Abstract: An image sensor includes: a sensor substrate on that a large number of semiconductor chips each of which has a plurality of image pickup elements, are linearly arranged to receive the reflected light converged by the lens; and a transparent plate that is interposed between the lens and the sensor substrate, and provides a light path region corresponding to the boundary region between adjacent semiconductor chips with a refractive function, so that the vertical light incident on the boundary region between semiconductor chips 6 is refracted and incident dividedly to the directions of respective image pickup elements.

Abstract: A display device has a display section having scanning lines, and first and second scanning drivers having output lines for supplying scanning signals to the two ends of the scanning lines in the display section. When the potential of at least one of the output lines of the first or second scanning driver is fixed or unfixed due to an error in the first or second scanning driver, the output line at the fixed or unfixed potential is disconnected from the corresponding scanning line in the display section.

Abstract: This invention has as its object to provide an image sensor which can effectively attain higher read resolution, and an image processing apparatus and information processing system using the same. To achieve this object, function members including a light source (6) for irradiating an object to be read (PP) with light, a sensor (3) for receiving light reflected by the object to be read (PP), and an imaging element (7) for forming an image of the reflected light on a light-receiving portion of the sensor (3) are attached to and supported by a support member (1) to have a predetermined positional relationship. In order to assure high attachment positional precision and rigidity for the function members, the support member (1) is formed to have a hollow shape. The support member (1) is formed to have the hollow shape along its longitudinal direction. Two side portions of the support member (1) are formed to have a hollow shape, and are coupled at end portions in the longitudinal direction.

Abstract: An image processing unit (20) includes a averaging circuit (21) and a memory (22) for storing pixel data. The memory (22) is a memory for storing the pixel data subjected to analog-to-digital conversion. The averaging circuit (21) performs an averaging process between two adjoining pixels on each line stored in the memory (22). The digital pixel data is stored in the memory (22) and the averaging process is performed between the two pixels in the main scanning direction using the pixel data read by a first photoelectric conversion element trains and the pixel data read by a second photoelectric conversion element trains. Therefore, the noise component can be reduced, whereas the S/N ratio can be improved. Accordingly, image quality is made improvable with a simple arrangement.

Abstract: A representative photosensor assembly comprises first through sixth arrays of photosensor elements and first through third arrays of charge shift registers. Each photosensor element in the first array, the third array and the sixth array of photosensor elements exhibit a first size, and each photosensor element in the second array, the fourth array and the sixth array of photosensor elements exhibit a size different than the first size. The first and second arrays of photosensor elements are operative to detect a first color of light, the third and fourth arrays of photosensor elements are operative to detect a second color of light, and the fifth and sixth arrays of photosensor elements are operative to detect a third color of light. The first, second and third arrays of charge shift registers are coupled between the first and second, third and fourth, and fifth and sixth arrays of photosensor elements, respectively.

Abstract: In an imaging apparatus such as a scanner or digital camera, a photosensitive device includes multiple linear arrays of photosensors. One of the arrays has a higher spatial resolution than other arrays. The high-resolution array is filtered to detect different portions of the color spectrum than the low-resolution arrays.

Abstract: A color image reading apparatus has a 3-line sensor formed by setting a plurality of line sensors on a single substrate, an imaging lens for imaging an object, a diffraction grating which is inserted in the optical path between the imaging lens and 3-line sensor and color-separates a light beam coming from the object into a plurality of color light beams, and a first cylinder unit which is inserted in the optical path between the object and the imaging lens, and temporarily images the object in the sub-scanning direction in the optical path before the imaging lens.

Abstract: A solid-state image-sensing device has a photosensitive element that produces an electric signal commensurate with the amount of light incident thereon, a transistor of which the first electrode and the control electrode are connected to one electrode of the photosensitive element, and a resetting portion for resetting the transistor by feeding a predetermined pulse signal to the second electrode of the transistor. The resetting portion resets the transistor in such a way as to inhibit the transistor from operating in a subthreshold region when the amount of light incident on the photosensitive element is below a predetermined level.

Abstract: A digitizer having a dual exposure technique is combined with an associated LUT for each exposure. Each LUT may have a transfer function including a logarithmic operator resulting in a digitized image with improved photometric resolution and increased dynamic range. A digitizer utilizing multiple exposures at approximately equal exposure time intervals provides a noise reduction for lower optical density portions of the data medium further contributing to increased dynamic range. Associated methods are also provided.

Abstract: An image reading apparatus that reads color images by means of scanning the document surface with CCD sensors that correspond to red (R), green (G) and blue (B) colors respectively, comprising: a diagonal line pattern 4 provided within the CCD sensors' reading ranges; a color shift correction factor arithmetic unit 40 that detects color shifts from the data obtained by reading the diagonal line pattern and calculates correction factors; and a correction arithmetic unit 42 that corrects the document image data for each color component read in the previous step using the calculated correction factors.

Abstract: The invention relates to a digital camera which provides high resolution at low cost by using a charge coupled device (CCD) with a high concentration of pixels in one dimension and rapidly scanning an image plane in the camera to provide high resolution in a second dimension. High resolution can thereby be achieved in both dimensions of the image plane without the need for an expensive CCD which employs a two dimensional array of pixels numbering in the thousands in both dimensions. For additional cost savings, the moveable one dimensional CCD concept can be retrofitted into an existing camera assembly thereby replacing the film and film handling equipment in the existing camera.

Abstract: In a method and a circuit arrangement for driving laser diodes arranged in close proximity to one another in a laser recording device, video signals modulated with the information to be recorded generate driver currents for the laser diodes. The light powers output by the laser diodes drop due to crosstalk between the laser diodes. For compensation of the crosstalk, correction units are connected between first laser diodes that form crosstalk sources and second laser diodes that form crosstalk sinks. In the correction units, the driver currents of the first laser diodes are converted into correction signals according to the transfer functions of the correction units, the correction signals correcting the driver currents of the second laser diodes such that the crosstalk is compensated. For determining the transfer functions of the correction units, the time curves of the light powers in the crosstalk sinks are measured and approximately electrically simulated as transfer functions.

Abstract: A document scanner for producing any combination of color or grayscale or bi-tonal document images having a selectable range of resolutions is provided that maximizes image production speed by minimizing the processing required to produce the particular type of images selected. The scanner includes an imaging camera including a high-resolution grayscale CCD sensor in combination with lower resolution red, green, and blue CCD sensors. The scanner further includes an image processing circuit for processing data generated by the grayscale and color CCD sensors into any combination of color, grayscale, or bi-tonal document images having high or low resolution. High-resolution color images are produced by superimposing the high-resolution grayscale image generated by the grayscale sensor with the lower resolution color images generated by the color CCD sensors. The image processing circuit may also produce high or low resolution, color, grayscale or bi-tonal images when selected at respectively lower bandwidths.

Abstract: A solid-state image sensing apparatus with a wide dynamic range, and a high performance, and further, a small size, and a low cost and its driving method are provided. A timing generator, before it supplies a reset pulse (134) to a reset gate (128), has a sample hold circuit (2) held an output voltage of a buffer circuit (130). In this reset stage, in case that the amount of incident light to a photo diode (122) is large, electric charges which the photo diode (122) generated overflow from the photo diode (122) and flow into an FD part (123), and further, overflow also in the FD part (124) and flow out to an electric source Vdd. At this time, a voltage of the FD part (124) is determined by a size of a current due to electric charges which flow out to the electric source, but since a current flowing in a channel is small and the reset gate (128) operates in a sub-threshold region, a voltage of the FD part (124) becomes a value which corresponded to logarithm of a current value.

Abstract: An image sensor module includes a printed circuit board (PCB) having a window defined therein and extending through the PCB. The inner periphery of the window is coated with a shelter. The PCB includes multiple leads formed thereon around the window and each lead divided into an inner lead and an outer lead. An image sensing chip is electrically connected to the PCB and includes multiple solder pad formed thereon. Each solder pad aligns with and electrically connected to a corresponding one of the inner leads. A lens set is mounted on the PCB and includes a holder surrounded the window and corresponding to a sensing area of the image sensing chip, wherein the peripheries between the holder, the PCB and the image sensing chip are underfilled with stabilizer to form an airtight condition between the holder, the PCB and the image sensing chip.

Abstract: An image reading apparatus includes image sensor chips and control chips for controlling the operation of the image sensor chips. Each image sensor chip, including a plurality of photoelectric converters, performs the outputting and resetting of accumulated electric charge due to light detection. Each control chip includes resolution data input terminals for inputting resolution data to specify resolution, and also a reset signal generator for generating a reset signal for performing the resetting of the accumulated electric charge. The reset signal is generated in a selected one of the cycles that corresponds to the resolution data inputted into the terminals.

Abstract: A drive method of a CCD color image sensor for realizing an electronic shutter function with the signal charge accumulation time varying from one color to another according to a simple structure is provided. Unnecessary charges occurring in photoelectric conversion element groups of colors are transferred in shift registers in the time period in which signal charges are accumulated in the photoelectric conversion element groups of at least colors of R, G, and B (t2<t<t5), and the signal charges accumulated in the photoelectric conversion element groups of colors in response to different time periods according to the colors set in the photoelectric conversion element groups of colors (R: t4<t<t5, G: t3<t<t5, and B: t2<t<t5) are transferred in the shift registers in the time period in which unnecessary charges are accumulated in the photoelectric conversion element groups of colors (t0<t<t1).

Abstract: An image preprocessing apparatus, which processes image signals of an image of a scanned object, includes an image sensing module, a multiplexing unit and an analog signal processor. The image sensing module includes a number of monochrome image sensors, as well as a black-and-white (B/W) image sensor, outputting a number of monochrome analog image signals and a B/W analog image signal respectively. The multiplexing unit receives the B/W analog image signal and some of the monochrome analog image signals and then selects either the B/W analog image signal or these monochrome analog image signals as the output of the multiplexing unit. The analog signal processor receives the output of the multiplexing unit and the monochrome analog image signals that are not received by the multiplexing unit, and outputs a digital signal.

Abstract: To eliminate after-image due to residual charges to provide an output form that is easy to obtain effective on-light output. The outputs of photo-diodes 1 are read out as sequential signal outputs on a common signal line 15 through connected amplifiers 3, and two states of before and after resetting the photo-diodes 1 are outputted in order for each light receiving element.

Abstract: A color image sensor is provided which includes a generally sector-shaped prism having a shorter edge surface facing a white light emitting surface of a white light emitting diode, a longer edge facing a read surface of the document, a front and a rear surfaces spaced from each other in the thickness direction of the prism. The front and rear surfaces are so curved as to collect white light emitted from the white light emitting diode onto the read surface of a document. The sensor further includes a semiconductor color sensor having a plurality of red light receiving elements, a plurality of blue light receiving elements and a plurality of green light receiving elements for receiving light reflected on the read surface at the respective light receiving elements for simultaneously outputting red, blue and green image signals, and a rod lens array for forming a non-magnified erect image on the light receiving elements of the, semiconductor color sensor in accordance with light reflected on the read surface.

Abstract: A representative method for scanning comprises: exposing a first linear array of photodetector elements to light for a first exposure time to acquire first, second, third and fourth accumulated charges; transferring the first, second, third and fourth accumulated charges to first, second, third, and fourth stages, respectively, of a charge shift register; exposing the first linear array to light for a second exposure time to acquire fifth, sixth, seventh and eighth accumulated charges; and transferring the fifth, the sixth, the seventh and the eighth accumulated charges to fifth, sixth, seventh, and eighth stages, respectively, of the charge shift register to interleave the first and second accumulated charges with the seventh and eighth accumulated charges.

Abstract: An image reading apparatus capable of taking full advantage of each device function and adjusting it even if each device function varies depending on respective machines. The image reading apparatus includes an illumination unit directing light toward an original document, a transducer unit transducing the light directed toward the original document and reflected therefrom to an electric signal, and a controller controlling the amount of light from the illumination unit according to a saturation characteristic and a frequency characteristic of the transducer unit.

Abstract: An image reading apparatus individually reads a predetermined white reference plate by flickering light sources of the respective colors before an original image is read by sequentially turning on the light sources during one line sync period. The flickering duty ratio of the light source obtained when the white reference plate is read is set for each color so as to maximize the output value from an A/D converter within its predetermined conversion range. When an original is read, the image reading apparatus changes the emission color by switching the light source to be flickered every line sync period, and turns on the light sources of the respective colors in accordance with different duty ratios set for these colors.

Abstract: Featured is a method for driving a CCD imaging device, including a plurality of photodetector columns each including a vertical array of photodetectors, a plurality of vertical CCDs, and a horizontal CCD, in a monitoring mode where only the signal charges from some of the photodetectors are used. The method includes reading a first signal charge from any one of said some photodetectors into a corresponding first packet of a corresponding one of the vertical CCDs, dividing the first signal charge in the first packet into smaller portions and placing one or more of the signal charge portions of the first signal charge into one or more second empty packets of the corresponding one of the vertical CCDs, and vertically transferring the signal charge portions in the first and the one or more second packets by the total number of the first and second packets.

Abstract: A graphical image scanner scans pixelated regions of a color image to measure light intensities in a plurality of hyperspectral bandpasses for each pixel. The scanner transforms the hyperspectral bandpass intensities into device-independent color representations for each pixel, using scientific color representations, for example, as defined in CIE-31 and CIE-76 colorimetry standards as devised by the Commission Internatonale de l'Eclairage (CIE).

Abstract: A photosensor array has transfer gates that are logically divided into sections, with separate control over each section. Sequential control of the transfer gate sections, coupled with shifting the charge shift register, enables each stage of the charge shift register to accumulate charges from multiple sensor elements. Multiple scanlines are then interleaved into the charge shift register. Because charges from multiple sensor elements are accumulated, the exposure time can be reduced. Because multiple scan-lines are interleaved, the amount of subsampling for lower sampling rates can be reduced or even eliminated. As a result, the overall time required to acquire just the data that is needed for lower sampling rates is substantially reduced.

Abstract: An image pickup apparatus in which a pixel area including arrangement of a plurality of pixels each having a photoelectric conversion portion and a common output portion for sequentially amplifying and outputting signals from the plurality of pixels included in the pixel area are formed on a single semiconductor substrate, comprises a power supply unit for effecting power supply control of the common output portion independently of control on power supply to the pixel area, and a control circuit for effecting control to supply no power to the common output portion in a predetermined period after starting photo charge accumulation in the photoelectric conversion portion and supply the power to the common output portion before the end of a photo charge accumulation period in the photoelectric conversion portion.

Abstract: A method and system provide for real-time compensation of an imaging system for variations in illumination intensity. An illumination system provides reflected illumination, and a charge coupled device system directly detects the reflected illumination from the illumination system. The CCD system then converts the reflected illumination into illumination data and a host processor converts the illumination data into adjusted control data and final image data. The adjusted control data is based on an illumination profile and a reference illumination intensity. The reference illumination intensity is measured before each document with a compensation reference, and is compared to the illumination profile to adjust control parameters in a real-time mode. Directly measuring the illumination intensity with the CCD system allows for a reduction in parts, manufacturing steps, and errors.

Abstract: This invention relates to an image reading apparatus which eliminates color misregistration upon reading in the sub-scanning direction, which occurs due to different afterglow or persistence characteristics of the respective colors of a light source upon executing the light quantity control of the light source for illuminating an original. Since the light quantity control of the light source is divisionally done a plurality of times in one accumulation period of a solid-state image sensing element, any deviation of the center of gravity in the quantity of light from the center C of one accumulation period can be minimized, and the color misregistration can be eliminated remarkably.

Abstract: Since a power supply circuit for a controller (31) and a power supply circuit for a buffer storage unit (32) are independently provided, the power voltage for the buffer storage unit (32) need only be reduced to obtain a corresponding reduction in the amplitude of the signal waveform of digital image data transmitted along an FFC (40), without the operation of the controller (31) being adversely affected. In addition, so long as a coil (47) is located at one position in the internal power supply circuit of a control chip (24), or the external circuit thereof near its power supply circuit, the signal waveform for the digital image data transmitted along the FFC (40) can be attenuated.

Abstract: An image reading device in which an image can be read efficiently and at high speed and with high image quality with little heat being generated at a time of light emission, and the device can be made compact. After lights of respective colors are collected and focused, the light is diffused in a vicinity of a film. Therefore, almost all of lights emitted from LED chip groups can be guided to a surface of the film.

Abstract: In a method for imaging, a plurality of image sensor elements (12) is used, which generate different output signal values when using different exposure times. For each image sensor element, an image signal value is generated by generating a first output signal value (y1(x)) when using a first exposure time (Tint,long) and an associated second output signal value (y2(x)) when using a second exposure time (Tint,short). If the first output signal value does not exceed a threshold value (yo) associated thereto, the image signal value (y(x)) is calculated using a first calculating rule on the basis of the first output signal value (y1(x)). If the first output signal value exceeds the threshold value (yo), the image signal value (y(x)) is calculated using at least a second calculating rule on the basis of at least the second output signal value (y2(x)).

Abstract: A digital CMOS sensor including a chip. A periphery of the chip has a lead frame connecting with the lead of the chip. A color filtering layer is directly vapor deposited on the chip and the lead frame for filtering specific frequency of optical wave and comparing the optical wave.

Abstract: A color image processing device includes n line sensors which are arranged with a prescribed interval L between one another, an image signal output unit which outputs image signals under a prescribed cycle from the line sensors and a line memory which stores the image signals for a plurality of lines and outputs the image signals with a delay. A control unit is provided for controlling to input one of the image signals of a certain cycle into the line memory, and to output an image signal from the line memory by delaying a certain number of lines, in accordance with a prescribed rate of magnification N.

Abstract: A system and method are provided to control an acquisition of a number of pixels in a scanning system. In one embodiment, the system includes an interface circuit with a multiplexer to route at least one color component of one of a number of pixels from a sensor to a register. In another embodiment, the system includes at least three registers to receive a color component associated with one of a number of pixels from a sensor, where at least one of the color components is acquired by a multiplexer having a number of inputs. For both embodiments, logic is included that controls the acquisition of various color components, where color components are acquired in random patterns and/or only a predetermined number of the total color components are acquired to reduce an amount of time necessary to scan a document and to eliminate the problem of color artifact.

Abstract: A timing generator includes a plurality of waveform generators. Each waveform generator includes a register which stores externally input data of a signal waveform to be generated and a waveform generation circuit which generates and outputs a signal on the basis of the data stored in the register, and updates the data stored in the register at a predetermined timing.

Abstract: A CCD is such that a single image sensing area is produced by performing exposure four times in four areas. Four correction circuits are provided in association with respective ones of the four areas. Four items of image data obtained based upon respective ones of the four areas are input to corresponding correction circuits, which apply a correction to prevent image disturbance at the area boundaries. One frame of image data is generated from corrected image data of respective ones of the areas and the image data is recorded on a memory card.

Abstract: Pixels in an image sensor array are arranged at an angle of 45 degrees relative to the axis of the array and read out in a zigzag fashion.

Abstract: Geometric configurations for photosites found on photosensitive chips for creating electrical signals from an original image, as would be found, for example, in a digital scanner, copier, facsimile machine, or other document generating or reproducing device. The photosensitive chips are mounted on a substrate to form a photosensitive array in a full width scanner or other photosensitive device. The geometric configurations reduce the Moiré patterns to provide a higher quality image.

Abstract: An image reading apparatus includes an image reading device having a plurality of solid-state image sensing device arrays arranged to be parallel to each other, the image reading device for optically reading an image on an original and a registration adjusting device for performing a position variable process operation to correct a gap of a position to be read on the original, which corresponds to intervals between the solid-state image sensing device arrays.

Abstract: An NchMOS transistor Q71 on the input side of a current mirror 70 is made function as a voltage operating-point setting portion so that a pixel signal line potential (voltage of a horizontal signal line 20) would be constantly stable nearly at the GND. Then, an amplification factor and linearity become good in an amplification transistor in the solid imaging device 3. A current copier 90 is made function as a current sampling portion so as to receive a signal current IIN of the solid imaging device 3 through the current mirror 70 to carry out sampling of a pixel signal in a resetting period in the shape of current component as the pixel signal is. Calculating differential between a current component in a detecting period and an offset current, which is the current component in a resetting period in sampling, allows an offset component included in the pixel signal to be removed and only pure signal Isig to be picked up at an output terminal Iout, so that the FPN restraining function can be fulfilled.

Abstract: In a digital still camera (DSC) a plurality of individual RGB filter elements each overly a corresponding one of a plurality of photosensitive elements of an image sensor such as an array of charge-coupled devices (CCDs). A coated mirror is positioned along a light path between a lens and the image sensor for shifting the light transmitted through the lens so that a portion of the incident light that would otherwise fall on a single photosensitive element is divided between at least two adjacent photosensitive elements. The plurality of individual RGB filter elements are arranged in a predetermined mosaic pattern between the lens and the image sensor for permitting the photosensitive elements to detect the intensity of the light incident thereon in a manner that allows a high quality color image to be reproduced. A processing circuit is mounted in the housing and is connected to the image sensor for processing the output signals from the image sensor.

Abstract: An imaging device having a CMOS photosensor array for capturing images is described in which the array is also used to input programming and/or data used to control the imaging operations. The data-input can be based upon variations in light color, value, intensity, and patterning, or any combinations of the foregoing, for the download of information to the device.

Abstract: An object of this invention is to quickly complete white balance calculation in photographing. To achieve this object, an image sensing apparatus includes an image sensing element in which a line on which first and second color filters are arranged and a line on which first and third color filters are arranged are alternately arrayed on pixels, an image sensing controller which forms an image of one frame by n fields (n is an odd number), and reads out pixel data of the image sensing element so as to contain all color components in each 1-field period, a white balance calculation device which performs process on the basis of image data read out from the image sensing element by the image sensing controller, and starts the process before read of one frame from the image sensing element is completed by the image sensing controller.

Abstract: Geometric configurations for photosites found on photosensitive chips for creating electrical signals from an original image, as would be found, for example, in a digital scanner, copier, printer, facsimile machine, or other document generating or reproducing device. The photosensitive chips are mounted on a substrate to form a photosensitive array in a full width scanner or other photosensitive device. The geometric configurations reduce the Moiré patterns to provide a higher quality image.

Abstract: A semiconductor device comprises a semiconductor IC chip provided with bond pads on its first surface, a wiring board provided with a through hole extending between the opposite surfaces thereof, conductive members electrically connecting the bond pads of the semiconductor IC chip to those formed on the wiring board, and a sealing resin coating coating the surface of the semiconductor IC chip and the conductive members, and bonding the side surfaces of the semiconductor IC chip to the side surfaces of the through hole of the wiring board.

Abstract: The present invention provides an image scanning apparatus having an illuminating device which irradiates illumination, an imaging element which has a light receiving part for receiving light and for generating signal charges, in which the light is an illumination irradiated from the illuminating device and influenced by the original, and has a transfer part for transferring the signal charges, and a controlling device which indicates timings at a predetermined state used to transfer signal charges generated by the light receiving part of the imaging element. In addition, the present invention provides an image scanning apparatus having an illuminating device, an imaging device which reads out signal charges generated by the light receiving part and outputs the signal charges as image data of the original, and a controlling device that prohibits illumination from irradiating in the illuminating device while image data of the original is output from the imaging device.

Abstract: A method for automatic prevention of vertical streaks involves processing output signals from a plurality of photosites to determine what gain is appropriate for each output signal. An exemplary preferred method distinguishes between different types of output signals for which a first type of gain is appropriate and other output signals for which a second type of gain is appropriate. The first type of gain is a proportionate gain. The second type of gain is determined from at least one gain which is appropriate for output signals generated by neighbor photosites. The second type of gain is applied to the output signals when the processing indicates that a light-absorbing optical obstruction associated with the photosites generating the output signals appears to be positioned in an optical path of the photosites on or between a scan surface area over which an object to be imaged by the photosites is positioned and a calibration strip facing the scan area surface.

Abstract: The focus controlling system of the present invention can include a calibration paper, an image capturing device, an input interface, and a processing and controlling device. The image capturing device is employed for scanning the calibration paper. The image capturing device has a focus point adjusting mechanism. The input interface is utilized for receiving a location data of a scanning point. The processing and controlling device is responsive to the input interface and the image capturing device to control the focus point adjusting mechanism. The focus controlling method of the present invention includes the following steps. First, a scanning point is set or detected and a compensated magnification ratio for the scanning point is then calculated. A focus point of a image capturing device is adjusted and a calibration paper is scanned. The adjusting step and the scanning step are then repeated until a magnification ratio of the calibration paper is about the value of the compensated magnification ratio.

Abstract: A single step multi-section exposure scanning method for a scanner. The scanner includes a photo-sensor and a stepper motor. The photo-sensor has N rows of sensor cells that correspond to each primary color. The scanning device is driven forward an exposure distance for each revolution of the stepper motor. The single step multi-section exposure scanning method includes the following steps. First, the photo-sensor moves forward one exposure distance. One row of sensor cells is exposed after moving every 1/Nth of the exposure distance. Thereafter, analogue voltages obtained through the exposed row of sensor cells are transmitted to an analogue/digital converter. The above process is repeated until the entire document is scanned.