Showing papers on "Image sensor published in 1983"

An electronically collimated gamma camera for single photon emission computed tomography. Part I: Theoretical considerations and design criteria

Abstract: The detection and imaging characteristics of a new type of gamma camera for single photon emission computed tomography have been investigated. Unlike conventional gamma cameras which use mechanical collimation, the new gamma camera utilizes electronic collimation which is obtained from a sequential interaction of gamma radiation with a dual position-and-energy sensitive detection system. Coincident counting between the two detectors provides localization of activity upon a multitude of conical surfaces throughout the object, wherefrom the three-dimensional activity distribution can be reconstructed. Not only does electronic collimation provide simultaneous multiple views of the object, but a large gain in sensitivity is also indicated over a conventionally collimated gamma camera under conditions of similar spatial resolution. Detector optimization studies have been performed to design a prototype system comprising a 33 X 33 array of high-purity germanium detectors coupled to an uncollimated conventional scintillation camera. The cumulative signal-to-noise ratio in projection images obtained with this system is expected to be about a factor of 4 higher (sensitivity about a factor of 15 higher) than that obtained in a corresponding projection image with a conventional gamma camera for imaging a uniformly distributed Tc-99m source in a 20-cm-diam X 20-cm-tall cylinder. A similar gain is expected in the tomographic images.

An electronically collimated gamma camera for single photon emission computed tomography. Part II: Image reconstruction and preliminary experimental measurements

Abstract: Iterative algorithms have been investigated for reconstructing images from data acquired with a new type of gamma camera based upon an electronic method of collimating gamma radiation. The camera is composed of two detection systems which record a sequential interaction of the emitted gamma radiation. Coincident counting in accordance with Compton scattering kinematics leads to a localization of activity upon a multitude of conical surfaces throughout the object. A two-stage reconstruction procedure in which conical line projection images as seen by each position sensing element of the first detector are reconstructed in the first stage, and tomographic images are reconstructed in the second stage, has been developed. Computer simulation studies of both stages and first-stage reconstruction studies with preliminary experimental data are reported. Experimental data were obtained with one detection element of a prototype germanium detector. A microcomputer based circuit was developed to record coincident counts between the germanium detector and an uncollimated conventional scintillation camera. Point sources of Tc-99m and Cs-137 were used to perform preliminary measurements of sensitivity and point spread function characteristics of electronic collimation.

Electronic picture camera with reduced memory capacity

Abstract: A completely electronic color camera for electronically recording an image of an object. The image signals from a solid-state image sensor having color filters are converted to digital form so that the digitized image signals are applied to the same number of coding compression circuits, e.g. differential pulse code modulation circuits, as the kinds of colors of the color filters per scanning line, are subjected to a color separation coding processing and are then stored directly in a memory without performing any additional processing. Error detecting and correctng circuits are provided. Error detecting and correcting data and lens setting data are added to the image data and recorded. The camera is reduced in size, is low in power consumption and requires a reduced memory capacity per frame.

Precision of Digital Vision Systems

Abstract: The precision of geometric features such as the centroid, area, perimeter, and orientation measured by a 2-D digital vision system is analyzed and tested experimentally. The digitizing error of various geometric features can be expressed in terms of the dimensionless perimeter of the object. As a result of this work, the sampling process can be simplified or eliminated. The analysis is also expanded to cover the 3-D digital vision systems.

Signal level control for video system

Abstract: An automatic signal level control for use in a video system using a solid state imager capable of integrating pulsed light images of a target imaged thereon. An automatic gain control is used to adjust the gain of a variable gain amplifier in the output circuit of the image sensor. A strobe lamp is used to illuminate the target during each imaging sequence. The feedback signal to the amplifier is compared to an upper and lower threshold and, in response thereto, the number of pulses generated during each illumination sequence are adjusted to maintain the video signal levels within a desired operating range.

Solid state image sensor

Abstract: A solid state image sensor comprising static induction transistors each forming a picture element Each static induction transistor in the solid state image sensor has a lateral structure in which the source and drain regions are formed by surface regions provided on the same side in an epitaxial layer forming the channel region and a signal charge storage gate region are formed by a buried gate region provided under the channel region and a surface gate region provided on the channel region, so that the source-drain current flows in parallel to the surface of epitaxial layer and is effectively controlled between the buried and surface gate regions

CoSTEL: a computer peripheral remote sensing device for 3-dimensional monitoring of human motion

Abstract: An automatic system (CoSTEL) which permits the reconstruction of the instantaneous 3-dimensional position of target points (infra-red light emitting body markers) in a laboratory frame was designed. The 3-dimensional CoSTEL transducer is based on a suitable spatial arrangement of three one-dimensional transducers. Each transducer is made of a charge-coupled device linear array image sensor lying on the focal plane of a toroidal lens and appropriately aligned with it. The system was conceived for 3-dimensional whole body movement analysis and is able to track eight landmarks per subject side simultaneously. Its basic features are resolution of 1/4000, maximum sampling frequency 1·1 kHz (100 Hz is actually used), large insensitivity to background light and transducer output in digital form. These features provide a high level of accuracy, reliability and working stability.

Package for solid state image sensors

Abstract: A package for solid state image sensor devices, such as CCD image sensors, includes a base plate on which a plurality of the image sensor devices are mounted in end-to-end abutting relation with the detector arrays of the image sensors being over an opening in the base plate, and a cover mounted on the base plate and extending over the image sensor devices to enclose the image sensor devices between the cover and the base plate. The base plate and cover are of polycrystalline silicon so as to have a coefficient of thermal expansion which matches that of the image sensor devices.

High-sensitive optical reading apparatus and method of reading optical information

Abstract: In an optical reading apparatus having an image sensor for converting optically readable information into an electrical signal, a sensor driving circuit is arranged to produce at least two clocks with which two or more groups of optical imaging elements of the image sensor are respectively driven. In one embodiment, the two clocks have a time or phase difference therebetween so that signal charges from one group of the imaging elements are derived at once after signal charges of another group are derived. The derived signal charges are read out in a sequence within a period equal to the time difference. This enables a charging time to be twice or more the time difference providing high sensitivity. Since at least two or more read data can be obtained within a single charging time, high-speed reading is also resulted. In another embodiment, the optical reader is switched so that one of high-speed mode and high-resolution mode is selected. In a further embodiment, the invention is adapted to a reader having an area image sensor.

Apparatus for inspecting a circuit pattern drawn on a photomask used in manufacturing large scale integrated circuits

Abstract: A photomask on which a circuit pattern is drawn is placed on an x-y table and is illuminated by a light source. A linear image sensor, on which the circuit pattern is imaged, measures the circuit pattern along the direction substantially perpendicular to a moving direction of the x-y table to generate an analog signal in units of measured positions on the mask. In order to eliminate the need for matching the size of the pixel to be measured with the pixel size of the design pattern data and allow effective detection of a defect smaller than the pixel size, an analog-to-digital converter is arranged to convert the analog signal to multi-level digital data, and a measured point calculation circuit calculates the position of the measured point in units smaller than the pixel size unit in accordance with the position of the x-y table. A reference data calculation circuit is provided to calculate multi-level reference digital data which is to be obtained when the design pattern is measured at a calculated measured point taking sensitivity distribution characteristics (including resolution characteristics of lens) of image sensor elements into consideration. A defect detector compares the measured data with the reference data to detect the presence or absence of defects of the circuit pattern on the photomask.

800 X 800 Charge-Coupled Device Image Sensor

Abstract: The design and performance of an 800 X 800 pixel charge-coupled device (CCD) imager are described. This device is fabricated utilizing a three-phase, three-level polysilicon gate process. The chip is thinned to 8 um and is employed in the rear illumination mode. Detailed measurements of the device performance, including dark current as a function of temperature, linearity, and noise, are presented. The device is coated with an ultraviolet (UV) downconverting phosphor which allows imaging with the same device over an extremely wide optical bandwidth.

Solid state image sensor

Abstract: A high-resolution image sensor uses integrated arrays of photosensitive elements in connection with a lens system which projects, onto the arrays, an erect, unmagnified, unreversed real image of the object being sensed (such as a line of a document). The arrays are staggered in two or more rows so that a single, large integrated array need not be used, yet the entire width of the document line can be covered by photosensitive elements while a 1:1 ratio is maintained between object size and image size. The real image is produced on the two or more rows of arrays by two or more optical systems which have a large depth-of-focus to allow for some variation in object distance. The sensor has a high image quality and is capable of detecting color.

Method and apparatus for detecting and filling-in dead spots of video signals from an image sensor

Abstract: Dead spots within an array of photo-sensitive video signal generation elements are detected based on an excessive rate-of-change in sequentially-accessed pre-stored digital sensitivity correction coefficients corresponding to the array of photosensitive elements. The coefficients are sequentially accessed for use in making synchronous real-time sensitivity corrections to the non-dead video output from corresponding ones of the sensor elements. In response to such detected dead spots, an artificial video signal is also substituted during any dead spot so as to "fill-in" the "missing" portions of the video signal otherwise present due to dead spots in the array of video signal generating elements. In the exemplary embodiment, the leading and trailing edge of such dead spots is detected by comparing arithmetic differences between successive correction coefficients to a predetermined threshold value. The synthetic video signal to be substituted during the "fill-in" period may simply be a continuation of the last valid video signal value (e.g., as maintained by an enabled sample-and-hold circuit) or it may involve a local average of pixel values in the immediate vicinity of the pixel(s) being filled-in or a global average of pixel values taken from a major portion of the entire frame of video signals being processed.

Novel Technologies for Automatic Focusing and White Balancing of Solid State Color Video Camera

Abstract: The consumer video market is rapidly spreading. In response, development of color video camera is strongly accelerated in these several years.

Zoom indicating apparatus for video camera or the like

Abstract: A zoom indicating apparatus for a video zoom camera that provides a viewfinder raster display of a scene within the field of view of the camera superimposes upon the raster display a zoom frame that indicates the portion of the scene that would be within the field of view of the camera at its maximum zoom setting. The apparatus converts a zoom setting signal from the camera to a signal corresponding to the magnification at that zoom setting, employs the magnification signal for generating zoom frame signals which define the size and location of the zoom frame on the display, and combines the zoom frame signals with the video signal from the camera to form a composite video signal that is applied to the display. The apparatus automatically adjusts the position of the zoom frame on the display so as to compensate for misalignment between the optical axis of the camera lens and the center of the scanned image on the camera sensor tubes.

Flashlight control apparatus for endoscope

Abstract: A light flash control apparatus is used for an endoscope in which a solid-state image sensor is employed. A image signal derived from the solid-state image sensor during the illumination by a halogen lamp is also utilized as a photo-metric signal. An adequate quantity of flashlight for the image sensor is calculated in advance based upon the photo-metric signal. The calculated exposure time i.e., the desirable quantity of flashlight is stored in an integration circuit. After the given exposure time passes since the flash tube is ignited, it is forcibly turned-off by a turn-off thyristor.

Optical fiber image sensor

Abstract: An optical fiber sensor is composed of an outer portion generally in the form of a tube which constitutes an illumination light transmission path. Inside the tube is formed or inserted an image path for directing image light back to an observation point. A longitudinal hole may be formed beside or surrounding the image path for conducting a fluid to the observed location. The sensor is especially suitable for medical image catheter or endoscopic usage.

Surface flaw inspection apparatus for a convex body

Abstract: A surface flaw inspection apparatus for a convex body having a light source for irradiating a surface of an object to be inspected with a luminous flux, an image sensor for receiving the reflected light on the surface of the object and producing a corresponding electrical signal, an inspection section for receiving the electrical signal from the image sensor and inspecting whether or not there is a flaw on the surface of the object, and a projection screen located in the light path from the light source through the surface of the object to the image sensor on which an image of the irradiated area of the surface of the object by the luminous flux is formed, in which the image sensor picks up the image formed on the projection screen.

Focus indicator apparatus for an electronic camera

Abstract: A focus indicator for a TV camera includes a first image sensor and a video processor which convert an object image to a first video signal, an optical system for exit pupil dividing part of the object image to prepare a split image, and a second image sensor for converting the split image to a second video signal. A composing circuit generates a composite video signal from the first and second video signals in such a way as to include the split image component, and a viewfinder displays an image including the split image. A user of the TV camera thus can perform focusing by observing the split image in the viewfinder.

High-resolution high-sensitivity solid-state imaging sensor

Abstract: A solid-state imaging sensor, which may be a color imaging sensor, having simultaneously a high resolution and high sensitivity. The horizontally extending electrodes, which are connected to be driven by outputs of a vertical shift register, are formed in a flattened zig-zag pattern with alternate ones of the horizontally extending electrodes being offset in phase from one another. Source diffusions are formed in the octagonally shaped areas thereby produced. FET switching devices are provided for each of the source diffusions for selectively coupling the source diffusions to corresponding ones of vertically extending electrodes. The source diffusions form active layers of light-sensing photodiodes.

Imaging sensor with automatic sensitivity control comprising voltage multiplying means

Abstract: A solid-state imaging sensor in which the sensitivity of the sensor is automatically adjusted in accordance with the overall intensity of the image being sensed. A charging potential applied to an image signal storage capacitor in each pixel of an array of pixels of which the sensor is composed is dynamically varied as the overall intensity of the image being sensed changes. A voltage multiplying circuit, which may be either light sensitive or light insensitive, supplies the variable charging potential. If the voltage multiplying circuit is light insensitive, an elongated photodiode is provided along two sides of the sensor array to adjust the charging potential.

Solid-state image pickup device

Abstract: PURPOSE:To simplify an adjusting operation for position matching, by equivalently executing the position matching of the optical center of an optical system and the image pickup center of an effective pickup surface of a solid image sensor, by means of electric signal processing CONSTITUTION:A titled device is provided with a solid image sensor S having an effective image pickup surface 3 that is larger than an effective image pickup surface 2 from which a video signal is fetched, in a normal video period An image pickup output signal from the effective image pickup surface 3 is read out by a read-out timing which has been corrected by the time DELTAtH, DELTAtV corresponding to spatial position shift amounts DELTAH, DELTAV of the image pickup center Os' of the effective image pickup surface 3 of the solid image sensor S, and the optical center Op of an optical system for irradiating the image pickup light, and when blanking processing for sampling a video signal in a normal video period is executed from this signal, it is possible to obtain a video signal by the effective image pickup surface 2 having the image pickup center Os which coincides with the optical center Op

Schottky-Barrier Infrared Charge-Coupled Device Focal Plane Arrays

Abstract: Recent development of high-performance Pd2Si and PtSi Schottky-barrier IR-CCD image sensors make these monolithic focal plane arrays attractive for many SWIR and thermal imaging applications. PtSi Schottky-barrier detectors operated at 80K have quantum efficiency of several percent in the 3 to 5 μm spectral range and cut-off wavelength of about 6.0 μm. Pd2Si Schottky-barrier detectors operated between 120 and 140K have cut-off wavelength of 3.6 μm and quantum efficiency in the range of 1.0 to 8.0% in the SWIR band. High-quality thermal imaging was achieved with a 64x128-element PtSi Schottky-barrier IR-CCD imager in a TV compatible IR camera operated with 60 frames per second. This paper reviews the Schottky-barrier IR-CCD technology developed at RCA. A model for photoyield of Schottky-barrier detectors (SBDs) is reviewed and compared with experimen-tal data. The architecture and design trade-offs of the SBD IR-CCD imagers are discussed. Also included is a discussion of the quantum efficiency requirements for staring thermal imagers and the performance achievable with the Schottky-barrier IR-CCD arrays.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Line-scan panoramic camera

Abstract: The present invention in general relates to a television camera for digital on-line image processing, comprising an optical imaging system which images an object area sensed by the camera into an image area adapted to be scanned element by element, and a processing circuit which produces video signals from the signals obtained with the scanning, the camera comprising a line sensor arranged in the optical image area, the line sensor being composed of sensor faces of a row of optical-electrical transducers so that the sensor faces are disposed in the optical images of correspondingly set-off elements of the object area and each sensor face defines, upon movement of the line sensor relative to the object area perpendicularly of the length of the line sensor, a scanning line.

Thin film photoelectric converting device

Abstract: A thin film photoelectric converting device comprises a plurality of sensor blocks, each block including a thin film transistor array which is paired with a storage type image sensor array, the thin film transistor array and said image sensor array being formed on the same insulating substrate, means for simultaneously turning ON as a group the thin film transistors in each block and for sequentially driving the thin film transistors of said blocks, and reading means comprising detection means and scanning means for sequentially reading electric charge signals sensed by the storage type image sensor elements in each block. The detection means includes a plurality of detectors of the same number as that of sensor elements in each block, said detectors simultaneously detecting electric charge signals of said image sensor elements in each block. The scanning means scans and reads out outputs of said detectors.

Picture data reading device

Abstract: A data reading device of the type employing a plurality of image sensors for reading separated colors is provided with a delay device in the processing circuitry of at least one of the image sensors. The delay device can be set to delay the signal output from the associated image sensor to an arithmetic circuit for a variable time corresponding to a multiple of the line scanning period. In this manner, the image sensors need not be so accurately positioned that the same line is read by each of the several sensors at the same time, but the picture data signals for the same line can nonetheless be fed to the arithmetic circuit simultaneously.

Electronic image sensing apparatus

Abstract: An electronic still camera is disclosed which includes a solid state image sensor such as charge transfer device (CTD) and a shutter mechanism. For obtaining a still picture of one frame composed of two fields according to an NTSC television system, the shutter mechanism is driven so as to be opened before and after a signal charge read out period of a CTD by a shutter period control circuit. With this arrangement, the field image light is incident on the CTD in every field period.

Selective iodine imaging using lanthanum K fluorescence.

Abstract: Time‐dependent subtraction techniques have tremendously improved the visualization of iodinated vessels. These techniques suffer from motion artifacts, however, since the mask image is acquired several seconds prior to the contrast image. A K‐edge subtraction technique for selectively imaging iodine using the characteristic x rays from a lanthanum secondary target is presented. The K α lines of lanthanum closely straddle the K edge of iodine. A prepatient iodine filter will alter the ratio of K α1 to K α2 intensities; by subtracting two images made with different K α1 /K α2 ratios, iodinated structures can be isolated. Since the method requires no mask image, motion artifacts are reduced. Preliminary images acquired with an image intensifier/photodiode array detector system are shown. Theoretical performance of this method is compared to other iodine‐selective imaging techniques on the basis of exposure and dose. The feasibility of using lanthanum K fluorescence for rapid clinical iodine‐selective imaging is discussed.

All-solid-state television camera

Abstract: An all-solid-state television camera is described consisting of an optical unit, an electronic unit, and a housing for them. The electronic unit is in the form of a substrate carrying a linear or two-dimensional array of a plurality of semiconductor image sensors in a matrix layout on a semiconductor wafer, which substrate comprises contact parts connected to the contact pads on the semiconductor wafer. The optical unit comprises, in the least complicated embodiment, a light funnel array placed onto the semiconductor wafer which array carries at least one lens array whose aspherical lenses serve as imaging optics and contribute via a respective associated light funnel to the exposure of the individual semiconductor image sensors with mutual light screening. A second light funnel array is provided on the object side of the lens array and has a sunshade function for the imaging optics. The optical unit furthermore includes color filters and a plate structure to control the intensity of the light incident on the imaging optics. The optics and electronic units are fixed in a sleeve which serves as a representative housing of the television camera.