Imaging circuitry with high frame rate edge detection
AssigneeSemiconductor Components Industries, LLC
InventorGal Fadida
Life of this patent
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Abstract
An image sensor may include an array of pixels arranged in rows and columns. Each pixel can include a subpixel circuit and one or more subtraction circuits. Each subpixel circuit can be selectively coupled to neighboring subpixel circuits in the same row via horizontal odd and even switches and can be selectively coupled to neighboring subpixel circuits in the same column via vertical odd and even switches. The horizontal and vertical switches can be turned on in separate phases to store difference values from pairs of neighboring subpixels into the one or more subtraction circuits. The difference values can be read out using comparators and one or more shift registers to output an edge image that includes only edge information.
Claims19
A sensor comprising:
- an array of pixels arranged in rows and columns, wherein each pixel in the array of pixels comprises a subpixel circuit, a first subtraction circuit, and a second subtraction circuit;
- a first horizontal signal line coupled to a first row of pixels in the array;
- first horizontal odd switches along the first horizontal signal line, wherein the first horizontal odd switches are configured to activate in a first phase during which difference values from first pairs of neighboring subpixels in the first row are stored in a first portion of the first subtraction circuits in the first row;
- and
- first horizontal even switches along the first horizontal signal line, wherein the first horizontal even switches are configured to activate in a second phase during which difference values from second pairs of neighboring subpixels in the first row are stored in a second portion of the first subtraction circuits, different than the first portion of the first subtraction circuits, in the first row.
A method of operating a sensor, comprising:
- accumulating charge in an array of pixels arranged in rows and columns, wherein each pixel in the array of pixels comprises a subpixel circuit, a first subtraction circuit, and a second subtraction circuit;
- in a first phase, activating horizontal odd switches and storing difference values from first pairs of neighboring subpixels in a first row of pixels in a first portion of the first subtraction circuits in the first row;
- in a second phase, activating horizontal even switches and storing difference values from second pairs of neighboring subpixels in the first row of pixels in a second portion of the first subtraction circuits in the first row;
- and
- outputting an edge image based on the stored difference values.
A sensor comprising:
- a pixel that includes a subpixel circuit and a subtraction circuit, wherein
- the subpixel circuit comprises a photodiode, a charge transfer transistor coupled between the photodiode and a floating diffusion node, a reset transistor coupled to the floating diffusion node, a source follower transistor having a gate terminal coupled to the floating diffusion node, and a row select transistor coupled in series with the source follower transistor,
- the subpixel is coupled to the subtraction circuit via a horizontal odd switch,
- the subpixel is coupled to a subpixel circuit of a neighboring pixel in a same row via a horizontal even switch,
- the subpixel is coupled to the subtraction circuit via a vertical even switch, and
- the subpixel is coupled to a subpixel circuit of a neighboring pixel in a same column via a vertical odd switch.
Dependencies are inferred from the claim text.