Imager method and apparatus having combined gate signals

• US 20090237540A1
• Filed: 03/20/2008
• Published: 09/24/2009
• Est. Priority Date: 03/20/2008
• Status: Abandoned Application

• Current Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Original Assignee: Micron Technology, Inc.
• Inventors: Johnson, Richard S.
• Application Number:
  US12/076,632
• Publication Number:
  US 20090237540A1
• Time in Patent Office: Days
• US Class Current: 348/308
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H04N 25/46 by combining or binning pixels
• 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 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 25/766 comprising control or output lines used for a plurality of functions, e.g. for pixel output, driving, reset or power
• CPC Class Codes: H04N 25/771 comprising storage means other than floating diffusion

Abstract

An imaging device and method for operating the device. The device comprises a pixel array having a plurality of pixels arranged in rows and columns and a plurality of readout circuits for the pixels. A reset circuit in one readout circuit is simultaneously operated with a dual conversion gain select circuit in another readout circuit using a common select line. Alternatively, a row circuit in one readout circuit is simultaneously operated with a dual conversion gain select circuit in another readout circuit using a common select line.

Claims

1. An imaging device, comprising:

a pixel array having a plurality of pixels arranged in rows and columns, each pixel of the array comprising at least a photosensor;

a plurality of pixel readout circuits each associated with at least one pixel, the pixel readout circuit comprising;

a storage node for receiving charges from a photo sensor;

a reset circuit responsive to a reset control signal for resetting the storage node;

a circuit for providing an output signal based on charges stored at the storage node;

a dual conversion gain circuit responsive to a dual conversion gain signal for selectively coupling the storage node to a capacitor; and

a select line for commonly providing a reset control signal to the reset circuit and a dual conversion gain signal to a dual conversion gain circuit of a different pixel readout circuit.

2. The imaging device of claim 1, wherein each pixel readout circuit is respectively associated with one pixel.

3. The imaging device of claim 1, wherein each pixel readout circuit is respectively associated with a plurality of pixels.

4. An imaging device, comprising:

a pixel array comprising a plurality of pixels arranged in rows and columns, at least one pixel in a first row of the array comprising;

a photosensor;

a floating diffusion region for storing photoelectric charge supplied by the photosensor;

a source follower transistor having a gate coupled to the floating diffusion region;

a reset transistor for resetting the floating diffusion region, the reset transistor having a gate coupled to a first reset select line; and

a dual conversion gain transistor for switchably coupling additional storage capacity to the floating diffusion region, the dual conversion gain transistor having a gate coupled to a second reset select line of a pixel in a second row following the first row.

5. The imaging device of claim 4, wherein the first reset select line is coupled to a gate of a dual conversion gain transistor of a third row previous to the first row.

6. The imaging device of claim 5, wherein the second and third rows are vertically adjacent the first row.

7. The imaging device of claim 4, wherein the additional storage capacity is a capacitor.

8. The imaging device of claim 4, wherein the floating diffusion region is arranged to receive charges from more than one associated pixel.

9. The imaging device of claim 4, further comprising a transfer transistor switchably coupling the photosensor to the floating diffusion region.

10. The imaging device of claim 4, further comprising a row transistor responsive to a row select signal for selectively coupling the pixel to a column line.

11. An imaging device, comprising:

a pixel array comprising;

a plurality of pixels arranged in rows and columns, each pixel comprising a photosensor; and

a plurality of readout circuits arranged in rows and columns, at least one readout circuit in a readout circuit row of said array comprising;

a floating diffusion region for storing a photoelectric charge supplied by at least one photosensor,

a source follower transistor having a gate coupled to the floating diffusion region, and

a reset transistor for resetting the floating diffusion region, the reset transistor having a gate coupled to a reset select line; and

a dual conversion gain transistor for switchably coupling a capacitance to the floating diffusion region, the dual conversion gain transistor to having a gate coupled to a reset select line of a readout circuit in a different readout circuit row.

12. The imaging device of claim 11, wherein the reset select line is coupled to a gate of a dual conversion transistor in a readout circuit of a next readout circuit row previous to the readout circuit row.

13. The imaging device of claim 11, wherein the gate of the dual conversion gain transistor is coupled to a gate of a reset transistor in a readout circuit of a next readout circuit row following the readout circuit row.

14. The imaging device of claim 11, wherein the next readout circuit row following the readout circuit row is a vertically adjacent row.

15. The imaging device of claim 11, wherein the next readout circuit row following the readout circuit row is not a vertically adjacent row.

16. The imaging device of claim 11, wherein each pixel further comprises a plurality of transfer transistors for switchably coupling the photosensors to the floating diffusion region, said transfer transistors being controlled by transfer select lines, each transfer select line controlling one transfer transistor coupled to the floating diffusion region.

17. A method of operating a pixel circuit, the method comprising:

activating a first select line coupled to a pixel readout circuit in a first row to activate a dual conversion gain transistor in the readout circuit in the first row and simultaneously activate a reset transistor in a readout circuit in a previous row.

18. The method of claim 17 further comprising activating a transfer select line to transfer a photoelectric charge from at least one pixel to the readout circuit.

19. The method of claim 17 further comprising:

activating a second select line coupled to the readout circuit in the first row to activate a reset transistor in the readout circuit in the first row and to simultaneously activate a dual conversion gain transistor in a readout circuit in a following row.

20. The method of claim 17, wherein the readout circuit is arranged to receive charges from a plurality of associated pixels.

21. The method of claim 17, wherein the readout circuit is arranged to receive charges from one associated pixel.

22. An imaging device comprising:

a first readout circuit associated with a first pixel, the first readout circuit having a reset circuit that resets a first storage location in response to a reset signal; and

a second readout circuit associated with a second pixel, the second readout circuit having a gain circuit that couples a second storage location to a capacitor in response to the reset signal.

23. The imaging device according to claim 22, wherein said first and second readout circuits each further comprise a circuit for providing an output signal based on charges stored the first and second storage locations, respectively.

24. An imaging device, comprising:

a pixel array comprising a plurality of pixels arranged in rows and columns, at least one pixel in a first row of the array comprising;

a photosensor;

a floating diffusion region for storing photoelectric charge supplied by the photosensor;

a row select transistor for selectively connecting the pixel to a column line, the row transistor having a gate coupled to a first row select line; and

a dual conversion gain transistor for switchably coupling additional storage capacity to the floating diffusion region, the dual conversion gain transistor having a gate coupled to a second row select line of a pixel in a second row following the first row.

25. The imaging device of claim 24, wherein the first reset select line is coupled to a gate of a dual conversion gain transistor of a third row previous to the first row.

26. The imaging device of claim 25, wherein the second and third rows are vertically adjacent the first row.

27. The imaging device of claim 24, wherein the floating diffusion region is arranged to receive charges from more than one associated pixel.

28. The imaging device of claim 24, further comprising a transfer transistor switchably coupling the photosensor to the floating diffusion region.

29. The imaging device of claim 24, further comprising a reset transistor responsive to a reset select signal for selectively resetting the floating diffusion region.

30. An imaging device comprising:

a first readout circuit associated with a first pixel, the first readout circuit having a row select circuit that connects the first pixel to a first column line in response to a row signal; and

a second readout circuit associated with a second pixel, the second readout circuit having a gain circuit that couples a second storage location to a capacitor in response to the row signal.

31. The imaging device according to claim 30, wherein said first and second readout circuits each further comprise a reset circuit that resets the first and second storage location in response to a reset signal, respectively.

32. A method of operating a pixel circuit, the method comprising:

activating a first select line coupled to a pixel readout circuit in a first row to activate a dual conversion gain transistor in the readout circuit in the first row and simultaneously activate a row transistor in a readout circuit in a previous row.

33. The method of claim 32 further comprising activating a transfer select line to transfer a photoelectric charge from at least one pixel to the readout circuit.

34. The method of claim 32 further comprising:

activating a second select line coupled to the readout circuit in the first row to activate a row transistor in the readout circuit in the first row and to simultaneously activate a dual conversion gain transistor in a readout circuit in a following row.

35. The method of claim 32, wherein the readout circuit is arranged to receive charges from a plurality of associated pixels.

36. The method of claim 32, wherein the readout circuit is arranged to receive charges from one associated pixel.