US 12,088,946 B2
Imaging device for reducing variations of amounts of electric charges accumulated in floating diffusion regions
Shota Yamada, Shiga (JP); Shigetaka Kasuga, Osaka (JP); Motonori Ishii, Osaka (JP); Akito Inoue, Osaka (JP); and Yutaka Hirose, Kyoto (JP)
Assigned to Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
Filed on Feb. 24, 2022, as Appl. No. 17/679,942.
Application 17/679,942 is a continuation of application No. PCT/JP2020/029234, filed on Jul. 30, 2020.
Claims priority of application No. 2019-163235 (JP), filed on Sep. 6, 2019.
Prior Publication US 2022/0182572 A1, Jun. 9, 2022
Int. Cl. H04N 25/778 (2023.01); G01S 7/481 (2006.01); G01S 7/4865 (2020.01); G01S 17/894 (2020.01); H04N 25/771 (2023.01)
CPC H04N 25/778 (2023.01) [G01S 7/4816 (2013.01); G01S 7/4865 (2013.01); G01S 17/894 (2020.01); H04N 25/771 (2023.01)] 10 Claims
OG exemplary drawing
 
1. 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.