Time-resolving sensor using shared ppd+spad pixel and spatial-temporal correlation for range measurement

A pixel in an image sensor, the pixel comprising:

• a plurality of a first type of diodes that each detects one or more incident photons;
• a time-resolving sensor that outputs a first reset signal, a second reset signal, a first measurement signal and a second measurement signal;
• and
• a control circuit coupled to the plurality of the first type of diodes and the time-resolving sensor, the control circuit controlling the time-resolving sensor to output the first reset signal and the second reset signal in response to a reset condition, and controlling the time-resolving sensor to output the first measurement signal and the second measurement signal in response to detecting by the at least two of the first type of diodes one or more incident photons that have been reflected from an object corresponding to a light pulse projected toward the object, a first ratio of a magnitude of a first signal to a sum of the magnitude of the first signal and a magnitude of a second signal being proportional to a time of flight of the one or more detected incident photons, and a second ratio of the magnitude of the second signal to the sum of the magnitude of the first signal and the magnitude of the second signal being proportional to the time of flight of the one or more detected incident photons, the first signal being formed by subtracting the first reset signal from the first measurement signal and the second signal being formed by subtracting the second reset signal from the second measurement signal.

An imaging unit, comprising:

• a light source that projects a light pulse;
• and
• an image sensor unit comprising an array of pixels, at least one pixel comprising:
• at least two diodes of a first type that each detects one or more incident photons;
• and
• a time-resolving sensor that outputs a first reset signal, a second reset signal, a first measurement signal and a second measurement signal;
• and
• a control circuit coupled to the at least two diodes of the first type and the time-resolving sensor of the at least one pixel, the control circuit controlling the time-resolving sensor to output the first reset signal and the second reset signal in response to a reset condition, and controlling the time-resolving sensor to output the first measurement signal and the second measurement signal in response to detecting by the at least two of the first type of diodes one or more incident photons that have been reflected from an object corresponding to a light pulse projected toward the object, a first ratio of a magnitude of a first signal to a sum of the magnitude of the first signal and a magnitude of a second signal being proportional to a time of flight of the one or more detected incident photons, and a second ratio of the magnitude of the second signal to the sum of the magnitude of the first signal and the magnitude of the second signal being proportional to the time of flight of the one or more detected incident photons, the first signal being formed by subtracting the first reset signal from the first measurement signal and the second signal being formed by subtracting the second reset signal from the second measurement signal.