Imaging device, drive method of imaging device, and imaging system

• US 10,277,839 B2
• Filed: 01/30/2017
• Issued: 04/30/2019
• Est. Priority Date: 02/16/2016
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Takenaka, Shintaro, Ikeda, Yasuji
• Primary Examiner(s): Haskins, Twyler L
• Assistant Examiner(s): Chiu, Wesley J
• Application Number:
  US15/419,592
• Publication Number:
  US 20170237912A1
• Time in Patent Office: 820 Days
• Field of Search: None
• CPC Class Codes: H04N 25/40 Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled
• CPC Class Codes: H04N 25/441 by reading contiguous pixels from selected rows or columns of the array, e.g. interlaced scanning
• CPC Class Codes: H04N 25/445 by skipping some contiguous pixels within the read portion of the array
• CPC Class Codes: H04N 25/46 by combining or binning pixels
• CPC Class Codes: H04N 25/74 Circuitry for scanning or addressing the pixel array
• CPC Class Codes: H04N 25/772 comprising A/D, V/T, V/F, I/T or I/F converters
• CPC Class Codes: H04N 25/778 comprising amplifiers shared between a plurality of pixels, i.e. at least one part of the amplifier must be on the sensor array itself

Abstract

Provided is an imaging device including row drive unit having a first storage unit that stores and outputs a first signal for a readout from the pixels on an associated row, a second storage unit that stores and outputs a second signal for an operation for causing the photoelectric conversion element on an associated row to be reset to a charge accumulation state, and a third storage unit that stores and outputs a third signal for maintaining the photoelectric conversion element on an associated row in a charge accumulation state or a reset state based on the first signal output from the first storage unit and the second signal output from the second storage unit.

Claims

1. An imaging device comprising:

a pixel unit in which pixels are arranged to form a plurality of rows, each of the pixels comprising a photoelectric conversion element that generates and accumulates charges in accordance with an incident light; and

a scanning unit comprising row drive units, each of the row drive units being arranged associated with each of the rows of the pixel unit and outputting a drive signal for driving the pixel unit on a row basis,

wherein each of the row drive units comprises;

a first storage unit configured to store a first signal for a readout from the pixels on an associated row and configured to output the first signal,

a second storage unit configured to store a second signal for an operation for causing the photoelectric conversion element on an associated row to be reset to a charge accumulation state and configured to output the second signal,

a third storage unit configured to store a third signal for maintaining the photoelectric conversion element on an associated row in the charge accumulation state or a reset state based on the first signal output from the first storage unit and the second signal output from the second storage unit and configured to output the third signal, and

a pixel drive signal generating unit configured to receive the first signal, the second signal and the third signal,

wherein the plurality of rows includes a first row, a second row, and a third row that is arranged between the first row and the second row,

wherein the pixel drive signal generating unit maintains the photoelectric conversion element included in the pixels on the first row and the second row in the charge accumulation state or the reset state by using the third signal, and

wherein the pixel drive signal generating unit maintains the photoelectric conversion element included in the pixels on the third row in the reset state by using the first signal during a period from a start of a readout from the pixels on the first row to an end of a readout from the pixels on the second row.

2. The imaging device according to claim 1, wherein the third storage unit stores and outputs the third signal further based on a fourth signal for resetting the photoelectric conversion element on all the rows.

3. The imaging device according to claim 1 further comprising a control unit configured to output, to the scanning unit, an address signal indicating a row to be driven of the pixel unit,

wherein the scanning unit further comprises an address decoder unit configured to output, to each of the row drive units, a decoded signal generated by decoding the address signal, and

wherein the decoded signal is input to the first storage unit and the second storage unit.

4. The imaging device according to claim 2 further comprising a control unit configured to output, to the scanning unit, an address signal indicating a row to be driven of the pixel unit,

wherein the scanning unit further comprises an address decoder unit configured to output, to each of the row drive units, a decoded signal generated by decoding the address signal, and

wherein the decoded signal is input to the first storage unit and the second storage unit.

5. The imaging device according to claim 3, wherein the decoded signal is not directly input to the third storage unit.

6. The imaging device according to claim 4, wherein the decoded signal is not directly input to the third storage unit.

7. The imaging device according to claim 1, wherein each of the pixels further comprises:

an amplification transistor configured to output a signal based on charges transferred to an input node thereof, and

a transfer transistor configured to transfer charges accumulated in the photoelectric conversion element to the input node of the amplification transistor,

wherein each of the row drive units comprises a transfer signal generating unit configured to generate a transfer signal for control of the transfer transistor based on the first signal output from the first storage unit, the second signal output from the second storage unit, and the third signal output from the third storage unit.

8. The imaging device according to claim 2, wherein each of the pixels further comprises:

an amplification transistor configured to output a signal based on charges transferred to an input node thereof, and

a transfer transistor configured to transfer charges accumulated in the photoelectric conversion element to the input node of the amplification transistor,

wherein each of the row drive units comprises a transfer signal generating unit configured to generate a transfer signal for control of the transfer transistor based on the first signal output from the first storage unit, the second signal output from the second storage unit, and the third signal output from the third storage unit.

9. The imaging device according to claim 7, wherein, when the first signal indicates not to perform a readout from the pixels on an associated row and the second signal indicates not to perform an operation for causing the photoelectric conversion element on an associated row to be reset to the charge accumulation state, the transfer signal generating unit uses the third signal to generate the transfer signal.

10. The imaging device according to claim 8, wherein, when the first signal indicates not to perform a readout from the pixels on an associated row and the second signal indicates not to perform an operation for causing the photoelectric conversion element on an associated row to be reset to the charge accumulation state, the transfer signal generating unit uses the third signal to generate the transfer signal.

11. The imaging device according to claim 1,

wherein each of the pixels comprises a plurality of the photoelectric conversion elements,

wherein each of the pixels further comprises:

an amplification transistor configured to output a signal based on charges transferred to an input node thereof, and

transfer transistors each of which is provided to each of the plurality of the photoelectric conversion elements and transfers charges accumulated in each of the plurality of the photoelectric conversion elements to the input node of the amplification transistor,

wherein the second storage unit comprises a plurality of storage circuits each of which is provided associated with each of the plurality of the photoelectric conversion elements and outputs the second signal,

wherein the third storage unit comprises a plurality of storage circuits each of which is provided associated with each of the plurality of the photoelectric conversion elements and outputs the third signal, and

wherein each of the row drive units comprises a plurality of transfer signal generating units, and each of the plurality of transfer signal generating units is provided associated with each of the plurality of the photoelectric conversion elements and generates a transfer signal for control of the transfer transistor based on the first signal output from the first storage unit, based on a plurality of the second signals each output from each of the plurality of storage circuits of the second storage unit, and based on the third signal output from one of the plurality of storage circuits of the third storage unit.

12. The imaging device according to claim 2,

wherein each of the pixels comprises a plurality of the photoelectric conversion elements,

wherein each of the pixels further comprises:

an amplification transistor configured to output a signal based on charges transferred to an input node thereof, and

transfer transistors each of which is provided to each of the plurality of the photoelectric conversion elements and transfers charges accumulated in each of the plurality of the photoelectric conversion elements to the input node of the amplification transistor,

wherein the second storage unit comprises a plurality of storage circuits each of which is provided associated with each of the plurality of the photoelectric conversion elements and outputs the second signal,

wherein the third storage unit comprises a plurality of storage circuits each of which is provided associated with each of the plurality of the photoelectric conversion elements and outputs the third signal, and

wherein each of the row drive units comprises a plurality of transfer signal generating units, and each of the plurality of transfer signal generating units is provided associated with each of the plurality of the photoelectric conversion elements and generates a transfer signal for control of the transfer transistor based on the first signal output from the first storage unit, based on a plurality of the second signals each output from each of the plurality of storage circuits of the second storage unit, and based on the third signal output from one of the plurality of storage circuits of the third storage unit.

13. The imaging device according to claim 11, wherein, when the first signal indicates not to perform a readout from the pixels on an associated row and all of the plurality of the second signals indicates not to perform an operation for causing the photoelectric conversion element on an associated row to be reset to the charge accumulation state, the transfer signal generating unit uses the third signal to generate the transfer signal.

14. The imaging device according to claim 12, wherein, when the first signal indicates not to perform a readout from the pixels on an associated row and all of the plurality of the second signals indicates not to perform an operation for causing the photoelectric conversion element on an associated row to be reset to the charge accumulation state, the transfer signal generating unit uses the third signal to generate the transfer signal.

15. An imaging system comprising:

an imaging device comprising;

a pixel unit in which pixels are arranged to form a plurality of rows, each of the pixels comprising a photoelectric conversion element that generates and accumulates charges in accordance with an incident light, and

a scanning unit comprising row drive units, each of the row drive units arranged associated with each of the rows of the pixel unit and outputting a drive signal for driving the pixel unit on a row basis,

wherein each of the row drive units comprises;

a first storage unit configured to store a first signal for a readout from the pixels on an associated row and configured to output the first signal,

a second storage unit configured to store a second signal for an operation for causing the photoelectric conversion element on an associated row to be reset to a charge accumulation state and configured to output the second signal,

a third storage unit configured to store a third signal for maintaining the photoelectric conversion element on an associated row in the charge accumulation state or a reset state, based on the first signal output from the first storage unit and the second signal output from the second storage unit and configured to output the third signal, and

a pixel drive signal generating unit configured to receive the first signal, the second signal and the third signal,

wherein the plurality of rows includes a first row, a second row, and a third row that is arranged between the first row and the second row,

wherein the pixel drive signal generating unit maintains the photoelectric conversion element included in the pixels on the first row and the second row in the charge accumulation state or the reset state by using the third signal, and

wherein the pixel drive signal generating unit maintains the photoelectric conversion element included in the pixels on the third row in the reset state by using the first signal during a period from a start of a readout from the pixels on the first row to an end of a readout from the pixels on the second row; and

a signal processing unit configured to process a signal output from the imaging device.

16. The imaging system according to claim 15, wherein the third storage unit stores and outputs the third signal further based on a fourth signal for resetting the photoelectric conversion elements on all the rows.

17. A drive method of an imaging device that comprises:

a pixel unit in which pixels are arranged to form a plurality of rows including a first row, a second row, and a third row that is arranged between the first row and the second row, each of the pixels comprising a photoelectric conversion element that generates and accumulates charges in accordance with an incident light, and

a scanning unit comprising row drive units, each of the row drive units arranged associated with each of the rows of the pixel unit and outputting a drive signal for driving the pixel unit on a row basis,

the drive method comprising;

at each of the row drive units,

storing in a first storage unit and outputting a first signal for a readout from the pixels on an associated row;

storing in a second storage unit and outputting a second signal for an operation for causing the photoelectric conversion element on an associated row to be reset to a charge accumulation state;

storing in a third storage unit and outputting a third signal for maintaining the photoelectric conversion element on an associated row in the charge accumulation state or a reset state, based on the first signal and the second signal;

receiving by a pixel drive signal generating unit the first signal, the second signal and the third signal;

maintaining by the pixel drive signal generating unit the photoelectric conversion element included in the pixels on the first row and the second row in the charge accumulation state or the reset state by using the third signal; and

maintaining by the pixel drive signal generating unit the photoelectric conversion element included in the pixels on the third row in the reset state by using the first signal during a period from a start of a readout from the pixels on the first row to an end of a readout from the pixels on the second row.

18. The drive method of the imaging device according to claim 17, wherein each of the row drive units stores and outputs the third signal further based on a fourth signal for resetting the photoelectric conversion elements on all the rows.