Pixel binning in an image sensor

Patent metadata

Field	Value
Publication number	US-10609348-B2
Application number	US-201715627409-A
Country	US
Kind code	B2
Filing date	Jun 19, 2017
Priority date	May 30, 2014
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

Pixel binning is performed by summing charge from some pixels positioned diagonally in a pixel array. Pixel signals output from pixels positioned diagonally in the pixel array may be combined on the output lines. A signal representing summed charge produces a binned 2×1 cluster. A signal representing combined voltage signals produces a binned 2×1 cluster. A signal representing summed charge and a signal representing combined pixel signals can be combined digitally to produce a binned 2×2 pixel. Orthogonal binning may be performed on other pixels in the pixel array by summing charge on respective common sense regions and then combining the voltage signals that represent the summed charge on respective output lines.

First claim

What is claimed is:

1. A method for binning charge in an image sensor having a pixel array that includes a plurality of pixels, the method comprising:
producing a first diagonal summed signal by summing charge in a first set of pixels positioned along a first diagonal direction and reading the first diagonal summed signal out of the pixel array;
producing a second diagonal summed signal by combining voltage signals read out of a second set of pixels positioned along a second diagonal direction and reading the second diagonal summed signal out of the pixel array; and
producing an orthogonal summed signal by summing charge in a third set of pixels positioned along a first orthogonal direction.

2. The method of claim 1 , wherein the first set of pixels includes pixels associated with a first green color plane and a second green color plane in a first Bayer color filter array.

3. The method of claim 2 , wherein:
the second set of pixels includes a first pixel associated with the first green color plane in a second Bayer color filter array and a second pixel associated with the second green color plane in a third Bayer color filter array.

4. The method of claim 1 , wherein the second diagonal direction is a different diagonal direction than the first diagonal direction.

5. The method of claim 1 , wherein the first diagonal direction and the second diagonal direction are a same diagonal direction.

6. The method of claim 1 , further comprising:
reading the orthogonal summed signal out of the pixel array.

7. The method of claim 1 , wherein the orthogonal summed signal comprises a first orthogonal summed signal, the method further comprising:
producing a second orthogonal summed signal by summing charge in a fourth set of pixels positioned along the first orthogonal direction; and
producing a combined signal by combining the first orthogonal summed signal and the second orthogonal summed signal.

8. The method of claim 1 , further comprising:
converting the first diagonal summed signal into a digital first diagonal summed signal; and
converting the second diagonal summed signal into a digital second diagonal summed signal; and
producing a combined signal by combining the digital first diagonal summed signal and the digital second diagonal summed signal.

9. A method for binning charge in an image sensor having a pixel array that includes a plurality of pixels, the method comprising:
producing a first orthogonal summed signal by summing charge in a first set of pixels positioned along a first orthogonal direction of the pixel array;
producing a second orthogonal summed signal by summing charge in a second set of pixels positioned along the first orthogonal direction;
producing a combined signal by combining voltages of the first orthogonal summed signal and the second orthogonal summed signal; and
producing a diagonal summed signal representing a sum of charges in a third set of pixels positioned along a diagonal direction of the pixel array.

10. The method of claim 9 , further comprising:
reading the diagonal summed signal out of the pixel array.

11. The method of claim 9 , wherein producing the diagonal summed signal comprises:
summing charge in the third set of pixels.

12. The method of claim 9 , wherein producing the diagonal summed signal comprises:
combining voltage signals read out of each pixel in the third set of pixels.

13. The method of claim 9 , wherein:
the charge in the first set of pixels is summed at a first common node of first readout circuitry shared by the first set of pixels; and
the charge in the second set of pixels is summed at a second common node of second readout circuity shared by the second set of pixels.

14. The method of claim 13 , wherein producing the combined signal comprises:
electrically coupling a first output line connected to the first readout circuitry to a second output line connected to the second readout circuitry.

15. The method of claim 9 , wherein the first set of pixels includes pixels associated with a blue color plane in a first Bayer color filter array, and the second set of pixels includes pixels associated with the blue color plane in a second Bayer color filter array.

16. The method of claim 9 , wherein the first set of pixels includes pixels associated with a red color plane in a first Bayer color filter array, and the second set of pixels includes pixels associated with the red color plane in a second Bayer color filter array.

17. The method of claim 9 , further comprising:
selectively enabling and disabling the first set of pixels and the second set of pixels.

18. An image capture device, comprising:
a pixel array divided into groups of pixels, each group of pixels including an at least 2×4 array of pixels that is operably connected to a respective sense region in a set of sense regions;
readout circuitry operably connecting the set of sense regions to a set of output lines;
a switch operably connecting a first set of the set of output lines to a second set of the set of output lines; and
a processing device operably connected to the pixel array, the readout circuitry, and the switch, wherein the processing device is adapted to:
selectively enable two or more pixels in a group of pixels to sum charge at a respective sense region;
selectively enable two or more pixels in different groups of pixels;
selectively enable the readout circuitry to produce, on one or more output lines of the set of output lines, one or more voltage signals representing respective summed charges in sense regions of enabled pixels; and
selectively enable the switch to combine the one or more voltage signals on different output lines in the set of output lines.

19. The image capture device of claim 18 , wherein the processing device is operably connected to the pixel array, the readout circuitry, and the switch to:
produce a first diagonal summed signal by summing charge in a first set of pixels positioned along a first diagonal direction and reading the first diagonal summed signal out of the pixel array;
produce a second diagonal summed signal by combining voltage signals read out of a second set of pixels positioned along a second diagonal direction and reading the second diagonal summed signal out of the pixel array; and
produce a combined signal by combining the first diagonal summed signal and the second diagonal summed signal.

20. The image capture device of claim 18 , wherein the processing device is operably connected to the pixel array, the readout circuitry, and the switch to:
produce an orthogonal summed signal by summing charge in a set of pixels positioned along a first orthogonal direction.

Assignees

• Apple Inc

Inventors

• Agranov Gennadiy A
• Molgaard Claus
• Bahukhandi Ashirwad
• Lee Chiajen
• Li Xiangli

Classifications

• H04N9/045

  Electricity · mapped topic

• H04N5/37457

  Electricity · mapped topic

• H04N5/347

  Electricity · mapped topic

• H04N9/04511 Primary

  Electricity · mapped topic

• H04N25/778

  comprising amplifiers shared between a plurality of pixels, i.e. at least one part of the amplifier must be on the sensor array itself · CPC title