Patents by Inventor Chengwu An

Chengwu An has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7911654
    Abstract: A method of estimating light output of a lamp in a scanner prior to the lamp being fully warmed-up. The method includes measuring a spectral characteristic of light emitted by a lamp in a scanner at a time t0 prior to the lamp being fully warmed-up and estimating the light output of the lamp at a time t1 based on the measured spectral characteristic, wherein t1 is greater than t0. A method of scanning, as well as a scanning apparatus is also provided.
    Type: Grant
    Filed: September 1, 2005
    Date of Patent: March 22, 2011
    Assignee: Lexmark International, Inc.
    Inventors: Chengwu Cui, Larry L. Kiser
  • Publication number: 20110044036
    Abstract: A tubular structure with an opening defined thereon and having an inner surface and an outer surface. The tubular structure being substantially circular in shape and is made of a highly thermal conductive material. A plurality of light sources mounted on the inner surface of the tubular structure. The inner surface is coated with a diffused white coating. Light emitted from the plurality of light sources is reflected from the inner surface before exiting the tubular structure from the opening. This structure ensures emitting a uniform diffused light and prevents non-uniform illumination when disposed in an imaging forming device.
    Type: Application
    Filed: October 13, 2009
    Publication date: February 24, 2011
    Inventors: Chengwu Cui, David Keith Jackson, Joshua Tyler Strow
  • Patent number: 7817315
    Abstract: A method for adjusting a controller of a scanner includes obtaining a scan of a predefined image. The method further includes moving the sensor-element signals of the control signal pattern generated by the controller earlier in the pattern by at least one unit and obtaining an additional scan. The obtaining and moving are repeated until a comparison of a latest additional scan to the image is worse than a comparison of a second-latest additional scan to the image. Another method obtains a noise-reducing heuristic which modifies a time parameter of a sensor-element signal. A set of repeated scans of a same scan line is obtained, noise is measured there from, the time parameter is modified by one predetermined unit, and the process repeats until the noise measured from the latest set of repeated scans is worse than that from the second-latest set of repeated scans.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: October 19, 2010
    Assignee: Lexmark International, Inc.
    Inventors: Chengwu Cui, Mark Lane Mayberry, Karl Mark Thompson
  • Patent number: 7791756
    Abstract: To reduce errors introduced by a scanner, an unmarked, digital master document may be generated and stored in digital form so that subsequent scanning of the document is unnecessary to place it in digital form for comparison to a marked version of the document. Additionally, regions or fields, rather than the entire digital master document, may be individually created, stored, and subsequently used for comparison to corresponding portions of a marked version. Further, test targets or patterns may be inserted into the content of a digital master document. Characteristics of image quality degeneration and distortion can be extracted from printed versions of the test targets or patterns and used to effect closed loop control to digitally reduce image quality degeneration caused by the scanner.
    Type: Grant
    Filed: May 3, 2005
    Date of Patent: September 7, 2010
    Assignee: Lexmark International, Inc.
    Inventor: Chengwu Cui
  • Publication number: 20100142008
    Abstract: Method and image scanning apparatus comprising an image capture unit having an illumination assembly for generating input light; a printed circuit board mounted to the image capture unit, a cooling unit generating an airflow which cools the illumination assembly of the image capture unit as well as the critical components mounted on the printed circuit board and the optical components of the image capture unit; and an adjustable baffle member moveably mounted to the frame of the image scanning apparatus for controlling the path of the airflow relative to the lamp. The cooling unit comprises at least one fan with the fan generating airflow for cooling the lamp of image capture unit.
    Type: Application
    Filed: December 8, 2008
    Publication date: June 10, 2010
    Inventors: James Thomas Beegle, Chengwu Cui, Adam Christopher Kelty, Charles Brandon Langrel, Joshua Tyler Strow
  • Publication number: 20100142010
    Abstract: Disclosed are a method and a computer program product for dissipating heat produced in a scan head assembly of an imaging apparatus during scanning of media sheets in the imaging apparatus. The method includes determining at least one of a temperature of the scan head assembly and a media sheet scan count. The method further includes moving the scan head assembly between a first position of the scan head assembly and a second position of the scan head assembly for dissipating heat, based on at least one of the temperature of the scan head assembly and the media sheet scan count.
    Type: Application
    Filed: December 8, 2008
    Publication date: June 10, 2010
    Inventors: Chengwu Cui, Charles Brandon Langrel
  • Publication number: 20100110509
    Abstract: An apparatus and methods of use for adjusting a sliding guide rod for an imaging device of a flatbed scanner to improve scanner skew misalignment comprising an attachment member movably mounting the sliding guide rod at one end thereof to one side of the flatbed scanner so as to allow skew-adjusting movement of the sliding guide rod at an opposite end thereof relative to the flatbed scanner and a skew adjustment assembly attached to an opposite side of the flatbed scanner and movably coupling and supporting the opposite end of the sliding guide rod to the opposite side of the flatbed scanner and being actuatable to cause the sliding guide rod to undergo skew adjustment relative to the flatbed scanner to correct scanner skew misalignment of the imaging device.
    Type: Application
    Filed: October 31, 2008
    Publication date: May 6, 2010
    Inventors: Chengwu Cui, Adam Christopher Kelty, Charles Brandon Langrel
  • Patent number: 7675641
    Abstract: Methods and devices for converting printed media into audio data. In one embodiment, a device includes a scanning platform for supporting the document to be scanned, a scanning mechanism for converting images on the document into image data, and a processor configured to convert the scanned image data into audio data. The device may further include printer components configured to create a hardcopy of the image data, an audio device such as a speaker, and an interface for outputting the image data or audio data.
    Type: Grant
    Filed: October 28, 2004
    Date of Patent: March 9, 2010
    Assignee: Lexmark International, Inc.
    Inventors: Chengwu Cui, Stuart Willard Daniel
  • Publication number: 20090279178
    Abstract: A scanhead of an imaging apparatus for providing image illumination uniformity for imaging of a media sheet, and a method thereof, are disclosed. The scanhead includes a lens, a lens shading plate and a sensor array. The lens is capable of receiving light reflected from the media sheet and focusing the received light. The lens shading plate is capable of assuming a lens shading plate position of a plurality of lens shading plate positions between the lens and the sensor array for receiving the light focused by the lens. The lens shading plate, on assuming the lens shading plate position, is capable of adjusting the light received from the lens for focusing the light onto the sensor array, thereby providing image illumination uniformity, for the imaging of the media sheet.
    Type: Application
    Filed: May 9, 2008
    Publication date: November 12, 2009
    Inventor: Chengwu Cui
  • Publication number: 20090180160
    Abstract: A method for uniformly illuminating a predetermined scan line position on a media sheet containing an image includes defining an optical path from a media sheet to a sensor, selecting a predetermined scan line position on the media sheet, and emitting a light beam from a light source whereby a portion of the light beam illuminates a first portion of the predetermined scan line and a portion of the light beam is reflected from a reflector to illuminate a second, opposed portion of the predetermined scan line position. A method for imaging a scan line on a media sheet includes these steps and also collecting at least a portion of the light beam reflected from or transmitted through the media sheet to image the portion of the media sheet defined by the predetermined scan line position. Still further, an optical imaging module is provided for accomplishing the described method.
    Type: Application
    Filed: January 10, 2008
    Publication date: July 16, 2009
    Inventor: Chengwu Cui
  • Publication number: 20090168125
    Abstract: A scanning device for simplex and duplex scanning. The device may include a scan head for capturing content appearing on a page; a substantially C-shaped first scan path for simplex scanning, the first scan path adapted to guide the page relative to the scan head for scanning a first side of the page; a second scan path for duplex scanning, the second scan path adapted to guide the page relative to the scan head for scanning a first side of the page and a second side of the page; a path diverter, the path diverter adapted to direct the page to the first path or the second path; and a controller for controlling the first and second scan paths and the diverter. The second scan path forms a loop for moving the first and second sides of the page so that each is temporarily disposed adjacent the scan head.
    Type: Application
    Filed: December 31, 2007
    Publication date: July 2, 2009
    Inventors: Stephen Wilson, Charles Brandon Langrel, Chengwu Cui
  • Publication number: 20090168116
    Abstract: A scanner includes a scan bar and a calibration strip. The scan bar has perpendicular fast-scan and slow-scan axes. The scan bar has an image sensor plane and includes a substantially linear array of sensor elements substantially aligned along the fast-scan axis. A first method for calibrating the scan bar includes imaging the calibration strip to the image sensor plane of the scan bar wherein the imaging is out of focus substantially-along the slow-scan axis. The first method also includes obtaining a calibration reading of the sensor elements from the imaging of the calibration strip. A second method includes imaging the calibration strip to the image sensor plane of the scan bar wherein the imaging is optically widened substantially-along the slow-scan axis. In a third method, the imaging is optically widened substantially-along the slow-scan axis using a cylindrical lens having an imaging-widening axis.
    Type: Application
    Filed: December 26, 2007
    Publication date: July 2, 2009
    Inventor: Chengwu Cui
  • Publication number: 20090168122
    Abstract: A scan module including an image sensor defining a scan field, at least one lamp positioned to illuminate at least a portion of the scan field, and a second light source positioned to provide illumination for the portion of the scan field.
    Type: Application
    Filed: December 26, 2007
    Publication date: July 2, 2009
    Inventor: Chengwu Cui
  • Publication number: 20090160122
    Abstract: The present application is directed to embodiments for moving a media sheet within a scanning device. The methods include moving the media sheet through a separation mechanism that prevents multiple media sheets from being moved simultaneously along the media path. Further, a buckle is formed in the sheet at a point upstream from a scanner. The buckle acts as a buffer to absorb any load release that could occur as the media sheet exits the separation mechanism. The load release could cause a change in the velocity of the media sheet as it moves across the scanner.
    Type: Application
    Filed: December 19, 2007
    Publication date: June 25, 2009
    Inventors: Charles Brandon Langrel, Chengwu Cui
  • Publication number: 20090153912
    Abstract: A scanner calibration strip medium is described which includes at least one of a plurality of text symbols and a plurality of halftoned non-text images. A scanner is described which includes a scan bar and a scanner calibration strip medium scannable by the scan bar. The calibration strip medium includes a plurality of text symbols having text pixels and a plurality of halftoned non-text images having halftoned non-text pixels. A method for segmenting a scanned document image into text symbols and halftoned non-text images is described which uses a scanner calibration strip medium which includes a plurality of text symbols having text pixels and a plurality of halftoned non-text symbols having halftoned non-text pixels, wherein the calibration strip medium has a known pixel classification including which pixels of the calibration strip medium are text pixels and which pixels of the calibration strip medium are halftoned non-text pixels.
    Type: Application
    Filed: December 18, 2007
    Publication date: June 18, 2009
    Inventors: Mohamed Nooman Ahmed, Chengwu Cui, Ahmed Hamad Mohamed Eid
  • Publication number: 20090153919
    Abstract: A method for providing a visible reference marker on a scanning unit for orienting an item to be scanned or copied includes the steps of emitting a light from a light source, guiding the light to a scanning unit having a contact glass scanning surface, and redirecting the light to define an illuminated reference marker substantially adjacent to the contact glass. A reference marker assembly for accomplishing that method is provided, including a light source, a waveguide for guiding light emitted from the light source to a scanning unit having a contact glass, and a redirector for redirecting the light to define an illuminated reference marker adjacent to the contact glass, for orienting an item to be copied or scanned. The light source may be a light emitting diode, and the redirector may be a light diffuser for redirecting the collected light to define an illuminated reference marker adjacent to the contact glass.
    Type: Application
    Filed: December 12, 2007
    Publication date: June 18, 2009
    Inventors: Charles B. Langrel, Chengwu Cui, Allen W. Waugerman
  • Publication number: 20090153920
    Abstract: A detachable transparent plate for a scan head assembly in a document scanning system that allows an operator to detach the transparent plate from the scan head assembly located above a media feed path to clean a top face of the transparent plate and easily reattach it to the scan head assembly. The scan head assembly has an optical system and a sealing member detachably mounted to a bottom end of the optical system. The transparent plate is received and supported by the sealing member and defines a portion of a bottom surface of the sealing member. The sealing member is detachable from the bottom end of the optical system to allow an operator access to the top face of the transparent plate of the sealing member for cleaning the top face of the transparent plate.
    Type: Application
    Filed: December 12, 2007
    Publication date: June 18, 2009
    Inventors: Chengwu Cui, Charles Brandon Langrel
  • Publication number: 20090153698
    Abstract: A method for adjusting a controller of a scanner includes obtaining a scan of a predefined image. The method further includes moving the sensor-element signals of the control signal pattern generated by the controller earlier in the pattern by at least one unit and obtaining an additional scan. The obtaining and moving are repeated until a comparison of a latest additional scan to the image is worse than a comparison of a second-latest additional scan to the image. Another method obtains a noise-reducing heuristic which modifies a time parameter of a sensor-element signal. A set of repeated scans of a same scan line is obtained, noise is measured there from, the time parameter is modified by one predetermined unit, and the process repeats until the noise measured from the latest set of repeated scans is worse than that from the second-latest set of repeated scans.
    Type: Application
    Filed: December 18, 2007
    Publication date: June 18, 2009
    Inventors: Chengwu Cui, Mark Lane Mayberry, Karl Mark Thompson
  • Publication number: 20080285096
    Abstract: A scanning system for generating an image includes a scanning device configured to receive light reflected from a document and to output a signal corresponding to the received light to collect image data for use in generating an image. An automatic document feed system is configured to move the document from a position upstream of the scanning device toward a position downstream of the scanning device along a document feed path in proximity to the scanning device to allow the scanning device to receive light reflected from the document. A processor includes logic that compensates for changes in document movement past the scanning device using document motion data to reduce motion error induced image defects.
    Type: Application
    Filed: May 15, 2007
    Publication date: November 20, 2008
    Inventors: Chengwu Cui, Phillip Daniel Erwin, JR., Charles Brandon Langrel, Mark Lane Mayberry, Stephen Ray Wilson
  • Publication number: 20080273222
    Abstract: A system for saving and retrieving job settings comprising a multifunction document management system and a settings form including a machine recognizable portion printed thereon, wherein the machine recognizable portion includes data indicative of at least one user-selected job setting and wherein the machine recognizable portion is readable by the multifunction document management system.
    Type: Application
    Filed: May 3, 2007
    Publication date: November 6, 2008
    Inventor: Chengwu Cui