Imaging device for reducing variations of amounts of electric charges accumulated in floating diffusion regions

An imaging device comprising:

• a solid-state imaging element having a plurality of pixel cells arranged in a matrix;
• and
• a controller configured to control the solid-state imaging element, wherein
• the pixel cells each include:
• an avalanche photodiode;
• a floating diffusion region configured to accumulate electric charges;
• a transfer transistor connecting a cathode of the avalanche photodiode and the floating diffusion region;
• and
• a reset transistor for resetting the electric charges accumulated in the floating diffusion region, and
• the controller is further configured to:
• control the reset transistor to discharge electric charges exceeding a predetermined electric charge amount, of the electric charges accumulated in the floating diffusion region, from the cathode of the avalanche photodiode via the transfer transistor, by setting a height of a potential barrier of the reset transistor to a height corresponding to the predetermined electric charge amount;
• and
• set the height of the potential barrier to a potential equal to or higher than a reference accumulation potential corresponding to a standard amount of electric charges accumulated in the floating diffusion region when electric charges whose amount is equal to a saturated electric charge amount are generated in the avalanche photodiode.