Abstract: A prediction value determination method, an encoder and a decoder are provided. The method is applicable to an encoder or a decoder, and the method comprises: acquiring reconstructed blocks of a block to be encoded, a number of the reconstructed blocks being more than one; processing template pixel matrices of the reconstructed blocks according to preset processing parameters to obtain processed template pixel matrices; determining a matched block of the block to be encoded according to the processed template pixel matrices; and determining a pixel matrix of the matched block of the block to be encoded as a prediction of the block to be encoded.

Abstract: An apparatus for reducing a temperature influence in measuring a switching current based on stray inductance. The apparatus includes a current detector configured to output a voltage derived from a differential component of a current so as to detect a switching current of a power module, a filter configured to filter the voltage output from the current detector, an integrator configured to integrate a voltage output from the filter, an ADC configured to convert an analog voltage output from the integrator into a digital voltage and sample the digital voltage, a scaler configured to convert a sampled integrator output value output from the ADC into a scaled current value, and a compensator configured to remove a temperature dependent DCR effect from the scaled current value.

Abstract: According to one embodiment, an image forming apparatus includes an image forming unit to form an image on a sheet and a sensor with a light emitting part having a light emission intensity that changes according to an input voltage level and a light receiving part that outputs an output value that changes according to the amount of incident light. The sensor is configured to detect a toner density of the image formed by the image forming unit. A power supply unit is provided to supply power to the light emitting part and change the input voltage level of the power supplied to light emitting part in a predetermined sequence until an end condition is satisfied during an inspection operation. A controller is configured to make an abnormality determination based on a state of the sensor when the end condition is satisfied during the inspection operation.

Abstract: An image processing system and method provide for receiving a current print job comprising a set of digital page images to be printed on print media sheets, identifying, for each page image, a set of input parameters, the set of input parameters including one or more of a print media sheet weight, a print media sheet size, a print media sheet thickness, a print media sheet porosity, a print media sheet coating, a print media sheet color, and an area coverage. The method further includes generating an adjustment for each page image, based on the set of input parameters and based on stored magnification errors generated for prior printed pages of print jobs, the adjustment being predicted to reduce at least one magnification error when the page image of the current print job is rendered on print media to form a printed image.

Abstract: An image forming apparatus includes a rotatable photosensitive member, a charging unit, a developing unit, a support frame, and a sensor unit. The sensor unit is detachably attached to the support frame in a direction that intersects a rotation-axis direction of the photosensitive member and includes a potential sensor, a support portion, a fixing portion, an electric board, and a linking portion. The support portion supports the potential sensor at an area from the charging unit to the developing unit in a rotational direction of the photosensitive member. The fixing portion is fixed to the support frame at a position that faces an area from the developing unit to the charging unit in the rotational direction of the photosensitive member. The support portion is positioned with respect to the support frame at a position downstream of the support portion in an attachment direction of the sensor unit.

Abstract: A printing instructing apparatus includes a designation-information transmission unit and a printing-information transmission unit. The designation-information transmission unit transmits, to a management server, designation information that is information different from printing information indicating content of a printing target and that includes printing designation information designating the printing information. The printing-information transmission unit transmits the printing information corresponding to the printing designation information to one of multiple printers without transmitting the printing information to the management server.

Abstract: An image forming apparatus includes: a photosensitive member; a charger unit configured to charge the photosensitive member; an exposing unit configured to form a latent image by scanning the photosensitive member by laser light which has a different spot diameter in accordance with a scanning position of the photosensitive member in a main scanning direction; a developing unit configured to develop an image by adhering a toner to the photosensitive member on which the latent image is formed; and a control unit configured to control a luminance of the laser light and a resolution of the photosensitive member in a sub-scanning direction in accordance with the scanning position of the photosensitive member in the main scanning direction.

Abstract: An example laser assembly for a laser printer may include a plurality of lasers to emit respective photons; a prism to redirect the respective laser beams emitted from the plurality of lasers toward a collimator lens of the laser printer to generate a photon beam; and one or more processors to: determine a timing schedule for individually activating the plurality of lasers based on a resolution setting of the laser printer, and when printing at a resolution corresponding to the resolution setting, control activation of each of the plurality of lasers to emit the respective photons according to the timing schedule to form the photon beam.

Abstract: An imaging system with image data path delay measurement includes (a) a first image sensor chip that includes a pixel array for generating a first image in response to light incident upon the pixel array, and a time mark generator for, upon receiving a time mark command, encoding a signature in the first image to generate a first marked image with the signature and image data from the first image, and (b) an image signal processing chip for processing the first marked image, wherein the image signal processing chip includes a data path delay measurement module for generating the time mark command and estimating image data path delay from the pixel array to the data path delay measurement module based upon time delay between (i) generating the time mark command and (ii) receipt of the signature as part of the first marked image.

Abstract: An image reading system includes a reading device, a first calibration unit, and a detection unit. The reading device is configured to read a white reference member to acquire white image data and configured to read an original document to acquire document image data. The first calibration unit is configured to calibrate shading of the document image data to generate first image data by performing converting a density value in the document image data to a gradation value that is proportional to the density value and falls within a predetermined range having a minimum gradation value, a maximum gradation value, and a target value less than the maximum gradation value. The density value equal to the corresponding density value is converted to the target value in the conversion. The detection unit is configured to detect pixels in the image data corresponding to an edge of the original document.

Abstract: A PWM signal generating apparatus configured to generate a PWM signal by applying parallel serial conversion to pattern data obtained by converting input data into a waveform pattern of a PWM signal having one pulse divided into a predetermined number of pulses, the PWM signal generating apparatus including: a clock generating circuit configured to generate a plurality of clock signals having mutually different phases; a conversion circuit configured to convert the input data into the waveform pattern of the PWM signal; an encoding circuit configured to generate, from the waveform pattern, a plurality of encoded signals synchronized with respective clocks of the plurality of clock signals generated by the clock generating circuit; and a decoding circuit configured to generate the PWM signal from the plurality of encoded signals output from the encoding circuit.

Abstract: An image forming apparatus that includes a first control unit and a second control unit. The first control unit performs control of a load by outputting a pulse signal based on a clock signal output by a first oscillator. The second control unit is connected to the first control unit by a serial communication signal line, and performs control of a load by outputting a pulse signal based on a clock signal output by a second oscillator. The second control unit measures a width of the pulse signal output from the first control unit via the serial communication signal line, compares a pulse signal width designated by an adjustment request with the measured width of the pulse signal, and corrects, based on a result of the comparing, the width of the pulse signal that is based on the clock signal output by the second oscillator.

Abstract: A rotary encoder system for registering the rotary angle position and/or angular speed of a rotary shaft which extends along an axis of rotation, including at least two optical marks at the rotary shaft, an optical sensor with a pixel matrix having pixel points, an imaging device for imaging each mark in a substantially axial direction on the pixel matrix as a mark image, and an evaluation device for reading and evaluating the pixel matrix in order to determine data in relation to the rotary angle position and/or angular speed. Further, the marks, the imaging device and pixel points are embodied in such a way that the mark images on the pixel matrix have at least the area of a pixel point, and the evaluation device is embodied to establish the location of the centroids of the mark images on the pixel matrix.

Abstract: An optical scanning device is provided with a housing, a plurality of laser light sources, and a substrate. The laser light sources are attached to a side wall of the housing in a state wherein three terminals are protruding outward. The substrate is disposed to face an outer surface of the side wall of the housing. The laser light sources include: a first laser light source having a predetermined angle with respect to the substrate; and a second laser light source having a symmetrical angle to the angle of the first laser light source with respect to the substrate. In the first laser light source, only one of the three terminals is bent in the direction to be separated from other two terminals, and the second laser light source is disposed by inverting 180° a laser light source having a configuration same as that of the first laser light source.

Abstract: A scanning projector and method is provided that generates a feedback signal from at least one photodetector. In the scanning projector, a scanning mirror is configured to reflect laser light into an image region and an over scanned region. The at least one photodetector is configured to receive a portion of the reflected laser light impacting the over scanned region, and provides the feedback signal responsive to the received portion of light. This feedback signal can then be used to provide precise control of the scanning mirror.

Abstract: An exposing unit forms a scanning line by exposing an image surface in a main scanning direction, and forms a plurality of pixels arrayed in the main scanning direction by sequentially forming a plurality of scanning lines shifted in a sub-scanning direction. A clock generator generates frequency-spread clocks having frequency that is spread with a particular modulation period and that changes in accordance with a modulated waveform corresponding to the particular modulation period. A driver drives the exposing unit to emit light during light emitting time that is determined from the frequency-spread clocks. The plurality of scanning lines is formed with respective phases of the modulated waveform. The phases corresponding to the plurality of scanning lines are shifted from each other for compensating, among the plurality of scanning lines, deviations of the light emitting time relative to a reference value, for each of the plurality of pixels.

Abstract: Disclosed is an image deformation device, including: a primary memory in which a positional correction amount data for each pixel, is stored; a reference memory having a smaller storing area than the primary memory; a transfer unit configured to transfer the positional correction amount data stored in the primary memory to the reference memory separately in multiple times; and a positional correction unit configured to carry out a positional correction process, wherein the transfer unit transfers the positional correction amount data according to the predetermined order and a progress of the positional correction process in the positional correction unit so that the positional correction amount data for one pixel has been already stored in the reference memory when the positional correction unit corrects the position of the one pixel.

Abstract: Included is an image bearing member; an exposure unit configured to form electrostatic latent images by scanning light on the image bearing member and to change the amount of light along the scanning direction of the light; a forming unit configured to form a toner patch on the basis of the electrostatic latent image formed by a plurality of different light amounts, to adjust the light amount of the exposure unit; a detection unit configured to detect the toner patch; and a control unit configured to adjust the light amount of the exposure unit along the scanning direction of the light depending on the detection result by the detection unit. The control unit changes the light amount of the exposure unit along the scanning direction of the light over a portion of regions rather than all regions in the scanning direction when forming the toner patch.

Abstract: An image forming apparatus for performing laser exposure is provided. The image forming apparatus includes a driving circuit for supplying drive current to a laser light source in accordance with an image pulse signal; a pulse width expansion portion for expanding a pulse width of the image pulse signal supplied to the driving circuit; and an adjustment control portion for setting, based on state data indicating a state related to light emission start characteristics of the laser light source, a value of the bias current supplied as a part of the drive current to the laser light source and an amount of expansion of the pulse width in such a manner that laser light emission occurs in a period of time having a length equal to a length of a pulse width of each pulse in the image pulse signal.

Abstract: In accordance with one embodiment, an image forming apparatus comprises a plurality of light-emitting elements arranged in a line, an image forming section and an exposure control section. The image forming section develops, with developing agent, a latent image formed on a photoconductive drum through the light from the light-emitting elements which emit light according to printing data. The exposure control section controls the operations of the plurality of light-emitting elements according to shifted printing data obtained by shifting the printing data in a case where the number of printings based on the same printing data is more than one.

Abstract: An optical scanning device includes a light source emitting light to form an image by optical scanning; and a control section generating a control signal, which is for turning on and off the light source, based on an image signal. Further, the control section generates a pulse signal having a redetermined time width when the image signal indicates that the light source is to be turned off.

Abstract: An exposure apparatus according to this invention uses, as a correction value, the difference between a threshold current obtained from the light emitting characteristics of a single laser light source when only the single laser light source emits a laser beam, and a threshold current obtained from the light emitting characteristics of the single laser light source when the single laser light source emits a laser beam while the bias currents are supplied to the remaining laser light sources other than the single laser light source. The exposure apparatus uses the correction value to correct bias currents and switching currents determined by APC, and exposes the surface of an image carrier with laser beams output from the plurality of laser light sources based on the corrected bias currents and switching currents.

Abstract: An image forming apparatus includes a photoconductor, a charger to charge the photoconductor, a multi-beam scanning unit, a development unit, and a transfer unit. The multi-beam scanning unit includes a vertical cavity surface emitting laser as a light source having light emitting elements arrayed in main and sub-scanning directions by setting an interval between light emitting elements adjacently disposed at a center portion of the scanning unit in the sub-scanning direction narrower than an interval between other light emitting elements adjacently disposed at other portions of the scanning unit in the sub-scanning direction, a deflecting element to deflect light emitted from the light emitting elements to scan the surface of photoconductor by an interlace scan, and a light intensity adjustment unit to adjust light intensity of the light emitting elements adjacently disposed at the center portion relative to a light intensity of other light emitting elements adjacently disposed at other portions.

Abstract: A method, non-transitory computer readable medium, and apparatus for adjusting a light intensity of a printhead are disclosed. For example, the method receives an image comprising a plurality of pixels, calculates a correction factor for each one of a plurality of pixels of the image by applying a filter to each one of the plurality of pixels of the image and summing a contribution of the light intensity of each one of a plurality of surrounding pixels to a pixel being analyzed to calculate an overlap value and comparing the overlap value to a development threshold range and adjusts the light intensity of a light source of the printhead in accordance with the correction factor of each one of the plurality of pixels of the image that require toner.

Abstract: A semiconductor laser driver to drive at least one semiconductor laser, the semiconductor laser including a storage device, an emission-intensity setting device, and a drive circuit. The storage device stores emission-intensity switching data to control light-emission intensity of the semiconductor laser, the emission-intensity setting device sets the light-emission intensity based on the emission-intensity switching data stored in the storage device, and, the drive circuit generates a driving current to drive the semiconductor laser based on the light-emission intensity set in the emission-intensity setting device.

Abstract: A method for characterizing the electronic properties of a semiconductor sample by exploiting transients in measured photoconductance, the transients being induced by illuminating the semiconductor sample with a small probing illumination that is superimposed over a larger background illumination. In one embodiment, a pulse-type probing illumination is utilized, with either the intensity of the probing illumination being gradually reduced or the intensity of the background illumination being gradually increased until the measured photoconductance rise and decay in the sample are substantially exponential. In another embodiment, a continuous probing illumination with a sinusoidally-modulated intensity is utilized, the modulated intensity of the probing illumination being gradually adjusted until the measured photoconductance is linearly dependent thereupon.

Abstract: A laser driving unit drives a semiconductor laser apparatus including a plurality of light sources, includes a light detecting part to detect light emissions from the light sources, a driving current generator to generate a driving current based on an input signal, an auxiliary driving current generator to generate an auxiliary driving current in an initial time period of an ON-time of the driving current, and an auxiliary current set part to set an auxiliary amount of the auxiliary driving current to be added to the driving current, for each of the light sources, based on a difference between the light emissions detected by the light detecting part and a target light emission of the light sources.

Abstract: A drive device to drive a plurality of three-terminal light emitting elements, comprising: a drive circuit including a first MOS transistor and configured to drive conducting three-terminal light emitting elements among a plurality of three-terminal light emitting elements based on a received drive signal. The first MOS transistor includes: a third terminal connected to a second power supply having a potential different from a potential of the first power supply; a fourth terminal connected to the second terminals connected in common, a second control terminal configured to control a conduction state between the third terminal and the fourth terminal based on the drive signal; and a substrate terminal set to have a potential different from the potential of the second power supply in a direction of increasing threshold voltage of the first MOS transistor.

Abstract: A drive device to drive a plurality of three-terminal light emitting elements includes a drive circuit. The drive circuit includes a first and second conductive type MOS transistor complementarily connected to each other and configured to drive three-terminal light emitting elements that are in conduction state based on a received drive signal. The first conductive type MOS transistor is formed in a substrate region and includes a channel formation region, which is a region wherein a channel is to be formed. An impurity with the same polarity as that of the substrate region is injected in the channel formation region.

Abstract: A light-emitting chip includes: a substrate; plural light-emitting elements arrayed in line on the substrate, each of the light-emitting elements including a light-emitting region having a length in an array direction of the array different from a length in a direction orthogonal to the array direction; and a light-up current supplying interconnection including plural connecting portions, each of the connecting portions being provided on the light-emitting region of a corresponding one of the light-emitting elements in a shorter direction of the light-emitting region either the array direction or the direction orthogonal to the array direction, each of the connecting portions being connected to an electrode provided on the light-emitting region, the light-up current supplying interconnection supplying a current for lighting up to the plural light-emitting elements through the plural connecting portions.

Abstract: In an exposure apparatus employing an over filled optical system, the light quantity distribution on a scanning plane is kept nearly constant for a plurality of scanning light quantities. It selects the light quantity of the light beam irradiated onto the photosensitive body from a plurality of levels, and sets the light quantity selected. According to the light quantity, it selects one of a plurality of correction current profiles, and supplies a light source with a current passing through the correction based on the correction current profile selected. Since the light quantity of the light beam irradiated onto the photosensitive body is corrected by the correction current, the light quantity of the light beam on the photosensitive body becomes nearly constant in the scanning direction.

Abstract: A drive device for outputting a drive signal for driving a plurality of light emitting elements time-divisionally, the drive device includes a plurality of input terminals receiving input of a drive control signal for the light emitting elements, and a plurality of output terminals connected to the light emitting elements, for outputting the drive signal based on the drive control signal input into the input terminals, in which the input terminals and the output terminals are arranged substantially in a line.

Abstract: An embodiment of the image processing apparatus for controlling the lighting of a line head that is driven with binary data and performs exposure with subline lighting to thereby form images, includes: a subline generating unit that generates a plurality of sublines from a same image data; an inclination correcting unit that exposes the generated sublines so as to generate correction image data used to correct an inclination of an exposure position; a gradation control unit that controls the lighting of sublines based on the correction image data generated by the inclination correcting unit to express gradation; and a light intensity correction unit that corrects and controls the light intensity based on the correction image data generated by the inclination correcting unit, wherein an output of the gradation control unit and an output of the light intensity correction unit are input into the line head in parallel.

Abstract: In an image forming apparatus, a quantized amount of correction A is applied to emission timing with which each light-emitting point is to be caused to give off light emission to thereby align points of exposure to light emitted from the light-emitting points, substantially with a straight line extending in the main scanning direction on a photoconductor. The amount of correction A is adjusted by adding or subtracting one to or from one of the tentatively determined amounts of correction A1, A2 for light-emitting point (P1, P2) at opposite ends of two adjacent light-emitting chips, if formula (1) is not satisfied: ? ? ? ? E - B ? < D 2 ( 1 ) where B is difference |C1?C2| between amounts of shift C1, C2 of the light-emitting points (P1, P2) stored in a memory, ?E is a value derived from |A1?A2| multiplied by the quantization unit D, |A1?A2| is the difference between the amounts of correction A1, A2.

Abstract: A driver apparatus drives light emitting elements connected to a common terminal. A clock driver outputs first and second pulses to first and second output terminals, respectively, alternately. A differentiating circuit includes an inductor and a resistor, and differentiates the first and second pulses to produce first and second clocks, respectively. A data driver circuit outputs a data signal to the common terminal in response to an ON/OFF command signal. A scanning circuit starts to operate in response to a starting signal such that the cascaded sub scanning stages turn on in sequence one at a time. A sub scanning stage turns on in response to the second clock, outputting a drive signal to a corresponding one of the light emitting elements. The light emitting elements emit light only when the drive signal and the ON/OFF command signal are fed to the light emitting elements.

Abstract: When the cathode of a light emitting thyristor is at the low (L) level, voltage is applied between the anode and cathode of the light emitting thyristor. In addition, because the gate of each thyristor and the gate of each light emitting thyristor are connected to each other in a self scanning circuit 100, voltage is also applied between the gate and cathode of the thyristor. At this time, by selectively turning only the gate of the light emitting thyristor, which is instructed by the self scanning circuit to emit light, to the high (H) level, the light emitting thyristor that is instructed is turned on. In particular, because an output signal of a clock driving circuit is differentiated by an RL differential circuit to generate an undershoot or overshoot waveform, the number of output terminals of the clock driving circuit can be reduced.

Abstract: An image forming apparatus includes: a light source that emits a light beam; a photosensitive member; a brushless motor including a stator where a plurality of coils are placed and a rotor where a plurality of magnets are placed; a rotary polygon mirror, which is rotated by the brushless motor, and which periodically deflects the light beam emitted from the light source to sequentially form scanning lines on the photosensitive member; an energization switching unit that turns on and off energizations of the coils; a voltage detecting unit that outputs a detection signal based on induced voltages that are generated in the coils by rotation of the rotor; and a control unit that controls turning on/off of the energizations by the energization switching unit based on the detection signal.

Abstract: Document processing systems and duplex printing methods are presented in which side 1 to side 2 image on paper (IOP) magnification errors are mitigated by use different speeds for raster output scanner (ROS) for scanning images for different final print sides, and by selective use of electronic registration adjustment by adding or removing sub-pixels from the image data to compensate for ROS speed change overshoot or undershoot.

Abstract: A method is provided to manufacture displays such as, for example, reflective displays, electrophoretic displays or liquid crystal displays. In one embodiment of the invention, a method is provided for aligning a patterned layer of color filter elements with a display assembly. The method includes activating a first set of addressable pixel elements to change an activation state of each pixel element in the first set of the pixel elements. A required alignment of the patterned layer of color filter elements with the display assembly can be determined based at least on the activated first or a second set of the pixel elements. The patterned layer of color filter elements is aligned with the display assembly according to the required alignment.

Abstract: A light scanning apparatus including: a light source to emit a laser beam; a light source driving unit to turn on and off the light source according to image data and a pixel clock; a rotary polygon mirror to deflect the light beam; a motor to rotationally drive the rotary polygon mirror; and a control unit to control a rotary speed of the motor to generate an acceleration control signal for accelerating the rotary speed and a deceleration control signal for decelerating the rotary speed, wherein for the acceleration control signal, the driving unit corrects the frequency of the pixel clock to be higher than the frequency, which is before the acceleration control, and for the deceleration control signal, the driving unit corrects the frequency of the pixel clock to be lower than the frequency, which is before the deceleration control.

Abstract: One aspect of this invention relates to an illumination device for an optical printer, the illumination device comprising: a first array of light sources comprising a plurality of light source elements that are each operable to emit light within a red band of the visible electromagnetic spectrum; a second array of light sources comprising a plurality of light source elements that are each operable to emit light within a blue band of the visible electromagnetic spectrum; and a third array of light sources comprising a plurality of light source elements that are each operable to emit light within a green band of the visible electromagnetic spectrum; wherein said first, second and third arrays of light sources are generally linearly arranged along respective substantially parallel notional lines on a substrate; and said plurality of light source elements of each said array are arranged such that respective adjacent light source elements of said plurality are offset from one another with respect to the associated

Abstract: Methods, algorithms, software, apparatuses and systems for processing image data for imaging devices having irregular scan paths (e.g., scan paths that deviate from a conventional horizontal and/or straight line). The irregular scan paths generally correspond to actual locations of a line of output from an image output device (e.g., a printer). The method generally includes steps of selecting one or more of the input pixels, correlating a location of the selected pixel with a location on an irregular scan path, and producing an adjusted pixel based on a value of the selected pixel, the location on the irregular scan path, and/or values of one or more pixels near the selected pixel.

Abstract: A driver circuit in an optical print head uses driving transistors to drive a row of light-emitting elements. The gate electrodes of the driving transistors are at least partly oriented so that driving current flows in the channels below the gate electrodes in a direction different from the direction of the row the light-emitting elements. This orientation reduces the temperature dependency of the driving current, so that the optical print head can produce the same high image quality at low ambient temperatures as at room temperature.

Abstract: A light-emitting device includes: a board; plural light-emitting chips that are one-dimensionally arrayed in a longitudinal direction of the board and that are connected to a first potential and a second potential; and plural capacitors that each include a first electrode and a second electrode arranged in a short-side direction of the board, and that are arrayed in the longitudinal direction of the board so that the first electrode and the second electrode are alternately positioned between each adjacent two of the capacitors. The first electrode is connected to the first potential for the light-emitting chips, and the second electrode is connected to the second potential for the light-emitting chips.

Abstract: Document processing systems and duplex printing methods are presented in which side 1 to side 2 image on paper (IOP) magnification errors are mitigated by use different speeds for raster output scanner (ROS) for scanning images for different final print sides, and by selective use of electronic registration adjustment by adding or removing sub-pixels from the image data to compensate for ROS speed change overshoot or undershoot.

Abstract: A drive circuit for supplying a drive current to a plurality of driven elements includes a plurality of drive output terminals to be connected to the driven elements. The drive output terminals are arranged with a specific pitch in between in an arrangement direction. The drive circuit further includes a plurality of drive transistors. Each of the drive transistors is arranged in an occupied area with a specific width in the arrangement direction larger than the specific pitch.

Abstract: An exposure head includes a light emitting segment that emits light; an electrical load that is electrically connected to a circuit in which a current to be supplied to the light emitting segment flows; and a current supply controller that supplies a first current to the light emitting segment to cause the light emitting segment to emit light and supplies a second current to the electrical load during the time when the current supply controller blocks the supply of the first current to the light emitting segment.

Abstract: An image forming apparatus includes: a light source that emits a light beam; a photosensitive member; a driving motor; a rotary polygon mirror, which is rotated by the driving motor, and which periodically deflects the light beam emitted from the light source to sequentially form scanning lines on the photosensitive member; a position detecting unit, which detects a rotational position of the driving motor, and which outputs a detection signal; a sensor, which receives the light beam deflected by the rotary polygon mirror, and which outputs a light receiving signal; a detecting unit, which receives the detection signal and the light receiving signal, and which detects a rotation direction of the driving motor based on a timing pattern of a detection of the rotational position of the driving motor and a reception of the light beam by the sensor.

Abstract: A method for determining a location on an image bearing surface of an image printing system where a toner image is to be printed is provided. The method comprises generating a first signal from a detector that is configured to detect a reference mark on the image bearing surface, and a second signal from a clock system that counts incremental movements of the image bearing surface, determining a first value that correlates the first signal and the second signal, where the first value corresponds to a value of the second signal at a start of characterization of the image bearing surface, and determining a second value using the first value, where the second value provides the location on the image bearing surface where the toner image is to be printed.

Abstract: An image-forming apparatus includes a light-irradiation unit configured to move a spot of laser light on a surface of a photosensitive member at a non-constant scanning velocity in a main scanning direction to form a latent image on the photosensitive member, an image data correcting unit configured to correct a length in the main scanning direction of image data by inserting one or more image data pieces into the image data, the number of the image data pieces increasing as the scanning velocity increases, and/or extracting one or more image data pieces from the image data, the number of the image data pieces increasing as the scanning velocity decreases, and a brightness correcting unit configured to correct a brightness of the laser light so that an emission brightness increases as the scanning velocity increases and/or the emission brightness decreases as the scanning velocity decreases.