By Clock Deviation Patents (Class 347/249)
  • Patent number: 10601572
    Abstract: A receiver circuit receives a transmission signal using serial communication, the transmission signal including image data and a synchronization signal that has a pulse period fluctuated in a predetermined fluctuation range. A data reception processing unit extracts the image data and the synchronization signal from the received transmission signal, and writes each line of the image data into a line memory among line memories while selecting the line memory line by line in turn in accordance with the synchronization signal. A line data reading unit reads each line of the image data from a line memory among the line memories while selecting the line memory line by line in turn in accordance with the synchronization signal. If the pulse period of the synchronization signal is not in the predetermined fluctuation range, an error detecting unit discards the image data written into the line memory in this pulse period.
    Type: Grant
    Filed: December 10, 2018
    Date of Patent: March 24, 2020
    Assignee: Kyocera Document Solutions, Inc.
    Inventor: Yukio Shibata
  • Patent number: 9925798
    Abstract: An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.
    Type: Grant
    Filed: February 23, 2017
    Date of Patent: March 27, 2018
    Assignee: RICOH COMPANY, LTD.
    Inventors: Naoto Watanabe, Toshiaki Tokita, Kohji Sakai, Nobuaki Kubo, Masayuki Muranaka
  • Patent number: 9720346
    Abstract: An image forming apparatus capable of correcting relative position in exposure position between laser beams that scan a photosensitive drum in a scanning direction of the laser beams. A semiconductor laser includes first and second light emitting elements for emitting first and second laser beams. These elements are arranged such that the laser beams expose positions on the photosensitive drum different in the sub scanning direction. A polygon mirror deflects the laser beams to scan the photosensitive drum. Relative position in the scanning direction between images to be formed on the photosensitive drum by exposure by the first and second laser beams is corrected based on correction data. An image data generation section generates drive signals associated with the respective light emitting elements. A semiconductor laser drive circuit causes the semiconductor laser to emit the first and second laser beams, based on the drive signals.
    Type: Grant
    Filed: April 26, 2013
    Date of Patent: August 1, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yasutomo Furuta, Shunsaku Kondo
  • Patent number: 9358806
    Abstract: An optical disk label writing method for writing a label on an optical disc uses a similar writing operation to that used to write data to the disc. The disc has a label side including a laser reactive material for forming the label image, and a tracking format that can be tracked by a writing laser in a similar way to a writing operation. A computer program is provided for converting a label image to a disk image file for writing to the label side.
    Type: Grant
    Filed: July 1, 2013
    Date of Patent: June 7, 2016
    Inventors: Anthony Miles, Robert Glyn Miles
  • Patent number: 9363465
    Abstract: A data processing apparatus which transmits a clock signal to a recording medium, transmits a command to the recording medium and receives data output from the recording medium in response to a timing signal obtained by delaying the clock signal. The apparatus transmits to the recording medium a transmission command in a predetermined data string including a predetermined pattern and receive the predetermined data output from the recording medium. The apparatus adjusts a delay amount of the timing signal based on a reception result of the predetermined data string in a first mode or second mode. The reception result is based on timing signals each including a delay amount, in a first range in the first mode and in a second range narrower than the first range in the second mode.
    Type: Grant
    Filed: December 12, 2014
    Date of Patent: June 7, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masamine Maeda
  • Patent number: 9310710
    Abstract: An image writing device includes an exposure device to repeatedly expose a surface of an image bearer along a main-scanning direction during an image forming period to write an image on the image bearer, a speed change detector to detect a change in moving speed in a sub-scanning direction of the surface of the image bearer, a first signal generation circuit to generate a first signal, an image forming period signal generation circuit to generate an image forming period signal synchronously with the first signal, a second signal generation circuit to generate a second signal, the second signal initially appearing in the image forming period being in synchronization with the first signal, and a line synchronization signal generation circuit to generate a line synchronization signal synchronously with the second signal and transmit the line synchronization signal to the exposure device during the image forming period.
    Type: Grant
    Filed: February 26, 2015
    Date of Patent: April 12, 2016
    Assignee: RICOH COMPANY, LTD.
    Inventors: Masashi Suzuki, Koichi Murota, Tatsuo Ohyama, Yuichiro Shukuya, Tatsuya Miyadera
  • Patent number: 9141061
    Abstract: Disclosed is an image forming apparatus includes: an image forming section, a control section, and a magnification factor adjusting section. The control section employs an index signal based on a detected result of a light beam irradiation, for controlling an operation timing of the image forming section in the toner image area; and when forming the band-shaped toner image on the area between the toner image areas being adjacent to each other, while controlling the magnification factor adjusting section to implement an operation for adjusting the image magnification factors in parallel, the control section employs a timing signal, created otherwise without depending on the detected result of the light beam irradiation, for controlling the operation timing of the image forming section.
    Type: Grant
    Filed: July 12, 2013
    Date of Patent: September 22, 2015
    Assignee: KONICA MINOLTA, INC.
    Inventor: Kouichi Takaki
  • Patent number: 9030518
    Abstract: A clock signal generating circuit that generates a clock signal, the clock signal generating circuit including a clock signal generator configured to generate a reference clock signal; and a plurality of dividers to which the reference clock signal is to be input. A division ratio of at least one of the plurality of dividers varies based on division ratio data that defines the division ratio of the at least one of the plurality of dividers. The division ratio data represents a value that fluctuates around reference division ratio data with respect to time.
    Type: Grant
    Filed: February 26, 2014
    Date of Patent: May 12, 2015
    Assignee: Ricoh Company, Ltd.
    Inventor: Shintaro Kawamura
  • Patent number: 9030517
    Abstract: A pixel clock generating device includes a time interval detection unit detecting a time interval between a first signal and a second signal in each of cyclically repeating N (?2) time periods; a comparing unit cyclically selecting a target value from N target values corresponding to the N time periods and outputting an error indicating a difference between the detected time interval and the selected target value for each of the N time periods; a frequency calculation unit correcting a frequency of the pixel clock signal based on the error and cyclically generating a frequency specification signal indicating the corrected frequency for each of the N time periods; a high-frequency clock generating unit generating a high-frequency clock signal; and a pixel clock generating unit generating a pixel clock signal based on the frequency specification signal and the high-frequency clock signal.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: May 12, 2015
    Assignee: Ricoh Company, Ltd.
    Inventor: Naruhiro Masui
  • Patent number: 8836746
    Abstract: A pixel clock generator device includes a high frequency clock generator, a phase shift data generator to generate phase shift data for controlling a phase shift amount of a pixel clock, a phase shift data pattern generator to read the phase shift data from the phase shift data generator, generate a pattern of the phase shift data for output, and when outputting a same phase shift data pattern for consecutive scan lines, generate, for a next scan line, a phase shift data pattern in which a pixel clock at a position moved by a random number of pixel clocks from a phase-shift position of a pixel clock in a phase shift data pattern for a current scan line is phase-shifted, and a pixel clock generator to generate, on the basis of a high frequency clock, a pixel clock phase-shifted in accordance with the generated phase shift data pattern.
    Type: Grant
    Filed: July 24, 2013
    Date of Patent: September 16, 2014
    Assignee: Ricoh Company, Ltd.
    Inventor: Shintaro Kawamura
  • Patent number: 8743169
    Abstract: A high-frequency clock generating circuit generates a plurality of high-frequency clock signals having different phases. A modulation-signal generating circuit generates a pulse modulation signal based on transition timing data including data pertaining to a turn-on timing at which a state of a light source is changed from a turn-off state to a turn-on state and a turn-off timing at which the state of the light source is changed from the turn-on state to the turn-off state by inputting any one of the high-frequency clock signals for a predetermined period including the turn-on timing and the turn-off timing.
    Type: Grant
    Filed: May 14, 2012
    Date of Patent: June 3, 2014
    Assignee: Ricoh Company, Ltd.
    Inventor: Dan Ozasa
  • Patent number: 8693300
    Abstract: A system includes a position detection module configured to detect at least a first position indicator and a second position indicator corresponding to a label side of an optical disc. A write clock adjustment module is configured to determine a number of cycles of a write clock that occur between the first position indicator and the second position indicator, determine a difference between the number of cycles of the write clock and a desired number of cycles of the write clock, and adjust a frequency of the write clock based on the difference.
    Type: Grant
    Filed: August 11, 2011
    Date of Patent: April 8, 2014
    Assignee: Marvell International Ltd.
    Inventors: Pantas Sutardja, Christopher Painter
  • Publication number: 20140078237
    Abstract: A scanning system for use in an imaging apparatus includes a first light source and a second light source for emitting light beams for generating an image. A driver circuitry has first and second outputs connected to the first and second light sources, respectively, for controlling the first and second light sources. A signal transmitter includes a first interface for communicating a clock signal to the driver circuitry and a second interface for communicating an image information signal to the driver circuitry. During a clock cycle of the clock signal, the driver circuitry captures a first bit information from the image information signal at a rising edge of the clock signal and a second bit information from the image information signal at a falling edge of the clock signal. Thereafter, the driver circuitry drives the first and second light sources based on the first and second bit information captured, respectively.
    Type: Application
    Filed: September 14, 2012
    Publication date: March 20, 2014
    Inventors: John Bruce Berry, William Pohl Corbett, JR.
  • Publication number: 20140028776
    Abstract: A pixel clock generator device includes a high frequency clock generator, a phase shift data generator to generate phase shift data for controlling a phase shift amount of a pixel clock, a phase shift data pattern generator to read the phase shift data from the phase shift data generator, generate a pattern of the phase shift data for output, and when outputting a same phase shift data pattern for consecutive scan lines, generate, for a next scan line, a phase shift data pattern in which a pixel clock at a position moved by a random number of pixel clocks from a phase-shift position of a pixel clock in a phase shift data pattern for a current scan line is phase-shifted, and a pixel clock generator to generate, on the basis of a high frequency clock, a pixel clock phase-shifted in accordance with the generated phase shift data pattern.
    Type: Application
    Filed: July 24, 2013
    Publication date: January 30, 2014
    Inventor: Shintaro KAWAMURA
  • Patent number: 8587626
    Abstract: A light source control circuit of an optical writing device, admitting connection of light sources and forming an electrostatic latent image on a photosensitive element by controlling a connected light source, includes: a skew correction unit that corrects a skew of a main scanning line of an electrostatic latent image formed by the light source relative to the photosensitive element; a pattern generating unit that outputs image data for forming a predetermined pattern in an electrostatic latent image; a local deviation correction unit that corrects a local deviation of an electrostatic latent image formed by the light source on the main scanning line by acquiring image data processed to form the pattern and by performing a predetermined process; a light source control unit that causes the light source to emit light based on image data in which the local deviation has been corrected; and a setting value input unit.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: November 19, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Kunihiro Komai, Izumi Kinoshita, Tatsuya Miyadera
  • Patent number: 8508568
    Abstract: A frequency adjusting unit adjusts a frequency of the clock signal to be supplied to a drive unit when an image is to be formed on the second face in response to a contraction ratio of the printing material on which an image has been formed on the first face. The phase difference determining unit determines a phase difference between the clock signal corresponding to the first face and the clock signal corresponding to the second face in response to a frequency difference and a sign thereof between the clock signal corresponding to the first face and the clock signal corresponding to the second face. The change control unit changes from the clock signal corresponding to the first face to the clock signal corresponding to the second face.
    Type: Grant
    Filed: September 23, 2011
    Date of Patent: August 13, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shunsaku Kondo
  • Patent number: 8493623
    Abstract: One or more printers or printing systems are connected to a scanning device. Each printer includes one or more color modules that are used during a printing operation. A printer prints a target for each color module or color channel. The printed targets are then scanned by the scanning device. The printed targets may be rotated to any angle and then scanned by the scanning device. The scanned raster data is processed by a controller to detect non-uniformities in at least one density image and to generate one or more correction profiles for the printer. When an image is to be printed, one or more controllers receive the image data and use the one or more correction profiles to correct or compensate for the non-uniformities during the exposure process.
    Type: Grant
    Filed: October 12, 2009
    Date of Patent: July 23, 2013
    Assignee: Eastman Kodak Company
    Inventors: Chung-Hui Kuo, Hwai-Tzuu Tai, Stacy M. Munechika, Cumar Sreekumar, Eric K. Zeise, Stephen J. Farnand, Thomas A. Henderson
  • Patent number: 8493578
    Abstract: A pixel clock generator includes a frequency divider 4 that generates a pixel clock PCLK based on a high frequency clock VCLK, a comparator 5 that calculates an error Lerr in the time obtained by integrating a cycle of the pixel clock PCLK for a target number RefN from a time when synchronization signals SPSYNC and EPSYNC are detected, a filter 6, and a frequency calculating unit 7 that sets a frequency dividing value M of the frequency divider 4. The filter 6 and the frequency calculating unit 7 calculate an average of a frequency of the pixel clock PCLK based on the error Lerr, determine a reference error value from the error Lerr in N-cycles, calculate offset values of the frequencies of N pieces of pixel clocks PCLK based on a difference between the reference error value and the error Lerr, and calculate the frequency dividing value M based on a result obtained by adding the circularly selected offset values and the average of the frequency of the pixel clock PCLK.
    Type: Grant
    Filed: September 15, 2009
    Date of Patent: July 23, 2013
    Assignee: Ricoh Company, Limited
    Inventor: Naruhiro Masui
  • Patent number: 8446601
    Abstract: A disclosed control device includes a first unit configured to generate image data of multiple images to be superposed one on the other to form a single image and transmit the image data. The second control unit transmits to the first control unit a horizontal sync reference signal for achieving synchronization of the images in a horizontal direction. Based on the horizontal sync reference signal, the first control unit transmits to the second control unit a transfer clock signal that indicates transmission timing of the image data and an effective area signal that indicates an effective area of the image data. The first control unit asserts the effective area signal for an effective-area-signal assertion period that occurs between two consecutive reference-signal assertion periods during which the horizontal sync reference signal is asserted.
    Type: Grant
    Filed: December 22, 2008
    Date of Patent: May 21, 2013
    Assignee: Ricoh Company, Ltd.
    Inventor: Eiji Tsuchida
  • Patent number: 8436884
    Abstract: According to one embodiment, when performing monochrome image forming, image processing circuits for color image forming, laser control circuits for the color image forming and data processing circuits for the color image forming in an integrated circuit are not operated.
    Type: Grant
    Filed: February 28, 2011
    Date of Patent: May 7, 2013
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventor: Kazumasa Takada
  • Patent number: 8395648
    Abstract: An optical writer includes a scanning part causing a light beam from a light source to perform scanning on a photosensitive body; an image information obtaining part obtaining image information of an image; a dithering information obtaining part obtaining dithering information of the image; a pixel clock generating part generating a pixel clock signal; and a light emission control part to control the light source based on the image information in accordance with the pixel clock signal. The pixel clock generating part modulates the clock frequency of the pixel clock signal in accordance with phase shift information for correcting a change in the speed of the scanning on main scanning lines on the photosensitive body, and determines the timing of modulating the clock frequency based on the dithering information on a main scanning line basis so that the timing of modulating the clock frequency differs between the main scanning lines.
    Type: Grant
    Filed: March 14, 2011
    Date of Patent: March 12, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Tatsuya Miyadera, Masayuki Hayashi, Yoshinori Shirasaki
  • Publication number: 20130021425
    Abstract: Provided is a recording apparatus including a self-excited oscillation semiconductor laser that has a double quantum well separate confinement heterostructure and includes a saturable absorber section to which a negative bias voltage is applied and a gain section into which a gain current is injected, an optical separation unit, an objective lens, a light reception element, a pulse detection unit, a reference signal generation unit, a phase comparison unit, a recording signal generation unit, and a control unit.
    Type: Application
    Filed: July 9, 2012
    Publication date: January 24, 2013
    Applicant: SONY CORPORATION
    Inventors: Goro Fujita, Tsutomu Maruyama
  • Patent number: 8326080
    Abstract: An example hard imaging device includes an interface to access image data corresponding to images to be formed using the hard imaging device. The example hard imaging device further includes processing circuitry in communication with the interface to access the image data, to access correction data corresponding to a geometric distortion of a scan lens of an optical scanning system of the hard imaging device, and to modify the image data according to the correction data to reduce image errors introduced during optical scanning of the image data using the optical scanning system.
    Type: Grant
    Filed: May 16, 2011
    Date of Patent: December 4, 2012
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: William D. Holland
  • Patent number: 8264516
    Abstract: A magnification adjustment method for a document processing system having a fixed frequency clock source providing a fixed frequency output signal to a plurality of raster output scanners (ROSs) and a numerically controlled oscillator (NCO)-based adjustable frequency clock source providing an adjustable frequency output signal to the ROSs is disclosed. The method includes: using a controller to determine a frequency setting for a phase increment control input signal to the adjustable frequency clock source; starting the document processing system; using the controller to set a phase accumulator control input to the frequency setting; sending a message to a ROS control module prior to imaging, including the correct clock source to use for the next image, the correct clock source being either the fixed frequency clock source or the adjustable frequency clock source; and applying the correct clock source synchronously to the beginning of an inter image panel zone.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: September 11, 2012
    Assignee: Xerox Corporation
    Inventors: James W. Stevens, David Mark Kerxhalli, Siddharth Rajiv Inamdar
  • Patent number: 8259148
    Abstract: A measuring section that measures the position shift in the main scanning direction of a plurality of light sources, a signal generating section that generates synchronized INDEX signals that in which the writing timing of the different light sources has been adjusted according to the position shifts, a signal generating section that generates the signals for driving the light sources based on the synchronized INDEX signals and image data, and a measuring section that detects the timing shift component in the main scanning direction included in the synchronized INDEX signal generated in the condition in which adjustments have been made according to the position shift, and further shift correction is carried out in the main scanning direction based on the timing shift component, for the synchronized INDEX signal which are adjusted and generated in accordance with the position shift of a plurality of light sources.
    Type: Grant
    Filed: March 19, 2010
    Date of Patent: September 4, 2012
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventor: Mutsumi Takagi
  • Patent number: 8228512
    Abstract: An image forming apparatus is disclosed that forms an image based on a control signal from an image processing controlling unit that processes input image information into image data. The apparatus includes a carriage that moves in a main scanning direction in accordance with the control signal; a conveyance unit that conveys a recording medium in a sub-scanning direction; an output detection unit that detects motor outputs of the carriage at any plural points when the carriage moves at a constant speed; and a jamming determination unit that compares an average value of the motor outputs of the carriage between the plural points with a predetermined tolerance to determine a conveyance failure.
    Type: Grant
    Filed: May 12, 2008
    Date of Patent: July 24, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshimitsu Ogura, Tetsuyoshi Nakata, Shigeru Yoshigai, Toshihiro Yamashiro
  • Patent number: 8223390
    Abstract: Systems and methods are provided for correcting color registration errors in a printing device comprising a plurality of print engines driven by a single pixel frequency clock. In some embodiments, the print engines can include a reference print engine and one or more non-reference print engines. An adjusted resolution may be computed for color data sent to each non-reference engine to offset color registration errors attributable to the non-reference engine. The adjusted resolution is computed using calibration information for the non-reference print engines relative to the reference engine, and resolution information for color data processed by the first reference engine. The resolution of color data processed by each non-reference print engine is adjusted according to the computed adjusted resolution for the non-reference engine and sent to the print engines for printing.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: July 17, 2012
    Assignee: Konica Minolta Laboratory U.S.A., Inc.
    Inventor: Peter Johnston
  • Patent number: 8194113
    Abstract: A high-frequency clock generating circuit generates a plurality of high-frequency clock signals having different phases. A modulation-signal generating circuit generates a pulse modulation signal based on transition timing data including data pertaining to a turn-on timing at which a state of a light source is changed from a turn-off state to a turn-on state and a turn-off timing at which the state of the light source is changed from the turn-on state to the turn-off state by inputting any one of the high-frequency clock signals for a predetermined period including the turn-on timing and the turn-off timing.
    Type: Grant
    Filed: January 27, 2009
    Date of Patent: June 5, 2012
    Assignee: Ricoh Company, Ltd.
    Inventor: Dan Ozasa
  • Patent number: 8149471
    Abstract: An image reading apparatus in which cross-talk noise occurring between plural reading units is reduced, an image reading method and an image reading program are provided. There are included plural reading units that respectively operate at different timings, a noise calculation unit that acquires first read data as a result of reading of a first read object as the read object by the plural reading units, acquires an operation state of the plural reading units during the reading of the first read object, and calculates, based on the operation state and the first read data obtained in the operation state, noise information based on the operation state, and a noise removal unit that acquires second read data as a result of reading of a second read object as the read object different from the first read object by the plural reading units, and removes noise from the second read data based on the noise information calculated by the noise calculation unit.
    Type: Grant
    Filed: March 26, 2008
    Date of Patent: April 3, 2012
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventor: Koji Kawai
  • Patent number: 8144179
    Abstract: An image forming apparatus that includes: a laser beam source; plural photoconductive members corresponding to plural colors; a modulation drive unit for performing pulse width modulation for each of colors by an image clock having a cycle of a pixel length,; a single piece of polygon mirror whose reflection surfaces are disposed in a rotation direction thereof with a plurality of different inclination angles with colors; a beam detector that is disposed adjacent to the photoconductive member; and an image clock/data switching unit configured to generate the image clock of a frequency varying with the colors for making the same a color-based image magnification, and switch the image clocks generated for each of the colors in synchronization with a detection signal coming from the beam detector.
    Type: Grant
    Filed: May 28, 2008
    Date of Patent: March 27, 2012
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Hiroyuki Fuse, Hidehito Sasaki
  • Patent number: 8125505
    Abstract: An image forming apparatus capable of forming a high-resolution image without complicating a circuit construction. A difference between a phase of an operation clock for a BD detection unit and a phase of an operation clock for an image processing unit is measured by a phase measurement unit of the image forming apparatus, and a timing of data delivery between the BD detection unit and the image processing unit is adjusted by a BD input timing adjuster based on a measurement result. A difference between the phase of the operation clock for the image processing unit and a phase of an operation clock for a laser drive unit is measured by the phase measurement unit, and a timing of data delivery between the image processing unit and the laser drive unit is adjusted by an image output timing adjuster based on a measurement result.
    Type: Grant
    Filed: July 27, 2010
    Date of Patent: February 28, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shoji Takeda
  • Patent number: 8081204
    Abstract: In an image recording apparatus, a shift amount for shifting a transition position of an output light amount from a light modulator element is obtained with respect to each pixel value-change point in a pixel line in order to correct displacement of writing. In a case where the shift amount excesses a width corresponding to one pixel on a substrate, a pixel value in the pixel line is altered so that the pixel value-change point moves by the number of pixels of an integer part of a value obtained by dividing the shift amount by the width, and the shift amount corresponding to the pixel value-change point is modified to a value equivalent to a decimal part. It is therefore possible to shift the transition position of the output light amount in excess of the distance corresponding to one pixel in recording an image, to record the image with accuracy.
    Type: Grant
    Filed: February 17, 2009
    Date of Patent: December 20, 2011
    Assignee: Dainippon Screen MFG Co., Ltd.
    Inventors: Yoshiki Mizuno, Takahide Hirawa
  • Patent number: 8059145
    Abstract: A color image forming apparatus including: an image forming section which forms an image based on image information on an image carrier provided in the image forming section; a detection section which detects a print mark for color misalignment correction formed on the image carrier by the image forming section, and outputs print mark detection information; and a control section for executing color misalignment correction control based on the print mark detection information outputted from the detection section, wherein, the control section obtains a trend of a color misalignment amount of the print mark by statistically processing data of the result of the print mark detection, calculates an execution timing of color misalignment correction base on the obtained trend, and executes the color misalignment correction at the calculated execution timing.
    Type: Grant
    Filed: January 16, 2008
    Date of Patent: November 15, 2011
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Tadayuki Ueda, Ryuji Okutomi, Hiroyuki Watanabe, Akifumi Isobe, Yoshihito Sasamoto, Takashi Nara
  • Patent number: 8058633
    Abstract: A pulse width modulation signal generating device which generates a pulse width modulation signal for modulating laser beam according to image data includes: a cycle signal output circuit which outputs a cycle signal having a cycle corresponding to a drawing rate for drawing the image data by the laser beam; and a pulse width modulation circuit which receives supply of the image data and the cycle signal and modulates a pulse wave having a cycle determined by the cycle signal by changing duty ratio of the pulse wave based on the image data to produce the pulse width modulation signal.
    Type: Grant
    Filed: May 15, 2009
    Date of Patent: November 15, 2011
    Assignee: Seiko Epson Corporation
    Inventor: Tomio Ikegami
  • Patent number: 8054502
    Abstract: A scanning optical apparatus includes, for example, a determination unit, a correction unit, a creating unit, and a drive control unit. The determination unit determines an amount of correction of an image clock for controlling an output timing of a beam for each pixel constituting one line in a main scanning direction of the beam. The correction unit corrects the image clock in accordance with the amount of correction that is determined. The creating unit creates an image signal that is utilized for driving a light source in accordance with the image clock that is corrected. The drive control unit controls driving of the light source in accordance with the image signal.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: November 8, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Katsuhide Koga
  • Patent number: 8031219
    Abstract: A frequency adjusting unit adjusts a frequency of the clock signal to be supplied to a drive unit when an image is to be formed on the second face in response to a contraction ratio of the printing material on which an image has been formed on the first face. The phase difference determining unit determines a phase difference between the clock signal corresponding to the first face and the clock signal corresponding to the second face in response to a frequency difference and a sign thereof between the clock signal corresponding to the first face and the clock signal corresponding to the second face. The change control unit changes from the clock signal corresponding to the first face to the clock signal corresponding to the second face.
    Type: Grant
    Filed: July 9, 2008
    Date of Patent: October 4, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shunsaku Kondo
  • Patent number: 8031220
    Abstract: An image forming apparatus includes an image bearing member configured to bear an image, an exposure unit configured to draw a scanning line on the image bearing member by exposing the image bearing member according to image data, and at least two detection units configured to detect an amount of deviation in exposing position due to the exposure unit. The image forming apparatus further includes a drive unit configured to drive an optical part located on an optical path extending from the exposure unit to the image bearing member to reduce the amount of deviation, a measurement unit configured to measure an amount of driving of the drive unit, an estimation unit configured to estimate a residual amount of deviation, and a modulation unit configured to modulate a writing frequency in the exposure unit based on the measured amount of driving to reduce the estimated residual amount of deviation.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: October 4, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hiroshi Nakahata
  • Publication number: 20110175975
    Abstract: Systems and methods are provided for aligning a video clock with the raster output scanner start-of-scan signal in printing systems. A system and method is proposed to align the pixel clock to an asynchronous reference signal generated in the raster output scanner. The proposed system and method adjusts a phase for a static phase value while performing a dynamic phase shifting for the start-of-scan signal alignment.
    Type: Application
    Filed: January 19, 2010
    Publication date: July 21, 2011
    Applicant: XEROX CORPORATION
    Inventors: Ramakanth DESANI, James W. STEVENS, Jess R. GENTNER, Terri A. CLINGERMAN
  • Patent number: 7973817
    Abstract: A pixel clock and pulse-modulation-signal generating device includes a high-frequency-clock generating unit that generates a high-frequency clock; a modulation-data generating unit that generates, based on pixel control data that specifies a pixel length and image data, phase data that indicates a transition timing of a pixel clock and modulation data that indicates a desired bit pattern that corresponds to the image data; a pixel-clock generating unit that generates a pixel clock based on the high-frequency clock, the phase data, and a horizontal synchronization signal; and a serial-modulation-signal generating unit that inputs the modulation data, and outputs a pulse modulation signal in a serial pulse string based on the high-frequency clock.
    Type: Grant
    Filed: August 24, 2007
    Date of Patent: July 5, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuhiro Nihei, Masaaki Ishida, Atsufumi Omori, Dan Ozasa
  • Patent number: 7965901
    Abstract: Hard imaging methods, hard imaging device fabrication methods, hard imaging devices, hard imaging device optical scanning systems, and articles of manufacture are described. A hard imaging method includes providing image data corresponding to a hard image to be formed and generating light responsive to the image data. The method further includes scanning the light to form a latent image corresponding to the hard image to be formed and accessing correction data corresponding to scanning errors of a scan lens intermediate a rotating reflection device and a photoconductor. The method also includes modifying the image data using the correction data before the generating and the modifying including modifying to reduce the introduction of image errors resulting from the scanning using the scan lens.
    Type: Grant
    Filed: October 31, 2003
    Date of Patent: June 21, 2011
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: William D. Holland
  • Patent number: 7940421
    Abstract: A tandem type color image forming apparatus, which can continuously form color images each containing two or more colors, including: a signal creating section having, for each color, two or more image area setting counters for generating an image valid area signal to set a starting position and a width of an image formation area in a sub-scanning direction; and a control section for executing color image formation control on a predetermined face of paper, based on an image top signal for controlling writing of an image on an image carrier and the image valid area signal for each color, wherein the control section sets each of the outputs of the image area setting counters independently according to a preset image formation mode, and selects and controls one of the image area setting counters for each image formation of each color.
    Type: Grant
    Filed: November 22, 2005
    Date of Patent: May 10, 2011
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventor: Kouichi Takaki
  • Patent number: 7834902
    Abstract: In a pixel clock creation method and device, a high frequency clock is created. A scanning time needed to scan a predetermined scanning length is detected in accuracy of half a period of the high frequency clock to output a detection value indicating the detected scanning time. The detection value and a predetermined target value are compared to output a comparison result. A phase data is created based on the comparison result. A pixel clock whose phase is controlled based on both the high frequency clock and the phase data is created.
    Type: Grant
    Filed: April 30, 2007
    Date of Patent: November 16, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuhiro Nihei, Masaaki Ishida, Atsufumi Omori, Dan Ozasa
  • Patent number: 7830402
    Abstract: A high-quality image forming apparatus that is capable of accurately adjusting the size and position of an image during image formation on a second surface of a transfer material, even when there has been expansion/contraction of the transfer material due to thermal fixing after image formation on a first surface thereof, to thereby avoid image displacement during two-sided image formation and multiple image formation.
    Type: Grant
    Filed: January 19, 2007
    Date of Patent: November 9, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Haruhiko Nakatsu
  • Patent number: 7791634
    Abstract: A comparator compares a time interval between a first synchronization signal and a second synchronization signal with a target value, and outputs an error therebetween. A frequency calculator calculates a set value of a pixel clock frequency based on the error output from the comparator, and outputs a frequency specification signal for specifying a pixel clock frequency according to the calculated set value. A frequency divider divides a high frequency clock generated by a high frequency clock generator by a frequency division ratio based on the frequency specification signal output from the frequency calculator, and generates the pixel clock.
    Type: Grant
    Filed: April 20, 2006
    Date of Patent: September 7, 2010
    Assignee: Ricoh Company, Limited
    Inventors: Naruhiro Masui, Hidetoshi Ema, Nobunari Tsukamoto
  • Patent number: 7777776
    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.
    Type: Grant
    Filed: November 1, 2006
    Date of Patent: August 17, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Izuru Horiuchi
  • Patent number: 7692679
    Abstract: A frequency modulation apparatus capable of reducing a peak level of a radiation noise of a characteristic frequency band due to an image clock. This frequency modulation apparatus is used in an image formation apparatus having an image bearing body to be scanned by a laser beam, and comprises an auxiliary clock calculating portion for calculating an auxiliary clock period based on a reference clock period and a modulation coefficient, and an image clock generating portion for generating the image clock in which a frequency is different at least in one portion and other portions of an image area on a main scan line to be scanned by the laser beam on said image bearing body based on the initial period value set in advance and said auxiliary clock period, and said image clock generating means perform a frequency modulation so that the frequency of said image clock changes within a predetermined fluctuation.
    Type: Grant
    Filed: September 4, 2008
    Date of Patent: April 6, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Mitsuo Shiraishi
  • Patent number: 7672345
    Abstract: A drive signal for driving a semiconductor laser is generated on the basis of an image signal inputted in synchronism with a pixel clock. A bias signal to the semiconductor laser is generated at a timing earlier than the drive signal by a predetermined time. The bias signal is disabled in synchronism with the leading edge of the drive signal.
    Type: Grant
    Filed: January 20, 2009
    Date of Patent: March 2, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Tsuyoshi Moriyama
  • Patent number: 7652684
    Abstract: An image forming apparatus forms an image by scanning on a photosensitive member in the main-scanning direction with a plurality of beams aligned in the sub-scanning direction. To detect differences in the main-scanning length of each beam on a photosensitive member, patterns for correction are formed on the photosensitive member using first and second beams at both ends among the plurality of beams. The positions of a first pixel and a last pixel in the main scanning direction on the photosensitive member, which pixels are to be formed by a third beam arranged between the first and second beams, are determined based on the detected first and second locations of the first and second test patterns respectively formed by the first and second beams, without forming a third test pattern by the third beam.
    Type: Grant
    Filed: March 13, 2008
    Date of Patent: January 26, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Junichi Noguchi
  • Publication number: 20090244254
    Abstract: In an image recording apparatus, a shift amount for shifting a transition position of an output light amount from a light modulator element is obtained with respect to each pixel value-change point in a pixel line in order to correct displacement of writing. In a case where the shift amount excesses a width corresponding to one pixel on a substrate, a pixel value in the pixel line is altered so that the pixel value-change point moves by the number of pixels of an integer part of a value obtained by dividing the shift amount by the width, and the shift amount corresponding to the pixel value-change point is modified to a value equivalent to a decimal part. It is therefore possible to shift the transition position of the output light amount in excess of the distance corresponding to one pixel in recording an image, to record the image with accuracy.
    Type: Application
    Filed: February 17, 2009
    Publication date: October 1, 2009
    Inventors: Yoshiki Mizuno, Takahide Hirawa
  • Patent number: 7595812
    Abstract: An image forming apparatus includes a light source that emits a light beam in a main scanning direction according to image data to be used for image formation, a control unit that controls the light source, and detectors that detect the light beam. The main scanning direction is divided into areas and a cycle of a pixel clock is corrected in each area independently based on detection results of the detectors so as to correct an image position and image magnification.
    Type: Grant
    Filed: January 24, 2006
    Date of Patent: September 29, 2009
    Assignee: Ricoh Company, Limited
    Inventor: Katsuhiko Maeda