849 results about "CMOS sensor" patented technology

An active pixel sensor (APS) image sensor comprises an array of pixel circuits corresponding to rows and columns of pixels, a plurality of amplifiers that buffer signals output by the array of pixel circuits, and a plurality of sample and hold circuits that read the buffered signals. A routing mechanism is positioned between the array of pixel circuits and the plurality of amplifiers. A controller selects a set of the pixel circuits for sampling and is configured to control the routing mechanism to couple each pixel circuit in the set to a different one of the amplifiers during a normal mode of operation and to couple each pixel circuit of a subset of pixel circuits in a first set of pixel circuits to a different amplifier of a first subset of the amplifiers, to couple each pixel circuit of a subset of pixel circuits in a second set of pixel circuits to a different amplifier of a second subset of the amplifiers, and to connect the amplifiers of the first and second subsets of amplifiers in pairs to a common one of the sample and hold circuits during a sub-sampling mode of operation.

Active pixel sensors are defined on double silicon on insulator (SOI) substrates such that a first silicon layer is selected to define radiation detection regions, and a second silicon layer is selected to define readout circuitry. The first and second silicon layers are separated by an insulator layer, typically an oxide layer, and the layers can be independently doped. Doping can be provided in the silicon layers of the SOI substrate during assembly of the SOI substrate, or later during device processing. A semiconductor substrate that supports the first and second layers can be removed for, for example, back side radiation detection, using a second insulator layer (typically an oxide layer) as an etch stop.

A MOS or CMOS sensor for high performance imaging in broad spectral ranges including portions of the infrared spectral band. These broad spectral ranges may also include portions or all of the visible spectrum, therefore the sensor has both daylight and night vision capabilities. The sensor includes a continuous multi-layer photodiode structure on a many pixel MOS or CMOS readout array where the photodiode structure is chosen to include responses in the near infrared spectral ranges. A preferred embodiment incorporates a microcrystalline copper indium diselenide/cadmium sulfide photodiode structure on a CMOS readout array. An alternate preferred embodiment incorporates a microcrystalline silicon germanium photodiode structure on a CMOS readout array. Each of these embodiments provides night vision with image performance that greatly surpasses the GEN III night vision technology in terms of enhanced sensitivity, pixel size and pixel count. Further advantages of the invention include low electrical bias voltages, low power consumption, compact packaging, and radiation hardness. In special preferred embodiments CMOS stitching technology is used to provide multi-million pixel focal plane array sensors. One embodiments of the invention made without stitching is a two-million pixel sensor. Other preferred embodiments available using stitching techniques include sensors with 250 million (or more) pixels fabricated on a single wafer. A particular application of these very high pixel count sensors is as a focal plane array for a rapid beam steering telescope in a low earth orbit satellite useful for tracking over a 1500-meter wide track with a resolution of 0.3 meter.

An imaging system (50) for providing vehicle security and convenience features that employs face recognition software to identify and track a person. The system (50) employs infrared emitters (30) that emit an infrared signal along a predetermined field-of-view, and an infrared sensor (34), such as a CMOS sensor used as a video signal array, that receives reflected infrared illumination from objects in the field-of-view. A processor (52) including the face recognition software, is employed to detect human faces to identify and track the person. Once a face is detected, it can be compared to a data base to identify the person. Various applications for the imaging system (50) to provide driver convenience and security include determining driver identification as the driver approaches the vehicle, determining if a potential thief is in the vehicle by face recognition, providing driver seat adjustment, rear and side mirror adjustment and steering wheel adjustment, providing vehicle speed control, automatically starting the vehicle, etc.

A CMOS imager includes an array of active pixel sensors, wherein each pixel is associated with a respective column in the array. The imager also includes multiple circuits for reading out values of pixels from the active sensor array. Each readout circuit can be associated with a respective pair of columns in the array and can include first and second sample-and-hold circuits. The first and second sample-and-hold circuits are associated, respectively, with first and second columns of pixels in the array. Each readout circuit also includes an operational amplifier-based charge sensing circuit that selectively provides an amplified differential output signal based on signals sampled either by the first sample-and-hold circuit or the second sample-and-hold circuit. The readout circuit also has an analog-to-digital converter for converting the differential output to a corresponding digital signal using a successive approximation technique. Use of the readout circuit can increase the parallel structure of the overall chip, thereby reducing the bandwidth which each readout circuit must be capable of handling.

An imager pixel including a photodetector, a first MOS transistor functioning as the driver of a source follower amplifier during signal readout, a second MOS transistor serving as a pixel readout transistor, a third MOS transistor serving as a photodetector reset transistor, and a reset noise cancellation circuit including a fourth MOS transistor, first and second capacitances, and an amplifier having a gain which is the inverse of the ratio of the first to the second capacitance.

A MOS or CMOS sensor with a multi-layer photodiode layer covering an array of active pixel circuits. The multi-layer photodiode layer of each pixel is fabricated as continuous layers of charge generating material on top of the MOS and/or CMOS pixel circuits so that extremely small pixels are possible with almost 100 percent packing factors. The sensor includes special features to minimize or eliminate pixel to pixel crosstalk. A micro-lens array with a micro-lens positioned above each pixel directs light illuminating the pixel toward the central portion of the pixel and away from its edges. Also, preferably carbon is added to doped amorphous silicon N or P bottom layer of the multi-layer photodiode layer to increase the electrical resistivity in the bottom layer to further discourage crosstalk. In preferred embodiments each of the pixels define a tiny surface area equal to or larger than about 3.24 square microns and smaller than or equal to about 25 square microns. Detailed descriptions are provided for two general types of sensors. The first type has a pixel count of about 0.3 to 1.9 million pixels and are especially suited for sues such as cell phone cameras. The second type with pixel count of between about 1.9 million pixels to more than 5 million pixels is especially suited for high definition television cameras.

Elimination of dark fixed pattern noise (DFPN) for tethered CMOS sensor-based digital video cameras is supported by supplying and maintaining a host-based dark image cache. Since the camera is tethered to a host computer system such as a PC, it takes advantage of the storage and processing capabilities of the host to manage the cache. By using a dark image cache for updating of the currently applicable dark image for DFPN cancellation processing, operation of the camera shutter for acquiring dark images is dramatically reduced, thereby using less system resources such as power, and increasing the MTBF of the electromechanical devices such as the camera shutter and associated controls. Dark images are obtained at different integration, gain, and temperature operating characteristics of the camera and stored in the cache. The cached dark images are referenced on the host according to a fixed, predetermined dark column of data in video frames generated by the CMOS sensor image array of the camera. The dark column data represents a portion of the CMOS sensor image array which is permanently and totally shadowed for use during DFPN cancellation processing.

An image capturing apparatus (100) of an image taker side has an image capturing unit (101) which captures an image using a CCD sensor, a CMOS sensor and the like, an image capturing restriction signal receiving unit (102) which receives an image capturing restriction signal transmitted by a communication terminal (200), and an image capturing restriction unit (103) which restricts the image capturing performed by the image capturing unit (101) according to a request of the image capturing restriction signal. Further, the communication terminal (200) of a subject side has an image capturing restriction signal generation unit (201) which transmits the image capturing restriction signal for requesting to restrict the image capturing.

The invention comprises a combination of a low resistivity, or electrically conducting, silicon layer that is transparent to long or short wavelength photons and is attached to the backside of a photon-sensitive layer of silicon, such as a silicon wafer or chip. The window is applied to photon sensitive silicon devices such as photodiodes, charge-coupled devices, active pixel sensors, low-energy x-ray sensors and other radiation detectors. The silicon window is applied to the back side of a photosensitive silicon wafer or chip so that photons can illuminate the device from the backside without interference from the circuit printed on the frontside. A voltage sufficient to fully deplete the high-resistivity photosensitive silicon volume of charge carriers is applied between the low-resistivity back window and the front, patterned, side of the device. This allows photon-induced charge created at the backside to reach the front side of the device and to be processed by any circuitry attached to the front side. Using the inventive combination, the photon sensitive silicon layer does not need to be thinned beyond standard fabrication methods in order to achieve full charge-depletion in the silicon volume. In one embodiment, the inventive backside window is applied to high resistivity silicon to allow backside illumination while maintaining charge isolation in CCD pixels.

A method and a system for dynamically detecting and correcting anomalous pixels in the raw data taken from an image sensor array such as a CCD or a CMOS sensor array, thus allowing the use of dumb cameras to capture digital images for subsequent use by an intelligent host—such as being displayed on a computer monitor. This invention uses software algorithms running on an intelligent host processor to dynamically correct the anomalous pixels in the raw data taken from an image sensor array typical of those in a digital still or a video camera. Using the combination of a dumb camera which provides raw data to an intelligent host, which does all the subsequent image processing, the system works by scanning an image frame for pixels that vary more than a specified amount in their brightness value from their neighboring pixels and designating those as defective pixels. The location and frequency of the photosites sending the defective pixels are stored in a statistical database in the computer's memory. The brightness value of a defective pixel is then replaced by a local brightness value obtained from the defective pixel's neighboring pixels. The process includes video subsampling, meaning that the defective pixel detection is carried out and repeated at a pre-specified frame rate to ensure optimum detection and correction at a minimal level of scanning. A statistical database is kept so that truly anomalous pixels can over time be distinguished from false detection of true anomalies in the target image, lighting or other environmentally induced anomalies.

An imager has one or more pixel circuits arranged to receive negatively biased control signals at one or more gates associated with charge holding regions to reduce dark current generation and flow.

Methods for fabricating CMOS image sensor devices are provided, wherein active pixel sensors are constructed with non-planar transistors having vertical gate electrodes and channels, which minimize the effects of image lag and dark current.

A MOS or CMOS based active pixel sensor with special sampling features to substantially eliminate clock noise. The sensor includes an array of pixels fabricated in or on a substrate, each pixel defining a charge collection node on which charges generated inside a photodiode region are collected, a charge integration node, at which charges generated in said pixel are integrated to produce pixel signals, a charge sensing node from which reset signals and the pixel signals are sensed. In preferred embodiments the sensor includes a continuous electromagnetic radiation detection structure located above the pixel circuits providing a photodiode region for each pixel. The sensor includes integrated circuit elements adapted to maintain voltage potentials of the charge integration nodes substantially constant during charge integration cycles. The sensor also includes integrated circuit elements having electrical capacitance adapted to store charges providing an electrical potential at the charge integration node. In preferred embodiments this is a pinned diode.

CMOS image sensor devices are provided, wherein active pixel sensors are designed with non-planar transistors having vertical gate electrodes and channels, which minimize the effects of image lag and dark current.

A configurable, compact multi-resolution linear image sensor array is disclosed. The multi-resolution image sensor array employs a spatial array of photoelectric sites with each site having an image output terminal and a cluster of switched photo-detector elements. To effect a high quality snapshot operation mode for a high pixel count array, a transfer control switch is added bridging each photo-detector element and its correspondingly connected negative input terminal of an operational amplifier to form an active pixel sensor circuit. To minimize a reset kTC noise associated with numerous traditional active pixel sensor circuits, an in-pixel KTC noise-correlated correlated multiple sampling (CMS) circuitry is also proposed to replace an otherwise traditional correlated double sampling (CDS) circuitry.

A MOS or CMOS based active pixel sensor designed for operation with zero or close to zero potential across the pixel photodiodes to minimize or eliminate dark current. In this preferred embodiment, the voltage potential across the pixel photodiode structures is maintained constant and close to zero, preferably less than 1.0 volts. This preferred embodiment enables the photodiode to be operated at a constant bias condition during the charge detection cycle. In preferred embodiments the pixel photodiodes are produced with a continuous pin or nip photodiode layer laid down over pixel electrodes of the sensor. In other preferred embodiments the pixel photodiode structures are produced beside and physically isolated from the regions where CMOS circuits are formed. In some of these preferred embodiments the isolated pixel photodiode structures are comprised of crystalline germanium deposited in cavities in a silicon substrate. This embodiment can be adapted especially for imaging at short wave infrared frequencies. Preferred embodiments are adapted for correlated double sampling.

An active pixel sensor (APS) that includes circuitry to eliminate artifacts in digital images. The APS includes a comparator for comparing a signal level from a pixel to an adjusted saturation voltage to determine if the pixel is saturated. If the pixel is saturated, an associated saturation flag is stored and used to replace the signal from the pixel with a maximum value corresponding to a brightest pixel in the image.

An electronic shutter switching transistor for a CMOS electronic is formed in a semiconductor substrate of a first conductivity type. The transistor comprises a pair of spaced apart doped regions of a second conductivity type opposite the first conductivity type disposed in the semiconductor substrate forming source/drain regions. A gate is disposed above and insulated from the semiconductor substrate and is self aligned with the pair of spaced apart doped regions. A well of the second conductivity type laterally surrounds the pair of spaced apart doped regions and extends deeper into the substrate than the doped regions. A buried layer of the second conductivity type underlies and is in contact with the well.

A method and circuit for performing Correlated Double Sub-Sampling (CDSS) of pixels in an active pixel sensor (APS) array. Each pixel outputs a reset voltage and then an image signal voltage. The method and the apparatus subsamples a plurality (L² ) of pixels by: storing L² analog reset charges output from the L² pixels into a first set of (N²) storage capacitors, and combining the (L²) reset charges; storing L² analog image signal charges output from the L² pixels into a second set of (N²) storage capacitors, and combining the (L²) image charges; and then obtaining a differential voltage (VS−VR) by subtracting (in the analog-domain) the voltage (VR) represented by the combined (L²) reset charges from the voltage (VS) represented by the combined (L²) image signal charges. When L equals one, the circuit performs conventional Correlated Double Sampling CDS upon the one pixel. When L is greater than one, the circuit performs Correlated Double Sub-Sampling (CDSS) of the L² pixels. Dynamic selection of a subsampling ratio B (where B equals 1:L² and L ranges from 1 up to N) is supported. Averaging units used to combine the reset and image signal charges, and analog-to-digital converters (ADCs) for converting the differential voltage to a digital pixel data, may be commonly biased by the same variable bias voltage.