Abstract: A low power SRAM (static RAM) for an image sensor includes a voltage generation circuit for providing a positive supply voltage VP and a negative supply VN, wherein VDD>Vp>Vn>Vgnd; a plurality of memory cells coupled to a respective plurality of column sense lines in a pixel array, the plurality of memory cells receiving differential inputs dp and dn; and a Gray counter coupled to switchably couple VP and VN to the differential inputs dp and dn of the plurality of memory cells. A method of operating an image sensor with a low power SRAM includes acquiring an image by the image sensor; generating VP and VN such that VDD>VP>VN>Vgnd; receiving an output g of a column of pixels at a clock input of a memory cell; and switchably coupling VP and VN to the differential inputs dp and dn of a plurality of memory cells in the SRAM according to a codeword from a Gray counter.

Abstract: An imaging system includes a pixel array configured to generate image charge voltage signals in response to incident light received from an external scene. An infrared illumination source is deactivated during the capture of a first image of the external scene and activated during the capture of a second image of the external scene. An array of sample and hold circuits is coupled to the pixel array. Each sample and hold circuit is coupled to a respective pixel of the pixel array and includes first and second capacitors to store first and second image charge voltage signals of the captured first and second images, respectively. A column voltage domain differential amplifier is coupled to the first and second capacitors to determine a difference between the first and second image charge voltage signals to identify an object in a foreground of the external scene.

Abstract: A method for detecting spoof fingerprints with an under-display fingerprint sensor includes illuminating, with incident light emitted from a display, a target region of a fingerprint sample disposed on a top surface of the display; detecting a first scattered signal from the fingerprint sample with a first image sensor region of an image sensor located beneath the display, the first image sensor region not directly beneath the target region, the first scattered signal including a first portion of the incident light scattered by the target region; determining a scattered light distribution based at least in part on the first scattered signal; and identifying spoof fingerprints based at least in part on the scattered light distribution.

Abstract: An image sensor module comprises an image sensor having a light sensing area, a cover glass for covering the light sensing area, a dam between the image sensor and the cover glass, which surrounds the light sensing area, and has an outer wall and an inner wall, where a cross-section of the inner wall parallel to the surface of the light sensing area of the image sensor forms a sawtooth pattern and/or, where a cross-section of the inner wall orthogonal to the surface of the light sensing area of the image sensor forms an inclined surface.

Abstract: A ramp generator providing ramp signal with high resolution fine gain includes a current mirror having a first and second paths to conduct a capacitor current and an integrator current responsive to the capacitor current. First and second switched capacitor circuits are coupled to the first path. A fractional divider circuit is coupled to receive a clock signal to generate in response to an adjustable fractional divider ratio K a switched capacitor control signal that oscillates between first and second states to control the first and second switched capacitor circuits. The first and second switched capacitor circuits are coupled to be alternatingly charged by the capacitor current and discharged in response to each the switched capacitor control signal. An integrator coupled is to the second path to generate the ramp signal in response to the integrator current.

Abstract: An optical fingerprint sensor with spoof detection includes a plurality of lenses; a pixel array including a plurality of first photodiodes, a line between a center of each first photodiode and an optical center of each lens forms an optical axis; at least one apertured baffle-layer positioned between the image sensor and the plurality of lenses, each having a respective plurality of aperture stops, each aperture stop being center-aligned with the optical axis; and a plurality of second photodiodes intercalated with the plurality of first photodiodes; and a color filter layer between the pixel array and the plurality of lenses, said color filter layer includes a plurality of color filters positioned such that each second photodiode is configured to detect electromagnetic energy having passed through lens, a color filter, and at least one aperture stop not aligned along the optical axis.

Abstract: A surface-mount device platform includes a surface-mounting region, a connection region, and a bendable region therebetween, each including a respective part of a base substrate. The base substrate includes electrically-conductive layers interspersed with electrically-insulating build-up layers. Each of the surface-mounting region, the connection region, and the bendable region spans between a bottom substrate-surface and a top substrate-surface of the base substrate. The surface-mounting region further includes an electrically-insulating first top rigid-layer, and device bond-pads exposed on a top surface of the first top rigid-layer facing away from the top substrate-surface in the surface-mounting region.

Abstract: A photodiode array has buried photodiodes and vertical selection transistors. Trenches are lined with gate oxide and metallic plugs of first material lie within the trenches. Gate contacts of second material contact the metallic plugs, with photodiode diffusion regions adjacent the trenches as sources of vertical transistors, the metallic plugs form gates of the vertical transistors, and buried photodiode regions form sources of the vertical transistors. In embodiments, the first conductive material is tungsten, titanium nitride, titanium carbide, or aluminum and the second conductive material is polysilicon. The array is formed by trenching, growing gate oxide, and depositing first material in the trenches. The first material is etched to define metallic plugs, the second material is deposited onto the metallic plugs then masked and etched; and drain regions implanted. Etching the second material is performed by a reactive ion etch that stops upon reaching the metallic plugs.

Abstract: An event sensing system includes a pixel array including a plurality of event driven pixel circuits configured to be illuminated by incident light. The event driven pixel circuits are configured to generate an event current in response to a detection of an event in the incident light. Output signals of a row of the pixel array are configured to be read out from the row of the pixel array to a line buffer in response to the detection of the event in the incident light. A random number generator is configured to randomly generate a filtering mask. A mask circuit is the output signals of the row of the pixel array from the line buffer and the filtering mask from the random number generator to filter the output signals of the row of the pixel array in response to the filtering mask.

Abstract: A pixel-array substrate includes a semiconductor substrate and a passivation layer. The semiconductor substrate includes a pixel array surrounded by a periphery region. A back surface of the semiconductor substrate forms, in the periphery region, a plurality of first peripheral-trenches extending into the semiconductor substrate. The passivation layer is on the back surface and lines each of the plurality of first peripheral-trenches.

Abstract: A chip comprises a semiconductor substrate having a first side and a second side opposite to the first side, a plurality of conductive metal patterns formed on the first side of the semiconductor substrate, a plurality of solder balls formed on the first side of the semiconductor substrate, and at least one code pattern formed using laser marking on the first side of the semiconductor substrate in a space free from the plurality of conductive metal patterns and the plurality of solder balls, wherein the at least one code pattern is visible from a backside of the chip, the at least one code pattern represents a binary number having four bits; and the binary number represents a decimal number to represent a tracing number of the chip.

Abstract: An image sensor with embedded wells for accommodating light emitters includes a semiconductor substrate including an array of doped sensing regions respectively corresponding to an array of photosensitive pixels of the image sensor. The semiconductor substrate forms an array of wells. Each well is aligned with a respective doped sensing region to facilitate detection, by the photosensitive pixel that includes said respective doped sensing region, of light emitted to the photosensitive pixel by a light emitter disposed in the well. The image sensor further includes, between adjacent doped sensing regions, a light-blocking barrier to reduce propagation of light to the doped sensing-region of each photosensitive pixel from wells not aligned therewith.

Abstract: A high k passivation layer, an anti-reflective coating layer, and a buffer layer are disposed over semiconductor substrate including photodiodes formed therein. Trenches are etched into the semiconductor substrate through the buffer layer, anti-reflective coating layer, and the high k passivation layer in a grid-like pattern surrounding each of the photodiodes in the semiconductor substrate. Another high k passivation layer lines an interior of the trenches in the semiconductor substrate. An adhesive and barrier layer is deposited over the high k passivation layer that lines the interior of the trenches. A deep trench isolation (DTI) structure is formed with conductive material deposited into the trenches over the adhesive and barrier layer to fill the trenches. A grid structure is formed over the DTI structure and above a plane of the buffer layer. The grid structure is formed with the conductive material.

Abstract: An image sensor has a plurality of pixels arranged in a row direction and in a column direction. Each pixel comprises a color filter that has a portion with a low transmissivity and a portion with a high transmissivity, and a photoelectric conversion element that includes a first photoelectric conversion cell which receives light transmitting through the portion with the low transmissivity of the color filter, and a second photoelectric conversion cell which receives light transmitting through the portion with the high transmissivity of the color filter. The plurality of pixels are arranged such that positions of the portions with the low transmissivity for pixels of one color are identical among the plurality of pixels, and the portions with the low transmissivity are positioned adjacent to each other between adjacent pixels of different colors in the row direction only.

Abstract: A pixel circuit includes a photodiode in semiconductor material to accumulate image charge in response to incident light. A tri-gate charge transfer block coupled includes a single shared channel region the semiconductor material. A transfer gate, shutter gate, and switch gate are disposed proximate to the single shared channel region. The transfer gate transfers image charge accumulated in the photodiode to the single shared channel region in response to a transfer signal. The shutter gate transfers the image charge in the single shared channel region to a floating diffusion in the semiconductor material in response to a shutter signal. The switch gate is configured to couple the single shared channel region to a charge storage structure in the semiconductor material in response to a switch signal.

Abstract: An autofocusing method includes capturing an image of a scene with a camera that includes a pixel array; computing a horizontal-difference image, and a vertical-difference image; and combining the horizontal-difference image and the vertical-difference image to yield a combined image. The method also includes determining, from the combined image and the intensity image, an image distance with respect to a lens of the camera at which the camera forms an in-focus image. The pixel array includes horizontally-adjacent pixel pairs and vertically-adjacent pixel pairs each located beneath a respective microlens. The horizontal-difference image includes, for each horizontally-adjacent pixel pair, a derived pixel value that is an increasing function of a difference between pixel values generated by the horizontally-adjacent pixel pair.

Abstract: A pixel cell includes a photodiode disposed proximate to a front side of a semiconductor layer to generate image charge in response to incident light directed through a backside of the semiconductor layer. A cell deep trench isolation (CDTI) structure is disposed along an optical path of the incident light to the photodiode and proximate to the backside of the semiconductor layer. The CDTI structure includes a plurality of portions arranged in the semiconductor layer. Each of the plurality of portions extends a respective depth from the backside towards the front side of the semiconductor layer. The respective depth of each of the plurality of portions is different than a respective depth of a neighboring one of the plurality of portions. Each of the plurality of portions is laterally separated and spaced apart from said neighboring one of the plurality of portions in the semiconductor layer.

Abstract: An optical fingerprint sensor (OFPS) for use with a liquid-crystal display (LCD) panel having a backlight module is positioned under the backlight module and captures an image of a fingerprint sensing area on the LCD panel through an aperture in both a reflector and a metal shield of the backlight module. The OFPS includes a sensor layer, a wafer-level optic layer bonded to the sensor layer and an infrared pass filter (IRPF) coating formed on a substantially flat top surface of the wafer-level optic layer. An OFPS may be formed with a flat top and may include a wafer-level optic layer having one or more lenses to direct light generated by a light source beneath the wafer-level optic layer. The wafer-level lenses may be bonded with the fingerprint scanner. The flat top of the OFPS may be made with an IRPF coating.

Abstract: A pixel cell includes a plurality of subpixels to generate image charge in response to incident light. The subpixels include an inner subpixel laterally surrounded by outer subpixels. A first plurality of transfer gates disposed proximate to the inner subpixel and a first grouping of outer subpixels. A first floating diffusion is coupled to receive the image charge from the first grouping of outer subpixels through a first plurality of transfer gates. A second plurality of transfer gates disposed proximate to the inner subpixel and the second grouping of outer subpixels. A second floating diffusion disposed in the semiconductor material and coupled to receive the image charge from each one of the second grouping of outer subpixels through the second plurality of transfer gates. The image charge in the inner subpixel is received by the first, second, or both floating diffusions through respective transfer gates.

Abstract: A projector assembly includes three coaxially aligned lenses and an aperture stop. The three coaxially aligned lenses include a first lens and, in order of increasing distance therefrom and on a same side thereof, a second lens and a positive meniscus lens. The first lens is a positive lens. The second lens is a negative lens. The second lens is located between the aperture stop and the positive meniscus lens. The projector assembly is one-sided telecentric at a plane proximate the positive meniscus lens.