Light receiving device, distance measuring device, and light receiving circuit
Provided are a light receiving device, a light receiving circuit, and a distance measuring device capable of minimizing dead time. A light receiving device according to the present disclosure may include: a light receiving circuit including a light receiving element; a power supply circuit configured to supply a power supply potential to the light receiving circuit; and a control circuit configured to control the power supply potential supplied by the power supply circuit on the basis of a signal output from the light receiving circuit in a reaction with a photon.
1 . A light receiving device, comprising:
a plurality of light receiving circuits, wherein
each light receiving circuit of the plurality of light receiving circuits includes a light receiving element, and
the plurality of light receiving circuits is configured to output a plurality of signals based on a reaction with a photon;
a power supply circuit configured to supply a power supply potential to the plurality of light receiving circuits;
a load circuit connected to at least one light receiving circuit of the plurality of light receiving circuits, wherein the load circuit is configured to supply a recharge current to the light receiving element of the at least one light receiving circuit;
an error detector configured to determine, based on a plurality of waveforms of the plurality of signals, a number of errors associated with the plurality of signals; and
a control circuit configured to change, based on the determined number of errors, at least one of the power supply potential of the power supply circuit or a parameter of the load circuit, wherein the parameter of the load circuit includes at least one of the recharge current of the load circuit or a resistance value of the load circuit.
2 . The light receiving device according to claim 1 , wherein
the at least one light receiving circuit is configured to perform a passive recharge,
the control circuit is further configured to adjust the recharge current for the at least one light receiving circuit, and
the number of errors associated with the plurality of signals reduces, based on the adjustment of the recharge current, to a specific number less than a threshold.
3 . The light receiving device according to claim 1 , wherein
the at least one light receiving circuit is configured to generate a pulse for an active recharge of the light receiving element of the at least one light receiving circuit, and
the control circuit is further configured to adjust a time delay associated with the pulse based on the number of errors associated with the plurality of signals.
4 . The light receiving device according to claim 1 , wherein
the plurality of signals includes a first signal and a second signal,
a pulse width of the first signal exceeds a first threshold,
an interval between pulses of the second signal is less than a second threshold,
the error detector is further configured to determine that at least one of the first signal or the second signal is associated with an error, and
the determination of the number of errors associated with the plurality of signals is based on the determination that the at least one of the first signal or the second signal is associated with the error.
5 . The light receiving device according to claim 1 , wherein the light receiving element is an avalanche photodiode.
6 . A distance measuring device, comprising:
a light emitting element;
a plurality of light receiving circuits, wherein
each light receiving circuit of the plurality of light receiving circuits includes a light receiving element, and
the plurality of light receiving circuits is configured to output a signal based on a reaction with a photon;
a power supply circuit configured to supply a power supply potential to the plurality of light receiving circuits; and
a control circuit configured to:
control the power supply potential of the power supply circuit based on the outputted signal, wherein
the control of the power supply potential is during a period in which the light emitting element prohibits emission of light,
at least one light receiving circuit of the plurality of light receiving circuits is configured to generate a pulse for an active recharge of the light receiving element of the at least one light receiving circuit; and
adjust, based on the outputted signal, a time delay associated with the pulse.
7 . The distance measuring device according to claim 6 , further comprising a plurality of load circuits connected to the plurality of light receiving circuits, wherein
each load circuit of the plurality of load circuits is configured to supply a recharge current to the light receiving element of a respective light receiving circuit of the plurality of light receiving circuits, and
the control circuit is further configured to control, based on the outputted signal, at least one of a resistance value of the plurality of load circuits or the recharge current of the plurality of load circuits.
8 . A light receiving circuit, comprising:
a light receiving element;
a passive recharge circuit including:
a current source;
a first switch configured to turn on one of:
a first contact side of the first switch connected to a reference potential, or
a second contact side of the first switch connected to the light receiving element;
a current mirror circuit configured to:
mirror a first current that flows between the reference potential and the current source; and
supply, from an output side of the current mirror circuit, a second current based on the mirroring of the first current; and
a first transistor having each of:
a first signal electrode connected to the reference potential,
a second signal electrode connected to each of the light receiving element and the output side of the current mirror circuit, and
a control electrode connected to the first switch; and
an active recharge circuit including:
a pulse generator having an input terminal and an output terminal;
a second switch; and
a second transistor having each of:
a first signal electrode connected to the reference potential,
a second signal electrode connected to the second switch,
a control electrode connected to the output terminal of the pulse generator, wherein
the input terminal of the pulse generator is connected to an output side of the light receiving circuit, and
the second switch is connected between the second transistor and the light receiving element.
9 . The light receiving circuit according to claim 8 , further comprising:
a plurality of first switches that includes the first switch; and
a plurality of first transistors that includes the first transistor, wherein
the passive recharge circuit is configured to supply a third current to the light receiving element based on switching of the plurality of first switches, and
a value of the third current is N multiples of a value of the first current, where ‘N’ is a positive integer.
10 . The light receiving circuit according to claim 8 , further comprising a readout circuit configured to generate a pulse in a case where the light receiving element reacts with a photon.
11 . A light receiving circuit, comprising:
a light receiving element;
a passive recharge circuit including:
a plurality of resistors connected in parallel between a reference potential and the light receiving element; and
a plurality of first switches, wherein each first switch of the plurality of first switches is connected in series with a respective resistor of the plurality of resistors;
an active recharge circuit including:
a pulse generator having an input terminal and an output terminal;
a second switch; and
a transistor having each of:
a first signal electrode connected to the reference potential,
a second signal electrode connected to the second switch,
a control electrode connected to the output terminal of the pulse generator, wherein
the input terminal of the pulse generator is connected to an output side of the light receiving circuit, and
the second switch is connected between the transistor and the light receiving element; and
a readout circuit configured to generate a pulse in a case where the light receiving element reacts with a photon, wherein
at least one of the passive recharge circuit or the active recharge circuit is configured to supply a current to the light receiving element, and
the current, supplied by the passive recharge circuit, is based on switching of the plurality of first switches.
12 . A light receiving device, comprising:
a plurality of light receiving circuits, wherein
each light receiving circuit of the plurality of light receiving circuits includes a light receiving element, and
the plurality of light receiving circuits is configured to output a plurality of signals based on a reaction with a photon;
a power supply circuit configured to supply a power supply potential to the plurality of light receiving circuits;
a load circuit connected to at least one light receiving circuit of the plurality of light receiving circuits, wherein the load circuit is configured to supply a recharge current to the light receiving element of the at least one light receiving circuit;
an error correction circuit configured to:
determine, based on a plurality of waveforms of the plurality of signals, a number of errors associated with the plurality of signals; and
correct the plurality of waveforms of the plurality of signals based on the determined number of errors; and
a control circuit configured to change, based on the determined number of errors, at least one of the power supply potential of the power supply circuit or a parameter of the load circuit, wherein the parameter of the load circuit includes at least one of the recharge current of the load circuit or a resistance value of the load circuit.
13 . The light receiving device according to claim 12 , wherein
the at least one light receiving circuit is configured to perform a passive recharge,
the control circuit is further configured to adjust, based on the number of errors associated with the plurality of signals, the recharge current in the passive recharge of the at least one light receiving circuit.
14 . The light receiving device according to claim 12 , wherein
the at least one light receiving circuit is configured to generate a pulse for an active recharge of the light receiving element of the at least one light receiving circuit, and
the control circuit is further configured to adjust a time delay associated with the pulse based on the number of errors associated with the plurality of signals.
15 . The light receiving device according to claim 12 , wherein
the plurality of signals includes a first signal and a second signal,
a pulse width of the first signal exceeds a first threshold,
an interval between pulses of the second signal is less than a second threshold,
the error correction circuit is further configured to determine that at least one of the first signal or the second signal is associated with an error, and
the determination of the number of errors associated with the plurality of signals is based on the determination that the at least one of the first signal or the second signal is associated with the error.