US 12,219,277 B2
Solid-state imaging device with offset current generation
Kengo Umeda, Tokyo (JP); and Youhei Oosako, Kanagawa (JP)
Assigned to Sony Semiconductor Solutions Corporation, Kanagawa (JP)
Appl. No. 18/016,552
Filed by Sony Semiconductor Solutions Corporation, Kanagawa (JP)
PCT Filed Aug. 17, 2021, PCT No. PCT/JP2021/029971
§ 371(c)(1), (2) Date Jan. 17, 2023,
PCT Pub. No. WO2022/050035, PCT Pub. Date Mar. 10, 2022.
Claims priority of application No. 2020-150066 (JP), filed on Sep. 7, 2020.
Prior Publication US 2023/0283921 A1, Sep. 7, 2023
Int. Cl. H04N 25/633 (2023.01); H04N 25/78 (2023.01)
CPC H04N 25/633 (2023.01) [H04N 25/78 (2023.01)] 12 Claims
OG exemplary drawing
 
1. A solid-state imaging device that generates a reference signal that is compared with an electric signal from a pixel in order to perform analog-to-digital (AD) conversion on the electric signal and has a voltage changing with a lapse of time, the solid-state imaging device comprising:
a first current circuit that causes a first current to flow;
an output circuit including a first input connected to the first current circuit, a second input that receives a reference voltage for determining an initial value of the reference signal, and an output that outputs the reference signal on a basis of voltages of the first input and the second input;
a first capacitive element that is connected to the first input or the output and changes the reference signal by accumulating or discharging the first current; and
an offset generation circuit that causes an offset current to flow through the output circuit or the first capacitive element, wherein
the output circuit is a differential amplifier circuit including a first current path that receives a voltage of the first input, a second current path that receives a voltage of the second input, and a detection transistor that amplifies a voltage generated in the second current path and outputs the amplified voltage from the output,
the first capacitive element is connected between the first input and the output,
the offset generation circuit causes the offset current to flow through the first or second current path,
the offset generation circuit includes a current source that causes the offset current to flow, a first offset switch connected between the first current path and the current source, and a second offset switch connected between the second current path and the current source,
when a voltage of the reference signal is offset in a first voltage offset direction in the AD conversion, the first offset switch is turned on and the second offset switch is turned off, and
when the voltage of the reference signal is offset in a second voltage offset direction in the AD conversion, the first offset switch is turned off and the second offset switch is turned on.