Managing optical power in laser system
View Patent ↗A device for managing power of a laser source in a laser-based apparatus includes switched-mode power controller circuitry. The power controller circuitry further includes a controller output configured to be coupled to reservoir capacitor of a laser source to provide a first mode of regulating charging of the reservoir capacitor between illuminations of the laser source and a second mode of regulating charging of the reservoir capacitor during illuminations of the laser source.
1 . A device for managing power of a laser source in a laser-based apparatus, the device comprising:
switched-mode power controller circuitry, including a controller output configured to be coupled to a reservoir capacitor of a laser source to provide a first mode of regulating charging of the reservoir capacitor between illuminations of the laser source and a second mode of regulating charging of the reservoir capacitor during illuminations of the laser source, wherein the switched-mode power controller circuitry can be either inductive or capacitive; and
power controller circuitry is configured to provide power for at least one of the laser source and an imager circuit based at least in part on a discharge characteristic of the reservoir capacitor during illumination by the laser source, using at least one inductive power regulator, or a continuous-time linear voltage regulator, a single or dual inductor power regulator,
wherein the power controller circuitry is configured to regulate charging and discharging of the reservoir capacitor based at least in part on an estimation of optical power, the estimation being derived from at least one of: a photodetector signal, a measured forward voltage of a laser emitter, or a measured temperature of the laser emitter.
2 . The device of claim 1 , wherein the power controller circuitry is configured to adjust the charging and discharging of the reservoir capacitor before a next illumination based on a detection of a fault indication.
3 . The device of claim 2 , wherein the fault indication is determined by a photosensor optically coupled to the laser source or a temperature sensor to determine the charging or discharging of the reservoir capacitor to maintain the power to either the laser source or imager circuitry.
4 . The device of claim 1 , wherein the power controller circuitry is further configured so that a second regulator of the at least one inductive power regulator is a linear regulator, that provides a minimum amount of power to the imager circuit or the laser source.
5 . The device of claim 1 , where a voltage regulator for charging the reservoir capacitor is also used for discharging power from the reservoir capacitor and delivering power to a laser source or other coupled circuitry.
6 . The device of claim 5 , wherein a characteristic of at least one reservoir capacitor is used to provide a fuel gauge indication for the reservoir capacitor.
7 . The device of claim 1 , wherein the power controller circuitry is configured to provide differently specifiable energy outputs respectively to the imager circuit and the laser source.
8 . The device of claim 7 , wherein the power controller circuitry is further configured to regulate charging of the reservoir capacitor, including in a first mode between illuminations by the laser source, based on monitoring at least one of a parasitic resistance of the reservoir capacitor or a parasitic inductance of the reservoir capacitor.
9 . The device of claim 1 , wherein an illumination monitor further includes a photodetector that is optically coupled to the laser source to transduce illumination light provided by the laser source before interaction with a target object or scene, and wherein the illumination is further based at least in part on an indication of the illumination light transduced by the photodetector.
10 . The device of claim 1 , wherein the power controller circuitry is configured to regulate charging and discharging of the reservoir capacitor based at least in part on an estimation of optical power, the estimation being derived from the measured temperature of the laser emitter.
11 . The device of claim 1 , wherein a charge pump is used to charge the reservoir capacitor and a buck switching voltage regulator is used to discharge the reservoir capacitor.
12 . The device of claim 1 , wherein the power controller circuitry comprises a shared switched-mode regulator to both (1) regulate charging of the reservoir capacitor, and (2) provide power to an imager circuit for collecting response light to the illuminations, wherein the power controller circuitry controls activation of the laser source based at least in part on an indication of response light collected by the imager circuit.
13 . The device of claim 1 , wherein the power controller circuitry is configured to regulate charging and discharging of the reservoir capacitor based at least in part on an estimation of optical power, the estimation being derived from the measured forward voltage of the laser emitter.
14 . The device of claim 1 , wherein the power controller circuitry is configured to regulate charging and discharging of the reservoir capacitor based at least in part on an estimation of optical power, the estimation being derived from the photodetector signal.
15 . A method for managing power of a laser source in a laser-based apparatus, the method comprising:
charging a reservoir capacitor in between illuminations of a laser source of the laser-based apparatus using a switched-mode voltage regulator and controlling an output of the switched-mode voltage regulator;
discharging the reservoir capacitor during illumination by the laser source to supplement an increase of power needed to support the illumination out of the laser source; and
regulating the charging and the discharging of the reservoir capacitor based at least in part on an estimation of optical power, the estimation being derived from at least one of: a photodetector signal, a measured forward voltage of a laser emitter, or a measured temperature of the laser emitter.
16 . The method of claim 15 , where an indication of charging and discharging of the reservoir capacitor is monitored by using measurement sensors to measure an indication of energy delivered to the laser source, imager circuitry or other coupled circuitry and charging and discharging of the reservoir capacitor is limited based on this indication.
17 . The method of claim 16 , wherein the power delivered by the reservoir capacitor is differently specifiable energy outputs respectively to the imager circuitry and the laser source.
18 . The method of claim 16 , where different frequencies of operation can be stored and used to enable different transient and power responses for the imager circuitry or laser driver.
19 . The method of claim 15 , where prior to the illumination of the laser source, a desired output voltage is elevated using the reservoir capacitor.
20 . The method of claim 15 , where charging and discharging characteristics of a reservoir capacitor are controlled by collecting response light to the illuminations, wherein a power controller circuitry controls activation of the laser source based at least in part on an indication of response light collected by an imager circuit or a photodetector.
21 . A device for managing power of a laser source in a laser-based apparatus, the device comprising:
means for charging a reservoir capacitor in between illuminations of a laser source of the laser-based apparatus and controlling its output; and
means for discharging the reservoir capacitor during illumination by the laser source to supplement an increase of power needed to support the illumination out of the laser source; and
means for regulating the charging and the discharging of the reservoir capacitor based at least in part on an estimation of optical power.
22 . The device of claim 21 , where prior to the illumination of the laser source, a desired output voltage is elevated using the reservoir capacitor.