Solid-state imaging device and electronic device with transistor groups
The present disclosure relates to a solid-state imaging device and an electronic device for suppressing deterioration of pixel characteristics while guaranteeing the operating range of VSLs. A solid-state imaging device according to a first aspect of this disclosure has multiple pixel sharing units each including multiple photoelectric conversion sections each configured to correspond to a pixel, an accumulation section configured to be shared by the plurality of photoelectric conversion sections and to accumulate charges generated thereby, and multiple transistors configured to control reading of the charges accumulated in the accumulation section. The plurality of transistors in each pixel sharing unit are arranged symmetrically. The plurality of transistors include a transistor that functions as a switch to change conversion efficiency. The present disclosure may be applied to back-illuminated CMOS image sensors, for example.
1. An imaging device comprising:
a first layer comprising:
a first transistor group;
a second transistor group including a reset transistor and a switch transistor; and
a photoelectric conversion section disposed between the first transistor group and the second transistor group;
a second layer comprising a floating diffusion; and
a third layer comprising an additional capacitance,
wherein the switch transistor is configured to selectively enable and disable the additional capacitance to change a conversion efficiency of the floating diffusion.
2. The imaging device according to claim 1 , further comprising a transfer transistor disposed between the first transistor group and the second transistor group.
3. The imaging device according to claim 1 , wherein the floating diffusion is coupled to the photoelectric conversion section and configured to accumulate charges generated by the photoelectric conversion section.
4. The imaging device according to claim 3 , wherein the switch transistor is configured to change the conversion efficiency of the floating diffusion by selectively enabling or disabling the additional capacitance with respect to the floating diffusion.
5. The imaging device according to claim 2 , wherein the second transistor group includes a gate of a reset transistor adjacent to a gate of the switch transistor.
6. The imaging device according to claim 5 , wherein the second transistor group includes a gate of a first transistor adjacent to a gate of a second transistor.
7. The imaging device according to claim 6 , wherein the second transistor group includes a gate of a third transistor adjacent to a gate of a fourth transistor.
8. The imaging device according to claim 1 , wherein the photoelectric conversion section includes a photodiode.
9. The imaging device according to claim 1 , wherein the conversion efficiency of the floating diffusion is changed based on an amount of luminance.
10. The imaging device according to claim 1 , wherein the photoelectric conversion section is part of a back-illuminated CMOS image sensor.
11. The imaging device according to claim 1 , wherein the switch transistor is configured to change the conversion efficiency of the floating diffusion by selectively enabling or disabling additional capacitance of a wiring with respect to the floating diffusion, wherein the wiring is formed in a comb-tooth pattern.
12. An apparatus comprising:
an image sensor configured to capture one or more images around a vehicle, the image sensor including:
a first layer comprising:
a first transistor group;
a second transistor group including a reset transistor and a switch transistor; and
a photoelectric conversion section disposed between the first transistor group and the second transistor group;
wherein, the switch transistor is configured to selectively enable and disable an additional capacitance to change a conversion efficiency of the floating diffusion.
13. A pixel circuit comprising:
a first layer comprising:
a first transistor group;
a second transistor group including a reset transistor and a switch transistor; and
a photoelectric conversion section disposed between the first transistor group and the second transistor group;
a plurality of transistors coupled to the photoelectric conversion section;
a second layer comprising a floating diffusion; and
a third layer comprising an additional capacitance,
wherein,
the switch transistor, an amplification transistor, the reset transistor, and a transfer transistor are each coupled to the floating diffusion, and
the switch transistor is configured to selectively enable and disable the additional capacitance to change a conversion efficiency of the floating diffusion.
14. The pixel circuit according to claim 13 , wherein the transfer transistor is disposed between at least two transistors of the plurality of transistors.
15. The pixel circuit according to claim 13 , wherein the floating diffusion is coupled to the photoelectric conversion section and configured to accumulate charges generated by the photoelectric conversion section.
16. The pixel circuit according to claim 15 , wherein the switch transistor is configured to change the conversion efficiency of the floating diffusion by selectively enabling or disabling additional capacitance with respect to the floating diffusion.
17. The pixel circuit according to claim 13 , wherein a gate of the reset transistor is adjacent to a gate of the switch transistor.
18. The pixel circuit according to claim 13 , wherein the photoelectric conversion section includes a photodiode.
19. The pixel circuit according to claim 13 , wherein the conversion efficiency of the floating diffusion is changed based on an amount of luminance.
20. The pixel circuit according to claim 13 , wherein the switch transistor is configured to change the conversion efficiency of the floating diffusion by selectively enabling or disabling additional capacitance of a wiring with respect to the floating diffusion, wherein the wiring is formed in a comb-tooth pattern.