Abstract: A method of, and apparatus for, reducing the visibility of banding artifacts on a printed medium comprising producing synthetic artifacts on the printed medium, overlapping scan lines at swath boundaries and controlling exposure along a scan line to reduce the visibility of the banding artifacts.

Abstract: An image-forming apparatus and print media recognition method therefor, wherein the apparatus comprises a first light-emitting element for emitting light to a print medium at a predetermined first incident angle, a second light-emitting element for emitting light to the print medium at a predetermined second incident angle, and a light-receiving element installed along an optical axis of total reflection light emitted from the first light-emitting element and reflected from a surface of the print medium. The apparatus further comprises a control unit for controlling the first and second light-emitting elements to alternately emit light for deciding a print medium material based on a reflection amount of light received by the light-receiving element and establishing print conditions adapted to the print media.

Abstract: An imager comprising a photosensitive surface; a light source which produces at least one scanning light beam; a deflector, arranged to deflect the at least one scanning light beam onto the photosensitive surface; and a sensor which measures the orientation of the deflector. The imager also comprises a controller operative to determine a placement error of said at least one scanning beam on the photosensitive surface, responsive to the orientation measurement by the sensor: and an actuator, responsive to the displacement error, and arranged to change the direction of deflection of the at least one light beam by the deflector. The sensor is configured to measure the orientation of the deflector substantially at a null in a vibrational mode of the deflector.

Abstract: An optical scanner is capable of effectively correcting a difference with respect to the sub-scanning direction between the positions of optical spots for scanning photoconductor drums of a tandem type color image forming apparatus. The optical scanner includes an optical axis adjusting part. The optical axis adjusting part uses a deflecting mirror or a wedge-shaped prism to deflect the optical axis of an optical beam with respect to the sub-scanning direction. As a result, it is possible to accurately correct a resist difference among individual image forming stations and form a high-quality color image without any color displacement.

Abstract: An exposing unit optically writes respective color-separated image data on a photosensitive drum to form a latent image by using both a forward direction scanning and a backward direction scanning. A writing control unit outputs input pixel data to the exposing unit a plurality of times for enlarging and printing an input image. The writing control unit includes an output unit that outputs a main-scanning effective gate signal of dot period lengths of common multiples of all available enlargement ratios; and a suppressing unit that suppresses an output of a pixel signal to an outside of a printing range.

Abstract: The image forming apparatus comprises: a first photosensitive drum; a second photosensitive drum; deflective scanning means for deflecting a laser beam and scanning by rotation; first laser irradiation means including a plurality of light emitting sources of laser beam for irradiating the first photosensitive drum, to irradiate the deflective scanning means with the laser; second laser irradiation means including a plurality of light emitting sources of laser for irradiating the second photosensitive drum, to irradiate the deflective scanning means with the laser beams; supporting means for supporting the first laser irradiation means and the second laser irradiation means; and a rotation supporting member for rotationally moving the first laser irradiation means, the second laser irradiation means and the supporting means integrally with respect to an axis generally parallel to the emanating axis of the laser beam to be emitted from the first laser irradiation means.

Abstract: An optical scanner includes a light source unit configured to emit light; an optical system configured to cause the light emitted from the light source unit to scan an object so as to form an image on the object; and a control unit configured to control the light source unit. The light source unit includes a plurality of light emitting units arranged in a sub scanning direction, and the control unit controls the light source unit to emit light at different positions on the object by using either n (n: positive integer) light emitting units or n+1 light emitting units selected from among the plurality of light emitting units, according to a positional shift amount of the image in the sub scanning direction.

Abstract: A system and method for fabricating an electrical circuit in which a digital control image (46) is generated by non-uniformly modifying (44) a representation of an electrical circuit (40), such that an electrical circuit pattern (72) recorded on a substrate (12) using the digital control image (46) precisely fits an already formed electrical circuit portion (62).

Abstract: An image forming apparatus includes an intermediate transfer member, a sensor, and two image forming units. Each of the image forming units includes an image carrier, an image writer, two development rollers, and a switcher. The image writer writes an electrostatic latent image on the image carrier. Each of the development rollers selectively driven by the switcher visualizes the electrostatic latent image to form toner images in four colors. The toner images are transferred and superimposed onto the intermediate transfer member to form a color toner image. The color toner image is transferred onto a transfer sheet. One or more marks are formed on the intermediate transfer member. The sensor detects one of the marks. The image writer starts writing in synchronism with a sync clock signal of the image writer output immediately after the sensor detects the mark or output after a predetermined time period elapses after the sensor detects the mark.

Abstract: A printing apparatus in which it is possible to set proper correction data by eliminating an erroneous operation of an operator is constructed. A code indicating the type of used printing paper P is formed on a test chart TC. When the correction data is generated, a printing paper type specifying section 25B of correction data generating means 25 judges whether the printing paper is proper or not based on the code, by setting the test chart TC on a flatbed scanner 5 and performing pre-scan on it. If it is the test chart TC using proper printing paper, then the density data in a plurality of pixel lines constituting the chart is acquired and the correction data is generated by performing the main scan, and the correction data is stored in a correction table 35 in association with the type of the printing paper.

Abstract: An image forming apparatus is provided with a laser scanning unit having at least two laser diodes to form an electrostatic latent image on a photosensitive body with laser beams emitted from the laser diodes; an engine driving unit having at least one driving motor to drive a plurality of built-in units; and a control unit arranged to control one of the laser scanning unit and the engine driving unit so as to adjust a process speed of the engine driving unit or a scan speed of the laser scanning unit with a certain rate depending on a selected resolution in order to enhance a resolution of an image.

Abstract: An electrophotographic image forming apparatus senses amounts of color misregistration of toner images, which are formed using n-number (where n is a natural number and n=2 holds) of photosensitive bodies, when light beams from a plurality of light sources are made to deflect and scan across the n-number of photosensitive bodies by a single rotating polygonal mirror. The timing of light emission from the light sources is controlled in such a manner that light beams from the light sources will be deflected and scanned by mirror surfaces of the polygonal mirror, from among the plurality of mirror surfaces that form the polygonal mirror, such that the amount of color misregistration of every toner image will be less than (n?1)/n pixels.

Abstract: An image exposing apparatus two-dimensionally scans a printing plate precursor with a light beam modulated based on an image signal to carry out image exposure on the printing plate precursor. The image exposing apparatus includes exposing device for emitting a light beam in a pulsed form with a predetermined pulse repetition period onto the printing plate precursor; branching device for branching at least a part of the light beam emitted from the exposing device; a pulse stretcher for stretching a pulse width of a branch beam branched by the branching device; synchronous signal generator for generating a synchronous signal synchronized with the pulse repetition period of the light beam from the branch beam having the pulse width stretched by the pulse stretcher; and modulating device for modulating the light beam emitted from the exposing device with an image exposure period synchronized with the synchronous signal.

Abstract: A light scanning unit that corrects skew of a scanning line. The light scanning unit, which scans light on an exposed surface of a photosensitive medium, includes a light source to generate and illuminate at least one beam that corresponds to an image signal while being controlled on and off. A beam deflector deflects and scans a beam provided from the light source. A reflection mirror is obliquely arranged so that a scanning line directed to the exposed surface may be inclined with respect to a segment perpendicular to a transferring direction of the exposed surface to direct the scanning line to the exposed surface of the photosensitive medium by reflecting the scanning line provided from the beam deflector.

Abstract: Systems and methods are described that dynamically correct field curvature and other focus errors in imaging systems that use rotating scanners to scan an image field. The dynamic correction controls the focusing of an image field such that focus is maintained across the width of a photosensitive element as a rotating scanner scans the field. The described systems and methods enable the use of post-objective scanning configurations in which the complexity and expense of objective lenses is significantly reduced.

Abstract: A method for image generation on a recording material reduces the nonlinear spacing error between individual beams. In the method for image generation on a recording material, in which, in order to produce recording points on the recording material, individual radiation sources are used which are disposed along a line on a carrier material and in which the individual radiation sources are driven in accordance with an image and the individual beams are imaged onto a radiation-sensitive layer of the recording material. The spacing of the recording points on the recording material is set by length changes in the direction of the line being produced thermally in the carrier material.

Abstract: Exemplary embodiments provide an apparatus, method, system, computer program and product, each capable of controlling a timing for starting image formation such that when forming a preceding image and a following image, a timing for starting formation of the following image is adjusted based on a timing for starting the preceding image.

Abstract: In an optical disc drive, adapted for forming a label on the label side 14 of a recordable optical disc 10, a determination of the rotation angle a is provided, so that the marking of the label side 14 can be synchronized upon. The method to determine the rotation angle a is based upon one or two of the signals 17?, 18?, 19? generated by the Hall-effect elements 17, 18, 19 which are normally present in an optical disc drive and are used to generate the tacho signal 24. Advantageously, the actual relationship between rotation angle a and the amplitude of these signals is recorded in a calibration procedure, so as to allow for a higher precision of the rotation angle a determined. This calibration procedure may be performed in the factory or by the user, and may not require any additional ad-hoc equipment if a synchronization pattern present in an optical disc is used.

Abstract: A color registration-pattern formed between continuous printing pages with different magnifications is read so as to correct color misalignment by converting the magnification into the reference magnification so as to calculate the present color misalignment correction. Thereby, a plurality of the color registration-patterns with different magnifications, which are formed between continuous printing pages with differentiated magnifications by the speed change of a polygon-mirror motor can be read so as to correct the color misalignment.

Abstract: An image forming apparatus includes an intermediate transfer member position detection unit configured to detect a position of the intermediate transfer member to output an image forming operation start signal, a pattern detection unit configured to detect a registration correction pattern formed on the intermediate transfer member based on the image forming operation start signal, a misregistration variation detection unit configured to read the registration correction pattern detected by the pattern detection unit based on the image forming operation start signal and to generate a reference clock signal based on the read registration correction pattern, and a polygonal mirror drive motor control unit configured to adjust a rotation speed of the polygonal mirror drive motor based on the reference clock signal generated by the misregistration variation detection unit.

Abstract: An image forming apparatus includes: a plurality of optical scanning parts that scan a photoconductor with light of plural colors to form an electrostatic latent image on the photoconductor based on print data; and a controller that, based on a first optical scanning part to which a horizontal synchronization signal is applied of the optical scanning parts, calculates an offset value for light-scan of a second optical scanning part of the optical scanning parts, and controls the optical scanning parts to scan the photoconductor with the light according to the calculated offset value.

Abstract: This invention relates to an efficient way to calibrate and control a raster output scanner (ROS). The scan non-linearity of a ROS may be measured and an appropriate calibration curve setting for the ROS may be determined. The setting and other scan line parameters may then be used as an address to a memory, such as a read-only memory (ROM). The memory may store a set of calibration curve data and the address is used to look up the data from one of these curves. The ROS may then be controlled based on the calibration data retrieved from memory.

Abstract: To detect differences in the main-scanning length of each beam on a photosensitive member, patterns for correction are formed on the photosensitive member using only beams (L1, LN) at both ends among a plurality of beams aligned in a sub-scanning direction. The patterns are transferred onto an intermediate transfer belt and detected with photosensors, a difference ?LN of scanning length between a 1-st line and a N-th line is calculated, and a difference ?Li of scanning length of a i-th line is calculated by ?Li=?LN×(i/N?1) so as to proportionally distribute ?LN to the i-th line. The scanning lengths of lines are respectively corrected to be equal each other using the obtained differences ?Li of scanning length. Thus, an image forming apparatus and a control method that reduce a decline in image quality, even when scanning incident angles of laser beams onto a photosensitive member differ for each of beams on forming images by scanning a multiple lines with a multiple beams, can be provided.

Abstract: A method and apparatus for compensating for scanning skew formed in an electrophotographic color image forming device. The method includes the step of making a scanning light that forms a scanning line ascend or descend in a sub-scanning direction within a range of one dot, and scanning the ascending or descending light in the main scanning direction. Also, the apparatus includes an optical scanner control unit which controls an optical scanning unit so that a scanning light that forms a scanning line ascends or descends in a sub-scanning direction within a range of one dot and the ascending or descending light is scanned in the main scanning direction.

Abstract: Systems and methods are provided for electronically adjusting an image to compensate for laser beam process direction position errors in an electrophotographic device. Initially, a bow profile is defined that characterizes the process direction position errors of a laser beam across a scan line. The device subsequently reads an image to be printed from a first memory location, performs pixel shifts on select columns thereof based upon the bow profile, and temporarily stores the adjusted image data to a second location of memory. The adjusted image data is then communicated to a printhead of the device.

Abstract: A pattern exposure method and a pattern exposure apparatus in which the throughput is improved with an inexpensive apparatus and without a low running cost. Output faces of a plurality of laser beams emitted from a plurality of semiconductor lasers respectively are arranged in two directions. One of the directions is the same direction as the scanning direction of a polygon mirror while the other is a direction crossing the scanning direction of the polygon mirror. In this event, the array pitch of the output faces arranged in the direction crossing the scanning direction of the polygon mirror is made equal to resolution of an exposure pattern. In this event, the wavelength of each laser may be made not longer than 410 nm.

Abstract: An image forming apparatus includes a first writing control device configured to control a writing of a first latent image, a second writing control device configured to control a writing of a second latent image, and a criterion timing determination device configured to determine a criterion timing for a series of image forming operations based on an image forming instruction and to transmit to the first writing control device one of (i) a signal of the criterion timing, or (ii) a signal of a writing instruction determined based on the criterion timing. The first writing control device is configured to start a writing process of the first latent image based on one of the signal of the criterion timing or the signal of the writing instruction received from the criterion timing determination device, and to transmit a signal of a timing for starting a writing process to the second writing control device.

Abstract: An image recording apparatus includes a recording drum rotatable with a printing plate mounted peripherally thereof, a recording head for recording an image on the printing plate mounted on the recording drum, a rotary encoder for detecting a rotation angle of the recording drum, a first and a second sensors for detecting the printing plate mounted on the recording drum, a detection range setting circuit for setting a range of detection of the first and second sensors with respect to the rotation angle of the recording drum according to information on the material of the printing plate, information on reflectance of the printing plate and the presence or absence and the type of positioning holes formed in the printing plate, and a determining circuit for determining a position of an edge of the printing plate mounted on the recording drum, by fetching signals from the first and second sensors based on the rotation angle of the recording drum and the range of detection set by the detection range setting circui

Abstract: Methods and apparatus include improving print quality of a bi-directionally scanning electrophotographic (EP) device, such as a laser printer or copy machine, according to temperature. A moving galvanometer or oscillator reflects a laser beam to create forward and reverse scan lines of a latent image. During use, the actual ambient temperature is obtained and used make corrections to improve print quality, such as by producing the latent image with a signal altered from an image data input signal to help ensure proper alignment of the forward and reverse scan lines.

Abstract: A method for correcting the skewed recording of a printing original on a recording material in an exposer includes the steps of projecting, with an exposure head, a linear array of exposure points generated by N laser beams onto the recording material and moving the exposure head continuously along an exposure drum in axial feeding direction as the exposure drum rotates. As a result, the printing original is recorded along a helix wound around the exposure drum. The laser beams are modulated with image data that is taken from a stored image point matrix along an angled read path, the read path running through the image point matrix at an angle formed by the helix with respect to a circumferential line of the exposure drum.

Abstract: An image forming apparatus to form a color image by using a plurality of laser units, each simultaneously scanning a plurality of scanning lines in a main scanning direction to write with laser beams emitted from a plurality of laser light sources. The apparatus includes: a control unit to control each of the laser units, which includes a reference laser light source and another laser light source, such that, while the laser light sources are synchronized with a clock, a write-start position of a laser beam emitted from the another laser light source is matched with a reference write-start position of a laser beam emitted from the reference laser light source, wherein the control unit selects in advance the reference laser light source in every laser units, based on a previously measured displacement between the plurality of laser beams in each of the laser units.

Abstract: A light beam scanning device is disclosed that includes a light emission source to emit a light beam, a deflection part to deflect the emitted light beam in the main scanning direction, first and second light beam detection parts to detect the deflected light beam at first and second positions, respectively, outside an image area on the opposite sides thereof in the main scanning direction, a time difference measurement part to measure the time difference between the light beam detections by the first and second light beam detection parts, and a control part to perform control so as to correct image magnification in the main scanning direction in the image area from the measured time difference. The control part performs control so that the condition of the amount of light at the time of detecting the light beam by the first and second light beam detection parts is constant.

Abstract: A color image-forming apparatus including two drums, two scanners for forming latent images on the two drums, four developing devices for developing the latent images on the drums into toner images with four colors, an intermediate transfer belt successively passing the drums so that the toner images are successively transferred onto the belt, a transfer unit for transferring the toner image on the belt onto a recording medium, and a control unit controlling the two scanners to form patterns of first, second, third, and fourth colors and controlling timing at which the two scanners write on the drums such that the patterns approach one another.

Abstract: An electrophotographic device comprises a printhead having at least one laser associated with a corresponding photoconductive surface. Where multiple laser beams are associated with the same photoconductive surface, the laser beams are spaced a predetermined distance from one another in a process direction, which is orthogonal to a scan direction in which the laser beams are swept. The electrophotographic device operates at one of at least two image transfer rates. A controller in the electrophotographic device selectively directs image data to the printhead based, at least in part, upon the selected image transfer rate, the facet resolution, and/or the desired output image resolution. The print speed can thus be adjusted over a relatively wide range.

Abstract: Systems and methods are described for stitching multiple images together in a printer to form a single, seamless, composite image. The use of multiple laser sources and multiple scan lenses with one or more scanner assemblies and various image stitching methods achieves seamless image stitching in a manner that provides benefits over prior printers using single laser sources and single scan lenses. Such benefits include, for example, a wider image format, smaller optical spot size, reduced cost, and reduced overall size for the printer.

Abstract: A laser exposing apparatus has a first laser source emitting a first laser beam, a second laser source emitting a second laser beam shorter in wavelength than the first laser beam, and an optical device for directing the first laser beam and the second laser beam to a photosensitive member. The second laser beam has a longer optical path length to the photosensitive member than the first laser beam.

Abstract: An imaging system is equipped with two or more exposure heads that are each able to image either a separate media sheet or a portion of a single media sheet loaded on a media carrier. The imaging time for any combination of media sheets is minimized by providing for the adjustment of the spacing between the dual exposure heads whenever the media configuration changes. In imaging a unitary image using two exposure heads to each image a sub-image, any discontinuity between the end of the first sub-image and the start of the next sub-image is reduced by changing the traversing speed of one of the exposure heads by a fractional amount.

Abstract: A printer includes laser beam detecting sensors for detecting a laser beams at two positions in the main scanning direction. Write clock generating circuits measure a number of counts of a predetermined clock during a period since one of the laser beam detecting sensors detects each of the beams until another sensor detects the beam. A write clock frequency adjusting circuit takes the number of counts for one laser beam as a reference value and adjusts write clock frequencies of other laser beams so as to coincide with the reference value.

Abstract: An image forming apparatus and an image forming method. The image forming apparatus includes a scanner mechanism for reading out image data from an original document, and a printer mechanism for printing an image based on the image data. The printer mechanism includes a first memory for writing in the image data in synchronization with a predetermined first clock signal, a first image processor for processing the image data in synchronization with a second clock signal, a second memory for writing in the image data in synchronization with the second clock signal, a second image processor for processing the image data in synchronization with a third clock signal, and a light controller for generating a light control signal from the image data in synchronization with the third clock signal.

Abstract: An optical scanner is provided having a memory device thereon. The memory device may store operational characteristics of the optical scanner or data that characterizes laser beam scan path and/or laser power requirements by each laser of the optical scanner. The memory device may be used to store historical information such as device temperature, cycles of operation and other historical information of components within a corresponding electrophotographic device. Still further, the electrophotographic device to which the optical scanner is installed may write operational data to the memory device, for example, to store a backup of registration and other operational parameters that are typically stored by the controller of the electrophotographic device.

Abstract: An image signal with an overshoot is generated on a positive-going edge of an input image signal with an overshoot producing unit. Then, a light signal with an overshoot is outputted from a recording light source in response to the image signal with the overshoot supplied from the overshoot producing unit. The light signal outputted from the recording light source is applied to scan a photosensitive medium to record an area gradation image on the photosensitive medium.

Abstract: An image processing device which carries out processing for composing a first image (a color patch image for printing simulation) and a second image (a color patch image for printer management) with image data of a print job, and printing-out. When image data is received from an image processing terminal, image data of a first image and a second image are generated by first and second image generating sections. A first image composing section composes image data of an object of printing and first image data. A color correcting section carries out color correction on the composed image. A second image composing section composes the second image and an image which has been composed by the first image composing section and color corrected. In this way, appropriate printing simulation using an output device such as a printer is possible.

Abstract: A misalignment detector includes a light source, a synthesizing unit, a focusing unit, an image sensor, and a misalignment calculator. The light source, the synthesizing unit, the focusing unit, and the image sensor are arranged in such a manner that light illuminated by the light source passes through the synthesizing unit so as to illuminate the position detection pattern, gets reflected from the position detection pattern, passes through the synthesizing unit so as to be focused by the focusing unit on the image sensor. A misalignment calculator detects an amount of misalignment of the laser beams based on an image formed in the image sensor.

Abstract: A light beam position detecting device detects the passage positions of a plurality of light beams for scanning the surface of a photosensitive drum. The light beam position detecting device has a sensor pattern for generating an output which is continuously changed in a wide range with a variation in the passage position of the light beam in a sub-scanning direction perpendicular to a main scanning direction of the light beam. The sensor pattern precisely detects the relative scanning position of the light beam in a wide range. The passage positions of the plurality of light beams for scanning the surface of the photosensitive drum are controlled to a preset position based on the output of the sensor pattern.

Abstract: An optical exposure method and a device are used for forming patterns on a printed board wiring or semiconductor board. A single exposing region of a surface to be exposed is irradiated with a plurality of optical beams having different irradiating areas and different scanning pitches, such as, a peripheral area is irradiated with an optical beam having a smaller irradiating area and an inner area is irradiated with an optical beam having a larger irradiating area.

Abstract: An optical scanning unit includes an optical deflector, a plurality of scanning optical systems, and a pixel-clock generating unit. A photodetector is arranged in at least two locations on a writing-start side and a writing-end side outside the writing area. The optical scanning unit measures a scanning time, and corrects respective dot positions of image data in the writing area to arbitrary positions based on an amount of fluctuation of the scanning time measured.

Abstract: This invention is to obtain a multi-beam scanning apparatus which always executes synchronization detection at the same timing to prevent any jitter, and an image forming apparatus using the apparatus. In a multi-beam scanning apparatus which guides a plurality of light beams emitted from a light source to an optical deflector, guides the plurality of light beams deflected by the optical deflector onto a target scanning surface through a scanning lens system, and guides some of the plurality of light beams deflected by the optical deflector to a synchronization detecting unit to execute synchronization using a sync signal obtained by the synchronization detecting unit, the synchronization detecting unit includes a BD slit which determines the synchronization detecting timing, and the BD slit has a smooth member.

Abstract: To provide a laser scanning control apparatus for driving a light source adapted to emit a laser beam in accordance with image data defined in pixels to scan an image bearing member in a main scanning direction with the laser beam emitted from the light source through a rotating polygon mirror, the laser scanning control apparatus being characterized by including a correction portion for, every one or more correction points on a main scanning line of the image bearing member to be scanned with the laser beam, extending the pixel length for each pixel located in the correction point concerned to thereby correct the scanning magnification of the main scanning line, and for changing the rotational speed of the rotating polygon mirror to correct the magnification in a sub scanning direction to thereby correct the output magnification.

Abstract: An imaging device for producing multicolor images from image data containing data representing an image of a first color and an image of a second color to be registered relative to the image of the first color onto a substrate by transferring toner of the first and second colors to the substrate is provided. The imaging device includes a first imager, a second imager, a photoreceptor belt, a plurality of rollers mounted to a frame of the imaging device, an angular position sensor, an image data source and a controller. The plurality of rollers define a process path along which the photoreceptor belt is driven past the first and second imagers in a process direction. The plurality of rollers includes a drive roller that exhibits an eccentricity for which a formula relating angular position as a function of the phase angle of the drive roller to eccentricity is known. The angular position sensor detects the phase angle of the drive roller.

Abstract: An apparatus for forming an image by use of a plurality of light beams, which are simultaneously modulated according to image signals and joined together on a photoconductive surface to form the image. The apparatus includes a photoconductive drum having a photoconductive surface and a reference mark, a pattern supplying unit which supplies image data in synchronization with a detection of the reference mark associated with a rotation of the photoconductive drum, and drawing systems which (i) create moiré stripes on the photoconductive surface by simultaneously drawing overlapping sets of slanted lines with the respective light beams according to the image data, and (ii) draw a reference position mark alongside the moiré stripes on the photoconductive surface according to the image data.