Light receiving device and range-finding device

A range-finding device comprising:

• a light receiving element in which a current flows because of avalanche multiplication caused in accordance with a photon that has been incident on the light receiving element in a state in which the light receiving element is charged to a predetermined potential based on a bias voltage, the light receiving element returning to said state by a recharge current;
• a detection circuit configured to invert a signal from an output node of the light receiving element in a case in which a current value of the current exceeds a threshold, the detection circuit including an inverter having an input and an output, the input being electrically connected to the output node of the light receiving element, the output providing an inversion of the signal from the output node of the light receiving element as an output signal;
• a current source configured to supply the recharge current to the light receiving element;
• a switch circuit configured to control supply of the bias voltage to the light receiving element in accordance with the output signal, the switch circuit including a gate, a first terminal and a second terminal, the gate being directly electrically connected to the output of the inverter, the first terminal being electrically connected to a predetermined voltage, and the second terminal being electrically connected to the output node of the light receiving element;
• a time measurement unit configured to measure a time from a light emission timing when a light source emits light to a light reception timing when the light receiving element receives light, and acquire a measured value;
• a histogram generation unit configured to generate a histogram of the measured value;
• and
• an arithmetic unit configured to compute a distance to an object to be measured based on the histogram, wherein
• the current source supplies a first current as the recharge current in a first period, the first current causing the light receiving element to approach said state of being charged to the predetermined potential at a first rate, and
• in response to the output signal from the detection circuit, the switch circuit provides a second current as the recharge current in a second period, the second current causing the light receiving element to approach said state of being charged to the predetermined potential at a second rate that is faster than the first rate.