Abstract: An image capture apparatus that includes an array of color filters for green, red, and magenta colors arranged over a semiconductor substrate in the manner of a primary color Bayer pattern except a magenta color replaces the blue color. Light passing through the magenta color filter is integrated separately in a magenta pixel for a shallow photodiode signal and a deep photodiode signal in a first photodiode and a deeper second photodiode in the substrate, respectively. A mezzanine photodiode may be disposed between the first and second photodiodes and held at a fixed voltage level or reset multiple times during charge integration. A red pixel value for the magenta pixel is a function of the deep photodiode signal and an adjacent red pixel's red pixel signal. A minimum exists in its derivative with respect to the former at a value of the former that varies with the latter.

Abstract: A device that analyzes an image. The device includes a circuit that receives an image that includes a plurality of pixels. The circuit creates a histogram of the image and analyzes the histogram to determine an acceptable exposure of the image. The histogram may include a plurality of bins versus a population of pixels associated with each bin. By way of example, the bins may be associated with an intensity of light. The images and histograms may include data defined by low dynamic range number of bits and/or an extended dynamic range number of bits. Certain features and criteria of the image may be determined and analyzed to determine whether the image has an acceptable exposure. If the image is unacceptable, an exposure characteristic can be changed and the process can be repeated until an acceptable image is obtained.

Abstract: A memory comprises a two dimensional array of memory cells. Each memory cell comprises a first transistor, a second transistor and a capacitor. A multi-bit datum is stored as one of a plurality of voltage signal levels driven over a vertical input signal line and further across a source and a drain of the first transistor to be stored onto a gate of the second transistor. The first transistor is selected by a horizontal WR control line. The gate of the second transistor is connected to a first terminal of the capacitor. A second terminal of the capacitor is connected to a horizontal RD control line. The RD control line is driven to couple the second transistor to drive a signal onto a vertical output signal line during a read of the stored signal on the gate.

Abstract: An auto-focus image system includes a focus signal generator and a pixel array coupled thereto that captures an image that includes a plurality of edges. The generator computes a focus signal from a plurality of edge-sharpness measures, each measured from and contributed by a different edge as a quantity with a unit that is a power of a unit of length. The generator reduces a relative weight of the contribution of an edge depending on a shape of a normalized gradient profile of the edge as identified by an n-tuple of values of n different shape measures (n?2). Each shape measure varies across normalized gradient profiles of different shapes. One shape measure may be the edge-sharpness measure itself. The weight may be zero if the n-tuple falls outside a predetermined region. At least one symmetrical shape that has perfect reflection symmetry receives reduced weight.

Abstract: An image sensor that has a plurality of pixels within a pixel array coupled to a control circuit and to one or more subtraction circuits. The control circuit causes an output transistor coupled to a pixel to provide a first reference output signal, a common reset output signal, and a first sense-node reset output signal, between which a subtraction circuit may form a weighted difference to create a noise signal. The control circuit causes the output transistor to provide a second sense-node reset output signal, a light response output signal and a second reference output signal, between which a subtraction circuit may form a weighted difference to create a normalized light response signal. The light response output signal corresponds to the image that is to be captured by the sensor. The noise signal is subtracted from the normalized light response signal to generate a de-noised signal.

Abstract: An auto focus image system that includes a pixel array coupled to a focus signal generator. The pixel array captures an image that has at least one edge with a width. The focus signal generator may generate a focus signal that is a function of the edge width and/or statistics of edge widths. A processor receives the focus signal and/or the statistics of edge widths and adjust a focus position of a focus lens. The edge width can be determined by various techniques including the use of gradients. A histogram of edge widths may be used to determine whether a particular image is focused or unfocused. A histogram with a large population of thin edge widths is indicative of a focused image. Edge corruption/partial corruption may be detected. Partially corrupted edge may have edge width calculated by relying more on the side that is not corrupted and less on the side that is corrupted. Edge or edge side corruption may be detected by detecting a presence of an adjacent edge of the opposite sign.

Abstract: An image sensor pixel that includes a photoelectric conversion unit supported by a substrate and an insulator adjacent to the substrate. The pixel includes a cascaded light guide that is located within an opening of the insulator and extends above the insulator such that a portion of the cascaded light guide has an air interface. The air interface improves the internal reflection of the cascaded light guide. The cascaded light guide may include a self-aligned color filter having air-gaps between adjacent color filters. These characteristics of the light guide eliminate the need for a microlens. Additionally, an anti-reflection stack is interposed between the substrate and the light guide to reduce backward reflection from the image sensor. Two pixels of having different color filters may have a difference in the thickness of an anti-reflection film within the anti-reflection stack.

Abstract: An image sensor that has a plurality of pixels within a pixel array coupled to a control circuit and to one or more subtraction circuits. The control circuit causes an output transistor coupled to a pixel to provide a first reference output signal, a common reset output signal, and a first sense-node reset output signal, between which a subtraction circuit may form a weighted difference to create a noise signal. The control circuit causes the output transistor to provide a second sense-node reset output signal, a light response output signal and a second reference output signal, between which a subtraction circuit may form a weighted difference to create a normalized light response signal. The light response output signal corresponds to the image that is to be captured by the sensor. The noise signal is subtracted from the normalized light response signal to generate a de-noised signal.

Abstract: An auto focus image system that includes a pixel array coupled to a focus signal generator. The pixel array captures an image that has a plurality of edges. The generator generates a focus signal that is a function of a plurality of edge-sharpness measures for the plurality of edges. The generator compares a sequence of gradients across the edge with one or more reference sequences of gradients and/or reference curves defined by data retrieved from a non-volatile memory. The generator may reject or de-emphasize the edge using result of the comparison. The edge sharpness measure is a quantity whose unit is a positive or negative, integer or non-integer power of a unit of length. It may be measured from the edge and/or a reference sequence/curve matched to the edge, or may be retrieved for the matched reference sequence/curve from a non-volatile memory.

Abstract: An auto-focus image system includes a focus signal generator and a pixel array coupled thereto that captures an image that includes a plurality of edges. The generator computes a focus signal from a plurality of edge-sharpness measures, each measured from and contributed by a different edge as a quantity with a unit that is a power of a unit of length. The generator reduces a relative weight of the contribution of an edge depending on a shape of a normalized gradient profile of the edge as identified by an n-tuple of values of n different shape measures (n?2). Each shape measure varies across normalized gradient profiles of different shapes. One shape measure may be the edge-sharpness measure itself. The weight may be zero if the n-tuple falls outside a predetermined region. At least one symmetrical shape that has perfect reflection symmetry receives reduced weight.

Abstract: An image sensor that has a two-dimensional pixel array consisting of blue, green, and red pixels. The blue pixel comprises a blue color filter, a doped region of a second conductivity type disposed in the substrate and arranged to collect charge carriers generated by photons that enter the substrate from the blue color filter, and a transfer switch connected to transfer charges from the doped region. A trap region of the second conductivity type is buried under the doped region. Charge carriers collected by the trap region during a charge integration period of the doped region are drained to a surface of the substrate. No charges collected by the trap region during the charge integration period is used for generating a color image that is generated using a signal that results from charge carriers collected by the doped region during the charge integration period.

Abstract: An image sensor that has a plurality of pixels within a pixel array coupled to a control circuit and to one or more subtraction circuits. The control circuit may cause an output transistor coupled to a pixel to provide a first reference output signal, a common reset output signal, and a first sense-node reset output signal, between which a subtraction circuit may form a weighted difference to create a noise signal. The control circuit may cause the output transistor to provide a second sense-node reset output signal, a light response output signal and a second reference output signal, between which a subtraction circuit may form a weighted difference to create a normalized light response signal. The light response output signal corresponds to the image that is to be captured by the sensor. The noise signal may be subtracted from the normalized light response signal to generate a de-noised signal.

Abstract: An image sensor pixel that includes a photoelectric conversion unit supported by a substrate and an insulator adjacent to the substrate. The pixel includes a cascaded light guide located within an opening of the insulator. The cascaded light guide may include a color filter having an air gap between adjacent color filters that is sealed from above by a transparent sealing film having a concave surface over the air gap to diverge light crossing into the air gap from the concave surface into adjacent color filters. A portion of a support wall between a pair of color filters may have a larger width above than below to form a necking to hold down the color filters for better retention.

Abstract: An auto-focus image system that includes a pixel array coupled to a focus signal generator. The pixel array captures an image that has a plurality of edges. The generator generates a focus signal that is a function of a plurality of edge-sharpness measures, each being measured from a different one of the plurality of edges. The edge-sharpness measure is a quantity that has a unit that is a power of a unit of length. It may be a distance in the edge. It may be an area. It may be a central moment. The generator may reduce a relative extent to which an edge contributes to the focus signal on basis of detecting that the edge does not have sufficient reflection symmetry in a sequence of gradients of an image signal across the edge according to a predefined criterion. The edge may be prevented from contributing altogether.

Abstract: An image sensor pixel array includes a photoelectric conversion unit comprising a photoelectron accumulation region of n-type in a substrate of p-type and vertically below a gate electrode of a transistor. A light guide transmits a light of red or green or yellow color across the gate electrode to the photoelectron accumulation region. The gate electrode may be made thinner by a wet etch. An etchant for thinning the gate electrode may be introduced through an opening in an insulating film on the substrate. The light guide may be formed in the opening after the thinning. An anti-reflection stack may be formed at a bottom of the opening prior to forming the light guide.

Abstract: An image sensor that has a plurality of pixels within a pixel array coupled to a control circuit and to one or more subtraction circuits. The control circuit may cause an output transistor coupled to a pixel to provide a first reference output signal, a common reset output signal, and a first sense-node reset output signal, between which a subtraction circuit may form a weighted difference to create a noise signal. The control circuit may cause the output transistor to provide a second sense-node reset output signal, a light response output signal and a second reference output signal, between which a subtraction circuit may form a weighted difference to create a normalized light response signal. The light response output signal corresponds to the image that is to be captured by the sensor. The noise signal may be subtracted from the normalized light response signal to generate a de-noised signal.

Abstract: A device that analyzes an image. The device includes a circuit that receives an image that includes a plurality of pixels. The circuit creates a histogram of the image and analyzes the histogram to determine an acceptable exposure of the image. The histogram may include a plurality of bins versus a population of pixels associated with each bin. By way of example, the bins may be associated with an intensity of light. The images and histograms may include data defined by low dynamic range number of bits and/or an extended dynamic range number of bits. Certain features and criteria of the image may be determined and analyzed to determine whether the image has an acceptable exposure. If the image is unacceptable, an exposure characteristic can be changed and the process can be repeated until an acceptable image is obtained.

Abstract: An image sensor pixel that includes a photoelectric conversion unit supported by a substrate and an insulator adjacent to the substrate. The pixel includes a cascaded light guide that is located within an opening of the insulator and extends above the insulator such that a portion of the cascaded light guide has an air interface. The air interface improves the internal reflection of the cascaded light guide. The cascaded light guide may include a self-aligned color filter having air-gaps between adjacent color filters. Air-gaps may be sealed from above by a transparent sealing film. The transparent sealing film may have a concave surface over the air-gap to diverge light that crosses the concave surface into the air-gap away from the air-gap into adjacent color filters. These characteristics of the light guide eliminate the need for a microlens.

Abstract: An auto-focus image system includes a focus signal generator and a pixel array coupled thereto that captures an image that includes a plurality of edges. The generator computes a focus signal from a plurality of edge-sharpness measures, each measured from and contributed by a different edge as a quantity with a unit that is a power of a unit of length. The generator reduces a relative weight of the contribution of an edge depending on a shape of a normalized gradient profile of the edge as identified by an n-tuple of values of n different shape measures (n?2). Each shape measure varies across normalized gradient profiles of different shapes. One shape measure may be the edge-sharpness measure itself. The weight may be zero if the n-tuple falls outside a predetermined region. At least one symmetrical shape that has perfect reflection symmetry receives reduced weight.

Abstract: An auto focus image system that includes a pixel array coupled to a focus signal generator. The pixel array captures an image that has at least one edge with a width. The focus signal generator may generate a focus signal that is a function of the edge width and/or statistics of edge widths. A processor receives the focus signal and/or the statistics of edge widths and adjust a focus position of a focus lens. The edge width can be determined by various techniques including the use of gradients. A histogram of edge widths may be used to determine whether a particular image is focused or unfocused. A histogram with a large population of thin edge widths is indicative of a focused image.