By Varying Intensity Of Light Beam Patents (Class 347/253)
  • Patent number: 10650204
    Abstract: A barcode detection method includes acquiring an image by a camera, acquiring a horizontal gradient and a vertical gradient of each pixel of the image within a region, generating a gradient phase and gradient magnitude of each pixel according to the horizontal gradient and the vertical gradient, performing a binarization process to the gradient magnitude of each pixel of the image within the region for generating a binarized image, vertically and horizontally sampling the binarized image for generating the gray level flip count in a vertical direction and a horizontal direction, locating an image region of a barcode according to the gray level flip count in the vertical direction and the horizontal direction, acquiring a plurality of gradient phases of all pixels within the image region for generating a gradient phase distribution, and generating a barcode format detection result according to the gradient phase distribution.
    Type: Grant
    Filed: August 14, 2018
    Date of Patent: May 12, 2020
    Assignee: WELTREND SEMICONDUCTOR INC.
    Inventors: Hsuan-Ying Chen, Hung-Chih Chiang, Ian Hsu
  • Patent number: 9921517
    Abstract: An image forming apparatus includes: a detection unit configured to detect light that a light source emits and that is reflected by a polygon mirror in a predetermined direction, and to output a synchronization signal; a speed control unit configured to perform acceleration/deceleration control of the polygon mirror based on the synchronization signal at a target speed; and a light intensity control unit configured to decide an emission intensity of the light source and notify the digital value to the light driving unit. The speed control unit changes control of the polygon mirror to a neutral control in which neither acceleration nor deceleration control is performed in a case the light intensity control unit changes the light intensity of the light source when the speed control unit is performing the acceleration/deceleration control.
    Type: Grant
    Filed: April 19, 2017
    Date of Patent: March 20, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Fumiaki Mizuno
  • Patent number: 9338427
    Abstract: Pixel depth values of a user-controlled virtual object in a three-dimensional scene may be re-scaled to avoid artifacts when the scene is displayed. Minimum and maximum threshold values can be determined for the three-dimensional scene from a target derived from pixel depth data for the three-dimensional scene. Each pixel depth value of the user-controlled virtual object can be compared to the minimum threshold value and the maximum threshold value. A depth value of each pixel of the user-controlled virtual object that falls below the minimum threshold value can be set to a corresponding low value. Each pixel depth value of the user-controlled virtual object that exceeds the maximum threshold value can be set to a corresponding high value.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: May 10, 2016
    Assignee: Sony Computer Entertainment America, LLC
    Inventor: Barry M Genova
  • Patent number: 8982422
    Abstract: An image forming apparatus for forming an image in accordance with light to be emitted from a light source includes: a digital half-toning unit configured to convert a uniform-pixel-value region of image data to a parallel-line pattern formed with a plurality of parallel lines extending obliquely with respect to a direction, in which pixels are arrayed, thereby expressing each gray level of the image data as an area percentage; a modulated-signal generating unit configured to generate a modulated signal by modulating the converted image data with a clock signal; a light-source driving unit configured to drive the light source according to the modulated signal; and an edge control unit configured to narrow a to-be-illuminated region, which is to be illuminated by the light from the light source, in each of edge neighborhoods of the lines constituting the parallel-line pattern, while increasing intensity of the light.
    Type: Grant
    Filed: May 5, 2014
    Date of Patent: March 17, 2015
    Assignee: Ricoh Company, Limited
    Inventors: Muneaki Iwata, Masaaki Ishida, Atsufumi Omori, Hayato Fujita
  • Patent number: 8928715
    Abstract: A light source driver includes a controller which outputs an undershoot current in synchronization with lighting complete timing in lighting information, wherein the controller is configured to output the undershoot current such that a voltage in a light source when the output of the undershoot current is complete is equal to a voltage in the light source before being turned on.
    Type: Grant
    Filed: December 24, 2013
    Date of Patent: January 6, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsufumi Omori, Masaaki Ishida, Muneaki Iwata, Hayato Fujita
  • Patent number: 8928720
    Abstract: Apparatus comprising a two-dimensional array of light sources (40) and a scanning device (26) arranged to scan light (14) emitted from the light sources (40) onto a medium (10) to generate a plurality of scan lines (52) on the medium (10), the light sources (24 and scanning device (26) being arranged such that a plurality of light sources (24) can be used to generate each scan line (52) of the plurality of scan lines (52).
    Type: Grant
    Filed: October 27, 2005
    Date of Patent: January 6, 2015
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: David K. Towner, Michael Plotkin, Dror Kella
  • Patent number: 8896643
    Abstract: An image forming apparatus including: a photoreceptor; a charger configured to charge a photoreceptor surface; an optical scanning device configured to expose the photoreceptor surface to form an electrostatic latent image thereon; a developing device configured to develop the electrostatic latent image to form a toner image thereon; a transfer member configured to transfer the toner image to a sheet; a fixing device configured to fix the toner image thereon; and a control unit configured to carry out exposure amount control for formation of an image having a pattern with a spatial frequency from 0.1 c/mm to 3.0 c/mm so that after the exposure, there will be an electric potential difference V1 between an edge portion and a non-edge portion of the pattern and so that there will be an electric potential difference V2 larger than V1 between an edge-surrounding portion and the other portions of a non-image area.
    Type: Grant
    Filed: December 30, 2013
    Date of Patent: November 25, 2014
    Assignee: Konica Minolta, Inc.
    Inventor: Yohei Nakade
  • Patent number: 8890917
    Abstract: In order to improve read stability, a printing condition is set based on not visual read of a user, but read with an optical information reading apparatus. A printing quality evaluation apparatus includes: an image acquiring section that acquires an image; a symbol extracting section that extracts the symbol in which the printing quality can be evaluated from the captured images acquired by the image acquiring section; a printing quality evaluation section that evaluates the printing quality of the symbol extracted by the symbol extracting section; an identification information recognition section that recognizes the identification information identifying each printing condition of the symbol; and an evaluation output section that outputs the identification information, which is recognized by the identification information recognition section, and an evaluation result of the printing quality of the printing quality evaluation section according to the symbol extracted by the symbol extracting section.
    Type: Grant
    Filed: January 12, 2012
    Date of Patent: November 18, 2014
    Assignee: Keyence Corporation
    Inventors: Hajime Matsuda, Takaaki Ito
  • Patent number: 8854408
    Abstract: An image forming apparatus includes; an exposure unit configured to perform, based on the image data, first exposure for a photosensitive member and second exposure for the photosensitive member exposed by the first exposure; a determination unit configured to determine a type of the image to be formed based on image data; and a control unit configured to control the exposure unit such that a difference in an exposure amount between the first exposure and the second exposure performed based on the image data when the type of the image is a character is larger than the difference in the exposure amount between the first exposure and the second exposure performed based on the image data when the type of the image is a picture.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: October 7, 2014
    Inventors: Nobuhiko Zaima, Tomohisa Itagaki, Takahiro Ishihara, Yasuhito Shirafuji
  • 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: 8803938
    Abstract: An image forming apparatus forms a first patch with a light amount obtained by reducing a target light amount of a light amount control unit by a predetermined percentage, and forms a second patch with a light amount obtained by a shading control unit reducing the target light amount by the predetermined percentage. Furthermore, the image forming apparatus determines a correction coefficient that is used for modification data for each scanning position in common so that there is no error between a detected value of the first patch and a detected value of the second patch.
    Type: Grant
    Filed: October 15, 2012
    Date of Patent: August 12, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yasutomo Furuta
  • Patent number: 8754921
    Abstract: A storage stores data of charging electric potentials at two or more points on a surface of an image carrier, and coordinates thereof expressed using a main-scanning position and a sub-scanning position thereof. A determination unit determines a correction value of a light power from the data of charging electric potentials at two or more points and coordinates thereof that have been read out from the storage unit. The correction value is applied to the light source so as to reduce the charging electric potential or the charging electric potential unevenness of coordinates on the surface of the image carrier. A correction unit uses the determined charging electric potential or correction value to correct the light power of the light source so as to mitigate an influence of charging unevenness at each set of coordinates.
    Type: Grant
    Filed: July 8, 2008
    Date of Patent: June 17, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masayuki Hirano
  • Patent number: 8736896
    Abstract: An optical scanning unit includes a light source including a plurality of light-emitting elements; a light detector to detect a light beam emitted from the light source; a light-flux splitter, angled to the optical axis of the light beam emitted from the light source, having an aperture, a portion of reduced thickness susceptible to warping, a concave face of the warped light-flux splitter as a reflecting face, and a convex face of the warped light-flux splitter opposite the concave face as a non-reflecting face; and a light-flux splitter pressing unit to press the light-flux splitter onto a light-flux splitter holding member without blocking the aperture. Light beam passed the aperture is used as a write-use light flux. The reflecting face reflects a light flux other than the write-use light flux as a monitor-use light flux. The light-flux splitter pressing unit presses a portion of maximum convexity of the non-reflecting face.
    Type: Grant
    Filed: May 23, 2011
    Date of Patent: May 27, 2014
    Assignee: Ricoh Company, Ltd.
    Inventor: Susumu Mikajiri
  • Patent number: 8724163
    Abstract: An optical scanning apparatus includes a light source, rotational polygonal mirror, correction data calculating unit, modification computing unit, and adjustment unit. The adjustment unit adjusts drive current supplied to the light source using the correction data calculated by the correction data calculating unit when a first of a plurality of modes is selected or using the correction data calculated by the modification computing unit when a second of the plurality of modes is selected.
    Type: Grant
    Filed: June 27, 2008
    Date of Patent: May 13, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yuichi Seki
  • Patent number: 8654169
    Abstract: An image forming device includes: an exposure head that includes a light emitting element and a light emission controller that causes the light emitting element to emit light on the basis of a control signal; a photoreceptor that is exposed to the light emitted by the light emitting element included in the exposure head so that a latent image is formed on the photoreceptor; a correcting section that corrects the control signal on the basis of the spectral sensitivity of the photoreceptor to a spectral distribution of the light emitting element; and a developing section that develops the latent image formed on the photoreceptor.
    Type: Grant
    Filed: September 17, 2010
    Date of Patent: February 18, 2014
    Assignee: Seiko Epson Corporation
    Inventors: Yoshio Arai, Nozomu Inoue
  • Patent number: 8633958
    Abstract: The present invention provides an image processing method which includes at least any one of image recording and image erasing, wherein a light irradiation intensity at a center position of the laser beam irradiated in the image recording is controlled; in the image recording, a first auxiliary line extended by a predetermined distance from a start point of each of image lines constituting an image in the opposite direction from the scanning direction and a second auxiliary line extended by a predetermined distance from an end point of each of the image lines in the scanning direction are prepared, and when the first and second auxiliary lines including an image line are continuously scanned, the image line is scanned with irradiating the laser beam, and the first and the second auxiliary lines are scanned without irradiating the laser beam to thereby record the image.
    Type: Grant
    Filed: February 1, 2012
    Date of Patent: January 21, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Kawahara, Yoshihiko Hotta, Tomomi Ishimi
  • Patent number: 8471885
    Abstract: An image processing method including calculating a density of a character to be recorded based on information of a type, size and line width of the character; adjusting an irradiation energy of a laser beam for recording the character based on the density of the character; and irradiating a recording medium with the laser beam whose irradiation energy is adjusted so as to record the character thereon.
    Type: Grant
    Filed: July 12, 2011
    Date of Patent: June 25, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomomi Ishimi, Shinya Kawahara, Toshiaki Asai, Yoshihiko Hotta
  • Patent number: 8390661
    Abstract: A method of calibrating an electrophotographic printer (30), the printer configured with a plurality of light settings, each light setting arranged to produce a different element type, the method comprising: determining (S10) a first light level required to print a first element type by applying a proportional change to a first initial light setting; and determining (S30) a second light level required to print a second element type by applying substantially the same proportional change to a second initial light setting.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: March 5, 2013
    Assignee: Hewlett-Packard Indigo B.V.
    Inventors: Ran Waidman, Eyal Shelef, Shlomo Harush
  • Patent number: 8310516
    Abstract: A light scanning apparatus having plural light sources includes a light source control unit configured to control the light sources to form L (L?2) light beam arrays aligned in a sub scanning direction each of which L light beam arrays are formed by causing M ((N?1)?M?1) light sources out of N (N?2) light sources assigned to each of the L light beam arrays to emit light as M light emitting sources, wherein each of the L light beam arrays forms a pixel and a total of L pixels aligned in the sub scanning direction are formed.
    Type: Grant
    Filed: August 30, 2006
    Date of Patent: November 13, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Jun Tanabe, Masaaki Ishida, Yasuhiro Nihei, Atsufumi Omori
  • Patent number: 8269811
    Abstract: In an image forming apparatus, an exposure device performs exposure on a non-image area of image pattern, performs an exposure on the image area in an exposure amount lower than the non-image area or does not perform exposure, and an exposure amount control device controls, with respect to pixels having the same density data, an exposure amount given by an exposure device to be smaller in a first portion, which is a thin-line of a width that is equal to or less than a predetermined number of pixels or which is an isolated dot of widths that are equal to or less than the predetermined number of pixels in two directions substantially orthogonal to each other, than in a second portion which is a line of a width exceeding the predetermined number or a surface of widths that exceed the predetermined number in two directions substantially orthogonal to each other.
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: September 18, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takahiro Nakase
  • Patent number: 8259146
    Abstract: The image densities of images formed with a plurality of laser beams on the basis of image data are measured. The quantity of each of the plurality of laser beams is adjusted in accordance with the measurement result.
    Type: Grant
    Filed: January 12, 2009
    Date of Patent: September 4, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hitoshi Fukamachi, Yoshihito Machida, Hideki Kubo, Atsushi Ushiroda
  • Patent number: 8233022
    Abstract: It is determined whether a low density area in which pixels having density less than a predetermined density exist in succession is included in an image signal or not, and if the low density area exists, an image is formed by irradiating the laser light in a first condition for a pixel to be interested in each pixel area within the low density area and irradiating the laser light in a second condition being different from the first condition for other pixels in the pixel area. In this way, it is possible to improve reproducibility of a highlight area in a high resolution image and improve reproducibility of characters and line images or the like.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: July 31, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takeo Yamamoto
  • Patent number: 8212852
    Abstract: An image-data transfer controller divides one line of image data for each of the light-emitting-element array units, transfers the divided image data to respective light-emitting-element array units, to drive each of the light-emitting elements in the light-emitting-element array units for an exposure in a main-scanning direction. The image-data transfer controller divides the one line of image data for each of the light-emitting-element array units and transfers the divided image data during one-line interval in the main-scanning direction, performs a plurality of data transfers in the one-line interval for driving each of the light-emitting elements by controlling a lighting time, and includes a plurality of lines of storing units.
    Type: Grant
    Filed: October 28, 2010
    Date of Patent: July 3, 2012
    Assignee: Ricoh Company, Limited
    Inventor: Naoichi Ishikawa
  • Patent number: 8199181
    Abstract: Restricting a screen line number to prevent degradation in graininess depending on the type of recording paper causes a problem in which the image quality of output matter deteriorates. An image forming apparatus according to the present invention changes an exposure area for one pixel used in image formation in accordance with recording paper in consideration of differences in the influence of the height of toner on graininess depending on recording paper.
    Type: Grant
    Filed: February 4, 2011
    Date of Patent: June 12, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Nobuhiko Zaima, Tomohisa Itagaki, Yasuhito Shirafuji, Takahiro Ishihara
  • Patent number: 8179433
    Abstract: The microscopic imaging apparatus includes a system controlling unit for obtaining a VD time setting value, and for obtaining the number of electric charge subtracting pulses, a synchronization signal generating unit for generating a vertical synchronization signal on the basis of the VD time setting value output from the system controlling unit and the horizontal synchronization signal, and a timing generating unit for extracting the electric charge of the imaging device by supplying the horizontal synchronization signal by the number of electric charge subtracting pulses to the imaging device as the electric charge subtracting pulses, and for generating a read pulse synchronous with the vertical synchronization signal in order to stop the accumulation of the electric charge of the imaging device after exposure is started.
    Type: Grant
    Filed: December 11, 2008
    Date of Patent: May 15, 2012
    Assignee: Olympus Corporation
    Inventor: Hiroshi Fujiki
  • Patent number: 8072478
    Abstract: An optical scanning device acquires a displacement amount of each of scanning light beams in the main scanning direction, and corrects, based on the displacement amount, writing energy density at a write position such that a variation in image density due to a variation of the displacement amount is reduced. The light beams are used for scanning a target surface to write image data on the target surface. The writing energy density is an amount of light per unit surface area of the target surface.
    Type: Grant
    Filed: September 9, 2008
    Date of Patent: December 6, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Jun Tanabe, Shigeaki Imai, Seizo Suzuki
  • Patent number: 8022976
    Abstract: An apparatus for switching and controlling the intensity of a laser beam directed toward a beam detect sensor for an image forming device. A printing power reference signal and a beam detect power reference signal is selectively connected to a laser driver through a first switch. A printing power reference holding capacitor and a beam detect power reference holding capacitor is selectively connected to the laser driver through a second switch that is controlled in tandem with the first switch. During each scan cycle, the output laser power is monitored and used to adjust one of the two holding capacitors based such that both the printing power and the beam detect power have a controlled reference.
    Type: Grant
    Filed: June 7, 2006
    Date of Patent: September 20, 2011
    Assignee: Lexmark International, Inc.
    Inventors: Mark Edwin Kirtley Lund, Eric Wayne Westerfield
  • Patent number: 7920157
    Abstract: In an image forming apparatus, an exposure device performs exposure on a non-image area of image pattern, performs an exposure on the image area in an exposure amount lower than the non-image area or does not perform exposure, and an exposure amount control device controls, with respect to pixels having the same density data, an exposure amount given by an exposure device to be smaller in a first portion, which is a thin-line of a width that is equal to or less than a predetermined number of pixels or which is an isolated dot of widths that are equal to or less than the predetermined number of pixels in two directions substantially orthogonal to each other, than in a second portion which is a line of a width exceeding the predetermined number or a surface of widths that exceed the predetermined number in two directions substantially orthogonal to each other.
    Type: Grant
    Filed: December 9, 2008
    Date of Patent: April 5, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takahiro Nakase
  • Patent number: 7872663
    Abstract: A light emitting device includes a plurality of light emitting elements, a first storage unit that stores first correction values corresponding to the light emitting elements, a counting unit that counts the number of pixels whose gray-scale values designated by image data are within a predetermined range included in an image, a selection unit that selects a first mode or a second mode according to the relationship between the number counted by the counting unit and a threshold value, and a driving unit that drives the light emitting elements corresponding to the predetermined number of pixels to emit amounts of light corresponding to the first correction values when the first mode is selected by the selection unit, and drives the light emitting elements corresponding to the predetermined number of pixels to emit amounts of light corresponding to the image data when the second mode is selected by the selection unit.
    Type: Grant
    Filed: December 13, 2006
    Date of Patent: January 18, 2011
    Assignee: Seiko Epson Corporation
    Inventor: Taketo Chino
  • Patent number: 7852510
    Abstract: Data-processing systems and methods include a rendering device which renders documents based upon the timing and duration of a laser beam associated with particular pixel data. Additionally, a controlling mechanism for controlling and adjusting the particular pixel data can be provided, wherein the controlling mechanism is subject to pixel clock signal in order to optimize a performance of the rendering device under varying rendering parameters and thereby enhance the quality of data rendered via the rendering device. Such a controlling mechanism can be implemented as a programmable phase locked loop circuit to which a pixel clock signal and a frequency are applied in order to provide at least one output signal for controlling the laser beam.
    Type: Grant
    Filed: April 28, 2005
    Date of Patent: December 14, 2010
    Assignee: Xerox Corporation
    Inventors: Mostafa R. Yazdy, Mehrdad Zomorrodi
  • Publication number: 20100277561
    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: Application
    Filed: May 29, 2008
    Publication date: November 4, 2010
    Inventors: Anthony Miles, Robert Glyn Miles
  • Patent number: 7812979
    Abstract: There is provided an information processing apparatus previewing on a display screen ink-character information and braille information which are printed and embossed on the same process sheet, the apparatus including: an ink-character previewing device for previewing the ink-character information; a braille previewing device for previewing the braille information; and a preview switching device controlling the ink-character previewing device and the braille previewing device and capable of selectively switching a display mode among a display of only the ink-character information, that of only the braille information, and that of the ink-character information and the braille information when printing and embossing operations are performed in a manner in which the ink-character information and the braille information are at least partially overlapped with each other on the process sheet.
    Type: Grant
    Filed: March 1, 2006
    Date of Patent: October 12, 2010
    Assignees: Seiko Epson Corporation, King Jim Co., Ltd.
    Inventors: Makoto Takada, Seiji Tanaka, Takayuki Uehara
  • Patent number: 7791630
    Abstract: A method of adjusting an exposure device suited for an electrophotographic printer, the exposure device includes a plurality of light-emitting elements. The method includes the steps of energizing selected light-emitting elements according to a selection scheme, using a pre-determined energy level for energizing each selected light-emitting element and obtaining a corresponding exposure intensity distribution from the exposure device. The method further includes the steps of predicting a toner area coverage distribution, based on the obtained exposure intensity distribution and on a pre-established transfer function, obtaining an attribute of the predicted toner area coverage distribution and determining the setting values for the energy levels for energizing each selected light-emitting element such that the obtained attribute becomes a target attribute.
    Type: Grant
    Filed: December 12, 2006
    Date of Patent: September 7, 2010
    Assignee: Oce-Technologies B.V.
    Inventors: Hendrik J. Stolk, Martijn C. H. Van Hoorn, Lambertus W. Ogink, Reinier J. Ramekers
  • Patent number: 7787006
    Abstract: Differing ratios of the amount of light from light source LD2 to the amount of light from light source LD1 are provided. An image pattern for adjustment that includes, for each color, an area made up of isolated dots by light source LD1 and an area made up of isolated dots by light source LD2, is printed for each ratio. In a copier, a density of each area is detected, a ratio at which a difference between the density of an area of isolated dots by light source LD1 and the density of an area of isolated dots by light source LD2 is smallest is decided as an adjustment ratio, and control is performed such that light sources LD1 and LD2 emit light at the adjusted ratio.
    Type: Grant
    Filed: May 22, 2007
    Date of Patent: August 31, 2010
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Tetsuya Sakai, Hironori Akashi
  • Patent number: 7782355
    Abstract: An electrostatic latent image is formed by exposing the same exposure point on a photosensitive drum to a laser beam having an emission wavelength of 420 nm and a laser beam having an emission wavelength of 780 nm. The exposure is performed in a pulse-height modulation manner by changing a total output of these two laser beams to write the electrostatic latent image while changing an output ratio between the two laser beams depending on the total output.
    Type: Grant
    Filed: May 12, 2008
    Date of Patent: August 24, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Makoto Oki
  • Patent number: 7764297
    Abstract: There is provided a photoreceptor cleanerless image forming apparatus capable of decreasing color mixture or an exposure error due to reverse transfer toner or untransferred toner. An image forming apparatus 100 according to the present invention comprises four image forming units 100a, 100b, 100c, and 100d configured to be photoreceptor cleanerless in a 4-drum tandem manner. Each image forming unit includes a photoreceptor 103a, 103b, 103c, or 103d, a charger 105a, 105b, 105c, or 105d, an exposure apparatus 106a, 106b, 106c, or 106d, and a developing apparatus 109a, 109b, 109c, or 109d. When exposure intensities Iy, Ic, Im, and Ik are assumed for exposure sources of the exposure apparatuses in the image forming units which form yellow, magenta, cyan, and black images, respectively, the exposure intensities are configured to satisfy conditions of Ik?Ic?Im?Iy and Ik >Iy. This decreases an exposure error (image hysteresis) in an image formed on paper.
    Type: Grant
    Filed: August 14, 2007
    Date of Patent: July 27, 2010
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventors: Shinji Aoki, Masashi Takahashi, Masashi Hiroki, Takeshi Watanabe
  • Patent number: 7750934
    Abstract: An image forming apparatus is capable of controlling an exposure in accordance with sensitivity variations of a photosensitive body. An actual exposure position (Pr) sometimes precedes an exposure position (Pc) recognized based on the count value (C). In this case, the correction value (Dc) of the exposure position (Pc) recognized based on the count value (C) is calculated by linear interpolation using reference correction values (D0?Dn) corresponding to the position until the home position (HP) of a photosensitive drum is detected. When the home position (HP) is detected, the correction value (Dc(Pc0)) of an exposure position (Pc) recognized after detecting the home position (HP) is so calculated as to make the difference between the correction value of the exposure position and that of a previous exposure position (Pn?) fall within a preset range (?).
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: July 6, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventor: Hidefumi Yoshida
  • Patent number: 7729216
    Abstract: A method is provided for recording visible marks on a recording medium using an input beam generated by an electromagnetic radiation source. The method comprises (a) substantially collimating the input beam to provide a substantially collimated beam, and (b) applying the substantially collimated beam to the recording medium to provide the visible mark on the recording medium.
    Type: Grant
    Filed: July 5, 2005
    Date of Patent: June 1, 2010
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Andrew L. Van Brocklin, Laurence M. Hubby, Jr., Daryl E. Anderson
  • Patent number: 7688340
    Abstract: A method and system for a color xerographic machine determines a lower bound for the ROS power levels so that color defects are not produced by light attenuation from one or more layers of toner particles on a latent image. The method computes a minimum ROS power level for the photoreceptor at its maximum and minimum charge levels. The minimum ROS power level is the level at which the discharge voltage does not drop beyond a maximum discharge voltage difference. The difference is related to a toner particle density that affects color reproduction. The minimum ROS power levels for the minimum and maximum photoreceptor charge levels are used to compute a functional relationship for minimum ROS power levels at other photoreceptor charge levels. Thereafter, the minimum ROS power level function may be used to compute minimum ROS power levels for other photoreceptor charge levels. The computed minimum ROS power levels may be used to control the power levels used during color reproduction performed by the machine.
    Type: Grant
    Filed: August 11, 2004
    Date of Patent: March 30, 2010
    Assignee: Xerox Corporation
    Inventors: Patricia J. Donaldson, Mark A. Scheuer, Daniel W. MacDonald
  • 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: 7663659
    Abstract: An image forming apparatus forms an image by laser beams from a plurality of lasers. The image forming apparatus includes a light amount control circuit that detects displacement in a sub-scanning direction of the main scanning line of a laser beam from the predetermined laser, from a reference position. The apparatus decides an allotted amount of light for each of the plurality of lasers in accordance with the detected displacement and controls to drive each of the plurality of lasers in accordance with the decided allotted amount of light for each laser.
    Type: Grant
    Filed: January 11, 2008
    Date of Patent: February 16, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuhide Koga, Shigeo Hata, Yasuyuki Aiko, Akihiko Sakai, Takashi Nagaya, Takashi Birumachi, Shingo Kitamura
  • Patent number: 7619791
    Abstract: A reference developing image is formed on a photoreceptor drum under an image forming condition measured in advance, and the density of this reference developing image is detected. A development bias voltage is corrected based on the detection result, and when a correction value of the development bias voltage exceeds a predetermined range, a reference output voltage of an ATC sensor for detecting the density of toner in a developing device is corrected based on the detected value of humidity around the developing device, the frequency of use of the apparatus, and the agitation stress of developer.
    Type: Grant
    Filed: March 2, 2004
    Date of Patent: November 17, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Motoyuki Itoyama, Syouichi Fujita, Hirofumi Sakita, Shuichi Morikuni
  • Patent number: 7613100
    Abstract: An optical pickup device comprises a first laser light source and a second laser light source that emit first laser light and second laser light, respectively, and further comprises an objective lens that receives the first and second laser light. The first laser light and the second laser light have different focal lengths from a principal point of the objective lens in accordance with a distance between a signal layer of a signal recording medium and a label layer of the signal recording medium. When the first laser light source and the second laser light source are simultaneously driven, the first laser light and the second laser light are controlled to simultaneously focus on the signal layer of the signal recording medium and the label layer of the signal recording medium, respectively. Thus, label information can be recorded simultaneously with recording of main information.
    Type: Grant
    Filed: September 28, 2005
    Date of Patent: November 3, 2009
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Kozo Suzuki, Shigeru Nakamura
  • Patent number: 7602411
    Abstract: An image forming apparatus receives halftone print data through an inputting section. A dot forming section irradiates the charged surface of an image bearing body with light to form a plurality of lines of dots in accordance with the halftone data. Dots on a same line have the same exposure energy and dots on different lines in a same pixel have different exposure energies. The plurality of lines may include as many lines as there are bits in the halftone print data. The plurality of lines may include a first predetermined number of lines and the halftone print data includes a second predetermined number of bits different from the first predetermined number. A conversion table converts halftone print data having a first number of bits into corresponding energy data having a second number of bits.
    Type: Grant
    Filed: June 10, 2004
    Date of Patent: October 13, 2009
    Assignee: Oki Data Corporation
    Inventor: Nobuo Wakasugi
  • Patent number: 7564475
    Abstract: A test pattern is written using multiple image beams in a non image zone at set time intervals. The test pattern is sensed and a profile of each beam is determined from the multiple image beams. A minimum reflectance of the profile is determined from the test pattern of each beam thereby providing an exposure of each respective beam. A centroid of a profile is determined from the test pattern of each beam thereby providing a position of each respective beam. At least one of the following is then determined: frequency, amplitude and phase of banding, which is inherent in a printing device, based on the sensed test pattern. A plurality of groups of image beams intensity changes is combined wherein each group is separated by a set displacement. A banding profile is determined from the group beam intensities. At least one banding compensation metric is determined based at least on one of the determined frequency, amplitude and phase of banding.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: July 21, 2009
    Assignee: Xerox Corporation
    Inventor: Howard A. Mizes
  • Patent number: 7557823
    Abstract: An image forming apparatus including a light source unit configured to emit a light beam, an optical deflector configured to generate a scanning light beam from the light beam of the light source unit, an optical writer having an optical system configured to guide the scanning light beam from the optical deflector onto a surface to be scanned of image carriers and forming an image thereon: and a memory unit to store a plurality of shading correction data that is configured to correct a light shading caused by a light loss between the light beam and the scanning light beam due to accumulation of dirt on the optical deflector.
    Type: Grant
    Filed: August 17, 2006
    Date of Patent: July 7, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Rumiko Ono, Hiroshi Yoshizawa
  • Patent number: 7489884
    Abstract: An image forming apparatus includes a first submodule used for image formation; a first phase detector detecting a phase of the first submodule; a second submodule used for image formation with the first submodule; a second phase detector detecting a phase of the second submodule; a density detector detecting density of an image formed by the first and second submodules; a correction setting section setting a first and second parameters to correct density non-uniformity in a slow-scan direction caused by the first and second submodules, respectively, based on the detected image density data; an output setting section deriving a first correction value for the phase of the first submodule from the first parameter and a second correction value for the phase of the second submodule from the second parameter, and outputting a correction value generated by merging the first and second correction values; and an imaging condition changing section changing imaging conditions in accordance with the correction value.
    Type: Grant
    Filed: June 5, 2006
    Date of Patent: February 10, 2009
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Junichi Ichikawa, Hideki Kimura
  • Patent number: 7483047
    Abstract: An inner ring signal and an outer ring signal according to specific patterns formed on the label side of the optical disc are generated. Timing starts when the outer ring signal reveals the end of a positioning pattern and stops to obtain a timing value when the inner ring signal reveals the start of a square wave defining a specified spoke. A starting spoke is defined according to the inner ring signal and the specified spoke. A deviation bit value is calculated according to the timing value and a bit number of a data to be marked on a certain track of the optical disc. The data is rotated according to the deviation bit value, and then marked on the certain track, starting with the starting spoke.
    Type: Grant
    Filed: December 27, 2006
    Date of Patent: January 27, 2009
    Assignee: Lite-On It Corp.
    Inventors: Chih Wei Huang, Tao-Yen Wei, Yi-Shih Wang
  • Patent number: 7463279
    Abstract: An image forming apparatus forms an image by laser beams from a plurality of lasers. The image forming apparatus includes a light amount control circuit that detects displacement in a sub-scanning direction of the main scanning line of a laser beam from the predetermined laser, from a reference position. The apparatus decides an allotted amount of light for each of the plurality of lasers in accordance with the detected displacement and controls to drive each of the plurality of lasers in accordance with the decided allotted amount of light for each laser.
    Type: Grant
    Filed: December 6, 2005
    Date of Patent: December 9, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuhide Koga, Shigeo Hata, Yasuyuki Aiko, Akihiko Sakai, Takashi Nagaya, Takashi Birumachi, Shingo Kitamura
  • Patent number: 7450144
    Abstract: A photo-printing system includes a laser exposure unit, a reference clock generation unit, an image input unit, and a controller. The image input unit receives first pixel data and second pixel data to be expressed after the first pixel in accordance with image data. In a first control, the first and second pixels are scanned for exposure in a laser emission region state wherein each of the scan-start timings of the first and second pixels are controlled in accordance with a reference clock. In a second control, the first pixel is scanned for exposure in a nonlinear light emission region state, and the second pixel having a density equal to or lower than a predetermined density is scanned for exposure in the laser emission region state, the scan-start timing of the second pixel is advanced with respect to the first control.
    Type: Grant
    Filed: March 22, 2006
    Date of Patent: November 11, 2008
    Assignee: Noritsu Koki Co., Ltd.
    Inventors: Yozo Ohki, Kazuhiro Yoshida