Solid-state image pickup device and system having photodiodes of varying sizes and sensitivities in each unity cell to detect movement of a subject

摘要

Certain embodiments provide a solid-state image pickup device including a first pixel, a second pixel, and an output circuit. The first pixel has a first photodiode and a first microlens that is formed above the first photodiode. The second pixel has a second photodiode and a second microlens which is formed above the second photodiode and is smaller than the first microlens. Further, the second pixel has a sensitivity of 1/n times of the first pixel and has a photoelectric conversion period of n times of the first pixel. The output circuit outputs a differential signal of a difference between a first detection signal based on a charge amount of the first signal charge and a second detection signal based on a charge amount of the second signal charge.

主权项

1. A solid-state image pickup device comprising:
a first pixel having a first photodiode which causes a first signal charge to be generated by receiving light and by photoelectrically converting the light; a second pixel having a second photodiode which causes a second signal charge to be generated by receiving light and by photoelectrically converting the light, and having a sensitivity of 1/n times of the first pixel; and an output circuit outputting a differential signal of a difference between a first detection signal and a second detection signal, the first detection signal being based on a charge amount of the first signal charge which is obtained by photoelectrically converting the light over a first photoelectric conversion period in the first pixel, and the second detection signal being based on a charge amount of the second signal charge which is obtained by photoelectrically converting the light over a second photoelectric conversion period having a length of n times of the first photoelectric conversion period in the second pixel, wherein the output circuit includes a detecting unit accumulating the first signal charge and the second signal charge, an amplifier transistor converting the first signal charge into the first detection signal, based on a charge amount of the first signal charge that is accumulated in the detecting unit, and converting the second signal charge into the second detection signal, based on a charge amount of the second signal charge that is accumulated in the detecting unit, and a differential amplifier having an inverting input terminal which is connected to the amplifier transistor and to which the first detection signal is input, a non-inverting input terminal which is connected to the amplifier transistor and to which the second detection signal is input, and an output terminal which outputs the differential signal as a difference between the first detection signal and the second detection signal.