Method for driving imaging apparatus

A driving method for driving an imaging apparatus comprising a plurality of pixels disposed in a matrix, and each pixel including:

• a photoelectric conversion unit;
• at least two charge holding units each configured to hold an electric charge generated by the photoelectric conversion unit, the at least two charge holding units including a first charge holding unit and a second charge holding unit;
• a floating diffusion;
• a first transfer unit configured to transfer an electric charge generated by the photoelectric conversion unit from the photoelectric conversion unit to the first charge holding unit;
• a second transfer unit configured to transfer an electric charge generated by the photoelectric conversion unit from the photoelectric conversion unit to the second charge holding unit;
• a third transfer unit configured to transfer an electric charge from the first charge holding unit to the floating diffusion;
• a fourth transfer unit configured to transfer an electric charge from the second charge holding unit to the floating diffusion;
• and
• an amplification transistor configured to output a signal based on at least one of an electric charge held in the first charge holding unit and an electric charge held in the second charge holding unit,
• the driving method comprising:
• performing a plurality of first transfer operations for transferring an electric charge stored in the photoelectric conversion unit to the first charge holding unit simultaneously in the plurality of pixel rows, while the third transfer unit is shifted from an off state to an on state after the third transfer unit is maintained in the off state;
• and
• performing a plurality of second transfer operations for transferring an electric charge stored in the photoelectric conversion unit to the second charge holding unit simultaneously in the plurality of pixel rows, while the fourth transfer unit is shifted from an off state to an on state after the fourth transfer unit is maintained in the off state;
• wherein a length of a time period in which electric charges to be transferred by performing the plurality of first transfer operations are stored in the photoelectric conversion unit is different from a length of a time period in which electric charges to be transferred by performing the plurality of second transfer operations are stored in the photoelectric conversion unit,
• wherein the plurality of second transfer operations is performed in respective periods between two of the plurality of first transfer operations, and
• wherein a number of times the plurality of first transfer operations is performed is different from a number of times the plurality of second transfer operations is performed.