Abstract: A method for refining a length of a scan line, where the scan line is produced from a facet of a scanning device. The method includes the steps of: (a) acquiring a plurality of scan line lengths produced from the facet, (b) determining from the plurality of scan line lengths, an average scan line length for the facet, and (c) determining from the average scan line length, a scan line length correction for the facet. A method for measuring a length of a scan line includes the steps of: (a) charging an electrical current integrator to a voltage while a scan line is produced from a facet, (b) measuring the voltage, and (c) determining from the voltage, the length of the scan line produced from the facet.

Abstract: A bi-directional electrophotographic raster imaging system that sweeps a modulated light beam across an imaging region of a photosensitive surface to create both forward-going and reverse-going scanlines of dot data on the imaging region, and which compensates for image misalignment that may be caused by varying the power used to drive a laser light source that generates the modulated light beam. An SOS photosensor detects the beginning of each scanline in both forward and reverse directions, outputting an SOS signal used to create both forward and reverse margins. When the laser power is varied, compensating data is used to correct the forward and reverse margins to keep them aligned (straight), even though the beginning of the scanline locations for both forward and reverse scans are affected in opposite directions by an increase or decrease in laser power.

Abstract: A frequency modulation device for use in an image forming apparatus. The image formation apparatus includes an image carrier and a laser device for scanning the image carrier along a plurality of scan lines. Each scan line is divided into segments having segment boundaries in which the same segment boundary in adjacent scan lines are offset. The frequency modulation device generates frequency data for use in modulating the input image data, which is utilized by the laser device to scan the image carrier, which permits output of an electrophotograph of high image quality by suppressing segment boundaries caused by moiré fringes or color shifting to below a level at which such boundaries are not visually detectable.

Abstract: An optical beam scanning device includes plural light sources, a pre-deflection optical unit, a light deflection unit, a post-deflection optical unit, and a horizontal synchronization unit. One of the formed plural latent images is formed by plural light beams while the other latent images are respectively formed by one light beam, and the light deflection unit deflects the light beams forming the plurality latent images by one surface or integrally processed surface thereof. The horizontal synchronization unit is on a position of an upstream side of scanning lines forming the latent image formed by the plural light beams and detects that the light beam forming the latent image formed by the plural light beams reaches a predetermined position. The image forming apparatus employs the optical beam scanning device and controls timing to form images by the respective light beams with reference to a moment when the light beam to be detected reaches a predetermined position.

Abstract: A light beam scanning apparatus according to an embodiment of this invention includes a reflection unit for reflecting a light beam, a rotation unit for rotating the reflection unit, a rotation control unit for controlling rotation of the rotation unit, a rotational speed detection unit for detecting a rotational speed of the rotation unit, a light amount control unit for, before the rotational speed detection unit detects that the rotational speed has reached a predetermined rotational speed, controlling light emission of the light beam and controlling the light amount of the light beam to a predetermined value, and a light emission control unit for, after the rotational speed detection unit detects that the rotational speed has reached the predetermined rotational speed, controlling a light emission timing of the light beam.

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 image-forming apparatus is disclosed that includes at least one imaging optical system forming an electrostatic latent image on the scanning surface of a medium moving in a sub scanning direction by scanning the scanning surface in a main scanning direction by periodically deflecting a laser beam with a rotary deflector, a pixel clock generation part generating a pixel clock signal for controlling the emission timing of the laser beam and changing the phase of the pixel clock signal, a region setting part setting the length of each of multiple regions based on image writing magnifications in a line in the main scanning direction, the regions being formed by dividing part of the scanning surface corresponding to the line in the main scanning direction, and a phase control part controlling the changing of the phase of the pixel clock signal region by region based on the image writing magnifications.

Abstract: An object is to obtain a multi-beam optical scanning apparatus in which a displacement of an image location of each of light beams emitted from a plurality of light emitting portions is reduced, and which is suitably usable in a high-speed and high-image-quality application, and an image forming apparatus using the multi-beam optical scanning apparatus.

Abstract: In a multi-beam scanning optical system, when at least three light fluxes emitted from a light source having at least three light-emitting points are deflected and reflected on a deflection unit and guided to a surface to be scanned by a scanning optical unit, at least three light fluxes are entered into a deflection surface of the deflection unit at irregular angles within a main-scanning section and entered into the surface to be scanned at an angle within a sub-scanning section, and provided that a variation in lengths of scanning lines which is caused when each of the at least three light fluxes is entered into the surface to be scanned at an angle within the sub-scanning section is represented as ?Y1, a variation in lengths of scanning lines which is caused when each of the at least three light fluxes is allowed to enter as a non-parallel light flux to the deflection surface within the main-scanning section is represented as ?Y2, and a variation in lengths of scanning lines which is caused from a differe

Abstract: An image forming apparatus which is capable of reducing a color misalignment in a color overlapping process, and a color misalignment due to variation of the circumferential length of an intermediate transfer member due to an environmental change over time during a successive copy operation. The image forming apparatus carries out image formation by primarily transferring an image electrophotographically formed on an image carrier onto the rotatably driven intermediate transfer member, and then secondarily transferring the images on the intermediate transfer member onto a recording medium. An image forming operation of primarily transferring the image onto the intermediate transfer member is controlled according to the length of the intermediate transfer member in a circumferentially moving direction thereof and a variation of a predetermined parameter relating to the intermediate transfer member.

Abstract: In an image forming apparatus which uses a semiconductor laser as a light source, a semiconductor laser is controlled by adjustment of an image write-in clock, and a highly accurate scanning position alignment is performed with a simple structure. An optical unit scans a rotational photo conductor by a laser light output by a semiconductor laser. A photodetector detects the laser light output by the semiconductor laser at a predetermined position. An electrostatic latent image is formed by scanning the rotational photo conductor based on the laser light detected by the photodetector. By dividing a clock output from a high-frequency clock generation circuit, an image clock which synchronized with the output of the photodetector is generated, and the phase of the image clock is changed.

Abstract: According to an aspect of the present invention, a light beam scanning apparatus comprises light emitting unit for emitting a light beam, scanning control unit for controlling scanning of the light beam, light quantity detecting unit for detecting the quantity of light in the light beam, light quantity control signal output unit for outputting a light quantity control signal that performs control such that the quantity of light in the light beam is kept fixed on the basis of a result of detection of the quantity of light in the light beam, and light emission control unit for controlling a light emission timing for the light beam on the basis of image data and controlling the quantity of light in the light beam on the basis of the light quantity control signal while the light emission timing is being controlled.

Abstract: A main control section controls a movable beam a such that a passage position thereof may come to a center of a gap between a sensor SK and a sensor SJ, and measures an output difference between a sensor SP and a sensor SO. In this case, the main control section successively measures an output difference between the sensors SP and SO while moving the movable beam a to the center of the gap between the sensors SK and SJ. Similarly, the main control section controls the movable beam a such that the passage position thereof may come to a center of a gap between the sensor SJ and a sensor SI.

Abstract: A writing device is provided which, in simple processes, can write in two dimensions and three dimensions, and which can form highly accurate patterns. An exposure head, a conductive material discharging head, and an insulating material discharging head are disposed at one scanning stage. At the one scanning stage, a pattern can be formed on a printed board which is on the scanning stage. As a result, processes can be simplified, time between patternings can be shortened, and pattern formation can be made to be faster. Moreover, positional offset of the exposure head and the discharging heads with respect to the printed board does not arise. Thus, it is easy to increase a density of a pattern, and a highly accurate pattern is formed.

Abstract: A scanning optical apparatus includes a light source capable of being modulated, a deflecting element for deflecting and scanning a beam emitted from the light source, a scanning optical element for imaging the deflected beam into a spot shape on a scanned surface, and an optical element for synchronous detection for directing the deflected beam from the deflecting element to a sensor to take the timing of image writing beginning. The scanning optical apparatus further inclueds a scanning position detecting device for making the optical axis of the optical element for synchronous detection and the principal ray of the beam from the deflecting element for taking the timing of image writing beginning coincident with each other, and detecting the position of the beam at a point having at least one image height separate from the optical axis of the scanning optical element.

Abstract: An image recording device, wherein deviation of an image-recording start position, which results from a difference in the amount of expansion and contraction based on temperature changes between a printing plate precursor, a rotating support, a mechanism for moving a recording head, and the like, is corrected so that an image can be recorded at a proper position. Temperature 1 near the rotating support is obtained by a first temperature sensor, and temperature 2 near the mechanism is obtained by a second temperature sensor. Then, an amount for correcting an image-recording start position is obtained from a correction table based on the temperatures 1 and 2 and on a size of the printing plate precursor, and the number of drive pulses for correction corresponding to the obtained amount of correction is outputted to a drive motor of the mechanism.

Abstract: A CPU first detects a position of a stationary laser beam using a beam position detection sensor, and then determines a target position of a movable laser beam relative to the stationary laser beam. The CPU effects a control to approach the movable laser beam to the target position in predetermined steps. When the CPU moves the movable laser beam, it checks whether the movable laser beam has moved to the target position. If the movable laser beam has not moved to the target position, the CPU performs a control once again to perform the first detection of the position of the stationary laser beam.

Abstract: An improved method and apparatus for controlling a scanning laser are provided by the present invention. In accordance with a preferred embodiment, a single feedback sensor is placed along the scan path of a scanning laser such that it senses the laser twice during each scan. The time intervals between the sensor sensing the laser are measured and examined to determine the position and direction of the scanning laser. These time intervals may also be used to ensure that the scanning device is operating at its resonant frequency. In systems that require detecting the laser as it enters and leaves the imaging window, a reflective device is used to create a beam path from the edge of the imaging window back to the single feedback sensor such that the sensor detects the laser four times during each scan.

Abstract: A light scanning unit of the present invention can reduce the degree of variation in the quantity of light on a photosensitive body by a scanning position and can reduce a difference in density of an image which occurs at image formation.

Abstract: A method of correcting registration in an electrophotographic machine includes the steps of adjusting one of a right margin and a left margin by setting a time delay, determining a longest line length of a calibration pattern, and adjusting an other of the right margin and the left margin to match the longest line length.

Abstract: In one embodiment, a delay circuit is configured to delay pixel information from an image source, such as a frame buffer. The delay circuit may be configured to delay the pixel information by an amount of time that would move a pixel projected on a surface by a distance less than a dimension of the pixel. A light modulator may modulate a light beam onto a surface, such as a display screen, based on the delayed pixel information. This advantageously allows for sub-pixel electronic alignment.

Abstract: An optical head having a laser source of beams at an input end and image forming beams at an output end and a plurality of optical components arranged along the beams between the input and output ends to obtain an image on a photosensitive printing plate from the beams. The optical components include reflecting surfaces adapted to fold the beams several times between the input and output ends times in such a way as to reduce the width and height of the optical head. The folded beams are located in a plurality of parallel surfaces perpendicular to the image formed on the photosensitive printing plate. The optical head further includes optical components adapted to adjust the width, location, orientation and intensity of the image from the beams.

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: The timing sensors provided in the light-receiving part of a beam-detecting unit have different lengths in the sub-scanning direction. The beam-passing position sensors provided in the light-receiving part of the beam-detecting unit are longer than the timing sensors, in the sub-scanning direction. The intensity of a light beam is controlled in a reference-pitch measuring routine.

Abstract: A simplified system for sensing the movement and/or position on both axes of a moving surface, such as a photoreceptor belt of a xerographic printer, or a sheet transport of an ink jet printer, utilizing a linear track of small and closely spaced “Z” shaped marks on or in a moving belt or roller surface. These marks are used to accurately incrementally directly detect surface motions in both orthogonal axes with a co-linear optical sensor linear array of a multiplicity of individual pixel optical detectors which respectively detect and compare the changes in positions relative thereto of the transverse and angled lines of those Z marks during frequent short measurement intervals. This exemplary system provides direct, and thus more accurate, surface movement measurement information, with much less critical and less costly marking requirements, and greater tolerance for variations in the subject surface, as compared to indirect or conventional encoder type positional sensors.

Abstract: A laser beam scanner converges a laser beam by using a first f? lens and a second f? lens in a main-scanning direction and in a sub-scanning direction, respectively, onto a photosensitive medium, thereby forming a scanning line on the photosensitive medium along the main-scanning direction. Before scanning the photosensitive medium, the laser beam that has passed through and been converged by the first f? lens, but not passed through the second f? lens, is guided to a beam detector and converged by a cylinder lens in the sub-scanning direction so that the laser beam falls within a detection area of the beam detector. The beam detector determines a scan start time by detecting the laser beam.

Abstract: An apparatus to generate a laser beam detect signal includes a reflective mirror arranged on a part of an optical path of a laser beam which forms an electrostatic latent image on a photosensitive body, a beam detect lens to focus the laser beam reflected from the reflective mirror, and a printed circuit board having a photo diode sensor to detect the laser beam passed through the beam detect lens, generating the laser beam detect signal to synchronize a starting point of an image formation of the electrostatic latent image. The apparatus to generate a laser beam detect signal also includes a fixing part to secure the beam detect lens on the printed circuit board so that a center of an optical axis of the beam detect lens is aligned with a detection area of the photo diode sensor. Alternatively, the beam detect lens and the photo diode sensor may be integrally formed with each other. As a result, deterioration of printing quality due to errors from part allowance and an assembling process is prevented.

Abstract: According to a beam control device of the present invention, if an exposure device including a light emitting section is instructed to form an image and a predetermined current is then supplied to an application specific integrated circuit and a main control section, then the main control section outputs an light emitting section on signal. Then, the light emitting section outputs light having its intensity changed according to image information.

Abstract: An image forming apparatus shifts a scanning position on a surface scanned of each of a plurality of optical beams in a main scanning direction and a sub-scanning direction, and scans a plurality of lines simultaneously in the main scanning direction by a deflecting part. A synchronization detecting sensor detects the plurality of optical beams. A counting part counts a clock having a higher frequency than a dot clock in an interval between a synchronization detection point of a first beam and a synchronization detection point of a second beam, the first and second beams being included in the optical beams detected by the synchronization detecting sensor. A determining part determines a starting position of writing for each of the plurality of optical beams based on a counted value counted by the counting part.

Abstract: A recording material is angled and wound on a rotating drum. Distortion (inclination) of an image can be eliminated with a comparatively simple control system, and the occurrence of distortion when there is a change in image recording specifications can be prevented. For standard specifications, although image recording lines have helical movement tracks during image-recording, a peripheral end of a printing plate and a peripheral end of an image region can be made to be parallel with one another without distortion of the image region. In contrast, when instructed specifications differ from the standard specifications, a conventional image region becomes distorted because an inclination angle of the printing plate cannot be varied. Accordingly, in a case in which instructed specifications differ from the standard specifications thus, image data is shifted in a sub-scanning direction by soft processing, and the distortion is alleviated.

Abstract: It is an object of the present invention to provide an image forming apparatus that is capable controlling the rotational speed of a polygon motor so as to reduce variations in the rotational speed of the polygon motor to the minimum possible level and enable steady rotation of the polygon motor with ease in controlling the rotational speed of the polygon motor to a target speed. When a photosensitive drum is exposure-scanned while the traveling direction of an exposure laser beam is deflected by the polygon mirror, a polygon motor for driving the polygon mirror is controlled according to target periods or target speeds of the polygon motor, which are determined for respective mirror planes of the polygon mirror.

Abstract: A laser imaging device is described. The laser imaging device includes a first laser, a second laser, and a controller. The first laser provides a first scan line having a first starting point, and the second laser provides a second scan line having a second starting point based on an adjusted beam detect signal. The controller is configured to generate the adjusted beam detect signal using a delay code and a beam detect signal associated with the second laser to substantially horizontally align the second starting point with the first starting point.

Abstract: An image forming apparatus includes at least one image forming mechanism configured to form an image based on image data. Each image forming mechanism includes an optical system, a sensor, an electronic circuit, and a controller. The optical system scans a photosensitive member with a light beam based on image data. The sensor detects the light beam and the electronic circuit stores a correction data table containing light amount data of the light source and corresponding start position shift amount data. The controller controls a light amount of the light source and adjusts a start position of image recording on the photosensitive member in accordance with a sync detect signal. The controller includes a write start position correction unit that adjust the start position of the image recording based on a start position shift amount data when the light amount varies.

Abstract: A light scanning unit of the present invention can reduce the degree of variation in the quantity of light on a photosensitive body by a scanning position and can reduce a difference in density of an image which occurs at image formation.

Abstract: This invention obtains an image forming apparatus and image forming method capable of achieving a simple, low-cost arrangement by controlling memory write-in/read-out similarly to image signal generation using a single beam even when an image is formed using a plurality of light beams. Write-in of a first light beam image signal in a memory A starts before a first light beam image signal for previous scanning is completely read out from the memory A. Write-in of a second light beam image signal in a memory B starts after a second light beam image signal for previous scanning is completely read out from the memory B.

Abstract: The sensors SP and SO detect a position in the sub-scanning direction through which a light beam scanned by the scanning unit passes. The correction pulse generator corrects the amplitude of the position signal obtained by the sensors SP and SO. The integrator integrates the position signal corrected by the correction pulse generator, and outputs the integration value corresponding to the sub-scanning direction position. The CPU 51 adjusts the correction amount of the correcting unit (the amplitude of the pulse) such that the integration value output from the integrator falls within a target range. The target range is varied in accordance with the light beam position that changes due to an influence caused by a change in the surrounding temperature or the like.

Abstract: A multi-beam scan optical system and an image forming apparatus using the same are provided in which high-quality printing can be realized at high speed with a relatively simple construction.

Abstract: The timing sensors provided in the light-receiving part of a beam-detecting unit have different lengths in the sub-scanning direction. The beam-passing position sensors provided in the light-receiving part of the beam-detecting unit are longer than the timing sensors, in the sub-scanning direction. The intensity of a light beam is controlled in a reference-pitch measuring routine.

Abstract: In a method and apparatus for compensating for static and dynamic inaccuracies in an optical scanner used in a typical surface inspection system, the scanner may have a scanning axis and a cross-scanning axis. A surface of an inspection article is scanned along a scanning axis and a scanning axis signal is output at predetermined distances along this axis. The scanning axis signal may be used to determine a speed of relative movement between the scanner and the inspection article. A jitter signal may be output whenever the scanner deviates from the scanning axis, and this signal may be used to calculate the amount of deviation. Information, such as the speed of relative movement, scan line resolution, and a scanning axis static position error may be used to generate a scan line. A generated scan line may be shifted to compensate for a cross-scanning axis error.

Abstract: An image forming apparatus is constructed to include an image bearing member which is rotatably supported to bear a toner image, a light beam scanning section to simultaneously scan the image bearing member by a plurality of light beams so as to form an electrostatic latent image, a developing section to develop the electrostatic latent image into the toner image, a transfer section to transfer the toner image onto a recording medium, and an ON start timing adjuster to adjust an ON start timing of one of the plurality of light beams, based on an image tone of each of a plurality of patterns of an image pattern formed by the light beam scanning section.

Abstract: An apparatus to detect a laser beam at a predetermined location within a light scanning unit of an image forming apparatus in order to synchronize a start position at which an electrostatic latent image is formed on a surface of a photosensitive body is disclosed. The apparatus includes laser beam detection optics, which may be formed of either a single unit lens or a cluster of one or more lenses that are placed in close proximity of each other. The laser beam detection optics receives the laser beam directed in the direction of the photosensitive body at a predetermined location relative to the start position on the photosensitive body, redirects the received laser beam towards a sensor, and focuses the laser beam on the sensing area of the sensor. The close proximity of, or the fact that the laser beam detection optics, minimizes the possibility of misalignment during the assembly that may result in the improper focusing of the laser beam on the sensor sensing area.

Abstract: A compact light-beam deflecting device with a photonic crystal is provided, which has the capability of deflecting a light beam incident on the photonic crystal by a controlled angle to output a transmitted light beam having a desired direction from the photonic crystal. This light-beam deflecting device comprises the photonic crystal designed to have a photonic band gap wavelength that is different from a wavelength of a light beam to be incident on the photonic crystal, and a deflection controller for applying an amount of energy to the photonic crystal to deflect the light beam incident on a side of the photonic crystal, and to provide a transmitted light beam, which forms the desired angle with respect to the light beam, from the other side of the photonic crystal.

Abstract: A multibeam scanning optical apparatus having a light source, an optical deflector, a scanning optical system, a detection optical element, and a photodetector. A plurality of light beams modulated in accordance with information signals are emitted from the light source and lead to the optical deflector. The light beams deflected by the optical deflector are then focussed on a surface to be scanned, typically a photosensitive drum, by way of the scanning optical system having an f&thgr; characteristic. Part of the deflected light beams are lead to the photodetector by a way of the detection optical system in order to control the timing of the start of scanning so that the centers of the scanning areas of the plurality of light beams agree with each other on the surface to be scanned.

Abstract: A scanning line alignment compensation apparatus and method for a laser printer. The scanning line alignment compensation apparatus includes a laser scanning unit (LSU) having a first laser diode and a second laser diode and at least one sync signal detection sensor that generates a sync signal based on at least one of the first laser diode and the second laser diode based on selectively driving either of the first laser diode and the second laser diode, and generates at least one offset sync signal having first and second sensor detection periods based on the sync signal generated based on the at least one of the first laser diode and the second laser diode; a compensation unit compensating for first and second video data input in synchronization with a video clock based on the first and second sensor detection periods; and a laser diode control unit outputting control signals to control the first laser diode and the second laser diode based on the compensated first and second video data.

Abstract: Disclosed are a frequency modulation apparatus and a frequency modulation method for generating an image clock that is used for turning on/off a laser beam that scans an image bearing member, such as a photosensitive drum. The frequency modulation apparatus divides, into a plurality of segments for each pixel, a main scan line on an image bearing member, and calculates auxiliary clock periods based on a reference clock period and variable-magnification coefficients corresponding to the segments. Then, the frequency modulation apparatus generates image clocks for the respective segments based on an initial predesignated period value and the obtained auxiliary clock periods. Furthermore, the frequency modulation apparatus includes a detecting device for detecting a difference between a reference value stored in a memory and an actual laser irradiation location, and corrects a shift in the laser irradiation location in accordance with the detection results obtained by the detecting device.

Abstract: A polygon scanning system and method is provided wherein two or more light beams impinge at different incident angles on a polygon facet and are sequentially used for scanning the surface of a substrate as the polygon is rotated. Embodiments include a system comprising a polygon having a reflective facet, a rotation mechanism for rotating the polygon, and a light source for directing a plurality of light beams to impinge on the facet such that each light beam impinges on the facet at a different incident angle. Each light beam is reflected by the facet to scan a particular portion of a surface of a substrate during a respective time interval when the rotation mechanism is rotating the polygon. Each of the plurality of light beams is reflected onto the substrate surface using a respective portion of the facet surface, such that the sum of the respective portions of the facet surface used to reflect the light beams is a very large percentage of the total surface area.

Abstract: A laser beam position sensing arrangement using two similar sensors where, instead of the first sensor being aligned normal to the beam scan path, the angle which bisects the two sensors is aligned normal to the beam scan path. The average of times T1 and T2 at which the laser beam is incident the respective sensors is used for the horizontal or start of scan value, and the difference (T2−T1) is proportional to the vertical or process direction value. From the difference between the two determined times, the longitudinal beam position may be determined.

Abstract: In a case of recording (printing) an image including texts and thin lines, the image is printed with an intended thickness without causing a crack in the thin lines. When the CAD mode is OFF in the apparatus proposed by this invention, assuming a pixel value indicative of a printing color component is 8 bits and the maximum value is 255, the value is reduced to, e.g., 90%, before halftoning is performed, and image forming is performed in accordance with the characteristic curve 751 which specifies the relation between the halftoning-processed data and the amount of exposure light. On the contrary, when the CAD mode is ON, halftoning is performed without reducing the pixel value indicative of a printing color components, and image forming is performed in accordance with the characteristic curve 753 which specifies the relation between the halftoning-processed data and the amount of exposure light.

Abstract: A laser imaging device is described. The laser imaging device includes a first laser, a second laser, and a controller. The first laser provides a first scan line having a first starting point, and the second laser provides a second scan line having a second starting point based on an adjusted beam detect signal. The controller is configured to generate the adjusted beam detect signal using a delay code and a beam detect signal associated with the second laser to substantially horizontally align the second starting point with the first starting point.