Abstract: To provide an image forming apparatus having a plurality of optical systems each simultaneously scanning two stations by one polygon mirror to minimize conveyance-directional color misregistration of an intermediate transferring belt. An electrophotographic color laser printer connected with a host computer is provided with a scanner unit common to first and second stations, a scanner unit common to third and fourth stations, and a registration-position detector for reading an image pattern formed on an intermediate transferring belt and detecting a registration position of an image of a laser beam. The plane phase of the polygon mirror in the first and second stations is controlled and central positions of image patterns by two laser beams are detected to correct the misregistration between these central positions.

Abstract: An electrophotographic apparatus has a beam spot made to have a small spot diameter by the use of a laser having an oscillation wavelength within the range of from 380 nm to 450 nm, and enables image reproduction at ultra-high resolution and with ultra-high image quality. The apparatus includes I) an electrophotographic photosensitive member unit having i) an electrophotographic photosensitive member having a photosensitive layer on a cylindrical support and ii) fitting members fitted to the end portions of the electrophotographic photosensitive member, and II) an exposure device having a laser having an oscillation wavelength within the range of from 380 nm to 450 nm, and in which a spot diameter Di (?m) of a beam spot formed on the surface of the electrophotographic photosensitive member by a laser beam emitted from the laser is 40 ?m or less, and the cylinder deflection De (?m) of the electrophotographic photosensitive member unit is 1.5 times or less the spot diameter Di (?m) of the beam spot.

Abstract: An integrated circuit for an optical encoder comprises a signal processing section for generating a position detection signal from a detection signal of a light receiving element, a belt-like power source potential layer which is formed at least between the signal processing section and the light receiving element and whose potential is pulled up to power source potential, and a plurality of conductive layers formed at various heights higher than the power source potential layer. A connection line which intersects the power source potential layer above the power source potential layer for electrically connecting the light receiving element and the signal processing section is formed by a conductive layer of the plurality of conductive layers other than the lowermost layer, in a region immediately above the power source potential layer. By keeping the power source potential layer as far away from the connection line as possible, power source noise entering the position detection signal is reduced.

Abstract: A method of inspecting an OLED device to locate and characterize defects in the registration of organic material(s) transferred from a donor in swaths in response to heat produced by a multichannel laser print head includes optically inspecting the OLED device after or during manufacture to identify the boundaries between swaths of transferred organic material(s), and determining if the swaths overlap at a seam of the boundary or if there is a gap between swath edges at the seam or if there is an offset between the edges of adjacent swaths.

Abstract: A method of controlling a laser to print symbols of an image on moving products with various velocities. The method may include grouping, organizing and/or moving symbols to stripes, leading edge clipping correction, trailing edge clipping correction and updating clipping correction in real-time.

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: A record head for applying laser light for drawing to a record medium and a record medium are supported so that they can be relatively moved in a main scanning direction and a sub scanning direction along the surface of the record medium through a move guide mechanism. The record head has a laser displacement sensor for detecting the distance to the light exposure position of the record medium in a noncontact manner. A record apparatus has an auto focus mechanism for correcting misregistration between the focus position of the laser light for drawing emitted from the record head and the record medium to a reference value based on the detection value of the laser displacement sensor, so that the focal distance between the record head and the record medium is held good regardless of deformation of a guide rail of the move guide mechanism, etc.

Abstract: A method of correcting plane-to-plane registration in an electrophotographic machine having a plurality of color planes includes the steps of printing a calibration pattern using each of the color planes; measuring at least one misregistration between the color planes on the calibration pattern; adjusting at least one top margin by setting a first time delay before a first line; adjusting one of a right margin and a left margin by setting a second time delay; determining a longest line length of the calibration pattern; and adjusting an other of the right margin and the left margin to match the longest line length.

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: 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 optical scanner can write a full-color image without occurrence of writing position differences even if a record density is switched. The optical scanner includes a black writing illuminant for optically writing an image at a plurality of record densities and a color writing illuminant for optically writing the image at a predetermined record density. The optical scanner adjusts a resist position for a full-color image with respect to the main and sub-scanning directions by switching a writing position of the black writing illuminant in accordance with a requested record density and then writes the full-color image at that writing position.

Abstract: An image forming apparatus capable of decreasing the image unevenness of a superimposed image at the time of forming starting (head) lines of the images in respective colors with different beams in order to decrease a shift of a superimposed image. Let a position, where an image in a first color is formed with a beam A as a leading beam, be (a). Let a starting position of formation of an image in a second color be (b), and one dot (line) of shift arises in the superimposed image. In order to decrease the shift of the superimposed image, image formation is performed with selecting a beam B as a beam which writes a head of the image (c). When image formation is performed for color shift reduction with changing a leading beam for each color image, tonality correction is performed to each beam for subsequent images so as to decrease image unevenness due to the difference between shapes and exposure power of respective beams.

Abstract: A multiple resolution imaging system employs an array of imaging devices each tracing a helical pattern on a recording medium. The imaging devices may be activated sequentially along multiple interlaced helical paths to allow a selectable image resolution with reduced imaging artifacts.

Abstract: An image forming device is provides, which comprises a body to be scanned that moves in a sub-scanning direction; a writing means for scanning the body in a main scanning direction with a light beam according to image information to form a reference image on the body and repeating the scanning plural times to form plural images; and a second body on which the plural images are overlaid to form a color image. The writing means starts writing the reference image at a start time ty1 when a main scanning synchronizing signal is firstly generated by the writing means after a time tx1 when a predetermined time has lapsed from detection of an image forming start signal of the sub-scanning direction for the reference image. A start time for an image other than the reference image is changed depending on the start time of the reference image.

Abstract: A color synchronization method and a color laser printer form a color image by forming an electrostatic latent image on a photosensitive body using a laser scanning unit, developing the electrostatic latent image, and transferring the developed image onto a transfer belt. The printer includes a light source which radiates light, a timing belt which rotates the photosensitive body, a plurality of timing displays, which are provided on the timing belt at a constant interval, and on which the light radiated from the light source is incident, and a light receiving portion which detects the light reflected or transmitted by the timing displays. Synchronization for each color is controlled in response to a signal received by the light receiving portion.

Abstract: First and second light receiving windows are formed on a head cover of a thermal head. The first light receiving windows are disposed to cross the lateral edges of the first king-sized recording paper. The second light receiving windows are disposed to cross the lateral edges of the second large-sized recording paper. First and second phototransistors are provided on the thermal head so as to measure quantity of light passed through the first and second light receiving windows. When printing the first recording paper, the first light receiving windows are partially shielded with lateral edges of the first recording paper and the second light receiving windows are completely shielded with the recording paper. Positions of the lateral edges are determined from the difference between output signals of the two phototransistors. When printing the second recording paper, the first light receiving windows are shielded by light-tight shielding stickers.

Abstract: There is provided an image forming apparatus able to form color images of higher quality without color deviation in an inexpensive way. A displacement driving unit is provided to move an optical element unit to displace a beam spot on a photoconductor in the sub scanning direction. A first detection unit is provided to detect the turning cycle of a transfer member, and a second detection unit is provided to detect writing timing of a laser beam from the optical element unit on the photoconductor. When writing a number of toner images on the photoconductor in sequence, the optical element unit is moved and the beam spot is displaced on the photoconductor in the sub scanning direction to correct the writing position on the photoconductor and eliminate deviation of image transfer positions on the transfer member.

Abstract: Disclosed is a scanning optical apparatus which can reduce color misregistration in a sub scanning direction to thereby obtain a good color image output, and a color image forming apparatus using the same. In the scanning optical apparatus, a beam emitted from light source means 1 is deflected by deflecting means 5, and the beam deflected by the deflecting means is imaged in a spot shape on a surface 7 to be scanned by scanning optical device, and light-scans on the surface to be scanned, and a scanning line scanning on the surface to be scanned has two or more extremums within the effective range of a scanning area.

Abstract: A method and apparatus for aligning in five degrees of freedom a multichannel laser printhead to be used in thermal transfer of material from a donor to a substrate is disclosed.

Abstract: An input value Y of digital data with respect to a D/A conversion unit for coarse adjustment and an input value X of digital data with respect to a D/A conversion unit for fine adjustment are controlled so as to allow a galvano-mirror to rotate in a direction in which a setting position of a laser beam B is within a predetermined position.

Abstract: An image forming apparatus forms on a photoconductive body an evaluation chart including first patterns and second patterns. In the first pattern, with respect to a row of dots formed in a main scan direction by a predetermined light beam, a row of dots formed by a next light beam is shifted in the main scan direction, and in the second pattern, with respect to the row of dots formed in the main scan direction by the predetermined light beam, the row of dots formed by the next light beam is shifted in the main scan direction but in a direction opposite to a shift direction of the first pattern. The evaluation chart includes a first pattern group which is formed by the first patterns which are repeated, and a second pattern group which is formed by the second patterns which are repeated.

Abstract: An image forming apparatus including a light beam generating and modulating device that generates and modulates a light beam based on an image signal, and a light beam deflecting device that deflects the modulated light beam and scans an image carrier to form an image. A pair of light beam detecting devices detects the deflected light beam at two separate positions on a main scanning line. A time difference measuring device measures a time difference between time periods when the light beam is detected by one of the light beam detecting devices and by the other of the light beam detecting devices. An image magnification correcting device changes write clock frequency of the light beam and rotation number of the light deflecting device based on the time difference to correct magnification error in the main scanning direction of the image on the image carrier.

Abstract: An optical scan apparatus includes an optical deflection unit (4), an image formation optical system (3), and curved surface mirrors (7a to b 7d). Light fluxes from the image formation optical system (3) come onto the deflection surface (4a) of die optical deflection unit (4) in an oblique direction. Light fluxes from the optical deflection unit (4) come onto the curved surface mirrors (7a to 7d) in an oblique direction. When a boundary is a plane (6) including a normal at the center of the deflection surface (4a) and parallel to the main scan direction, the curved surface mirrors (7a to 7d) are arranged in the same space divided by the boundary and the scan speeds of fluxes scanning the surfaces to be scanned (8a to 8d) are almost identical. Thus, it is possible to obtain identical drive frequencies of the light sources (1a to 1d), thereby simplifying the circuit.

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: 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: 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: An image detection device includes a light source, an image sensor, a light guiding device, an image focusing device and a housing. The light source is configured to irradiate a pattern image with a light beam. The light guiding device is located on a first light path from the light source to the pattern image and is configured to guide the light beam irradiated by the light source to the image and further guide the light reflected from the pattern image to the image sensor along a second light path. The image focusing device is located on the second light path of from the light guiding device to the image sensor and is configured to focus the light reflected from the pattern image on the image sensor. The housing is configured to contain the light source, the image sensor, the light guiding device and the image focusing device.

Abstract: The relationship between first and second side images is evaluated to determine how the position of the paper and/or the size and arrangement of an image can be manipulated to compensate for paper shrinkage caused by fusing. Show through is reduced by performing setup to adjust a pixel clock frequency and/or a photoreceptor speed, determining a residual magnification error, determining margin shifts to compensate for the residual magnification error, and applying the margin shifts. Paper shrink effects on registration can be compensated for using determinations made during a typical printer setup. Show through errors can be reduced without using a paper conditioner to pre-shrink or re-wet the paper. In simplex and duplex printing, the show through errors worsen as the image moves away from the registration edge. Using information obtained during setup, a margin shift is determined that results in a significant reduction in the maximum show through for each image.

Abstract: Described is a method for imaging a printing form (10) using one or more laser diode bars having a number n of individually controllable laser diodes (16) whose imaging spots (20) lie essentially in a row on the printing form (10), for the case that at least one laser diode (16) on the laser diode bar (14) cannot be activated, but a maximum number m of laser diodes (16) whose neighboring imaging spots (20) have a distance a on the printing form (10) are able to be activated. The relative speed between the imaging device (12) and the printing form (10) is increased by the factor (n/m). The exposure time per printing dot (69) is shortened by the factor (m/n). In order to input in each case an amount of energy per printing dot (69) on the printing form (10), imaging is carried out using the m activatable laser diodes (16) with an imaging intensity which is a function of the exposure time and of the specific amount of energy per printing dot (69).

Abstract: One color is determined as a reference, and adjustment is carried out such that other color is matched with a detection signal generated from a synchronous detector of this color. Each control circuit of other color generates a mark pulse signal by determining an optional position based on a DP generated from each synchronous detector. A reference color control circuit receives a mark signal, and measures time relative to the reference. A CPU checks whether a result of this measurement coincides with a target value. The CPU changes the setting according to the difference, and repeats the measurement until when there is no difference, thereby obtains an adjustment value.

Abstract: An optical scanning device includes a plurality of light sources, a drive circuit connected to the light sources to drive the light sources independently with from each other in a modulating manner, a deflector having a plurality of deflecting surfaces to deflect rays emitted from the light sources and scan imaging optical systems directing the deflected rays onto different scan surfaces respectively. The optical scanning device further includes synchronization detection means for receiving the rays before start writing onto the scan surface and outputting synchronization detection signals, delay time adjusting means for adjusting delay time, the delay time being a time period after outputting the synchronization detecting signal until starting the writing operation, and frequency adjustment means for adjusting driving frequencies of the light sources.

Abstract: A multi-beam scanning device including a multi-beam light source including plural laser diode arrays emitting plural laser beams and at least one coupling lens; a deflector configured to deflect the plural laser beams; an optical system configured to guide the deflected plural laser beams to an image forming surface; a body configured to contain the multi-beam light source, deflector and scanning optical system; and an adjustment member located between the body and the multi-beam light source and configured to adjust the beam pitch of the plural laser beams in the sub-scanning direction. An image forming apparatus including an image bearing member, the above-mentioned scanning device and an image forming device.

Abstract: An edge detection apparatus for detecting an edge on a surface. The apparatus comprises a source of coherent radiation for generating a radiation beam and directing the beam onto the surface. A radiation detector is located so as to detect radiation diffusely reflected, but not specularly reflected, from the surface. A system is provided for causing relative scanning movement between the radiation beam and the surface. A monitor is coupled to the detector for monitoring the intensity of the detected radiation.

Abstract: Correction of a positional deviation of split scanning lines in a sub scanning direction and modification of an image information split position are performed with a simple circuit configuration. When addresses of storage units in which split image information pieces A and B are stored are determined by address specification units, a overlap area is allocated in advance so that a split position is set based on image information split position information. As a result, dummy signals corresponding to off signals for a light source are stored in a storage unit other than storage units in which image information is stored. The dummy signals exert no influence on counterparts in the overlap area, and it is unnecessary to change a write address each time a split position is modified.

Abstract: A method and a device for imaging a printing form (48) via at least two imaging modules (40,418) which each have at least one light source are disclosed for avoiding the banding effect that an imaging in a transition region (416). The two imaging modules (40,418) are provided in such a manner that a number of at least partially not-simply connected printing dots are produced in the transition region (416) by the first imaging module (40) and the complementary, not-simply connected printing dots are produced in the transition region (416) by the second imaging module (418).

Abstract: Upon adjustment before the adjustment of a heat development recording apparatus, a continuous recording pattern is outputted. The recording density of this continuous recording pattern is measured by a recording density measuring unit. A shading correction table for each pixel is formed and the shading correction table is registered in a storing unit. On the other hand, after the heat development recording apparatus is shipped without mounting the recording density measuring unit thereon, a discrete recording pattern is outputted. The recording density of the discrete recording pattern is measured for each discrete recording position to generate a shading correction table. The shading correction table registered in the storing unit is updated. Therefore, it is possible to reduce a cost while a good shading correction function is ensured.

Abstract: A method for printing is described. The method includes providing a printing system for printing a code on a product moving in a direction. The code is constructed from a plurality of pixels in a first data set indicating the positions of the pixels and generates a corrected data set indicating the position that each pixel would occupy if each pixel was moved at the velocity of the product until the pixel was printed. The method also includes printing the code according to the corrected data set.

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 laser imaging apparatus includes a scanning unit that emits at least one scanning laser beam, which scans on a surface to be scanned in a main scanning direction to form a scanning section. A plurality of position marks formed on the surface are detected to determine the distortion of the surface to be scanned. A calculating system is provided to calculate an inclination of each scanning section with respect the main scanning direction, and a scaling factor of each scanning section with respect to a predetermined length in the main scanning direction based on the shape of the surface to be scanned. Then, when image is formed, the rotational position of the surface to be scanned is changed in accordance with the inclination, and a start position of each scanning section on the surface to be scanned is changed in accordance with the scaling factor.

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 the photoconductive surface and a reference mark, a pattern supplying unit which supplies image data in synchronization with detection of the reference mark associated with rotation of the photoconductive drum, and drawing systems which create moir{acute over (e )} stripes on the photoconductive surface by simultaneously drawing overlapping sets of slanted lines with the respective light beams according to the image data, and draw a reference position mark on the photoconductive surface according to the image data.

Abstract: A pixel clock generation apparatus includes a detector detecting a time interval between two horizontal synchronization signals. A comparing part compares the time interval detected by the detector and a target value, and outputs the difference. A phase shift data generation part stores one or more lookup tables each storing a pattern of phase shift data for controlling a phase shift amount of a pixel clock, and reads and outputs the phase shift data from the lookup table based on the difference that is output from the comparing part. A high frequency clock generation part generates a high frequency clock. A pixel clock generation part generates the pixel clock whose phase is controlled in accordance with the phase shift data based on the high frequency clock.

Abstract: A color shift correcting method for correcting a color shift due to misregistration of images in different colors, where a multi-color image is formed by developing latent one-color images written onto respective image carriers by an optical writing device, and directly or indirectly transferring developed one-color images onto a movable element, said method comprising the step of:

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 system architecture for scanned non-linearity correction in a printer uses any raster output scanner having scanned non-linearity profile previously stored in memory from a test station installed with any pixel board. The pixel board includes a correction table register wherein the pixel board utilizes the scanned non-linearity profile of the raster output scanner to calculate the correction table register to correct for pixel misregistration.

Abstract: A display apparatus includes a scanning assembly that scans about two or more axes, typically in a raster pattern. A plurality of light sources emit light from spaced apart locations toward the scanning assembly such that the scanning assembly simultaneously scans more than one of the beams. The light sources are positioned such that their beams each illuminate discrete regions of the image field that are substantially non-overlapping with respect to the other discrete regions. The image is thus formed from a set of “tiles”. By activating a first light source during a forward sweep of the mirror and activating a second light source during a reverse sweep of the mirror, two halves a common line can be written during a single sweep of the mirror. Shifting the position of the sources such that the two halves are aligned reduces raster pinch. In alternative embodiments, the same approach is used for imaging.

Abstract: An electronic still camera with a printer includes a vibration detector and a system controller. The vibration detector detects vibration relative to a moving direction of an exposure head of the printer. When the vibration detector detects the vibration exceeding a prescribed level, the system controller interrupts a printing operation of the printer. After that, when the vibration detector detects the vibration falling below the prescribed level, the system controller resumes the printing operation. The exposure head is adapted to be moved, performing the printing operation one line by one line. Until the printing operation for one line is completed, the system controller suspends to interrupt the printing operation.

Abstract: A color image forming apparatus for forming a color image on a storage medium using a laser beam generated from a laser generating means includes a plurality of image data interfaces provided between the color image forming apparatus and a peripheral device, image data interface conversion means for converting each of the image data interfaces into an image data interface for the laser generating means, and a single control means for controlling a drive timing of the laser generating means, the control means controlling the drive timing of the laser generating means for each one of a plurality of colors based on image data input from the image interface conversion means.

Abstract: An image forming apparatus, which includes a plurality of image forming portions transferring a yellow image, a magenta image, a cyan image, and a black image formed on a plurality of photoconductor drums to a sheet conveyed on a conveying belt, a marking unit forming marks on the conveying belt, a detecting unit detecting the marks with three or more sensors aligned in a direction normal to a direction in which the sheet is conveyed, a calculating unit calculating an amount of color misalignment in accordance with results detected by the detecting unit, and a correcting unit correcting the color misalignment in accordance with the calculated amount of color misalignment, wherein the calculating unit calculates an amount of skew difference in accordance with results detected by two sensors among the three or more sensors, wherein one sensor of the two sensors is disposed on one end of the three or more sensors and the other sensor of the two sensors is disposed on the other end of the three or more sensors, w

Abstract: The image recording method and apparatus deflect light from a group of two-dimensionally disposed light source elements to move an image formed on a recording medium in accordance with a movement of the recording medium, or shift modulation data of the group of two-dimensionally disposed light source elements in a first moving direction of the recording medium on the group of two-dimensionally disposed light source elements in synchronism with the movement of the recording medium, and thereby have the image remain stationary relatively to the recording medium in the main scanning direction, as well as shift sequentially modulation data of the group of two-dimensionally disposed light source elements in a direction opposite to a second moving direction of the optical system in synchronism with a movement of the optical system in the auxiliary scanning direction, and thereby having the image also remain stationary relatively to the recording medium in the auxiliary scanning direction.

Abstract: A method includes providing a plurality of clock signals. Each of the clock signals is associated with a respective one of a plurality of printheads in an electrophotographic machine. Each of the clock signals has a respective frequency. The method also includes using the printheads to create a plurality of raster lines. Each printhead is used to create the raster lines with a respective length. The length is dependent upon the frequency of the associated clock signal.