Patent application number | Description | Published |
20080211050 | Image sensor with inter-pixel isolation - An image sensor with a plurality of photodiodes that each have a first region constructed from a first type of material and a second region constructed from a second type of material. The photodiodes also have an insulating region between the first and second regions. The photodiodes are arranged in an array. In corner regions of the array, the second regions are offset relative to the insulating regions to capture more photons of incoming light. | 09-04-2008 |
20090027545 | Exposure control for an imaging system - 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. | 01-29-2009 |
20090039400 | IMAGE SENSOR WITH INTER-PIXEL ISOLATION - An image sensor with a plurality of photodiodes that each have a first region constructed from a first type of material and a second region constructed from a second type of material. Located adjacent to the first region and between second regions of adjacent photodiodes is a barrier region. The photodiodes are reversed biased to create depletion regions within the first regions. The barrier region limits the lateral growth of the depletions regions and inhibits depletion merger between adjacent photodiodes. | 02-12-2009 |
20090059044 | WIDE DYNAMIC RANGE CMOS IMAGE SENSOR - An image sensor with a pixel array that includes at least one pixel. The sensor may also include a circuit that is connected to the pixel and provides a final image pixel value that is a function of a sampled reset output signal generated from the pixel. The final image pixel value is set to a reserved value if the sampled reset output signal exceeds a threshold. The final image may be a function of first, second and/or third images and a field that provides information on whether the final image includes a first exposure rate, a second exposure rate and/or a third exposure rate. | 03-05-2009 |
20090102963 | Auto-focus image system - An auto focus image system that includes an image sensor coupled to a controller. The image sensor captures an image that has at least one edge with a width. The controller generates a focus signal that is a function of the edge width. A lens receives the focus signal and adjust a focus. The edge width can be determined by various techniques including the use of gradients. A histogram of edge widths can 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. | 04-23-2009 |
20100002112 | CMOS IMAGE SENSOR WITH NOISE CANCELLATION - An image sensor having one or more pixels within a pixel array. A vertical signal line across the pixel array conductively connects to a drain terminal of a transistor of one of the pixels. The drain terminal is driven to a first drain voltage via the vertical signal line so that the transistor enters a triode region. A gate of the transistor is placed into a tri-state during the triode region, the gate being at a first gate voltage prior to the tri-state. The drain terminal is driven to a second drain voltage during the tri-state, whereby the gate is capacitively coupled to a second gate voltage. The second drain voltage may be higher than the first drain voltage so as to effectuate a gate voltage boosting for the transistor. The transistor may be a reset transistor having a drain terminal conductively coupled to reset said photodetector. | 01-07-2010 |
20100128144 | AUTO-FOCUS IMAGE SYSTEM - 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. | 05-27-2010 |
20100149385 | NOISE-CANCELLING IMAGE SENSORS - 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 denoised signal. | 06-17-2010 |
20100155870 | LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR - 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 light guide that is located within an opening of the insulator and extends above the insulator such that a portion of the light guide has an air interface. The air interface improves the internal reflection of the light guide. Additionally, the light guide and an adjacent color filter are constructed with a process that optimizes the upper aperture of the light guide. These characteristics of the light guide eliminate the need for a microlens. | 06-24-2010 |
20100157121 | IMAGE SENSOR WITH TIME OVERLAPPING IMAGE OUTPUT - An image sensor system with an image sensor that generates a first image and a second image. The first and second images are transmitted to a processor in a time overlapping manner. By way of example, the images may be transferred to the processor in an interleaving manner or provided on separate dedicated busses. | 06-24-2010 |
20100265384 | LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR - 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. Additionally, 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. | 10-21-2010 |
20100283112 | Light Guide Array for An Image Sensor - An image sensor pixel that includes a photoelectric conversion unit ( | 11-11-2010 |
20100317142 | LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR - 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 light guide that is located within an opening of the insulator and extends above the insulator such that a portion of the light guide has an air interface. The air interface improves the internal reflection of the light guide. Additionally, the light guide and an adjacent color filter are constructed with a process that optimizes the upper aperture of the light guide. These characteristics of the light guide eliminate the need for a microlens. | 12-16-2010 |
20110013045 | CMOS IMAGE SENSOR WITH PROCESSOR CONTROLLED INTEGRATION TIME - An image sensor that has one or more pixels within a pixel array. The pixels are arranged within a plurality of rows within the array. Each row of the pixel array can be selected by a row decoder in response to an edge of a control signal. The control signal may be one of a plurality of signals generated by a processor coupled to the image sensor. The processor can control the exposure time of the pixels by varying the control signals. The control signals may also have an embedded narrow pulse that is used to determine the location of a “window” in the pixel array. | 01-20-2011 |
20110027936 | LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR - 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. | 02-03-2011 |
20110031381 | LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR - 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 cross 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. Additionally, 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. | 02-10-2011 |
20110058082 | CMOS Image Sensor with Noise Cancellation - An image sensor that has one or more pixels within a pixel array coupled to a control circuit and to one or more subtraction circuits. The control circuit may cause each pixel to provide a first reference output signal and a reset output signal and may then cause each pixel to provide a light response output signal and a second reference output signal. The light response output signal corresponds to the image that is to be captured by the sensor. The subtraction circuit may provide a difference between the reset output signal and the first reference output signal to create a noise signal, and may provide a difference between the second reference output signal and the light response output signal to create a normalized light response output signal. The noise signal may then be subtracted from the normalized light response output signal to generate an image signal having reset noise cancelled therefrom. | 03-10-2011 |
20110068430 | IMAGE SENSOR WITH INTER-PIXEL ISOLATION - An image sensor with a plurality of photodiodes arranged in an array. A barrier region is disposed between adjacent photodiodes and inhibits depletion region merger between adjacent photodiodes, thereby inhibiting a capacitive coupling between the adjacent photodiodes. | 03-24-2011 |
20110089514 | COLOR-OPTIMIZED IMAGE SENSOR - An image sensor pixel array includes a photoelectric conversion unit comprising a second region in a substrate and vertically below a gate electrode of a transistor. A first region under a top surface of the substrate and above the second region supports a channel of the transistor. A color filter transmits a light via a light guide, the gate electrode and the first region to generate carriers collected by the second 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. | 04-21-2011 |
20110102651 | OPTIMIZED LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR - An image sensor has a plurality of pixels in a pixel array. Each pixel includes a photoelectric conversion unit below an insulating layer and a light guide to transmit light to the photoelectric conversion unit. Across five or more pixels arrayed in a direction, the light guides have a spacing between them that varies non-monotonically across the five or more pixels. A width of the light guide and/or a horizontal pitch between consecutive light guides may vary non-monotonically across same. A light guide of a pixel that detects light of shorter wavelengths only may be narrower than a light guide of another pixel that detects light of longer wavelengths. A color filter may be coupled to the light guide. A width of a gap between consecutive color filters may vary non-monotonically across same. A pitch between the gaps may vary non-monotonically across same. | 05-05-2011 |
20110111549 | Image Sensor with Pixel Wiring to Reflect Light - An image sensor with a plurality of photodiodes pixels. At least one of the photodiodes pixels includes a reflective element that prevents light from traveling onto an adjacent photodiode pixel. The reflective element may be a floating contact adjacent a routing wire of the image sensor. The reflective element may have an aspect ratio that maximizes the reflective surface of the element. | 05-12-2011 |
20110134312 | AUTO-FOCUS IMAGE SYSTEM - 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 adjusts 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. The generator may eliminate an edge having an asymmetry of a gradient profile of an image signal. The generator may also eliminate an edge that fails a template for an associated peaking of the gradient. | 06-09-2011 |
20110135215 | AUTO-FOCUS IMAGE SYSTEM - 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 adjusts 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. The generator may eliminate an edge having an asymmetry of a gradient profile of an image signal. | 06-09-2011 |
20110163405 | Image Sensor with Pixel Wiring to Reflect Light - An image sensor with a plurality of photodiode pixels supported by a substrate. At least one of the photodiode pixels includes a reflective element that prevents light from traveling onto an adjacent photodiode pixel. The reflective element may be a floating contact on a dielectric barrier that insulates the contact from a substrate. The reflective element may be a via that may or may not be an essential part of an electrical connection between two or more integrated devices. The reflective element may be elongated in a horizontal section parallel to the substrate to maximize the reflective surface area and thus longer than standard vias and contacts. The reflective element may be non-rectilinear. The via may be directly above but insulated from a conductor by a dielectric layer thinner than an inter-metal dielectric (IMD) thickness between interconnect layers, and may straddle one or more conductors. | 07-07-2011 |
20110164151 | IMAGE SENSOR WITH INTERLEAVED IMAGE OUTPUT - An image sensor with a light reader circuit coupled to a pixel array. The light reader circuit retrieves a first image and a second image generated by the pixel array. The image sensor may also include a memory controller and/or data interface that transfers the first and second images to an external device in an interleaving manner. | 07-07-2011 |
20110273610 | AUTO-FOCUS IMAGE SYSTEM - 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. | 11-10-2011 |
20120008375 | CMOS IMAGE SENSOR WITH NOISE CANCELLATION - 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. | 01-12-2012 |
20120008872 | AUTO-FOCUS IMAGE SYSTEM - 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. The focus signal generator may generate a focus signal that is a function of a width of the edge and/or statistics of widths of edges. A processor receives the focus signal and/or the statistics of the widths and adjusts a focus position of a focus lens. The width can be determined by various techniques including the use of gradients. An width determined along a prescribed direction is corrected for a slant of a boundary to which the edge belongs relative to the prescribed direction. The correction may use a peak gradient in the prescribed direction along the edge in conjunction with a largest gradient of a perpendicular direction within a predefined neighborhood of the peak gradient. | 01-12-2012 |
20120013789 | EXPOSURE CONTROL FOR AN IMAGING SYSTEM - 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. | 01-19-2012 |
20120026373 | WIDE DYNAMIC RANGE CMOS IMAGE SENSOR - An image sensor with a pixel array that includes at least one pixel. The sensor may also include a circuit that is connected to the pixel and provides a final image pixel value that is a function of a sampled reset output signal generated from the pixel. The final image pixel value is set to a reserved value if the sampled reset output signal exceeds a threshold. The final image may be a function of first, second and/or third images and a field that provides information on whether the final image includes a first exposure rate, a second exposure rate and/or a third exposure rate. | 02-02-2012 |
20120075511 | COLOR IMAGE SAMPLING AND RECONSTRUCTION - 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. | 03-29-2012 |
20120217377 | OPTIMIZED LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR - An image sensor has a plurality of pixels in a pixel array. Each pixel includes a photoelectric conversion unit below an insulating layer and a light guide to transmit light to the photoelectric conversion unit. Across five or more pixels arrayed in a direction, the light guides have a spacing between them that varies non-monotonically across the five or more pixels. A width of the light guide and/or a horizontal pitch between consecutive light guides may vary non-monotonically across same. A light guide of a pixel that detects light of shorter wavelengths only may be narrower than a light guide of another pixel that detects light of longer wavelengths. A color filter may be coupled to the light guide. A width of a gap between consecutive color filters may vary non-monotonically across same. A pitch between the gaps may vary non-monotonically across same. | 08-30-2012 |
20120218434 | EXPOSURE CONTROL FOR AN IMAGING SYSTEM - 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. | 08-30-2012 |
20120242856 | AUTO-FOCUS IMAGE SYSTEM - 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. | 09-27-2012 |
20120314121 | AUTO-FOCUS IMAGE SYSTEM - 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. | 12-13-2012 |
20120314960 | AUTO-FOCUS IMAGE SYSTEM - 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, such as a distance in the edge, an area, or an even-order central moment. A relative weight of the contribution by an edge is reduced depending on at least a pair of shape measures, each being computed from a plurality of sample-pair differences of the edge. One may be the edge-sharpness measure. The weight may be zero if the pair of shape measures falls outside a predetermined region. At least one symmetrical sequence of gradients exists such that an edge with it has reduced relative weight. | 12-13-2012 |
20130034927 | LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR - 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. | 02-07-2013 |
20130044255 | AUTO-FOCUS IMAGE SYSTEM - An auto-focus image system includes a pixel array and a focus signal generator coupled to the pixel array. The pixel array captures an image that has more than one edge. The generator generates a focus signal. Each edge has a width and contributes a quantity to compute the focus signal. The quantity may remain unchanged if all pixel values that enter a computation of the quantity are scaled up by a common multiplier. The quantity may have a dimension based solely on a dimension of length. The quantity may be the width. The generator eliminates an edge whose gradient profile has a first width at a first percentage height of the gradient profile that falls outside a tolerance region. The tolerance region varies with a second width of the gradient profile at a second percentage height. Alternatively, the edge's contribution to the focus signal is deemphasized. | 02-21-2013 |
20130083232 | AUTO-FOCUS IMAGE SYSTEM - 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. | 04-04-2013 |
20130182961 | AUTO-FOCUS IMAGE SYSTEM - 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. | 07-18-2013 |
20130222653 | NOISE-CANCELLING IMAGE SENSORS - 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. | 08-29-2013 |
20130223739 | EXPOSURE CONTROL FOR AN IMAGING SYSTEM - 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. | 08-29-2013 |
20130249038 | COLOR-OPTIMIZED IMAGE SENSOR - 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. | 09-26-2013 |
20130265480 | AUTO-FOCUS IMAGE SYSTEM - 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. | 10-10-2013 |
20130292547 | LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR - 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. | 11-07-2013 |
20130300902 | COLOR IMAGE SENSOR PIXEL ARRAY - 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. | 11-14-2013 |
20140022443 | AUTO-FOCUS IMAGE SYSTEM - 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. | 01-23-2014 |
20140063293 | NOISE-CANCELLING IMAGE SENSORS - 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. | 03-06-2014 |
20140117208 | LIGHT GUIDE ARRAY FOR AN IMAGE SENSOR - 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. | 05-01-2014 |
20140139707 | AUTO-FOCUS IMAGE SYSTEM - 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. | 05-22-2014 |
20140333803 | NOISE-CANCELLING IMAGE SENSORS - 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. | 11-13-2014 |
20140347915 | CMOS IMAGE SENSOR WITH NOISE CANCELLATION - 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. | 11-27-2014 |
20150035107 | COLOR IMAGE SAMPLING AND RECONSTRUCTION - 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. | 02-05-2015 |