Feed Back Of Light For Intensity Control Patents (Class 347/236)
  • Patent number: 10571824
    Abstract: In an optical writing device that deflects light beams from first and second light source sections and performs scanning by first and second scanning optical systems, in reflective optical elements disposed in the optical axis direction from after the polygon mirror to before a separation mirror, a number of hold points on each of a writing start side and a writing end side in scanning is same, and in reflective optical elements disposed from after the separation mirror up to a surface to be scanned, a number of hold points on a writing start side of the first scanning optical system is same (one) with that on a writing end side of the second scanning optical system, and a number of hold points on a writing end side of the first scanning optical system is same (two) with that on a writing start side of the second scanning optical system.
    Type: Grant
    Filed: November 28, 2018
    Date of Patent: February 25, 2020
    Assignee: KONICA MINOLTA, INC.
    Inventors: Akira Taniyama, Hideo Uemura, Takashi Kurosawa, Naoki Tajima
  • Patent number: 10496006
    Abstract: An image forming apparatus includes a photosensitive member; a charging device, a developing device, a transfer device, and a controller. The controller is capable of executing an operation in a first mode in which an image forming operation is controlled so that an exposure start enable timing is set during movement of the photosensitive member through one full circumference from first passing, through an exposure position, of a region of the photosensitive member which has passed through a charging position, and executing an operation in a second mode in which an image forming operation is controlled so that the exposure start enable timing is set after the movement of the photosensitive member. On the basis of image information of the first sheet of an image forming job, the controller selects an executing mode from a plurality of modes including at least the first mode and the second mode.
    Type: Grant
    Filed: November 20, 2018
    Date of Patent: December 3, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasushi Takeuchi
  • Patent number: 10481519
    Abstract: A print head includes: current-driven non-single crystal light emitting elements arranged in a line; thin film transistors that are provided in one-to-one correspondence with the light emitting elements and each supplies a driving current to a corresponding one of the light emitting elements; a detector that detects, when one of the light emitting elements corresponding to one of the thin film transistors emits light, an output voltage of the one of the thin film transistors; and a hardware processor that determines a control voltage to be applied to each of the thin film transistors when next light is emitted according to the output voltage of the one of the thin film transistors detected by the detector and a driving current to be supplied by each of the thin film transistors to cause each of the light emitting elements to emit light with a target light amount.
    Type: Grant
    Filed: September 14, 2017
    Date of Patent: November 19, 2019
    Assignee: Konica Minolta, Inc.
    Inventors: So Yano, Yoshikazu Watanabe, Sotaro Yokota
  • Patent number: 10454243
    Abstract: A light source driver circuit is provided that has at least first and second current source circuits that are electrically coupled to a node of the driver circuit. The first and second current source circuits source first and second fractions, respectively, of a total current needed to drive a light source into a node of the driver circuit. The driver circuit uses a sum of the first and second fractions of the total current in combination with a modulation current to drive the light source. By incorporating at least first and second current source circuits into the driver circuit, each of the current sources can be kept sufficiently small in size that they contribute very little parasitic capacitance, and therefore allow the driver circuit to achieve high-bandwidth operations while also allowing the driver circuit to operate at a low supply voltage.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: October 22, 2019
    Assignee: Avago Technologies International Sales Pte. Limited
    Inventors: Dezhao Bai, Vishal Giridharan, Faouzi Chaahoub
  • Patent number: 10384464
    Abstract: An optical print head including a light emitting member, an optical member, a detection unit, and a correction unit. The light emitting member is elongated in a longitudinal direction with light emitting elements arranged along the longitudinal direction. The optical member is elongated in the longitudinal direction with optical elements arranged along the longitudinal direction, the optical elements collecting light emitted by the light emitting elements. The detection unit detects an index value of linear expansion difference in the longitudinal direction of the light emitting member and the optical member. The correction unit uses the index value to correct an emitted light amount for each of the light emitting elements in order to offset differences in light collection efficiency caused by the linear expansion difference.
    Type: Grant
    Filed: October 4, 2017
    Date of Patent: August 20, 2019
    Assignee: KONICA MINOLTA, INC.
    Inventors: Takaki Uemura, Makoto Obayashi, Masayuki Iijima
  • Patent number: 10345732
    Abstract: Provided is an image writing device including a deflector having deflective reflection surfaces for deflecting light flux emitted from a light source and a scanning imaging optical system that condenses the light flux as a light spot on a scanned surface of a latent image carrier, and performing optical scanning on the scanned surface at a constant speed, the image writing device further including: a surface detector that detects a deflective reflection surface that deflects the light flux; a storage that prestores a beam irradiation position in a sub scanning direction corresponding to each main image height on each of the deflective reflection surfaces; and a hardware processor that controls, on the basis of a beam irradiation position in the sub scanning direction corresponding to each main image height on the deflective reflection surface a light quantity of the light flux to be irradiated to the beam irradiation position.
    Type: Grant
    Filed: January 19, 2018
    Date of Patent: July 9, 2019
    Assignee: KONICA MINOLTA, INC.
    Inventors: Takashi Kurosawa, Naoki Tajima, Daisuke Kobayashi
  • Patent number: 10336008
    Abstract: A method for automatically calibrating a device for generatively producing a three-dimensional object (8) comprises the following steps: irradiating an applied layer of a material (3) or a target by means of a first scanner (14) in order to produce a first test pattern (33) in the material (3) or the target; irradiating the applied layer of the material (3) or the target by means of a second scanner (15) in order to produce a second test pattern (34) in the material (3) or the target; detecting the first and second test patterns (33, 34) by means of a camera (24) and assigning the first and second test patterns (33, 34) to the first and second scanners (14, 15), respectively; comparing the first and/or the second test pattern (33, 34) with a reference pattern and/or comparing the first and second test patterns (33, 34) with one another; determining a first deviation of the first test pattern (33) from the reference pattern and/or a second deviation of the second test pattern (34) from the reference pattern an
    Type: Grant
    Filed: May 8, 2014
    Date of Patent: July 2, 2019
    Assignee: EOS GMBH ELECTRO OPTICAL SYSTEMS
    Inventors: Hans Perret, Jochen Philippi
  • Patent number: 9939755
    Abstract: An image forming apparatus including: a setting unit configured to set light intensity correction data stored in a storage unit according to an exposure position while a light beam is being scanned on a photosensitive member at a first scan speed; and a light intensity controller configured to control a light intensity based on the correction data set by the setting unit, wherein the setting unit calculates a light intensity correction data corresponding to a position between a plurality of positions based on the stored correction data, set the correction data according to the exposure position while the light beam is being scanned at a second scan speed lower than the first scan speed; and fixes a switching period for switching the correction data according to the exposure position while the light beam is being scanned on an image forming area of the photosensitive member regardless of the scan speed.
    Type: Grant
    Filed: April 17, 2017
    Date of Patent: April 10, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takahiro Kamikura, Satoru Takezawa
  • Patent number: 9703230
    Abstract: An incidence angle of laser light with respect to a photosensitive member in a main-scanning direction is different depending on an exposure position. Hence, the spot shape of the laser light on the photosensitive member is different in the main-scanning direction. A filter coefficient is changed in the main-scanning direction, and image data is corrected with the filter coefficient.
    Type: Grant
    Filed: March 27, 2014
    Date of Patent: July 11, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Izuru Horiuchi, Yoichi Takikawa, Jun Hirabayashi
  • Patent number: 9588455
    Abstract: An image forming apparatus includes exposing units, a photoconductor, developing units, a processor, and a memory storing instructions. Each exposing unit includes light emitting elements arranged in a main scanning direction and divided into blocks each illuminating at a corresponding light emitting time point. The instructions cause the image forming apparatus to: change a light emitting time point for one of two blocks contained in respective two exposing units at the same position in the main scanning direction, to reduce an image distance in a sub-scanning direction between two images each to be formed by illumination of at least one light emitting element contained in a corresponding one of the two blocks; illuminate the light emitting elements of each of the exposing units at light emitting time points including the light emitting time point obtained by the change; and develop electrostatic latent images formed on the photoconductor.
    Type: Grant
    Filed: January 28, 2015
    Date of Patent: March 7, 2017
    Assignee: BROTHER KOGYO KABUSHIKI KAISHA
    Inventor: Junichi Yokoi
  • Patent number: 9557563
    Abstract: An optical scanning device includes: a light source that emits a laser beam modulated and driven according to an image forming signal; a scanning optical system that includes a polygon mirror to scan a surface of a photoconductor with the laser beam from the light source; a surface identifying unit that associates a sub-scanning position by the polygon mirror with each surface of the polygon mirror; and a light-amount adjusting unit that adjusts a light amount of the light source according to the sub-scanning position, for each surface of the polygon mirror.
    Type: Grant
    Filed: May 27, 2015
    Date of Patent: January 31, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Mitsuo Suzuki, Kohji Sakai
  • Patent number: 9500980
    Abstract: An image forming apparatus capable of controlling an amount of light beam to be a target value even when an emission characteristic of a light source varies. A photosensitive member is exposed to the light beam emitted form a light source. A light receiving element receives the light beam. Voltage for prescribing the driving current is set in a voltage setting unit. A voltage control unit controls the voltage so that the light amount of the light beam received by the light receiving element becomes a target light amount. A determination unit determines a correction parameter for correcting the voltage based on at least the voltage set in the voltage setting unit. A correction unit corrects the voltage set in the voltage setting unit with the correction parameter. A current supply unit supplies a driving current corresponding to the corrected voltage to the light source based on image data.
    Type: Grant
    Filed: May 13, 2015
    Date of Patent: November 22, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Yuichi Seki
  • Patent number: 9463641
    Abstract: A method for dynamically compensating for thermal expansion and contraction of a light emitting diode print bar having first and second light emitting diodes having first and second ideal positions, respectively, the method including: a) determining a first measured position of the first light emitting diode and a second measured position of the second light emitting diode; b) comparing the first measured position and the second measured position to the first ideal position and the second ideal position, respectively; and, c) correcting a first difference between the first measured position and the first ideal position and a second difference between the second measured position and the second ideal position based on results from the step of comparing.
    Type: Grant
    Filed: March 27, 2015
    Date of Patent: October 11, 2016
    Assignee: Xerox Corporation
    Inventors: Mark P. Haefner, Paul A. Hosier, Roger L. Triplett, Terri A. Clingerman
  • Patent number: 9459552
    Abstract: A drive circuit for a printing apparatus includes a first driver arranged on an electrical path from a first current supply unit to a first connection portion for a light-emitting element, a second driver arranged on an electrical path from a second current supply unit to the first connection portion, a third driver arranged on an electrical path from the second current supply unit to a second connection portion for a light-emitting element, and a switch unit configured to selectively connect the second current supply unit to one of the second driver and the third driver and disconnect the connection between the second current supply unit and the other of the second driver and the third driver when the second current supply unit is connected to the one of the second driver and the third driver.
    Type: Grant
    Filed: January 12, 2016
    Date of Patent: October 4, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Wataru Endo
  • Patent number: 9420119
    Abstract: A scanning optical system manufacturing method includes receiving a scanning beam, emitted from a scanning unit including an incident optical system and a deflecting device and passed through an image-forming optical system, in an area having a width in the main scanning direction narrower than a spot diameter of the scanning beam by a light-receiving unit configured to be capable of being displaced at each image height position in the main scanning direction, calculating, based on an output of the light-receiving unit, a peak light quantity at each image height position of the scanning beam, smoothing distribution data of the peak light quantity at each of the image height position acquired by the calculating, and determining, based on the data acquired by the smoothing, either nondefective/defective states of the scanning unit and the image-forming optical system or a nondefective/defective state of only the image-forming optical system.
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: August 16, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hiroki Yoshida
  • Patent number: 9398695
    Abstract: Methods and apparatus are provided to fabricate massive monolithic arrays of individually addressable light emitting diodes, assemble a plurality of such massive monolithic arrays of individually addressable light emitting diodes, control each individual light emitting diode, and to assemble the same in manner to achieve the accuracy and stability for a massive number of individually controlled light emitting diodes that can then be focused using projection optics on to a photoreceptive surface. In addition methods and apparatus are provided to move the imaging system thus described relative to the photoreceptive surface in two axes orthogonal to each other thus exposing the photoreceptive surface.
    Type: Grant
    Filed: April 9, 2014
    Date of Patent: July 19, 2016
    Assignee: 4233999 Canada Inc.
    Inventor: Najeeb Ashraf Khalid
  • Patent number: 9377739
    Abstract: A toner density is calculated from outputs of light-receiving elements based on a difference between a reflection property of a supporting member and a reflection property of a toner pattern. Light-emitting elements aligned in one direction that is inclined to a sub-direction emit a detection light in such a manner that a distance between adjacent spots falling on the supporting member in a second direction is equal to or smaller than a width of the toner pattern in the second direction. The light-receiving elements receive a reflected light reflected from the supporting member and/or the toner pattern. The light-receiving elements are aligned, opposed to the supporting member, in a one direction corresponding to the light-emitting elements.
    Type: Grant
    Filed: July 18, 2014
    Date of Patent: June 28, 2016
    Assignee: RICOH COMPANY, LTD.
    Inventor: Koji Masuda
  • Patent number: 9283771
    Abstract: A method of manufacturing a print head includes a first step of finding first light quantity related data showing a light quantity in a light spot formed by lighting up each of light-emitting units by a driving unit by using a first threshold, a second step of finding first magnitude related data showing a magnitude in the light spot formed by lighting up the light-emitting unit by the driving unit by using a second threshold, a third step of finding first ratio data showing a ratio between the first light quantity related data and the first magnitude related data, a fourth step of finding light quantity correction data to the light-emitting unit forming the light spot as a target by using the first ratio data, and a fifth step of retaining the found light quantity correction data to the print head.
    Type: Grant
    Filed: January 16, 2015
    Date of Patent: March 15, 2016
    Assignee: RICOH COMPANY, LTD.
    Inventor: Shigeaki Imai
  • Patent number: 9140899
    Abstract: Exemplary embodiments provide a projection-type display apparatus, which can address or realize a reduction in weight and size, a reduction in power consumption, and a reduction in noise, and address or realize a reduction in price, and a control method for the projection-type display apparatus, as well as a control program for the projection-type display apparatus. The projection-type display apparatus includes a solid-state light source that emits light, a mirror device that controls an emitting direction of the incident light to thereby subject the incident light to temporal modulation, and a projecting device that projects the modulated light.
    Type: Grant
    Filed: June 10, 2014
    Date of Patent: September 22, 2015
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Yasunaga Miyazawa, Hiroshi Hasegawa
  • Patent number: 9103725
    Abstract: A method of compensating for electromagnetic radiation. The method may include measuring electromagnetic radiation emanating from circuitry at a first frequency and adjusting at least one of the electrical settings of the circuitry based on the measurement of the electromagnetic radiation to reduce the electromagnetic radiation at the first frequency emanating from the circuitry.
    Type: Grant
    Filed: February 7, 2013
    Date of Patent: August 11, 2015
    Assignee: FINISAR CORPORATION
    Inventors: Henry Meyer Daghighian, The'Linh Nguyen, Chris Kocot
  • Patent number: 9069095
    Abstract: A method is described for obtaining an accurate and precise value for radiation output of a radiation generator. Radiation is generated in the radiation generator, and the radiation output of the radiation generator is measured using a radiation monitoring device. An instantaneous inferred radiation output is determined from operating parameters of the radiation generator, and over a period of time a calibration factor between the measured and the instantaneous inferred radiation output is determined. The accurate and precise value for radiation output is determined from the instantaneous inferred radiation output and the determined calibration factor.
    Type: Grant
    Filed: December 16, 2013
    Date of Patent: June 30, 2015
    Assignee: Schlumberger Technology Corporation
    Inventors: Sicco Beekman, Christian Stoller, Robert Arthur Adolph
  • Patent number: 9035988
    Abstract: A light source driving device which drives a plurality of light emitting parts provided in a light source to emit a plurality of light beams based on image information, includes a plurality of driving circuits configured to drive the plurality of light emitting parts. Each of the driving circuits includes a signal generation circuit that generates a modulation signal to control a light emitting intensity of the corresponding light emitting part based on the image information, a detection circuit that detects a light emitting status of the corresponding light emitting part; and a light emitting circuit that outputs a driving signal to the corresponding light emitting part to emit a light beam in accordance with the modulation signal and adjustment data obtained based on the light emitting status of at least one of the plurality of light emitting parts.
    Type: Grant
    Filed: May 23, 2008
    Date of Patent: May 19, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Yasuhiro Nihei, Masaaki Ishida, Atsufumi Omori, Jun Tanabe
  • Patent number: 9030513
    Abstract: A color image forming apparatus has a light emitting element emitting light, a laser driving unit causing the light emitting element to emit light of a light amount at a first emission level for visualizing a toner image onto a first area where the toner image is to be visualized on a charged photosensitive member and to emit light of a light amount at a second emission level for weak emission onto a second area where the toner is not to be adhered to the charged photosensitive member. In addition, an acquiring unit acquires information of an integrated number of rotations of the photosensitive member, a drive current adjusting unit adjusts the drive current for the second emission level, and changes a magnitude of the drive current for the second emission level in accordance with the information of the integrated number of rotations of the photosensitive member.
    Type: Grant
    Filed: July 23, 2014
    Date of Patent: May 12, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kiyoto Toyoizumi, Masaru Shimura, Hideo Nanataki, Kengo Kawamoto
  • Patent number: 9019330
    Abstract: Optical scanning device includes as follows. Light emitting element emits light beam in First direction and Second direction. Mirror unit reflects light beam emitted in First direction. First light receiving element receives light beam reflected by Mirror unit. Reference signal generator generates BD signal based on signal output from First light receiving element. Second light receiving element receives light beam emitted in Second direction. Light quantity controller measures signal output from Second light receiving element and automatically controls the light quantity of light beam emitted during APC period. Light quantity controller starts the automatic control at a timing at which light beam reflected by Mirror unit passes through the position of Second light receiving element and is received by First light receiving element and completes the automatic control before light beam reflected by Mirror unit reaches the position of Second light receiving element next.
    Type: Grant
    Filed: March 26, 2013
    Date of Patent: April 28, 2015
    Assignee: KYOCERA Document Solutions Inc.
    Inventor: Hideyuki Ogasawara
  • Patent number: 8994768
    Abstract: In an optical scanning apparatus, a light source includes a plurality of light emitting elements. A light beam output from the source is scanned and deflected by a polygon mirror so as to form an electrostatic latent image on a surface of a light sensitive member. A control unit controls the source so that the source outputs the light beam in a first period before a second period in which the light beam deflected by the mirror forms the image. During the first period for outputting the light beam from the source a period for scanning a non-image region of the member in a state in which the rotation speed of the mirror is being accelerated or decelerated is made longer than a period for scanning the non-image region of the member in a state in which the rotation speed of the mirror is controlled at a constant speed.
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: March 31, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shunsaku Kondo
  • Patent number: 8982178
    Abstract: The present invention provides a method and device for acquiring real-time video images of a terminal, sad method comprising: acquiring light intensity of an existing environment when the terminal acquires the real-time video images; comparing the light intensity of the existing environment with a light intensity threshold value set by the terminal system; acquiring images preset by the terminal and sending the preset images to an existing receiver which is communicating with the terminal if the light intensity of the existing environment is lower than the light intensity threshold value set by the terminal system. The present invention can ensure the quality of video conversation when the light intensity is weak, save power energy, improve the user experience, and is beneficial to promote the video communication terminal.
    Type: Grant
    Filed: October 9, 2011
    Date of Patent: March 17, 2015
    Assignee: Huizhou TCL Mobile Communication Co., Ltd.
    Inventor: Zhibing Yang
  • Patent number: 8963977
    Abstract: An image forming apparatus includes a light source including a plurality of light emitting elements for emitting a light beam for exposing the photosensitive member, the light emitting elements being arranged respectively corresponding to one pixel of the image in a direction of a rotational axis of the photosensitive member, an output unit for outputting pixel data for driving each of the light emitting elements, a drive unit for driving the light emitting elements based on the output pixel data, a storage unit for storing a cumulative number of times of light emission of a target light emitting element included in the light emitting elements, and a light amount control unit for controlling a light amount of a light beam emitted by the target light emitting element and the other light emitting elements based on the stored cumulative number of times of light emission of the target light emitting element.
    Type: Grant
    Filed: June 19, 2013
    Date of Patent: February 24, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasutomo Furuta
  • Patent number: 8957928
    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.
    Type: Grant
    Filed: May 24, 2011
    Date of Patent: February 17, 2015
    Assignee: Ricoh Company, Ltd.
    Inventor: Tatsuo Ohyama
  • Patent number: 8953009
    Abstract: An image forming apparatus using the laser scan method or the LED method, which is capable of reducing a variation of spot diameter with a simple mechanism, and of forming a high-quality image by adjusting the density depending on the image resolution with a low cost. The image forming apparatus forms an image by developing an electrostatic latent image formed by irradiating a charged photoconductor with light emitted from a light source with developer. A detecting unit detects a distance between an attention pixel and an adjacent image that is adjacent to an image including the attention pixel across a white background. An adjustment unit adjusts a density of the attention pixel based on the distance measured with the detecting unit and a spot diameter of the light on a surface of the photoconductor.
    Type: Grant
    Filed: January 29, 2013
    Date of Patent: February 10, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasutomo Furuta
  • Patent number: 8947485
    Abstract: A drawing control device includes: a fill-stroke generating unit that generates a fill stroke that includes a plurality of strokes that fill a drawing area; a shape-stroke generating unit that generates a shape stroke which is a stroke of a shape to be formed on the drawing area; a first detecting unit that detects an overlap portion where the fill stroke and the shape stroke overlap with each other; a modifying unit that removes the overlap portion from the fill stroke to modify the fill stroke to obtain a drawing stroke; a drawing-instruction generating unit that generates a drawing instruction for drawing each stroke in the drawing stroke; and a drawing control unit that controls a drawing device by using the drawing instruction to cause the drawing device to draw the drawing stroke on an object.
    Type: Grant
    Filed: October 26, 2010
    Date of Patent: February 3, 2015
    Assignee: Ricoh Company, Limited
    Inventor: Fumihiro Hasegawa
  • Patent number: 8933979
    Abstract: An image forming apparatus comprises a light source, a photosensitive member and a control unit. The light source turns on in response to a driving current supplied based on image data. An electrostatic latent image is formed on the photosensitive member by exposing the photosensitive member to a light beam output from the light source turned on. The control unit controls the value of the driving current supplied to the light source in accordance with a driving state of the light source so that the value of the driving current supplied to the light source differs and changes with the passage of time in accordance with the driving state of the light source prior to the driving current being supplied to the light source.
    Type: Grant
    Filed: November 10, 2011
    Date of Patent: January 13, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yuichi Seki
  • Patent number: 8922613
    Abstract: A light beam scanning device which is capable of performing high-accuracy light amount control without complicated control even when the device includes a laser diode having non-linear I-L characteristics. Gain circuits set the amount of light to be emitted from the laser diode. A PD circuit board detects the amount of the emitted light. A laser controller controls the amount of the emitted light by adjusting drive current applied to the laser diode based on a detection output from the PD circuit board. A CPU corrects data for correcting the drive current. The CPU decides a light amount correction range for correcting the light amount based on the correction data, calculates the slope of the I-L characteristics in the light amount correction range based on light amounts at two points within the light amount correction range and drive currents associated with the respective light amounts, and corrects the correction data using the calculated slope.
    Type: Grant
    Filed: April 26, 2013
    Date of Patent: December 30, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Daisuke Akagi
  • Patent number: 8917303
    Abstract: The optical writing device includes: a light source including a plurality of light-emitting element assemblies; a line information storage for storing pixel information constituting an image; a light source driver for driving the light-emitting elements; an error information acquire for acquiring inclination error information and arrangement error information; a correction value generator for generating correction value information for correcting the inclination of the main scanning line; a correction value holder for holding the generated correction value information; and a driven pixel adjuster for adjusting positions in the sub-scanning direction, wherein the correction value generator generates the correction value information such that a position of the image to be shifted to correct the error of the arrangement of the light-emitting element assemblies is different from that to correct the inclination of the main scanning line.
    Type: Grant
    Filed: July 8, 2013
    Date of Patent: December 23, 2014
    Assignee: Ricoh Company, Limited
    Inventor: Tatsuya Miyadera
  • Patent number: 8913096
    Abstract: An optical scanning device that scans a scanning surface in a main scanning direction. The device includes a surface emitting laser as a light source, an optical deflector that deflects a light flux from the light source while rotating around a rotation axis, a monitor light receiving element, a synchronization detection light receiving element, a monitor optical system that directs the monitor light flux to the monitor light receiving element, a synchronization detection optical system that directs the synchronization detection light flux to the synchronization detection light receiving element, and a scanning optical system that directs a scanning light flux to the scanning surface. A combined focal length of the monitor optical system in the main scanning direction is smaller than a combined focal length of the synchronization detection optical system in the main scanning direction.
    Type: Grant
    Filed: August 19, 2011
    Date of Patent: December 16, 2014
    Assignee: Ricoh Company, Limited
    Inventor: Kohji Sakai
  • Patent number: 8907999
    Abstract: An electrophotographic image forming apparatus that are capable of reducing the variation of the rise time of the laser light source due to the temperature change of the laser light source with a simple configuration. A laser light source emits a laser beam according to a driving signal in order to expose an image bearing member. A voltage detection unit detects terminal voltage of the laser light source. A drive unit has a voltage source that can control output voltage and supplies current corresponding to the output voltage of the voltage source to the laser light source when making the laser light source emit the laser beam according to the driving signal. A control unit controls the voltage source so that the output voltage of the voltage source generates current overshot to a target current based on the detection result of the voltage detection unit.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: December 9, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shigeru Kasahara
  • Patent number: 8902463
    Abstract: An image forming apparatus includes: Photoreceptors; an image carrier; a plurality of light emitting element arrays each configured to emit a light beam to a corresponding one of the photoreceptors independently; an angle adjustment unit to adjust a mounting angle of the light emitting element arrays to a frame of the image forming apparatus; a pattern forming unit to form a positional error correction pattern of each color on the image carrier; a optical detector to detect the correction pattern formed on the image carrier; a positional error calculation unit to calculate a printing skew error and a main scanning scaling error of the light emitting element arrays based on the correction pattern detected by the optical detector; a skew correction unit to correct the printing skew error detected by the positional error calculation unit; and further a main scanning scaling error correction unit.
    Type: Grant
    Filed: September 25, 2012
    Date of Patent: December 2, 2014
    Assignee: Ricoh Company, Ltd.
    Inventor: Yuichiro Shukuya
  • Patent number: 8896648
    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.
    Type: Grant
    Filed: March 14, 2011
    Date of Patent: November 25, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsufumi Omori, Masaaki Ishida
  • Patent number: 8878886
    Abstract: A light beam scanning device capable of suppressing lowering of accuracy of light amount control when scanning a photosensitive member using light beams. A semiconductor laser has light emitting elements for emitting respective light beams. A polygon mirror deflects the light beams such that each light beam scans a photosensitive member in a predetermined direction. A photodiode sensor is disposed where the light beams enter. A CPU controls the light amount of each light beam based on an output from the sensor. The first and second light emitting elements are arranged such that respective light beams therefrom are adjacent to each other in the direction and there is time during which both the light beams enter the sensor. The CPU executes the control for the first and second light emitting element, at receptive different cycles of scanning of the light beams.
    Type: Grant
    Filed: January 18, 2012
    Date of Patent: November 4, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yuta Nito
  • Patent number: 8872872
    Abstract: An optical scanning apparatus, including: light sources; a deflector configured to deflect beams emitted from the light sources; and imaging optical systems configured to focus the beams deflected by a deflecting surface of the deflector on surfaces to be scanned, respectively, wherein: the beams entering the deflecting surface are P-polarized beam; the optical scanning apparatus further includes at least one reflection optical element reflecting a beam in a sub-scanning cross section on each of optical paths from the deflecting surface to the surfaces to be scanned; the optical paths include first and second optical paths having different numbers of the reflection optical elements from each other; and the optical scanning apparatus further includes an adjustor configured to adjust an output of a light source corresponding to at least one of the first and the second optical paths from among the light sources so that predetermined conditions are satisfied.
    Type: Grant
    Filed: October 19, 2012
    Date of Patent: October 28, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Jun Igarashi
  • Patent number: 8866865
    Abstract: An image forming apparatus includes a light source that emits light beams for scanning a photoconductive element and for image forming of image data, a storage unit that stores a correction amount of a turn-on time of the light source associated with a preset turn-on pattern of the light beams, an acquiring unit that compares a pattern of the image data with the turn-on pattern, so as to acquire the correction amount corresponding to the pattern of the image data which is associated with the turn-on pattern, from the storage unit; and a light source controller that controls turn-on of the light source by a turn-on time corrected with acquired correction amount.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: October 21, 2014
    Assignee: Ricoh Company, Limited
    Inventor: Katsuhiko Maeda
  • Patent number: 8854407
    Abstract: An image-forming position displaces from an ideal position occurring due to a portion of a support substrate bending in a direction approaching a photosensitive drum. This displacement is set as a first gap data. Spot size expansion caused by bending of the support substrate can be reduced by using light amount control data that has been corrected in response to this first gap data. Furthermore, by using light amount control data corrected in response to second gap data that indicates displacement to an ideal position from exposure areas occurring due to decentering of the photosensitive drum, spot size expansion caused by decentering of the photosensitive drum can be reduced.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: October 7, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasuo Kamei
  • Patent number: 8830286
    Abstract: A color image forming apparatus has a plurality of photosensitive members, a light emitting element emitting light, a laser driving unit causing the light emitting element to emit light of a light amount at a first emission level for visualizing the toner image onto a first area where the toner image is to be visualized on the charged photosensitive member and to emit light of a light amount at a second emission level for weak emission onto a second area where the toner is not to be adhered to the charged photosensitive member. In addition, an acquiring unit acquires information associated with a remaining lifetime of each of the photosensitive members, a first drive current adjusting unit adjusts the first drive current, and a second drive current adjusting unit adjusts the second drive current, with the second drive current adjusting unit changing a magnitude of the second drive current in accordance with the information associated with the remaining lifetime of each of the photosensitive members.
    Type: Grant
    Filed: May 16, 2012
    Date of Patent: September 9, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kiyoto Toyoizumi, Masaru Shimura, Hideo Nanataki, Kengo Kawamoto
  • Patent number: 8823762
    Abstract: Density unevenness caused by an optical facet angle error or the like of a polygon mirror which has a plurality of reflection planes is corrected after shipment with a simple configuration. At least one of the plurality of reflection planes is identified as a reference plane. A plurality of pieces of light amount adjustment data for changing the light amount of light deflected for each reflection plane with the reference plane as a reference, and at least one piece of light amount correction data for correcting the light amount based on the plurality of pieces of light amount adjustment data are stored. When a light source emits light, one mode can be selected out of a test print mode (S5) in which light is emitted in a light amount based on the plurality of pieces of light amount adjustment data and a corrected print mode (S13) in which light based on the light amount correction data is emitted.
    Type: Grant
    Filed: April 10, 2013
    Date of Patent: September 2, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Katsuyuki Yamazaki
  • Patent number: 8817060
    Abstract: An optical device includes: a light source including a plurality of light emitting spots that output laser beams, respectively; a separating unit that separates each of the laser beams output from the plurality of light emitting spots into a monitor beam and a scanning beam; a light-quantity measuring unit that measures a light quantity of the monitor beam; a storage unit in which respective drive currents with which the plurality of light emitting spots of the light source output a prescribed light quantity of laser beams are stored in advance; a light-source control unit that drives the light source with the drive currents stored in the storage unit and causes the plurality of light emitting spots to output the laser beams; and a determining unit that determines whether the light source operates properly on the basis of the light quantity measured by the light-quantity measuring unit.
    Type: Grant
    Filed: June 20, 2011
    Date of Patent: August 26, 2014
    Assignee: Ricoh Company, Limited
    Inventor: Hidetoshi Yamashita
  • Patent number: 8810623
    Abstract: An optical scanning device includes a MEMS mirror, a driving unit for oscillating the MEMS mirror using a drive voltage which varies in a basic cycle, a light detection unit for receiving laser light deflected by the MEMS mirror and outputting a detection signal, a correction value calculation unit for calculating a correction voltage value used in correcting the drive voltage, a DC voltage generation unit for generating a DC voltage having a voltage value smaller than the correction voltage value, a DC voltage amplification unit for amplifying the DC voltage generated by the DC voltage generation unit to have a voltage value equal to the correction voltage value, and a waveform shaping unit for shaping the waveform of the amplified DC voltage so that the DC voltage varies in the basic cycle and outputting the shaped DC voltage as the drive voltage to the driving unit.
    Type: Grant
    Filed: February 21, 2013
    Date of Patent: August 19, 2014
    Assignee: KYOCERA Document Solutions Inc.
    Inventor: Hideji Mizutani
  • Patent number: 8810616
    Abstract: A device including: a photoreceptor; an LED printbar; and a computer processor for: determining how long LEDs on the printbar are energized while the device is operated to generate an image output; determining that a first plurality of LEDs has been energized less than a second plurality of LEDs; energizing the first plurality of LEDs for a correction time period as the LEDs are aligned with an inter-document zone (IDZ); and de-energizing the second plurality of LEDs during the time period. Energizing the second plurality of LEDs is unrelated to energizing the LEDs for purposes of evaluating an image. The time period is concurrent with operation of the device to generate an image output.
    Type: Grant
    Filed: December 1, 2010
    Date of Patent: August 19, 2014
    Assignee: Xerox Corporation
    Inventor: Paul A. Hosier
  • Patent number: 8780406
    Abstract: A visible laser beam scanned by a galvano-scanner system is aligned at each of positioning points on the top surface of a master work by manual operation to record sensor position signals of position sensors on galvano-scanners. The sensor position signals on each positioning point are recorded to create a drive pattern in accordance with recorded sensor position signals. The drive pattern no longer has optics system error sources including focus error and attachment error as well as errors caused by scale, offset and the like, also eliminating the need for entering a distance as far as the top surface of the work. Therefore, the drive pattern with error components removed can be created with ease.
    Type: Grant
    Filed: May 16, 2008
    Date of Patent: July 15, 2014
    Assignee: Harmonic Drive Systems Inc.
    Inventor: Nozomu Tanioka
  • Publication number: 20140192131
    Abstract: An image forming device includes a photoreceptor drum including a target surface that is scanned in a main scanning direction and a sub-scanning direction, an exposure head including a plurality of light emitting segments aligned in parallel to the main scanning direction, an exposure driving unit which selectively drives the plural light emitting segments, a storing unit which stores a profile where the respective positions of the plural light emitting segments correspond to a correction amount from the main scanning direction toward the sub-scanning direction at every position, and a correcting unit which smoothes a local change of the correction amount in the profile.
    Type: Application
    Filed: January 8, 2014
    Publication date: July 10, 2014
    Applicants: Toshiba Tec Kabushiki Kaisha, Kabushiki Kaisha Toshiba
    Inventor: TAKAHIRO HAMANAKA
  • Patent number: 8767028
    Abstract: An image forming apparatus having: a light source for emitting a beam; a deflector for deflecting the beam; a light receiving element for receiving the beam and generating a detection signal; a converter for converting electric potentials of the detection signal into data values and generating time data associated with the data values; and a first calculator for calculating a position of center of the beam from the data values and the time data.
    Type: Grant
    Filed: September 13, 2011
    Date of Patent: July 1, 2014
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Daisuke Fujita, Shinpei Arino
  • Patent number: 8749605
    Abstract: An image forming apparatus includes a photosensitive body, an exposure unit, a pulse generating unit, a smoothing unit, a drive current generating unit, and a second emitting control unit. The exposure unit includes a light source for emitting a light beam, and causes the light beam emitted from the light source to perform scanning in a main scanning direction, thereby drawing a main scanning line on the photosensitive body. The second emitting control unit causes the light source to emit the light beam, in an APC period of automatically controlling the light quantity of the light beam, by causing the pulse generating unit to generate a pulse signal having a duty ratio of 100 percent, causing the smoothing unit to smooth the pulse signal thereby generating an analog signal, and causing the drive current generating unit to generate a drive current based on the analog signal.
    Type: Grant
    Filed: February 27, 2013
    Date of Patent: June 10, 2014
    Assignee: Kyocera Document Solutions Inc.
    Inventors: Kenichi Onishi, Okito Ogasahara, Naohiro Anan, Yasuaki Sakamoto