Solid-state imaging device, method for driving solid-state imaging device, and electronic apparatus

A method for driving a solid-state imaging device, the solid-state imaging device including:

• a pixel part having a pixel arranged therein, the pixel performing photoelectric conversion;
• and
• a reading part for reading a pixel signal from the pixel in the pixel part,
• wherein the pixel includes:
• a photoelectric conversion element for storing therein, in a storing period, charges generated by the photoelectric conversion;
• a transfer element for transferring, in a transfer period following the storing period, the charges stored in the photoelectric conversion element;
• an output node to which the charges stored in the photoelectric conversion element are transferred through the transfer element;
• an output buffer part for converting the charges at the output node into a voltage signal at a level determined by the amount of the charges and outputting the voltage signal;
• a charge storing part for storing overflow charges overflowing at least from the photoelectric conversion element to the output node;
• a comparator for performing a comparing operation of comparing the voltage signal output from the output buffer part against a referential voltage to output a digital comparison result signal;
• and
• a memory part for saving data corresponding to the comparison result signal from the comparator,
• wherein when the pixel signal is read out from the pixel, the comparator performs:
• under control of the reading part,
• a first comparing operation of outputting a digital first comparison result signal obtained by processing the voltage signal corresponding to the overflow charges overflowing from the photoelectric conversion element to the output node in the storing period;
• a second comparing operation of outputting a digital second comparison result signal obtained by processing the voltage signal corresponding to charges stored in the photoelectric conversion element that are transferred to the output node in the transfer period following the storing period;
• and
• a third comparing operation of outputting a digital third comparison result signal obtained by processing the voltage signal corresponding to a sum of (i) the charges stored in the photoelectric conversion element that are transferred to the output node in the transfer period following the storing period and (ii) charges stored in the charge storing part, and
• wherein whether or not to allow writing of data corresponding to the third comparison result signal obtained as a result of the third comparing operation into the memory part is controlled depending on a state of the first comparison result signal obtained as a result of the first comparing operation and a state of the second comparison result signal obtained as a result of the second comparing operation, so that access to the memory part is controlled depending on a state of the comparison result signal from the comparator.

An electronic apparatus comprising:

• a solid-state imaging device;
• and
• an optical system for forming a subject image on the solid-state imaging device,
• wherein the solid-state imaging device includes:
• a pixel part having a pixel arranged therein, the pixel performing photoelectric conversion;
• and
• a reading part for reading a pixel signal from the pixel in the pixel part, wherein the pixel includes:
• a photoelectric conversion element for storing therein, in a storing period, charges generated by the photoelectric conversion;
• a transfer element for transferring, in a transfer period following the storing period, the charges stored in the photoelectric conversion element;
• an output node to which the charges stored in the photoelectric conversion element are transferred through the transfer element;
• an output buffer part for converting the charges at the output node into a voltage signal at a level determined by the amount of the charges and outputting the voltage signal;
• a charge storing part for storing overflow charges overflowing at least from the photoelectric conversion element to the output node;
• a comparator for performing a comparing operation of comparing the voltage signal output from the output buffer part against a referential voltage to output a digital comparison result signal;
• a memory part for saving data corresponding to the comparison result signal from the comparator;
• and
• a memory control part for controlling access to the memory part depending on a state of the comparison result signal from the comparator,
• wherein, under control of the reading part, the comparator is configured to perform:
• a first comparing operation of outputting a digital first comparison result signal obtained by processing the voltage signal corresponding to the overflow charges overflowing from the photoelectric conversion element to the output node in the storing period;
• a second comparing operation of outputting a digital second comparison result signal obtained by processing the voltage signal corresponding to charges stored in the photoelectric conversion element that are transferred to the output node in the transfer period following the storing period;
• and
• a third comparing operation of outputting a digital third comparison result signal obtained by processing the voltage signal corresponding to a sum of (i) the charges stored in the photoelectric conversion element that are transferred to the output node in the transfer period following the storing period and (ii) charges stored in the charge storing part, and
• wherein the memory control part controls whether or not to allow writing of data corresponding to the third comparison result signal obtained as a result of the third comparing operation into the memory part, depending on a state of the first comparison result signal obtained as a result of the first comparing operation and a state of the second comparison result signal obtained as a result of the second comparing operation.