality of temperature sensors to detect a temperature of the emission section, wherein each temperature sensor of the plurality of temperature sensors is configured to detect a temperature detection value that corresponds to the temperature, the method comprising:
storing, in a memory of the light source apparatus, a correction value for the temperature detection value of each temperature sensor of the plurality of temperature sensors; and
correcting the temperature detection value from each temperature sensor of the plurality of temperature sensors based on the correction value stored for each temperature sensor of the plurality of temperature sensors in the memory,
wherein the correction is performed in an emission target period in which the plurality of light-emitting elements of the emission section is driven to emit the light by the driving circuit section.
11. A sensing module, comprising:
an emission section comprising an array of a plurality of light-emitting elements;
a driving circuit section configured to drive the plurality of light-emitting elements of the emission section to emit light;
a temperature detection section that includes a plurality of temperature sensors to detect a temperature of the emission section, wherein each temperature sensor of the plurality of temperature sensors is configured to detect a temperature detection value that corresponds to the temperature;
a control section configured to:
store, in a memory of the sensing module, a correction value for the temperature detection value of each temperature sensor of the plurality of temperature sensors; and
correct the temperature detection value from each temperature sensor of the plurality of temperature sensors based on the correction value stored for each temperature sensor of the plurality of temperature sensors in the memory,
wherein the correction is performed in an emission target period in which the plurality of light-emitting elements of the emission section is driven to emit the light by the driving circuit section; and
an image sensor configured to capture an image based on the light emitted by the emission section and reflected by a subject.
12. The light source apparatus according to claim 1 , wherein each temperature sensor of the plurality of temperature sensors includes a diode as a temperature detection element for the detection of the temperature detection value.
13. The light source apparatus according to claim 1 , wherein the plurality of temperature sensors are at substantially equal intervals on a plane in correspondence with the array of the plurality of light-emitting elements.
14. The light source apparatus according to claim 8 , wherein the driving method is switched between a simultaneous emission of the plurality of light-emitting elements and a time-division emission of the plurality of light-emitting elements,
the simultaneous emission causes the plurality of light-emitting elements to emit the light simultaneously inside the emission target period, and
the time-division emission causes the plurality of light-emitting elements to emit the light at alternating times inside the emission target period.