Solid-state image sensor and image sensing system

A solid-state image sensor comprising:

• a first signal line;
• a second signal line;
• a first pixel including a first photoelectric converter and a first transistor;
• a second pixel including a second photoelectric converter and a second transistor, a first main electrode of the first transistor and a first main electrode of the second transistor being connected to a common node;
• a current source provided in a path between the common node and a predetermined voltage;
• and
• a readout unit connected to a second main electrode of the first transistor via one of the first signal line and second signal line and connected to a second main electrode of the second transistor via the other one of the first signal line and the second signal line,
• wherein the readout unit reads out a signal from the first photoelectric converter in a first period during which a voltage corresponding to charges generated in the first photoelectric converter is supplied to a control electrode of the first transistor, and a ramp signal is supplied to a control electrode of the second transistor, and
• wherein the readout unit reads out a signal from the second photoelectric converter in a second period during which a voltage corresponding to charges generated in the second photoelectric converter is supplied to the control electrode of the second transistor, and a ramp signal is supplied to the control electrode of the first transistor.