Showing papers on "Image sensor published in 1982"

Image sensor assembly

Abstract: A compact image sensor package for use in an endoscope or borescope in which a lens system, a solid state image sensor and a circuit board are mounted in tandem within a cylindrical sealed housing. The assembly is positioned within the viewing head of the instrument so that an image of a given target is recorded on the sensor and an electrical output signal indicative of the image data is transmitted out of the package via either an optical or electrical transmission line.

No image lag photodiode structure in the interline CCD image sensor

Abstract: An undesirable image lag with a long time constant was found in the interline CCD image sensor having N+P-junction photodiode (PD). This paper clarifies the image lag mechanism and proposes a new photodiode structure having no image lag. The image lag measurement method and the experimental results are also given. The experimental results quantitatively agreed with the analytical model, in which signal electrons are assumed to be transferred from the PD to the vertical CCD as a small subthreshold current. To eliminate the image lag, a P+NP-structure PD with low donor concentration was proposed, where all the signal electrons can be quickly transferred before the subthreshold condition begins. As a result, the decay lag values of the 1st and the 2nd fields were reduced to half and the decay lags after the 3rd field were not observed.

Electronic still camera with individual non-volatile memory units

Abstract: An electronic still camera is disclosed having an optical system, a transducer in the form of CCD image sensors for producing image representing signals responsive to an image focused on the sensors by the optical system, an actuable shutter control and circuits in the camera for transmitting image representing signals from the transducer to a recording device having a plurality of individual no-volatile integrated circuit memory units. A controller means in the form of a microprocessor is operated by a shutter control and controls the transmission of image representing signals from the transducer through the circuits to record only a separate single image in each of the individual memory units.

Method and apparatus for remotely reading and decoding bar codes

Abstract: A remote bar code reading camera for detecting dark and light areas of a bar code carried on an object disposed at a distance from the camera has a substantially continuously operating non-coherent light source for illuminating the bar code, an optical arrangement with a rectangular aperture for directing the reflected light from the bar code onto an image sensor, the optical arrangement having a depth of field such that reflections from remote objects are accurately transmitted to the image sensor, and a processing circuit for shaping and analyzing the signals from the image sensor. The processing circuit includes an external random access memory which, during a first portion of a signal processing cycle is used with loading circuitry to store digital information corresponding to the scanned bar code, and during a second portion of a processing cycle is utilized as the working memory for a microcomputer for decoding the information. The camera has an interface means for transferring the decoded data to an external device.

Interline CCD image sensor with an anti blooming structure

Abstract: THE APPLICATION OF AN overflow drain and barrier positioned beside the photosensitive area? has made it possible to suppress blooming of CCD image sensors. However, this method was found to sacrifice photosensitivity and dynamic range. This paper will describe an interline CCD sensor where the vertical overflow drain is positioned under, rather than beside the photodiode. Thus the cell area can now be used effectively for photoelectron generation and storage, and increased photosensitivity and dynamic range can be maintained. Furthermore, this technique eliminates the blooming phenomenon.

Video signal transmission system for endoscope using solid state image sensor

Abstract: A video signal transmission system for an endoscope converts an electrical video signal produced by a solid state image sensor into an optical signal and transmits the optical signal to a control section through a fiber optic cable or like light carrying medium. Because the fiber optic cable used for the present invention transmits light indicative of a time serial signal from the solid state imaging sensor, it will be clear that the cable may be constituted by a single length of optical fiber and, in this respect, substantially differs from usual light carrying fiber bundles which are installed in general endoscopes as image guides for transmitting light images simply as light.

Image pick-up apparatus

Abstract: An apparatus for picking-up an image of an object including a solid state image sensor having a number of image sensing elements and an objective lens for projecting the image of the object onto the image sensor is disclosed. In order to remove a curvature of field of the objective lens, the image sensor is curved into a spherical shape having a radius of curvature equal to that of the curvature of field. The solid state image sensor may be curved in any desired shape to correct various aberrations of the objective lens.

Some Accuracy and Resolution Aspects of Computer Vision Distance Measurements

Abstract: The distance between an object and stereo vision sensors can be measured using image processing and known system parameters. A detailed distance measurement synthesis procedure to meet system specifications is presented and illustrated with an example. An error analysis shows that error is proportional to distance. System parameters such as separation between sensor elements, sensor focal length, and sensor array dimensions are related in the design and error equations presented. The main desired design goal is to establish the smallest image sensor array size which will meet system operating specifications. Minimum and maximum distance, object height, optic parameters, scene shift, and sensor array parameters are related.

Simplified Laser-Speckle Strain Gauge

Abstract: An automatic method of measuring surface strain by electro-optical techniques is described. It is a real-time and point-by-point method in which a specimen surface is illuminated by a thin laser beam and the displacements of the speckle pattern resulting from the surface deformation are detected by linear image sensors followed by a microcomputer. The displacements are calculated as the peak positions of the cross-correlation functions of image sensor signals before and after the deformation. By adopting a differential system consisting of two image sensors positioned symmetrically about the surface normal we can eliminate the effect of rigid body motion. The sensitivity depends on the surface to sensor distance, while the gauge length is given by the diameter of the laser spot. These relations derived from physical optics are verified by experiments using a metal plate specimen subject to tensile strain that is monitored by an electrical resistance strain gauge. The minimum strain value measured was a few ten microstrains with a gauge length of 1 mm. We could also measure thermal strain by this method.

Two-dimensional semiconductor image sensor with regulated integration time

Abstract: A two-dimensional image sensor integrated on a semiconductor substrate has a plurality of sensor elements disposed in rows and columns. The sensors in each row and column are individually selected in succession via parallel outputs of a first vertical shift register for readout of the sensor elements. Regulation of the integration time during which charge carriers collect in the sensor elements due to incident light is achieved by selecting the sensor elements in each row a further n times via a second vertical shift register after each readout of the charges optically generated therein and within the time span during which the charges collected in the sensor elements of the next n rows are respectively transferred for readout into the column lines. The further n selections eliminate charges formed in the interim in the column lines so that the integration time of all sensor elements is variably shortened by the duration of readout of the n rows.

Film video player with zoom and scan

Abstract: A film video player for sensing photographic images having a given resolution to produce a standard video signal having a lower resolution, includes a zoom lens for selectively varying the magnification of the film image with respect to the image sensor and means for selectively translating the film image vertically and horizontally with respect to the image sensor, whereby the available resolution of the film image is more effectively utilized by the film video player.

Imaging system having vari-focal lens for use in endoscope

Abstract: An imaging system for use in an endoscope includes a vari-focal lens system provided in a viewing head to be inserted into a cavity or opening of a living body or machinery, a solid-state image sensor for imaging an image formed by the lens system to produce electrical signals representative of the image, a supporting unit for supporting the lens system and the image sensor thereon so as to change the spacing between the lens system and the image sensor on the optical axis of the lens system, and controller circuitry operable in response to magnification of the lens system for estimating the position of a focus of the lens system to control the supporting unit so as to position the image sensor substantially at the estimated position of the focus.

X-ray diagnostic apparatus

Abstract: An X-ray diagnostic apparatus comprises an X-ray tube, a fluorescent plate for converting X-rays transmitted through an object irradiated with X-rays from the X-ray tube into visible light rays, a light image intensifier for intensifying the visible light rays, an image sensor for sensing an image contained in the output light rays from the intensifier and converting it into video signals, image processing unit for image-processing the output signals from the image sensor to intensify the image and to add together the image-processed video signals of a plurality of frames, and a monitor for visualizing the output signal from the image processing unit, where the video signals after image-processing are added together to increase the amplitude of the video signal.

Method of tracing/recording image lines and apparatus therefor

Abstract: An apparatus for tracing and recording image lines includes a coordinate reader which detects coordinate values of an image to be traced; an image sensor which is movable in a plane relative to a table; a memory in which image signals detected by means of the sensor are written; and a central processing unit which controls the above elements of the apparatus. Trace data are obtained by means of the coordinate reader which detects coordinate values of the image lines. Then, the image is positioned on the table, where record data are obtained based on the trace data by means of the image sensor which generates image signals corresponding exactly to the image.

Shading correction device

Abstract: A device for carrying out the shading correction of an image signal is provided. The present device includes an image sensor capable of scanning a reference density reflecting plate over a predetermined number of times along different scanning lines and averaging means for taking an average among the repeated scannings thereby forming an error-free reference data to be later used in the operation of shading correction.

Dichromatic reading device

Abstract: A dichromatic reading device is disclosed in which the difference is taken between output signals from a first image sensor receiving reflected light directly and a second image sensor receiving the reflected light after being passed through a filter which blocks a specific color component of the reflected light. The difference is converted into a binary signal which provides one color image information and which together with a binary signal obtained from at least the second image sensor and inverted, is NANDed to provide a second color image information.

A CCD image sensor and a microcomputer make magnetic domain observation clear and convenient

Abstract: Laborious surface polishing has been inevitably necessary for domain observations of bulk magnetic materials by Kerr effect. We have made it possible to observe the magnetic domain without any surface polishing for bulk magnetic materials. A CCD (charge coupled device) image sensor and a microcomputer did the contrast enhancement and noise reduction. Domains in rapidly quenched amorphous magnetic materials have been observed clearly without any surface polishing.

Solid state image sensor exhibiting reduced image smearing effects

Abstract: The invention provides a solid state image pickup device having a plurality of photoelectric transducers and a vertical transfer CCD (charge coupled device) unit. A concentration of an impurity of a semiconductor substrate region surrounding each of the vertical transfer CCD in the vicinity of each of the photoelectric transducers is higher than that below each of the photoelectric transducers.

Image sensor and rangefinder device having background subtraction with paired analog shift registers

Abstract: A rangefinder device includes means for projecting a beam of light to illuminate a spot on an object in a scene, an image sensor for sensing an image of the scene, and signal processing means responsive to signals produced by the image sensor for determining the relative location of the illuminated spot in the image of the scene to determine the distance to the object. The rangefinder device features means for removing the contribution due to ambient scene illumination from the photosignals, including an improved image sensor having an array of photosensors and a pair of analog shift registers for receiving the photosignals from the array of photosensors. One of the analog shift registers receives photosignals from the photosensor array when the beam is turned off, and the other analog shift register receives photosignals from the array when the beam is turned on. The shift registers are read out simultaneously and the signals therefrom are differenced to yield a series of photosignals free from background scene information. The difference signals are supplied serially to a peak detector to determine the location of the illuminated spot. In a preferred embodiment, the rangefinder is designed to operate from a single low voltage power source.

An Amorphous Si High Speed Linear Image Sensor

Abstract: An amorphous silicon thin film linear image sensor of a sandwich structure has been developed. The sensor consists of a transparent ITO as an upper electrode, an a-Si: H layer and Cr or Al lower electrodes. The a-Si: H layer is formed by RF glow discharge. These layers are deposited on a glass or ceramic substrate. The sensor has good photoelectric characteristics as follows: Photo-sensitivity is 10-7 A/cm2 1x, photo-response time is less than 0.5 ms and photo- to dark-current ratio is larger than 3×103. The sensor can be operated by a -5 V single power source and this same power source can be used for the driving circuits. A 1056-bit, 8 bit/mm linear image sensor has been fabricated. Using the device, images of a document have been read and reproduced successfully.

Static induction transistor image sensor with noise reduction

Abstract: A SIT (Static Induction Transistor) image sensor with a high-sensitivity and a high-fidelity is disclosed. The image sensor comprises a SIT image cell array and a scanning circuit which scans in turn a plurality of SIT image cells in such a manner that respective scanning time in all the cells are equal throughout a sequential scanning operation for the SIT image sensor. A reading line and a refreshing line may be combined into a single line. A differential amplifier is provided for correcting a picture element information to remove a noise component therefrom.

Image sensor and rangefinder device with background subtraction using interlaced analog shift register

Abstract: A rangefinder device includes means for projecting a beam of light to illuminate a spot on an object in a scene, an image sensor having an array of photosensors for sensing an image of the scene, and signal processing means responsive to the photosignals from the photosensors for determining the relative location of the illuminated spot in the scene. The device includes an improved image sensor comprising an array of N photosensors for sensing the image of the scene and generating N photosignals in response thereto, and an analog shift register having 2N cells for receiving the photosignals, in parallel, into N alternate cells. The sensor is operated once with the light beam off and the photosignals generated thereby, representing the background illumination, are entered into the N alternate cells of the shift register. Then the contents of the shift register are shifted by one cell. Next, the sensor is operated with the beam on and the N photosignals, representing the background plus the light beam illumination, are entered into the shift register, with the result that the background signals are interlaced with the background plus light beam signals in the shift register. The photosignals are read out of the shift register serially, and the pairs of signals originating from each respective photosensor are differenced to yield a series of N photosignals free from background scene information. The difference signals are supplied serially to a peak detector to determine the location of the illuminated spot.

Endoscope with image correction means

Abstract: In an endoscope for displaying an image of an object on a monitor screen, a static induction transistor (SIT) image sensor having a number of light receiving elements is arranged at a light emitting side of an image guide bundle. In order to eliminate dead spots appearing in the displayed image due to broken fibers in the image guide bundle, pixel signals of light receiving elements corresponding to the dead spots are formed by interpolation with the aid of pixel signals derived from light receiving elements adjacent to the relevant light receiving elements to be interpolated. As an interpolation function, for example, an average of the pixel signals derived from the adjacent light receiving elements is used. The addresses of the light receiving elements corresponding to the dead spots are stored previously in a PROM during a manufacturing stage. In this manner, the interpolated image of the object having an excellent image quality can be displayed on the monitor.

System for detecting the position of a sheet on its support

Abstract: An apparatus for determining the position of a sheet when the sheet is placed on a support having at least two spaced apart CCD linear image sensors recessed in the sheet support and partially covered by the edge portions of the sheet. The CCDs operate as line cameras, and are scanned to generate signals correlated with the points of intersection of the sheet edges and the axes of the image sensors. Preferably the apparatus has circuitry for storing calibration values of the CCD signals obtained when the image sensors are not covered by the sheet, circuitry for storing corresponding scanning signal values when the image sensors are covered by the sheet, circuitry for comparing corresponding calibration and scanning values for obtaining difference values, and circuitry for detecting maxima in the gradient of the difference values for adjacent image points to find the locations of the points of intersection of the sheet edges and the axes of image sensors. These locations are used by software driving an X-Y plotter head or by a sheet positioning mechanism to correct for variations in sheet position.

Method for driving solid-state image sensor

Abstract: A method for driving a solid-state image sensor in which the bias charges in a horizontal readout CCD (charge-coupled device) shift register are transferred onto vertical signal lines with the signal charges and then the signal and bias charges are transferred back into the horizontal readout CCD shift register from which are read out the signal charges (generated at the photosensor or photodiodes).

Image sensor and rangefinder device having background subtraction with bridge network

Abstract: A rangefinder device includes means for projecting a beam of light to illuminate a small area on an object in a scene, an array of photosensors for sensing an image of the scene, and signal processing means responsive to the photosignals from the photosensors for determining the relative location of the illuminated small area in the image of the scene. The rangefinder device includes an image sensor having means for removing the contribution due to ambient scene illumination from the photosignals. The image sensor includes a plurality of photosensitive elements, comprising a photosensor, a charge storage element and a bridge network of switches arranged for selectively connecting the photosensor to the charge storage element in such a manner as to selectively add photocurrent to the storage element or to remove photocurrent from the storage element. The rangefinder device is first operated with the light beam on and the bridge networks connected to add photocurrent to the storage elements. The device is then operated with the light beam off and the bridge networks connected to remove photocurrent from the storage elements. The difference signals remaining in the storage elements are free from contributions due to ambient scene illumination. The image sensor includes an analog shift register for receiving the difference signals in parallel from the storage elements and delivering them serially to a peak detector circuit. The peak detector circuit locates the position of the illuminated small area by sensing the maximum difference signal in a series.

Image pickup device

Abstract: PURPOSE:To prevent the effect of blooming, by feedback control of a scanning frequency based on the added level made of a control signal and a hold output, in an image pickup device using a charge storage type image sensor. CONSTITUTION:An image pickup signal Va from a charge storage type image sensor 1 is given to a controller section B via an input buffer 10 and distributed to a comparison operating circuit 2 and a sample hold circuit 3. The circuit 2 outputs a control signal Vc1 according to the rate of output from two high and low reference level comparators C2 and C3. In the sample hold circuit 3, vacant image pickup signals Vb1 and Vb2 from non-exposure parts 1a, 1b of the sensor 1 are picked up and a peak level stored in sample hold circuits 3a, 3b is outputted as a hold output Vc2 via an addition circuit 3c. This control signal Vc1 and a hold output Vc2 are added and inputted to a V/F converter 7, allowing the scanning frequency of the sensor 1 to be changed proportionally according to the added output level Vc3.

Film video player having flash illuminated area image sensor and single frame CCD image sensor for use therewith

Abstract: A film video player for sensing a color negative film image to produce color positive video signals includes a single frame charge coupled device (CCD) image sensor having an integral color filter array for producing color negative video signals when illuminated with a negative color image. The single frame CCD image sensor is flash illuminated with an image from the color negative film during the vertical retrace intervals of the video signals. Signal processing circuitry inverts and color corrects the signals produced by the sensor to produce color positive video signals. To reduce readout clock frequencies, the single frame image sensor is provided with a pair of parallel output registers. Even numbered columns of the array are read out via one of the registers, and odd numbered columns the other. Odd numbered columns are overlayed with green filter stripes and even numbered columns are overlayed with alternate red and blue stripes. The signals from the output register serving the odd numbered columns are demultiplexed by switching back and forth between two identical output amplifiers.

Scene-Based Nonuniformity Compensation for Imaging Sensors

Abstract: Multidetector imaging focal plane arrays like CCD TV cameras and infrared arrays possess large detector-to-detector dark current (offset) and responsivity (gain) variations which can completely mask the useful information. Conventional compensation techniques require temperature references of constant radiance over the entire field of view and a mechanical/electrooptical shutter to calibrate the focal plane. This detracts from the mechanical simplicity of multi-detector staring (nonscanning) focal planes. This correspondence describes a real-time offset and responsivity (gain) compensation technique which dispenses with temperature references and shutters in staring focal planes. It makes use of the scene statistics for calibration and continuously updates the compensation coefficients without interrupting the field of view. The results of real-time simulations of this technique with a number of sensors are presented. Real-time LSI/VLSI hardware architectures are addressed. The technique can be implemented with the addition of very little hardware to a conventional compensation technique requiring temperature references. The technique is also suitable for multi-detector scanning focal planes and for the removal of shading in TV sensors as well.

Apparatus and method for reading multi-color original

Abstract: A multi-color original reading apparatus comprises a single image sensor for sensing a multi-color original image, a plurality of light sources for illuminating the original image with lights of different colors, while turning on and off the light sources, and a driver for driving the image sensor in time with the turning on and off of the light sources.