Pixel Binning in an Image Sensor

• US 20180109742A1
• Filed: 06/19/2017
• Published: 04/19/2018
• Est. Priority Date: 05/30/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Agranov, Gennadiy A., Molgaard, Claus, Bahukhandi, Ashirwad, Lee, Chiajen, Li, Xiangli
• Granted Patent: US 10,609,348 B2
• Time in Patent Office: Days
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/447 by preserving the colour pattern with or without loss of information
• CPC Class Codes: H04N 25/46 by combining or binning pixels
• CPC Class Codes: H04N 25/70 SSIS architectures; Circuits associated therewith
• 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
• CPC Class Codes: H04N 25/78 Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters

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.

Claims

1-26. -26. (canceled)

27. 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.

28. The method of claim 27, 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.

29. The method of claim 28, 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.

30. The method of claim 27, wherein the second diagonal direction is a different diagonal direction than the first diagonal direction.

31. The method of claim 27, wherein the first diagonal direction and the second diagonal direction are a same diagonal direction.

32. The method of claim 27, further comprising:

reading the orthogonal summed signal out of the pixel array.

33. The method of claim 27, 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.

34. The method of claim 27, 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.

35. 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; and

producing a combined signal by combining voltages of the first orthogonal summed charge and the second orthogonal summed charge.

36. The method of claim 35, further comprising:

producing a diagonal summed signal representing a sum of charges in a third set of pixels positioned along a diagonal direction and reading the diagonal summed signal out of the pixel array.

37. The method of claim 36, wherein producing the diagonal summed signal comprises:

summing charge in the third set of pixels.

38. The method of claim 36, wherein producing the diagonal summed signal comprises:

combining voltage signals read out of each pixel in the third set of pixels.

39. The method of claim 35, 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.

40. The method of claim 39, 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.

41. The method of claim 35, 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.

42. The method of claim 35, 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.

43. The method of claim 35, further comprising:

selectively enabling and disabling the first set of pixels and the second set of pixels.

44. An image capture device, comprising:

a pixel array divided into groups of pixels, each group of pixels 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 signals representing the charge in sense regions of enabled pixels; and

selectively enable the switch to combine voltages on different output lines in the set of output lines.

45. The image capture device of claim 44, 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.

46. The image capture device of claim 44, 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.