IMAGE SENSOR, CONTROL METHOD THEREFOR, AND IMAGE CAPTURING APPARATUS
First Claim
1. An image sensor comprising:
- a pixel portion in which a plurality of unit pixels each provided with a plurality of photoelectric conversion portions and a floating diffusion portion shared by the plurality of photoelectric conversion portions are arrayed in matrix form;
an analog-digital converter that compares an analog signal with a reference signal that changes over time at a predetermined gradient, and converts the analog signal to a digital signal by counting, in a first direction or a second direction that differs from the first direction, from a start of the comparison until a transition point of a result of the comparison; and
a control circuit that controls the analog-digital converter;
wherein the control circuit controls the analog-digital converter in a first mode to;
convert a reset level of the floating diffusion portion by counting in the first direction or the second direction to acquire a first noise signal,acquire a first optical signal by counting, in the first direction, an analog signal obtained by transferring a first photo charge accumulated in one or more photoelectric conversion portions including at least a first photoelectric conversion portion, among the plurality of photoelectric conversion portions, to the floating diffusion portion,acquire a second noise signal by counting, in the second direction, a potential that the floating diffusion portion has after the first optical signal is acquired, andacquire a second optical signal by counting, in the first direction, an analog signal obtained by transferring a second photo charge accumulated in at least a second photoelectric conversion portion not included in the one or more photoelectric conversion portions, among the plurality of photoelectric conversion portions, to the floating diffusion portion.
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Accused Products
Abstract
An image sensor has a plurality of unit pixels each provided with a plurality of photoelectric conversion portions and a floating diffusion portion, and an analog-digital converter. The analog-digital converter is controlled to: convert a reset level of the floating diffusion portion by counting in a first or second direction to acquire a first noise signal, acquire a first optical signal by counting in the first direction an analog signal of a first photo charge accumulated in a first photoelectric conversion portion, acquire a second noise signal by counting in the second direction a potential that the floating diffusion portion has after the first optical signal is acquired, and acquire a second optical signal by counting in the first direction an analog signal of a second photo charge accumulated in a second photoelectric conversion portion.
22 Citations
14 Claims
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1. An image sensor comprising:
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a pixel portion in which a plurality of unit pixels each provided with a plurality of photoelectric conversion portions and a floating diffusion portion shared by the plurality of photoelectric conversion portions are arrayed in matrix form; an analog-digital converter that compares an analog signal with a reference signal that changes over time at a predetermined gradient, and converts the analog signal to a digital signal by counting, in a first direction or a second direction that differs from the first direction, from a start of the comparison until a transition point of a result of the comparison; and a control circuit that controls the analog-digital converter; wherein the control circuit controls the analog-digital converter in a first mode to; convert a reset level of the floating diffusion portion by counting in the first direction or the second direction to acquire a first noise signal, acquire a first optical signal by counting, in the first direction, an analog signal obtained by transferring a first photo charge accumulated in one or more photoelectric conversion portions including at least a first photoelectric conversion portion, among the plurality of photoelectric conversion portions, to the floating diffusion portion, acquire a second noise signal by counting, in the second direction, a potential that the floating diffusion portion has after the first optical signal is acquired, and acquire a second optical signal by counting, in the first direction, an analog signal obtained by transferring a second photo charge accumulated in at least a second photoelectric conversion portion not included in the one or more photoelectric conversion portions, among the plurality of photoelectric conversion portions, to the floating diffusion portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An image capturing apparatus in which an image sensor is mounted, wherein the image sensor comprising:
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a pixel portion in which a plurality of unit pixels each provided with a plurality of photoelectric conversion portions and a floating diffusion portion shared by the plurality of photoelectric conversion portions are arrayed in matrix form; an analog-digital converter that compares an analog signal with a reference signal that changes over time at a predetermined gradient, and converts the analog signal to a digital signal by counting, in a first direction or a second direction that differs from the first direction, from a start of the comparison until a transition point of a result of the comparison; and a control circuit that controls the analog-digital converter; wherein the control circuit controls the analog-digital converter in a first mode to; convert a reset level of the floating diffusion portion by counting in the first direction or the second direction to acquire a first noise signal, acquire a first optical signal by counting, in the first direction, an analog signal obtained by transferring a first photo charge accumulated in one or more photoelectric conversion portions including at least a first photoelectric conversion portion, among the plurality of photoelectric conversion portions, to the floating diffusion portion, acquire a second noise signal by counting, in the second direction, a potential that the floating diffusion portion has after the first optical signal is acquired, and acquire a second optical signal by counting, in the first direction, an analog signal obtained by transferring a second photo charge accumulated in at least a second photoelectric conversion portion not included in the one or more photoelectric conversion portions, among the plurality of photoelectric conversion portions, to the floating diffusion portion.
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12. An image sensor comprising:
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a pixel portion in which a plurality of unit pixels each provided with a plurality of photoelectric conversion portions and a floating diffusion portion shared by the plurality of photoelectric conversion portions are arrayed in matrix form; and a control circuit that controls the pixel portion; wherein the control circuit performs control to; reset the floating diffusion portion, and acquire a first noise signal based on a potential that the floating diffusion portion has after the resetting, transfer a first photo charge accumulated in one or more photoelectric conversion portions including at least a first photoelectric conversion portion, among the plurality of photoelectric conversion portions, to the floating diffusion portion, and acquire a first optical signal based on the potential of the floating diffusion portion to which the first photo charge was transferred, acquire a second noise signal based on the potential that the floating diffusion portion has after the first optical signal is acquired, and transfer a second photo charge accumulated in at least a second photoelectric conversion portion not included in the one or more photoelectric conversion portions, among the plurality of photoelectric conversion portions, to the floating diffusion portion, and acquire a second optical signal based on the potential of the floating diffusion portion to which the second photo charge was transferred.
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13. A control method of an image sensor having a pixel portion in which a plurality of unit pixels each provided with a plurality of photoelectric conversion portions and a floating diffusion portion shared by the plurality of photoelectric conversion portions are arrayed in matrix form, and an analog-digital converter that compares an analog signal with a reference signal that changes over time at a predetermined gradient, and converts the analog signal to a digital signal by counting, in a first direction or a second direction that differs from the first direction, from a start of the comparison until a transition point of a result of the comparison, the analog-digital converter:
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converting a reset level of the floating diffusion portion by counting in the first direction or the second direction to acquire a first noise signal, acquiring a first optical signal by counting, in the first direction, an analog signal obtained by transferring a first photo charge accumulated in one or more photoelectric conversion portions including at least a first photoelectric conversion portion, among the plurality of photoelectric conversion portions, to the floating diffusion portion, acquiring a second noise signal by counting, in the second direction, a potential that the floating diffusion portion has after the first optical signal is acquired, and acquiring a second optical signal by counting, in the first direction, an analog signal obtained by transferring a second photo charge accumulated in at least a second photoelectric conversion portion not included in the one or more photoelectric conversion portions, among the plurality of photoelectric conversion portions, to the floating diffusion portion.
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14. A control method of an image sensor having a pixel portion in which a plurality of unit pixels each provided with a plurality of photoelectric conversion portions and a floating diffusion portion shared by the plurality of photoelectric conversion portions are arrayed in matrix form, the method comprising:
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resetting the floating diffusion portion, and acquiring a first noise signal based on a potential that the floating diffusion portion has after the resetting, transferring a first photo charge accumulated in one or more photoelectric conversion portions including at least a first photoelectric conversion portion, among the plurality of photoelectric conversion portions, to the floating diffusion portion, and acquiring a first optical signal based on the potential of the floating diffusion portion to which the first photo charge was transferred, acquiring a second noise signal based on the potential that the floating diffusion portion has after the first optical signal is acquired, and transferring a second photo charge accumulated in at least a second photoelectric conversion portion not included in the one or more photoelectric conversion portions, among the plurality of photoelectric conversion portions, to the floating diffusion portion, and acquiring a second optical signal based on the potential of the floating diffusion portion to which the second photo charge was transferred.
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Specification