CMOS IMAGE SENSOR WITH SHARED SENSING NODE

• US 20140117209A1
• Filed: 01/03/2014
• Published: 05/01/2014
• Est. Priority Date: 01/31/2005
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV), Carl Zeiss AG (Carl-Zeiss-Stiftung), Tarsium B.V.
• Original Assignee: Intellectual Ventures II LLC (Intellectual Ventures LLC)
• Inventors: Kwon, Oh-Bong
• Granted Patent: US 9,728,574 B2
• Time in Patent Office: Days
• US Class Current: 250/208.1
• CPC Class Codes: H01L 27/14641 Electronic components shared by two or more pixel-elements, e.g. one amplifier shared by two pixel elements
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/59 by controlling the amount of charge storable in the pixel, e.g. modification of the charge conversion ratio of the floating node capacitance
• CPC Class Codes: H04N 25/77 Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components

Abstract

A CMOS image sensor has a pixel array provided with a plurality of unit pixels arranged in a matrix shape of rows and columns. Each of the unit pixels includes a photocharge generation means for generating photocharges by absorbing an external light; and a sensing node for receiving the photocharges transferred from the photocharge generation means, wherein the sensing node of the unit pixel in a previous scan line is shared with a sensing node of a unit pixel in a current scan line in response to a line select signal of the current line.

Claims

1. A method, comprising:

collecting charge generated by a first pixel of a plurality of pixels;

transferring charge generated by the first pixel to a first sensing node of the first pixel and to a second sensing node of a second pixel of the plurality of pixels; and

generating, based on charge transferred to both the first sending node and the second sensing node, an output signal that is indicative of charge collected by the first pixel.

2. The method of claim 1, further comprising coupling the first sensing node to the second sensing node in response to a select signal.

3. The method of claim 1, further comprising selectively coupling the first sensing node to the second sensing node prior to said transferring.

4. The method of claim 1, further comprising

after said generating an output signal, decoupling the first sensing node from the second sensing node and coupling the first sensing node to a third sensing node of a third pixel;

transferring charge generated by the third pixel to the first sensing node and the third sensing node; and

generating, based on charge transferred to both the first sending node and the third sensing node, another output signal that is indicative of charge collected by the third pixel.

5. The method of claim 1, comprising:

applying a select signal to a gate of a transistor providing a source/drain pathway between the first sensing node and the second sensing node prior to said transferring; and

turning on the transistor and coupling the first sensing node to the second sensing node in response to said applying.

6. The method of claim 1, further comprising resetting the first sensing node and the second sensing node to a reset level in response a reset signal for the first pixel.

7. The method of claim 1, further comprising:

applying a select signal to a gate of a select transistor; and

turning on the select transistor and transferring the output signal to an output line in response to said applying.

8. A method, comprising:

producing an electrical signal with an image sensor pixel in response to receiving light with the image sensor pixel;

selectively coupling a sensing node of the image sensor pixel to another sensing node of another image sensor pixel; and

receiving the electrical signal with both the sensing node and the other sensing node.

9. The method of claim 8, further comprising generating, based on the electrical signal received by the sensing node and the other sensing node, an output signal indicative of light received by the image sensor pixel.

10. The method of claim 8, further comprising scanning, row-by-row, an image sensor comprising rows of image sensor pixels to generate output signals indicative of light received by the rows of image sensor pixels, wherein said scanning comprises:

in response to scanning a row of image sensor pixels that includes the image sensor pixel, generating, based on the electrical signal received by the sensing node and the other sensing node, an output signal indicative of light received by the image sensor pixel; and

in response to scanning another row of image sensor pixels that includes the other image sensor pixel, generating another output signal indicative of light received by the other image sensor pixel.

11. The method of claim 10, wherein said scanning the row of image sensor pixels that includes the image sensor pixel occurs after said scanning the other row of image sensor pixels that includes the other image sensor pixel.

12. The method of claim 8, further comprising generating a row select signal that selects a row of image sensor pixels that includes the image sensor pixel, wherein said selectively coupling occurs in response to the row select signal.

13. The method of claim 8, further comprising scanning, column-by-column, an image sensor comprising columns of image sensor pixels to generate output signals indicative of light received by the columns of image sensor pixels, wherein said scanning comprises:

in response to scanning a column of image sensor pixels that includes the image sensor pixel, generating, based on the electrical signal received by the sensing node and the other sensing node, an output signal indicative of light received by the image sensor pixel; and

in response to scanning another column of image sensor pixels that includes the other image sensor pixel, generating another output signal indicative of light received by the other image sensor pixel.

14. The method of claim 13, wherein said scanning the column of image sensor pixels that includes the image sensor pixel occurs after said scanning the other column of image sensor pixels that includes the other image sensor pixel.

15. A method, comprising:

integrating photocharge with a pixel array that includes a plurality of sensing pixels arranged in a matrix of rows and columns;

selecting a first row of sensing pixels from the plurality of sensing pixels in response to a select signal;

connecting a first sensing node of a first sensing pixel in the first row with a second sensing node of a second sensing pixel in a second row of sensing pixels in response to the select signal;

transferring photocharge from a photodiode of the first sensing pixel to both the first sensing node and the second sensing node; and

generating an output signal indicative of the photocharge transferred to the first sensing node and the second sensing node.

16. The method of claim 15, further comprising after said generating an output signal, selecting a third row of sensing pixels from the plurality of sensing pixels in response to another select signal;

connecting a third sensing node of a third sensing pixel in the third row with the first sensing node in the first row in response to the other select signal;

transferring photocharge from another photodiode of the third sensing pixel to both the first sensing node and the third sensing node; and

generating another output signal indicative of the photocharge transferred to the first sensing node and the third sensing node.

17. The method of claim 15, wherein said connecting comprises:

applying the select signal to a gate of a transistor providing a source/drain pathway between the first sensing node and the second sensing node; and

turning on the transistor in response to said applying.

18. The method of claim 15, further comprising resetting the first sensing node and the second sensing node to a reset level in response to a reset signal for the first sensing pixel.

19. The method of claim 15, further comprising:

applying a reset signal to a gate of a reset transistor providing a source/drain pathway between a first power terminal and the first sensing node; and

turning on the reset transistor and resetting the first sensing node and the second sensing node to a reset level in response to said applying.

20. The method of claim 15, further comprising:

applying a select signal to a gate of a select transistor; and

turning on the select transistor and transferring the output signal to an output line in response to said applying.