Solid state image sensor, method for driving a solid state image sensor, imaging apparatus, and electronic device
A solid state image sensor includes a pixel array, as well as charge-to-voltage converters, reset gates, and amplifiers each shared by a plurality of pixels in the array. The voltage level of the reset gate power supply is set higher than the voltage level of the amplifier power supply. Additionally, charge overflowing from photodetectors in the pixels may be discarded into the charge-to-voltage converters. The image sensor may also include a row scanner configured such that, while scanning a row in the pixel array to read out signals therefrom, the row scanner resets the charge in the photodetectors of the pixels sharing a charge-to-voltage converter with pixels on the readout row. The charge reset is conducted simultaneously with or prior to reading out the signals from the pixels on the readout row.
1. A device, comprising:
a plurality of charge-to-voltage converters;
a pixel array having a plurality of pixels arranged therein, each pixel including a photodetector as well as a transfer transistor configured to transfer charge photoelectrically converted by the photodetector to one of the charge-to-voltage converters;
a plurality of reset transistors configured to reset the photodetectors;
a plurality of amplifier transistors configured to output a signal corresponding to the potential of the photodetectors;
a reset gate power supply for the reset transistor; and
an amplifier power supply for the reset transistor,
wherein,
the reset transistor, the amplifier transistor and the charge-to-voltage converter are shared by at least two pixels,
the reset gate power supply has a voltage level that is higher than a voltage level of the amplifier power supply,
the voltage level of the amplifier power supply is fixed, and
the reset gate power supply selectively takes either a first voltage level or a second voltage level, the second voltage level being higher than the first voltage level, each of the first and second voltage levels being higher than the voltage level of the amplifier power supply.
2. The device of claim 1 , further comprising:
a booster circuit, both the booster circuit and the pixel array being on a same substrate;
wherein
the voltage level of the reset gate power supply is generated as a result of the booster circuit boosting the voltage level of the amplifier power supply.
3. A method for driving a device including a plurality of charge-to-voltage converters, a pixel array having a first plurality of pixels arranged therein, each pixel including a photodetector as well as a transfer gate configured to transfer charge photoelectrically converted by the photodetector to one of the charge-to-voltage converters, a plurality of reset gates configured to reset the photodetectors, a plurality of amplifiers configured to output a signal corresponding to the potential of the photodetectors, a reset gate power supply, and an amplifier power supply, wherein a second plurality of pixels share one each of the charge-to-voltage converters, reset gates and amplifiers, wherein the second plurality of pixels is a subset of the first plurality of pixels, the method comprising the steps of:
setting the voltage level of the reset gate power supply higher than the voltage level of the amplifier power supply; and
resetting the charge-to-voltage converters to the voltage level of the reset gate power supply.
4. An imaging apparatus, comprising:
a solid state image sensor, and
optics configured to focus incident light onto the photodetector surface of the solid state image sensor,
wherein,
the solid state image sensor includes a plurality of charge-to-voltage converters, a pixel array having a first plurality of pixels arranged therein, each pixel including a photodetector as well as a transfer gate configured to transfer charge photoelectrically converted by the photodetector to one of the charge-to-voltage converters, a plurality of reset gates configured to reset the photodetectors, a plurality of amplifiers configured to output a signal corresponding to the potential of the photodetectors, a reset gate power supply, and an amplifier power supply,
a second plurality of pixels share one each of the charge-to-voltage converters, reset gates and amplifiers, wherein the second plurality of pixels is a subset of the first plurality of pixels,
the reset gate power supply has a voltage level that is higher than a voltage level of the amplifier power supply.
5. A device, comprising:
a plurality of charge-to-voltage converters;
a pixel array having a first plurality of pixels arranged therein, each pixel including a photodetector as well as a transfer gate configured to transfer charge photoelectrically converted by the photodetector to one of the charge-to-voltage converters;
a plurality of reset gates configured to reset the photodetectors; and
a plurality of amplifiers configured to output a signal corresponding to the potential of the photodetectors,
wherein,
a second plurality of pixels share one each of the charge-to-voltage converters, reset gates and amplifiers,
the second plurality of pixels is defined to be four consecutive pixels belonging to the same pixel column, with adjacent pixels among the four pixels being paired into two groups, wherein the second plurality of pixels is a subset of the first plurality of pixels,
in one group, a charge-to-voltage converter and a reset gate are shared between the two pixels therein, with the reset gate being disposed between the respective photodetector regions of the two pixels, and
in the other group, a charge-to-voltage converter and an amplifier are shared between the two pixels therein, with the amplifier being disposed between the respective photodetector regions of the two pixels.
6. The solid state image sensor according to claim 5 device of claim 5 , wherein
each charge-to-voltage converter includes a first charge-to-voltage converter disposed between the respective photodetector regions of the two pixels in one group, and a second charge-to-voltage converter disposed between the respective photodetector regions of the two pixels in the other group, and
the first and second charge-to-voltage converters are electrically connected to each other.
7. An imaging apparatus, comprising:
a solid state image sensor, and
optics configured to focus incident light onto the photodetector surface of the solid state image sensor,
wherein,
the solid state image sensor includes a plurality of charge-to-voltage converters, a pixel array having a first plurality of pixels arranged therein, each pixel including a photodetector as well as a transfer gate configured to transfer charge photoelectrically converted by the photodetector to one of the charge-to-voltage converters, a plurality of reset gates configured to reset the photodetectors, and a plurality of amplifiers configured to output a signal corresponding to the potential of the photodetectors,
a second plurality of pixels share one each of the charge-to-voltage converters, reset gates and amplifiers,
the second plurality of pixels is defined to be four consecutive pixels belonging to the same pixel column, with adjacent pixels among the four pixels being paired into two groups, wherein the second plurality of pixels is a subset of the first plurality of pixels,
in one group, a charge-to-voltage converter and a reset gate are shared between the two pixels therein, with the reset gate being disposed between the respective photodetector regions of the two pixels, and
in the other group, a charge-to-voltage converter and an amplifier are shared between the two pixels therein, with the amplifier being disposed between the respective photodetector regions of the two pixels.
8. An imaging apparatus, comprising:
a pixel array having a plurality of pixels arranged therein, each pixel including a transfer transistor;
a plurality of floating diffusion regions, each provided in the center of four pixels arranged in a 2×2 layout in the horizontal and vertical directions;
a plurality of amplifier transistors; and
a plurality of reset transistors, wherein the drain electrode of each reset transistor and the drain electrode of each amplifier transistor are disposed separately, and
wherein,
the transfer transistors constituting the four pixels are disposed in four directions around the floating diffusion, such that the floating diffusion is enclosed by the transfer transistors,
each floating diffusion, amplifier transistor, and reset transistor are shared among the four pixels, and
a group of eight pixels formed by vertically disposing two sets of the four pixels is taken to be the basic component unit of the pixel array.
9. An imaging apparatus, comprising:
a pixel array having a plurality of pixels arranged therein, each pixel including a transfer transistor;
a plurality of floating diffusion regions, each provided in the center of four pixels arranged in a 2×2 layout in the horizontal and vertical directions;
a plurality of amplifier transistors; and
a plurality of reset transistors,
wherein,
the transfer transistors constituting the four pixels are disposed in four directions around the floating diffusion, such that the floating diffusion is enclosed by the transfer transistors,
each floating diffusion, amplifier transistor, and reset transistor are shared among the four pixels, and
a group of eight pixels formed by vertically disposing two sets of the four pixels is taken to be the basic component unit of the pixel array, wherein a pulse is applied to the drain electrode of each reset transistor, and a constant potential is applied to the drain electrode of each amplifier transistor.
10. A device, comprising:
a plurality of charge-to-voltage converters;
a pixel array having a first plurality of pixels arranged therein, each pixel including a photodetector as well as a transfer gate configured to transfer charge photoelectrically converted by the photodetector to one of the charge-to-voltage converters;
a plurality of reset gates configured to reset the photodetectors;
a plurality of amplifiers configured to output a signal corresponding to the potential of the photodetectors;
a reset gate power supply; and
an amplifier power supply,
wherein,
a second plurality of pixels share one each of the charge-to-voltage converters, reset gates and amplifiers, and
the reset gate power supply has a voltage level that is higher than a voltage level of the amplifier power supply, and
wherein the drain electrode of each reset gate and the drain electrode of each amplifier are disposed separately.
11. A device, comprising:
a plurality of charge-to-voltage converters;
a pixel array having a first plurality of pixels arranged therein, each pixel including a photodetector as well as a transfer gate configured to transfer charge photoelectrically converted by the photodetector to one of the charge-to-voltage converters;
a plurality of reset gates configured to reset the photodetectors;
a plurality of amplifiers configured to output a signal corresponding to the potential of the photodetectors;
a reset gate power supply; and
an amplifier power supply,
wherein,
a second plurality of pixels share one each of the charge-to-voltage converters, reset gates and amplifiers, and
the reset gate power supply has a voltage level that is higher than a voltage level of the amplifier power supply, and
wherein a pulse is applied to the drain electrode of each reset gate, and a constant potential is applied to the drain electrode of each amplifier.
12. A device, comprising:
a plurality of charge-to-voltage converters;
a pixel array having a first plurality of pixels arranged therein, each pixel including a photodetector as well as a transfer gate configured to transfer charge photoelectrically converted by the photodetector to one of the charge-to-voltage converters;
a plurality of reset gates configured to reset the photodetectors;
a plurality of amplifiers configured to output a signal corresponding to the potential of the photodetectors;
a reset gate power supply; and
an amplifier power supply,
wherein,
a second plurality of pixels share one each of the charge-to-voltage converters, reset gates and amplifiers,
the reset gate power supply has a voltage level that is higher than a voltage level of the amplifier power supply, and
wherein the second plurality of pixels is a subset of the first plurality of pixels.
13. A device, comprising:
a plurality of charge-to-voltage converters;
a pixel array having a first plurality of pixels arranged therein, each pixel including a photodetector as well as a transfer gate configured to transfer charge photoelectrically converted by the photodetector to one of the charge-to-voltage converters;
a plurality of reset gates configured to reset the photodetectors; and
a plurality of amplifiers configured to output a signal corresponding to the potential of the photodetectors,
wherein,
a second plurality of pixels share one each of the charge-to-voltage converters, reset gates and amplifiers,
the second plurality of pixels is defined to be four consecutive pixels belonging to the same pixel column, with adjacent pixels among the four pixels being paired into two groups,
in one group, a charge-to-voltage converter and a reset gate are shared between the two pixels therein, with the reset gate being disposed between the respective photodetector regions of the two pixels, and
in the other group, a charge-to-voltage converter and an amplifier are shared between the two pixels therein, with the amplifier being disposed between the respective photodetector regions of the two pixels, wherein the drain electrode of each reset gate and the drain electrode of each amplifier are disposed separately.
14. A device, comprising:
a plurality of charge-to-voltage converters,
a pixel array having a first plurality of pixels arranged therein, each pixel including a photodetector as well as a transfer gate configured to transfer charge photoelectrically converted by the photodetector to one of the charge-to-voltage converters;
a plurality of reset gates configured to reset the photodetectors; and
a plurality of amplifiers configured to output a signal corresponding to the potential of the photodetectors,
wherein,
a second plurality of pixels share one each of the charge-to-voltage converters, reset gates and amplifiers,
the second plurality of pixels is defined to be four consecutive pixels belonging to the same pixel column, with adjacent pixels among the four pixels being paired into two groups,
in one group, a charge-to-voltage converter and a reset gate are shared between the two pixels therein, with the reset gate being disposed between the respective photodetector regions of the two pixels, and
in the other group, a charge-to-voltage converter and an amplifier are shared between the two pixels therein, with the amplifier being disposed between the respective photodetector regions of the two pixels, wherein a pulse is applied to the drain electrode of each reset gate, and a constant potential is applied to the drain electrode of each amplifier.