Abstract: A white-level correction circuit for an analog-to-digital converter which converts an analog image signal of a pixel, which is input from an external source, to digital image data based on white-level reference voltage and black-level reference voltage inputs. The white-level correction circuit stores white-level reference data for the pixel in a memory and reads the data from the memory in synchronization with the input of the analog image signal. A digital-to-analog converter converts the read white-level reference data to an analog signal comprising the white-level reference voltage. The digital image data is decoded and white-level reference voltage correction data is generated by correcting the read white-level reference data, based on the decoded digital image data, and the white-level correction data is stored in the memory.

Abstract: An image reading apparatus has a projecting light source and a photo-sensitive device for receiving the projected light. In addition, a device is provided for measuring characteristics of the image reading apparatus while changing a light emission amount from the light source on the basis of an instruction by the user.

Abstract: The present invention is an apparatus for scanner system having an infrared ray source, and this scanner system can be utilized in a region where there is lack of visible light. The present invention includes an infrared ray source, a mirror, a lens set, a filter, a charge couple device (CCD), a pro-processing means, an analogue to digital converter, and a post-processing means.

Abstract: The present system provides a thermal imaging device including a detector array responsive to thermal infrared radiation. The detector array has a linearly-arrayed plurality of spaced-apart detector elements defining cooperatively a length dimension for the detector array. Each of the plurality of detector elements provides a corresponding individual electrical signal indicative of the thermal infrared radiation incident thereon. The detector elements vary from one another in the plurality of detector elements, and the thermal imaging device responsively provides a visible-light image replicating a viewed scene. The thermal imaging device includes a scanning device scanning the viewed scene across the plurality of detector elements in a direction generally perpendicular to the length dimension.

Abstract: A facsimile machine adapted to be connected to a data transmission line ( which it shares with a terminal (18), comprising connecting means (1, 20, 40) adapted to be connected, at the input, to the line (19) and to transmit, to a data processing interface (80) of the facsimile machine, differential signaling signals of the line (19) in order, as a function of these signals, directly to connect the interface (80) to the line (19), in which the connecting means (1, 20, 40) comprise a differential amplifier (20) connected to the line (19) by two high-impedance inputs.

Abstract: A video scrambling and descrambling system that produces color video that is difficult or annoying to watch by randomly switching the color components of a component or composite video. In the scrambling portion, component or composite video is decoded into a luminance component and its two color components. A random switching signal is generated to randomly switch the relationship of the color component signals. The randomly switched color component signals may be encoded together with the luminance signal to produce a component or composite video signal that is scrambled. The random switching signal may be transmitted as part of the encoded signal or through a separate data channel medium. A descrambling portion first separates the scrambled component or composite video signal into a luminance component and two scrambled color components.

Abstract: Signal processing circuit for a multi-pixel scanner array is calibrated by establishing gain and offset correction factors from selected scanner signal measurements and known gain/offset settings that provide accurate calibration of the processing circuit on a pixel-by-pixel basis without concern for variations of component and response values within the signal processing circuit itself from nominal values. When used as a film scanner apparatus, measurements of signal responses taken at open gate conditions are compensated by adjusting exposure values for imager operation during film scanning to make the minimum response output of the apparatus for film D.sub.min equal to the minimum derived of open gate condition during the calibration process.

Abstract: In an image signal processing apparatus, an amplifier for amplifying the output signal of an image sensor and an A/D converter for performing an A/D conversion upon the output signal of the amplifier are provided. When the output signal of the image sensor indicates a white level reference signal, a gain G of the amplifier is controlled so that the output signal of the A/D converter is brought close to a predetermined value. When the gain G reaches its minimum or maximum value, an alarm signal is generated.

Abstract: An image acquisition system includes a transport mechanism for transporting sheets of objects past a sensor. The sensor scans the objects and generates data streams which are scaled by a multiplier to compensate for the speed variation of the transport mechanism. At speeds much lower than a nominal speed, the scanning rate of the sensor is increased to generate several data streams for each scanned line, which are then combined in a single speed corrected signal stream for further processing.

Abstract: An image signal processing device is arranged to convert an analog image signal into a digital image signal after the analog image signal is clamped, to separate, in the form of a digital signal, a synchronizing signal from the digital image signal and to control a clamping action on the analog image signal according to a state of the separated digital synchronizing signal. The arrangement enables the device to always stably perform the clamping action.

Abstract: An image processing apparatus having a solid state image sensor for inputting an optical image thereto and converting the image into an electrical signal; an image memory having a general-purpose DRAM formed by at least one chip and required to control the refresh operation from the outside of the memory chip; a timing signal generator for generating timing of read from the solid state image sensor; a transfer/storage control device for horizontally reading data from the solid state image sensor synchronously with the horizontal read timing signal generated from the timing signal generator, transferring the read data and storing the data in the DRAM; a first refresh signal generator for refreshing the DRAM at predetermined time intervals when no data is read from the solid state image sensor; and a second refresh signal generator for refreshing the DRAM a predetermined number of times during the dormant period of the horizontal read timing signal.

Abstract: There is disclosed an image processing apparatus capable of smoothing the image in obtaining a binary image, by eliminating notches through comparison of the input image data with certain notch image patterns stored in the apparatus in advance. In order to maintain an effect of smoothing even when the resolution of the input image data is increased, the image patterns employed for the above-mentioned comparison are varied according to the resolution of the input image data.

Abstract: An image signal sent from an image sensor is input to the inverting terminal of a differential amplifier. An A/D converter converts an output of the differential amplifier to digital output data. A comparison circuit compares the digital output data with a reference value in a dummy bit period to produce a comparison result, for instance, a difference between the digital output data and the reference value. Based on the comparison result, a correction value setting circuit modifies a correction value so that a DC offset becomes closer to the reference value. For example, the correction value setting circuit adds the difference obtained by the comparison circuit to the correction value. A D/A converter converts the modified correction data to an analog voltage, which is input to the noninverting terminal of the differential amplifier.

Abstract: An integrated circuit for processing an analog image signal obtained from a CCD, etc. and converting the processed image signal to a digital image signal. The integrated circuit includes a circuit for adjusting an offset voltage included in the analog image signal, a circuit for sampling/holding the image signal from the adjusting circuit, a variable amplifier for varying an amplitude of the image signal output from the sampling/holding circuit, an analog/digital converter for converting the image signal from the variable amplifier to a digital signal, and a circuit for detecting a DC component included in the digital image signal and providing the detection result to the adjusting circuit. Correction of a DC voltage component of the analog image signal and amplitude adjustment of the analog image signal can be performed by using a single LSI, and the LSI can be connected to various types of CCDs without using an additional circuit.

Abstract: An image processing apparatus includes an edge detector for detecting whether or not a target pixel of an input image signal is at an edge portion of a discontinuous density image; a first quantizer for generating quantized image data with respect to the target pixel by using a first error spreading filter having a relatively high error spreading effect, such that a density error between the input image signal and an output multilevel image signal is incorporated in "m" neighboring pixels surrounding the target pixel; a second quantizer for generating quantized image data with respect to the target pixel by using a second error spreading filter having a relatively low error spreading effect, such that a density error between the input image signal and the output multilevel image signal is incorporated in "m" neighboring pixels surrounding the target pixel; and a selector for selecting either the quantized image data generated by the first quantizer or the quantized image data generated by the second quantizer

Abstract: A circuit is provided for correcting an image signal received from a camera wherein the camera includes a plurality of charge coupled devices, each for providing a light signal indicative of the intensity of light incident thereon and wherein the plurality of light signals from the plurality of charge coupled devices are indicative of an image received by the camera. The correction circuit includes a gain memory for storing a plurality of gain correction factors wherein each gain correction factor is associated with a respective charge coupled device of the camera. The correction circuit further includes an offset memory for storing a plurality of offset correction factors wherein each offset correction factor is associated with a respective one of the plurality of charged coupled devices. The gain memory is responsive to a control circuit for multiplying the plurality of electric signals by the appropriate gain correction factor.

Abstract: An image scanner for reading a document optically with a CCD image sensor or similar line image sensor, and electrically processing, e.g., amplifying and digitizing the resulting image signal. When an error occurs in the scanner, it can be located easily and rapidly.

Abstract: An on-screen display apparatus includes a CPU (14), a display RAM (26), and a line ROM (28). Character codes of characters constituting each sentences are stored in a series of addresses of the line ROM and, when a given sentence is to be displayed, a head address of a series of addresses is written in the display RAM by the CPU. A decoder (30) sequentially and automatically reads the character codes from address beginning at the head address at every predetermined timings by referring position data of display positions on a screen of a monitor television (54) from a count circuit (48). Therefore, font data of the characters constituting that sentence are sequentially outputted from a character ROM (32) to be displayed on the monitor television in a manner that the character is superposed on a television video signal.

Abstract: An automatic offset and gain control method for use in an electronic high quality scanning apparatus, operating on the source signal values outputted preferably in digitized form when the scanning apparatus scans a given source document and which represent on a pixel-related basis the density values of such source segment, produces corrected signal values representative of the full range of black and white or colors of the original. In the control method, first, a minimum density value relative to the source document is determined. Then, a high density value and a low density value are identified by reference to calibrated high and low density values and from these three values the control unit calculates and stores in a memory corrections for offset and gain. These corrections are applied to the source values to continuously correct the same and thus reproduce a corrected version of the source document.

Abstract: An image scanner is comprised of a light source for illuminating an original document, an image sensor for receiving a reflected light from the original document and converting the same into an output signal of image data, a device for relatively moving the original document and the image sensor, an iris mechanism provided on an optical path between the original document and the image sensor, a reference reflection plane provided such that a light from the light source is reflected and the reflection light becomes incident on the image sensor, a comparing circuit for comparing a level of an output signal from the image sensor with a reference level when the image sensor receives the light from the reference reflection plane, and a device for correcting a dynamic range of the image scanner by controlling the iris mechanism on the basis of the compared output.

Abstract: A control circuit for processing image data received from an imager, like a CCD, with the circuit providing automatic compensation for those factors usually associated with imaging systems. The imager generates image data for a predetermined number of pixel positions in a scan line at a predetermined rate for a document being moved relative to the scan line. This image data is processed, amplified, and fed (at the predetermined rate) into a flash A/D converter used in the circuit. Offset and gain compensation data are supplied as reference levels to the converter at the predetermined rate to provide offset and gain compensation for each pixel position in the scan line. This ensures predictable post processing performance with regard to binarization, compression, and machine reading plus a consistent and undistorted gray level representation of the imaged document.

Abstract: A system for calibration and closed loop feedback control of image signals from charge coupled imaging devices. During periodic iterative calibration, sampling the output of dark reference cells on a CCD nets an initial D.C. restoration voltage (black) level. A white reference strip is scanned and the system gain is adjusted. The process continues until the scanned values equal the expected values, whereat the calibration process is concluded and the offset value becomes fixed for subsequent scanning. During each scan line of regular scanning, black and white signal levels are adjusted to provide full dynamic range of system operation. Dark cells are sampled and produce a voltage that is modified by the offset voltage, that was determined during calibration. The white reference strip is scanned and the system gain is adjusted.

Abstract: A multiple value image input device corrects image data representing images from a document by scanning density indicating segments arranged along the main scanning direction of linear image sensor, each of the segments being set at a different optical density, and using the values obtained by such scanning to correct image data obtained by subsequent scanning of the document. The correction generally involves finding at least two values of the correction image data for each value of the image data, and applying to each value of the image data a function determined from the selected correction image data values. Further correction can be accomplished by scanning subsidiary density indicating segments and further correcting the image data based on results of scanning the second density reference area.

Abstract: An image density reading apparatus in which an image of a document is irradiated by a light source and a density signal is generated from an image light reflected from the image. In the apparatus, there is an amplifier for amplifying a density signal on the basis of an amplifying gain and a signal processor for processing the amplified density signal in accordance with a predetermined processing algorithm to output a gain control signal. The amplifier is provided with a switch for changing a gain in response to the gain control signal.

Abstract: An illuminator for applying light to an image, a reader for photoelectrically reading the light applied image, an amplifier for amplifying an analog signal outputted from the reader, an A/D converter for converting an analog signal outputted from the amplifier into a digital signal, a logarithmic transformer for logarithmically transforming the digital signal outputted from the A/D converter, a first controller for changing the logarithmic transformation of the logarithmic transformer, and a second controller for changing the gain of the digital signal in accordance with a change of the logarithmic transformation characteristic caused by the first controller.

Abstract: An image forming apparatus such as a digital color copy machine is disclosed. The image forming apparatus provides an image reader, an amplifier for amplifying image signals read by the image reader, a laser driver for driving a laser diode to form an image on a recording medium and a switching circuit for switching the amplification gain according to the kind of image to be formed.

Abstract: An image data control system for use in an image reading equipment, in which analog signals output from a line sensor, which represent the amounts of light reflected from an original sheet are converted into digital signals by analog/digital conversion, and then the digital signals are converted into density signals to obtain original sheet reading signals in the form of the density signals, the system characterized in that offset control are performed by an offset control circuit and dark time output adjustment by the unit of picture elements are performed by a dark time correction circuit, respectively, after performing gain control by a gain control circuit.

Abstract: An optical reader head with a video compensation circuit for use in high speed document reading. The reader head utilizes small focussed bulbs to illuminate the scanning line, with the head being comprised of first and second body sections housing a lens which focusses the light reflected from a document at the scanning line to a light array comprised of 256 sensors. Light from four adjacent sensors along the scanning line is integrated to produce a composite pixel which becomes one of 64 such composite pixels for a scanning line of data permitting the use of low wattage bulbs and also eliminating the possibility of burning a jammed document. A peak comparison EPROM is used for adjusting document background levels, for example, for use in thresholding the pixel data.

Abstract: A gain control circuit used in a shading compensation circuit includes a signal processing circuit for an image signal successively output from each of cells of a line image sensor and a gain control signal corresponding to shading data output from an external signal system and converting the image signal into a signal with level corresponding to the gain control signal and for outputting a compensation image signal, and signal feedback circuit for inverting a reference compensation image signal and holding an inverted version of the reference compensation image signal and for feeding the inverted version of the reference compensation image signal back to a terminal of the signal processing circuit and which the image signal is input.

Abstract: An automatic gain control circuit in which a first image signal from an image reading apparatus is amplified by a variable gain amplifier with a gain being automatically adjusted. The automatic gain control circuit comprises a gain adjusting part for automatically adjusting the gain of the variable gain amplifier with a white signal of a white reference part of the first image signal to supply a second image signal from the variable gain amplifier, and a pseudo white signal inputting part for inputting a pseudo white signal to the gain adjusting part before the image reading apparatus starts an image reading, the pseudo white signal being at a predetermined level approximately equal to that of the white signal of the first image signal, the first image signal being switched by the pseudo white signal inputting part with the pseudo white signal only at timings in synchronism with the inputting of the pseudo white signal to the gain adjusting part.

Abstract: A video imaging device permits a first teleconference participant to transport information contained on copy material to a second teleconference participant for display in a portion of a video image viewed by the second teleconference participant. The video imaging device automatically reconfigures itself to transmit information contained on transparent, translucent, or opaque copy material.

Abstract: There is disclosed an image reading apparatus capable of preparing unsharp mask data from an image with a simple structure. For this purpose there is employed a first line sensor with plural photoelectric converting elements, and a second line sensor with larger photoelectric converting elements of a greater length, both being arranged parallel and desired data being obtained by processing the signal from these sensors.

Abstract: An image reader comprises a line image sensor for reading images of an original for every line, a CPU for extracting the density level of the background based on the read image data for comparing the extracted density level with a reference level to find the difference, light adjusting circuit for adjusting the intensity of a lamp for exposing the original so as to make the difference obtained by the operation equal to 0 and a compare circuit for converting the read image data to binary data, wherein the adjustment of the intensity of the lamp by the light adjusting circuit is carried out in parallel to the conversion of the image data by the compare circuit.

Abstract: An image reader for an image forming apparatus has an array of CCD sensors in the form of chips which are arranged in a zigzag configuration along an image reading line. A reference white plate is located in association with the position of and outside of the effective image reading range of one of two CCD sensors which are situated at opposite ends of the array. The CCD sensor with which the reference white plate is associated produces a reference white signal by reading the reference white plate. The output gain of this CCD sensor is controlled on the basis of the reference white signal. The reference white signal is added to output signals of the other CCD sensors in the form of a pilot signal, whereby the output gains of the other CCD sensors are controlled.

Abstract: Scanning equipment for a low-cost facsimile machine which includes a variable gain amplifier and a comparator circuit for correcting nonuniformities in lighting, lenses, light sensors and the like. Each line of a document being scanned is subdivided into a number of picture elements that individually suffer from different degrees of nonuniformity. Stored correction signals, associated with each picture element, are used by the variable gain amplifier and the comparator in processing an analog output signal from the line scanner to thereby correct nonuniformities. In one illustrative embodiment of the invention, the stored correction signals regulate the magnitude of the line scanner's analog output signal which is then compared with a fixed black/white threshold voltage. In another illustrative embodiment of the invention, the stored correction signals are used to generate a number of black/white threshold voltages which are then compared with the line scanner's analog output signal.

Abstract: The translation of an optical image into video signals by a video sensor illuminated by the optical image is adjusted by illuminating the sensor at a first level of light intensity sufficient to provide the video signals at maximum amplitude while adjusting the amplitude of the video signals to a first level, and then illuminating the sensor at a second reduced level of light intensity while adjusting the black level of the video signals so that the black level is at least equal to the amplitude of the signals produced by the sensor in the absence of illumination.

Abstract: Process and apparatus for the white balancing of the opto-electrical converters of the scanning elements in reproducers for the point-by-point and line-by-line scanning of black and white documents and color documents. The light from the illuminant of the documents being scanned is converted in the opto-electrical converters into video signal levels or color signal levels, and the sensitivity or amplification of the opto-electric converters is so set that the video signal levels or color signal levels correspond to preset reference signal levels. The inconvenient process of scanning the illuminant of the document to be scanned, in order to obtain the light required for white balance, is replaced by a process by which the light from the scanning light source may be dimmed by means of a regulable iris diaphragm, thus corresponding to the scanning light from the illuminant of the document to be scanned.

Abstract: An image processing apparatus includes an image generator, a processor for trimming an image generated by the image generator and a reproducer for outputting a plurality of printouts of different images by repeating the trimming by the processor without manually entering trimming data.

Abstract: An object such as a stimulable phosphor sheet on which image information is recorded is scanned by a light beam such as a laser beam, and light bearing the image information from the object is photoelectrically detected to produce an image signal representing the image information. A monitor signal representing the light beam is divided into a high-frequency component and a low-frequency component. A corrective signal is produced multiplying a ratio of the high-frequency component to the low-frequency component by a constant. The corrective signal is then subtracted from the image signal.