Solid-state imaging device, imaging device, and signal reading medium that accumulates an amplified signal without digitization
This solid-state imaging device includes a first substrate and a second substrate which have circuit elements constituting pixels disposed therein are electrically connected to each other. The pixels includes: a photoelectric conversion element disposed in the first substrate; an amplifier circuit that amplifies a signal generated in the photoelectric conversion element to output the amplified signal; a signal accumulation circuit which is disposed in the second substrate and accumulates the amplified signal which is output from the amplifier circuit; and an output circuit that outputs the amplified signal accumulated in the signal accumulation circuit from the pixel.
1. A solid-state imaging device comprising:
a first substrate and a second substrate which have circuit elements constituting pixels disposed therein are electrically connected to each other, wherein
the pixels comprise:
a photoelectric conversion element disposed in the first substrate;
an amplifier circuit that amplifies a signal generated in the photoelectric conversion element to output the amplified signal;
a signal accumulation circuit which is disposed in the second substrate and accumulates the amplified signal which is output from the amplifier circuit without digitization thereof;
an output circuit that outputs the amplified signal accumulated in the signal accumulation circuit from the pixel;
a noise reduction circuit that reduces noise in the amplified signal which is output from the amplifier circuit;
a first reset circuit that resets the photoelectric conversion element;
a second reset circuit that resets an input section of the amplifier circuit;
a transfer circuit that transfers a signal generated in the photoelectric conversion element to the input section of the amplifier circuit;
a second amplifier circuit that amplifies the amplified signal accumulated in the signal accumulation circuit to output a second amplified signal; and
a third reset circuit that resets an input section of the second amplifier circuit,
wherein the noise reduction circuit removes noise generated in an input section of the amplifier circuit resulting from an operation of a circuit connected to the amplifier circuit or noise resulting from the operating characteristics of the amplifier circuit
the noise reduction circuit includes:
a clamp section that clamps the amplified signal which is output from the amplifier circuit; and
a sample-and-hold section that samples and holds a signal corresponding to the amplified signal clamped in the clamp section and accumulates the amplified signal in the signal accumulation circuit.
2. The solid-state imaging device according to claim 1 , wherein
the second reset circuit resets the input sections of the amplifier circuits of all the pixels collectively after the first reset circuits reset the photoelectric conversion elements of all the pixels collectively,
the clamp section clamps the amplified signal which is output from the amplifier circuit after the input section of the amplifier circuit is reset,
the transfer circuit transfers signals generated in the photoelectric conversion elements of all the pixels collectively to the input section of the amplifier circuit after elapsing a predetermined period until the first reset circuits reset the photoelectric conversion element of all the pixels collectively, and
the sample-and-hold section samples and holds a signal corresponding to a fluctuation in the amplified signal generated by transferring the signal by the transfer circuit and accumulates the sampled and held signal in the signal accumulation circuit, and then, the output circuit outputs the second amplified signal after the sample-and-hold section samples and holds the signal corresponding to the fluctuation in the amplified signal generated by transferring the signal by the transfer circuit and accumulates the sampled and held signal in the signal accumulation circuit and the second amplified signal after the third reset circuit resets the input section of the second amplifier circuit are output from the pixel in a time-division manner.
3. The solid-state imaging device according to claim 1 , further comprising
a differential processing circuit that performs differential processing on two kinds of signals which are output by the output circuit.
4. The solid-state imaging device according to claim 1 , wherein
the second reset circuit resets the input sections of the amplifier circuits of all the pixels collectively after the first reset circuits reset the photoelectric conversion elements of all the pixels collectively,
the clamp section clamps the amplified signal which is output from the amplifier circuit after the input section of the amplifier circuit is reset,
the transfer circuit transfers signals generated in the photoelectric conversion elements of all the pixels collectively to the input section of the amplifier circuit after elapsing a predetermined period until the first reset circuits reset the photoelectric conversion element of all the pixels collectively,
the sample-and-hold section samples and holds a signal corresponding to a fluctuation in the amplified signal generated by transferring the signal by the transfer circuit and accumulates the sampled and held signal in the signal accumulation circuit, and
the output circuit outputs the second amplified signal after the sample-and-hold section samples and holds the signal corresponding to the fluctuation in the amplified signal generated by transferring the signal by the transfer circuit and accumulates the sampled and held signal in the signal accumulation circuit and the second amplified signal when the third reset circuit resets the input section of the second amplifier circuit are output from the pixel in a time-division manner.