Solid-state imaging device and imaging apparatus

1. A solid-state imaging device comprising:

a pixel array formed of a plurality of pixels arranged in rows and columns, each pixel including

a photoelectric conversion element configured to convert incident light into a signal charge,

a floating diffusion,

a transfer transistor configured to transfer the signal charge generated by the photoelectric conversion element to the floating diffusion,

an amplifier transistor configured to convert the signal charge transferred to the floating diffusion into an image signal which is a voltage signal and output the image signal, and

a reset transistor configured to supply a reset potential to the floating diffusion; and

a driver circuit configured to control operation of the transfer transistor and the reset transistor through a plurality of control lines each provided for a corresponding one of the rows of the pixels of the pixel array and connected to a power-supply line,

wherein the driver circuit performs all reset operation in which the signal charges are reset at all pixels and reading operation in which the image signal is read from each row of the pixels of the pixel array,

an impedance controller configured to control an impedance value for the power-supply line in the reading operation to be less than an impedance value for the power-supply line in the all reset operation is provided,

any one of the rows of the pixels of the pixel array is sequentially selected in the reading operation, and

when a first line part extends from one of the control lines connected to the pixels at a selected one of the rows in the reading operation to the power-supply line, and a second line part extends from another one of the control lines connected to the pixels at a non-selected one of the rows in the reading operation to the power-supply line, an impedance value at a common part between the first line part and the second line part is less in the reading operation than in the all reset operation.

2. The solid-state imaging device of claim 1 , wherein

an impedance switcher circuit connected to the power-supply line and having two or more switchable current paths is provided as the impedance controller.

3. The solid-state imaging device of claim 2 , wherein

the impedance switcher circuit includes a first transistor and a first impedance element connected together in parallel to each other in the power-supply line, and

the first transistor is turned off in the all reset operation, and is turned on in the reading operation.

4. The solid-state imaging device of claim 2 , wherein

the impedance switcher circuit includes a second transistor and a third transistor connected together in parallel to each other in the power-supply line.

5. The solid-state imaging device of claim 1 , wherein

the plurality of control lines include a first control line connected to a gate electrode of the transfer transistor,

the power-supply line is a line configured to supply a potential for bringing the transfer transistor into a non-conduction state to the first control line, and

the impedance controller controls the impedance value for the power-supply line in the reading operation to be less than the impedance value for the power-supply line in the all reset operation.

6. The solid-state imaging device of claim 1 , wherein

the power-supply line supplies a negative potential.

7. The solid-state imaging device of claim 1 , wherein

the power-supply line includes first and second power-supply lines,

the driver circuit is provided for each row of the pixels, and includes a plurality of buffer circuits connected to the first and second power-supply lines,

a second impedance element is provided in the second power-supply line,

a first switch is provided between the first power-supply line and each buffer circuit,

a second switch is provided between the second power-supply line and each buffer circuit, and

the impedance controller includes the first and second power-supply lines, the first and second switches, and the second impedance element.

8. The solid-state imaging device of claim 7 , further comprising:

a third switch provided between the first and second power-supply lines and configured to control connection.

9. The solid-state imaging device of claim 7 , wherein

the plurality of control lines include a first control line connected to a gate electrode of the transfer transistor,

the first or second power-supply line is a line configured to supply a potential for bringing the transfer transistor into a non-conduction state to the first control line, and

the impedance controller controls the impedance value for the power-supply line in the reading operation to be less than the impedance value for the power-supply line in the all reset operation.

10. The solid-state imaging device of claim 9 , wherein

in the all reset operation, the first switch is turned off, and the second switch is turned on, and

in the reading operation,

at one of the rows which is selected for reading the pixel signal, the first switch is turned on, and the second switch is turned off, and

at another one of the rows which is not selected for reading the pixel signal, the first switch is turned off, and the second switch is turned on.

11. The solid-state imaging device of claim 1 , wherein

a plurality of transfer transistors are provided at each pixel, and

the transfer transistors are connected to the floating diffusion.

12. An imaging apparatus comprising:

a solid-state imaging device configured to output a pixel signal corresponding to incident light;

an imaging optical system configured to guide the incident light to the solid-state imaging device; and

a signal processor configured to process the pixel signal output from the solid-state imaging device,

wherein the solid-state imaging device includes

a pixel array formed of a plurality of pixels arranged in rows and columns, each pixel including

a photoelectric conversion element configured to convert the incident light into a signal charge,

a floating diffusion,

a transfer transistor configured to transfer the signal charge generated by the photoelectric conversion element to the floating diffusion,

an amplifier transistor configured to convert the signal charge transferred to the floating diffusion into an image signal which is a voltage signal and output the image signal, and

a reset transistor configured to supply a reset potential to the floating diffusion, and

a driver circuit configured to control operation of the transfer transistor and the reset transistor through a plurality of control lines each provided for a corresponding one of the rows of the pixels of the pixel array and connected to a power-supply line,

the driver circuit performs all reset operation in which the signal charges are reset at all pixels and reading operation in which the image signal is read from each row of the pixels of the pixel array,

an impedance controller configured to control an impedance value for the power-supply line in the reading operation to be less than an impedance value for the power-supply line in the all reset operation is provided,

any one of the rows of the pixels of the pixel array is sequentially selected in the reading operation, and

when a first line part extends from one of the control lines connected to the pixels at a selected one of the rows in the reading operation to the power-supply line, and a second line part extends from another one of the control lines connected to the pixels at a non-selected one of the rows in the reading operation to the power-supply line, an impedance value at a common part between the first line part and the second line part is less in the reading operation than in the all reset operation.

13. The imaging apparatus of claim 12 , further comprising:

a capacitor arranged outside the solid-state imaging device,

wherein the solid-state imaging device further includes a pad connected to each of the power-supply line and the capacitor.

14. A solid-state imaging device comprising:

a pixel array formed of a plurality of pixels arranged in rows and columns, each pixel including

a photoelectric conversion element configured to convert incident light into a signal charge,

a floating diffusion,

a transfer transistor configured to transfer the signal charge generated by the photoelectric conversion element to the floating diffusion,

an amplifier transistor configured to convert the signal charge transferred to the floating diffusion into an image signal which is a voltage signal and output the image signal, and

a reset transistor configured to supply a reset potential to the floating diffusion; and

a driver circuit configured to control operation of the transfer transistor and the reset transistor through a plurality of control lines each provided for a corresponding one of the rows of the pixels of the pixel array and connected to a power-supply line,

wherein the driver circuit performs reading operation in which the image signal is read from each row of the pixels of the pixel array, and

when a first power-supply line extends from one of the control lines connected to the pixels at a selected one of the rows in the reading operation to the power-supply line, and a second power-supply line extends from another one of the control lines connected to the pixels at a non-selected one of the rows in the reading operation to the power-supply line, the number of pixels connected to the first power-supply line are less than the number of pixels connected to the second power-supply line.

15. The solid-state imaging device of claim 14 , wherein

the driver circuit performs reset operation in which the signal charges are reset at the pixels and the reading operation in which the image signal is read from each row of the pixels of the pixel array, and

an impedance controller configured to control an impedance value at a common part between the first and second power-supply lines in the reading operation to be less than an impedance value at the common part in the reset operation is provided.

16. The solid-state imaging device of claim 14 , wherein

a fourth switch configured to control connection is provided between the first and second power-supply lines.

17. The solid-state imaging device of claim 14 , wherein

the control lines include a first control line connected to a gate electrode of the transfer transistor, and

the first or second power-supply line is a line configured to supply a potential for bringing the transfer transistor into a non-conduction state to the first control line.