Photoelectric conversion apparatus
A photoelectric conversion apparatus includes a plurality of pixels each including a respective avalanche photodiode, wherein the plurality of pixels includes an active pixel that outputs a photon detection signal according to detection of a photon and an inactive pixel that does not output the photon detection signal, and wherein the photoelectric conversion apparatus further includes a control unit that recharges a voltage to be applied between an anode and a cathode of the avalanche photodiode of the inactive pixel.
1. A photoelectric conversion apparatus comprising:
a plurality of pixels each including a respective avalanche photodiode;
wherein the plurality of pixels includes an active pixel that outputs a photon detection signal according to detection of a photon and an inactive pixel that does not output the photon detection signal, and
wherein the photoelectric conversion apparatus further comprises a control unit that recharges a voltage to be applied between an anode and a cathode of the avalanche photodiode of the inactive pixel.
2. The photoelectric conversion apparatus according to claim 1 , further comprising a reading circuit,
wherein the active pixel outputs the photon detection signal to the reading circuit,
wherein the inactive pixel does not output the photon detection signal to the reading circuit, and
wherein an output terminal of the inactive pixel is not electrically connected to the reading circuit.
3. The photoelectric conversion apparatus according to claim 2 ,
wherein each of the plurality of pixels further includes a respective recharge circuit connected to the avalanche photodiode,
wherein, in the plurality of pixels, the voltage to be applied to the avalanche photodiode is recharged by controlling the recharge circuit according to a recharge signal.
4. The photoelectric conversion apparatus according to claim 3 , wherein the recharge circuit switches resistance between the avalanche photodiode and a power source according to the recharge signal.
5. The photoelectric conversion apparatus according to claim 3 , wherein a period corresponding to a pulse width of the recharge signal of the inactive pixel and a period corresponding to a pulse width of the recharge signal of the active pixel differ from each other.
6. The photoelectric conversion apparatus according to claim 3 , wherein the active pixel detects a photon during an exposure period.
7. The photoelectric conversion apparatus according to claim 3 , wherein the inactive pixel outputs no signal outside the plurality of pixels.
8. The photoelectric conversion apparatus according to claim 3 , wherein, in the inactive pixel, both or one of generation and output of the photon detection signal of the inactive pixel is stopped by a thinning-out operation or a crop operation.
9. The photoelectric conversion apparatus according to claim 3 , wherein the inactive pixel outputs a signal according to a waveform of the recharge signal.
10. The photoelectric conversion apparatus according to claim 3 , further comprising:
a counter to which an output signal from the inactive pixel is input,
wherein a node different from the anode or the cathode of the inactive pixel is connected to an input node of the counter.
11. The photoelectric conversion apparatus according to claim 6 , wherein the voltage to be applied to the active pixel is recharged according to the recharge signal during the exposure period of the active pixel, wherein the recharge signal is a clock signal input in a first cycle.
12. The photoelectric conversion apparatus according to claim 11 ,
wherein the voltage to be applied to the inactive pixel is recharged according to the recharge signal that is a clock signal input in a second cycle, and
wherein the second cycle is longer than the first cycle.
13. The photoelectric conversion apparatus according to claim 3 , further comprising:
a counter that counts detected photons according to the photon detection signal,
wherein the voltage to be applied to the avalanche photodiode is recharged according to a reset signal that resets a count of the counter.
14. The photoelectric conversion apparatus according to claim 3 ,
wherein the recharge signal includes:
a first recharge signal that controls a first pixel area including only the inactive pixel; and
a second recharge signal that controls a second pixel area including both the inactive pixel and the active pixel, and
wherein the first recharge signal and the second recharge signal differ in phase.
15. The photoelectric conversion apparatus according to claim 14 ,
wherein the inactive pixel generates a third recharge signal by a logical operation between the second recharge signal and a stop signal, and
wherein a pulse count of the third recharge signal per unit time is less than a pulse count of the second recharge signal per unit time.
16. A photoelectrical conversion system comprising:
the photoelectric conversion apparatus according to claim 2 ; and
a signal processing unit that generates an image using a signal output from the photoelectric conversion apparatus.
17. A moving body comprising:
the photoelectric conversion apparatus according to claim 2 ; and
a control unit that controls movement of the moving body using a signal output from the photoelectric conversion apparatus.