PHOTOELECTRIC CONVERSION APPARATUS, PHOTOELECTRIC CONVERSION SYSTEM, AND DRIVING METHOD FOR THE PHOTOELECTRIC CONVERSION APPARATUS

• US 20160037113A1
• Filed: 07/30/2015
• Published: 02/04/2016
• Est. Priority Date: 07/31/2014
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hashimoto, Seiji, Takahashi, Hidekazu, Furubayashi, Atsushi
• Granted Patent: US 9,781,374 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/771 comprising storage means other than floating diffusion

Abstract

An output control unit configured to set an amplitude of a signal output to a signal line to be smaller as compared with a case where an amplification unit outputs a signal on the basis of a potential of the input node or put the amplification unit into a non-operating state is provided.

Claims

1. A photoelectric conversion apparatus comprising:

a photoelectric conversion unit;

an amplification unit;

a signal line; and

an output control unit, wherein

the photoelectric conversion unit includes a first electrode, a second electrode, a photoelectric conversion layer that is arranged between the first electrode and the second electrode and accumulates signal carriers, and an insulating layer arranged between the photoelectric conversion layer and the second electrode,

an optical signal based on the accumulated signal carriers is output to an input node of the amplification unit,

an output node of the amplification unit is connected to the signal line,

a magnitude relationship between a potential applied to the first electrode and a potential applied to the second electrode is a first relationship in a first period during which the photoelectric conversion layer accumulates the signal carriers, and the magnitude relationship is a second relationship that is opposite to the first relationship in a second period during which the signal carriers are discharged from the photoelectric conversion layer while the second electrode is applied with a potential having a different value from the potential applied in the first period, and

the output control unit restricts a potential range of the signal line to be within a predetermined range narrower than a potential range of an output of the amplification unit in at least a part of the second period, or the output control unit puts the amplification unit into a non-operating state in at least a part of the second period.

2. The photoelectric conversion apparatus according to claim 1, wherein

the magnitude relationship is the first relationship in a third period during which the photoelectric conversion layer accumulates the signal carriers while the second electrode is applied with a potential having a different value from the potential applied in the second period, and

the second period is a period that occurs after the first period, and the third period is a period that occurs after the second period.

3. The photoelectric conversion apparatus according to claim 1, further comprising:

a current source connected to the signal line; and

a selection transistor, wherein

the amplification unit is an amplification transistor,

an input node of the amplification transistor is the input node of the amplification unit,

a current is supplied from the current source to the amplification transistor when the selection transistor is put into a conductive state, and

the selection transistor is the output control unit that puts an electric path between the amplification transistor and the signal line into a non-conductive state in at least a part of the second period to put the amplification transistor into the non-operating state.

4. The photoelectric conversion apparatus according to claim 1, further comprising:

a current source connected to the signal line; and

a switch that switches a conductive state and a non-conductive state of an electric path between the current source and the amplification unit, wherein

the amplification unit is an amplification transistor, and

a current is supplied from the current source to the amplification transistor when the switch is put into a conductive state, and the switch is the output control unit that puts the electric path between the current source and the amplification transistor into the non-conductive state in at least a part of the second period to put the amplification transistor into the non-operating state.

5. The photoelectric conversion apparatus according to claim 1, wherein

the photoelectric conversion unit further includes a current source connected to the signal line and a potential supply unit that supplies a potential to the signal line,

the amplification unit is an amplification transistor, and

the potential supply unit is the output control unit that supplies the potential to the signal line in at least a part of the second period to set an amplitude of a signal output to the signal line to be smaller as compared with a case where the amplification transistor outputs a signal on the basis of the potential of the second electrode.

6. The photoelectric conversion apparatus according to claim 1, further comprising:

a capacitance element including a first node and a second node, wherein

the first node is connected to the second electrode,

a first potential is supplied to the second node in the first period, and

a second potential is supplied to the second node in the second period.

7. The photoelectric conversion apparatus according to claim 6, further comprising:

a second switch,

wherein the second switch is the output control unit that puts an electric path between a third node at which the second electrode is connected to the first node and an input node of the amplification unit into a non-conductive state in at least a part of the second period to set an amplitude of a signal output to the signal line to be smaller as compared with a case where the amplification unit outputs a signal based on the potential of the second electrode.

8. The photoelectric conversion apparatus according to claim 6, further comprising:

a plurality of photoelectric conversion units,

wherein the first node is commonly connected to each of the plurality of photoelectric conversion units.

9. The photoelectric conversion apparatus according to claim 8, wherein

electric paths between only a part of photoelectric conversion units among the plurality of photoelectric conversion units and the amplification unit are all put into a conductive state, and the optical signals are output from the second electrodes of the part of photoelectric conversion units to the amplification unit, and

thereafter, electric paths between all the photoelectric conversion units among the plurality of photoelectric conversion units and the amplification unit are all put into a conductive state, and a signal obtained by adding the optical signals output from the respective second electrodes of all the photoelectric conversion units to each other is output to the amplification unit.

10. The photoelectric conversion apparatus according to claim 9, wherein one micro lens is provided with respect to the plurality of photoelectric conversion units.

11. The photoelectric conversion apparatus according to claim 9, wherein

light is incident on the photoelectric conversion apparatus from an optical system,

lights ejected from mutually different exit pupils of the optical system are incident on each of the plurality of photoelectric conversion units,

electric paths between only a part of photoelectric conversion units among the plurality of photoelectric conversion units and the amplification unit are all put into a conductive state, and the optical signals are output from the second electrodes of the part of photoelectric conversion units to the amplification unit, and

thereafter, electric paths between all the photoelectric conversion units among the plurality of photoelectric conversion units and the amplification unit are all put into a conductive state, and a signal obtained by adding the optical signals output from the respective second electrodes of all the photoelectric conversion units to each other is output to the amplification unit.

12. The photoelectric conversion apparatus according to claim 8, further comprising:

a plurality of transfer units each provided so as to corresponding to each to the plurality of photoelectric conversion units,

each of the plurality of transfer units transfers the optical signal based on the signal carriers from the second electrode of each of the plurality of photoelectric conversion units to the amplification unit, and

the first node is connected to each of the plurality of photoelectric conversion units via each of the plurality of transfer units.

13. The photoelectric conversion apparatus according to claim 12, wherein

a capacitance value of the capacitance element is a first capacitance value in a case where only one transfer unit among the plurality of transfer units is on in a period during which the photoelectric conversion layer accumulates the signal carriers, and

the capacitance value of the capacitance element is a second capacitance value that is higher than the first capacitance value in a case where plural transfer units among the plurality of transfer units is on in the period during which the photoelectric conversion layer accumulates the signal carriers, the plurality of transfer units.

14. The photoelectric conversion apparatus according to claim 6, further comprising:

a capacitance potential supply unit,

wherein the capacitance potential supply unit supplies the first potential and the second potential to the second node.

15. The photoelectric conversion apparatus according to claim 8, further comprising:

a capacitance potential supply unit, wherein

the capacitance potential supply unit supplies the first potential and the second potential to the second node,

when the signal carriers are discharged from the photoelectric conversion layer, in a case where electric paths between N photoelectric conversion units among the plurality of photoelectric conversion units and the amplification unit are all put into a conductive state, the second node of the capacitance element is supplied with the second potential,

when the signal carriers are discharged from the photoelectric conversion layer, in a case where electric paths between M photoelectric conversion units that are more than the N photoelectric conversion units among the plurality of photoelectric conversion units and the amplification unit are all put into a conductive state, the capacitance potential supply unit supplies a third potential to the second node of the capacitance element, and

the third potential is a potential having a value higher than the second potential.

16. The photoelectric conversion apparatus according to claim 8, further comprising:

a capacitance potential supply unit, wherein

the capacitance potential supply unit supplies the first potential and the second potential to the second node,

when the signal carriers are discharged from the photoelectric conversion layer, in a case where electric paths between N photoelectric conversion units among the plurality of photoelectric conversion units and the amplification unit are all put into a conductive state, the second node of the capacitance element is supplied with the second potential,

when the signal carriers are discharged from the photoelectric conversion layer, in a case where electric paths between M photoelectric conversion units that are more than the N photoelectric conversion units among the plurality of photoelectric conversion units and the amplification unit are all put into a conductive state, the capacitance potential supply unit supplies a third potential to the second node of the capacitance element, and

the third potential is a potential having a value lower than the second potential.

17. The photoelectric conversion apparatus according to claim 1, wherein the photoelectric conversion layer includes a quantum dot.

18. A photoelectric conversion system comprising:

the photoelectric conversion apparatus according to claim 1; and

an output signal processing unit configured to generate an image by processing a signal based on the optical signal output by the photoelectric conversion apparatus.

19. A photoelectric conversion system comprising:

the photoelectric conversion apparatus according to claim 10; and

an output signal processing unit, wherein

the photoelectric conversion apparatus outputs both

a first signal based on the optical signal output from a part of the photoelectric conversion units among the plurality of photoelectric conversion units and

a second signal based on the optical signal outputs from all the photoelectric conversion units among the plurality of photoelectric conversion units to the output signal processing unit,

a phase difference is detected by using a difference between the first signal and the second signal, and

an image is generated by using the second signal.

20. A driving method for a photoelectric conversion apparatus including a photoelectric conversion unit, an amplification unit, a signal line,

the photoelectric conversion unit including a first electrode, a second electrode, a photoelectric conversion layer that is arranged between the first electrode and the second electrode and accumulates signal carriers, and an insulating layer arranged between the photoelectric conversion layer and the second electrode, the driving method comprising:

setting a magnitude relationship between a potential applied to the first electrode and a potential applied to the second electrode to be a first relationship in a first period during which the photoelectric conversion layer accumulates the signal carriers;

setting the magnitude relationship to be a second relationship that is opposite to the first relationship in a second period during which the signal carriers are discharged from the photoelectric conversion layer while the second electrode is applied with a potential having a different value from the potential applied in the first period; and

restricting a potential range of the signal line to be within a predetermined range narrower than a potential range of an output of the amplification unit in at least a part of the second period or putting the amplification unit into a non-operating state in at least a part of the second period.