Methods of driving image sensors including unit pixels having photoelectric conversion and floating diffusion regions

摘要

A method of driving an image sensor including a plurality of unit pixels, each unit pixel having photoelectric conversion and floating diffusion regions, may include resetting a potential level of the floating diffusion region by a first voltage level, the first voltage level being lower than a power supply voltage; converting incident light into electrical charges in the photoelectric conversion region; and accumulating at least one of collected, first overflowed, and second overflowed electrical charges in the floating diffusion region based on the incident light, the collected electrical charges indicating electrical charges that are collected in the photoelectric conversion region, the first overflowed electrical charges indicating charges overflowed from the photoelectric conversion region within potential well capacity of the floating diffusion region, and the second overflowed electrical charges indicating charges overflowed from the photoelectric conversion region over the potential well capacity of the floating diffusion region.

主权项

1. A method of driving an image sensor including a plurality of unit pixels, each unit pixel having a photoelectric conversion region and a floating diffusion region, the method comprising:
resetting a potential level of the floating diffusion region by a first voltage level during a reset mode, the first voltage level being lower than a level of a power supply voltage; converting incident light into electrical charges in the photoelectric conversion region during an integration mode; accumulating at least one of collected electrical charges, first overflowed electrical charges, and second overflowed electrical charges in the floating diffusion region based on illuminance of the incident light, the collected electrical charges indicating electrical charges that are collected in the photoelectric conversion region, the first overflowed electrical charges indicating electrical charges that have overflowed from the photoelectric conversion region and are within potential well capacity of the floating diffusion region, and the second overflowed electrical charges indicating electrical charges that have overflowed from the photoelectric conversion region and are over the potential well capacity of the floating diffusion region; and providing an image signal corresponding to the illuminance of the incident light based on at least one of the collected electrical charges, the first overflowed electrical charges, and the second overflowed electrical charges during a readout mode after the integration mode; wherein providing the image signal includes:
generating a first output signal by sampling the potential level of the floating diffusion region during a first sampling period of the readout mode;generating a reference signal by sampling the potential level of a reset state of the floating diffusion region during a second sampling period of the readout mode;generating a second output signal by sampling the potential level of the floating diffusion region during a third sampling period of the readout mode; andgenerating the image signal based on the reference signal, the first output signal, and the second output signal.