1
Chengwu Cui, Raymond E Clark: Gamut mapping algorithm for business graphics. Lexmark International, Coats & Bennett PLLC, October 18, 2005: US06956581 (11 worldwide citation)

A gamut mapping algorithm especially adapted for printing business and presentation graphics with highly chromatic colors. To perform gamut mapping, gamut triangles corresponding to an input gamut and output gamut are defined and used to scale the lightness and chroma of input colors. The rescaled i ...


2
Mohamed N Ahmed, Chengwu Cui, Michael E Lhamon, Shaun T Love: System and methods for multiple imaging element scanning and copying. Lexmark International, June 17, 2008: US07388693 (7 worldwide citation)

A scanning or copying system can include imaging elements and one or more system processors that are programmed or adapted to perform image processing methods and algorithms on image data, and in some instances, to enhance the image. Image data is acquired using imaging elements. Some imaging elemen ...


3
Mary Ellen Biddle, Brian Edward Cooper, Chengwu Cui, Buford Rodney Goble, Ross William McFarland, Steven Frank Weed, Bryan Scott Willett: Shingle masks that reduce banding effect on ink jet printers. Lexmark International, Frederick H Gribbell, July 20, 2004: US06764162 (6 worldwide citation)

An improved shingle mask is provided for use on ink jet printers which use multi-pass printing (shingling) to form bitmap images. The shingle mask is derived from a shingle mask density distribution which exhibits a substantially trapezoidal shape; the shingle mask density distribution is derived fr ...


4
Chengwu Cui, Stuart Willard Daniel: Method and device for converting scanned text to audio data via connection lines and lookup tables. Lexmark International, March 9, 2010: US07675641 (2 worldwide citation)

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 da ...


5
Chengwu Cui: Methods for identifying marks using a digital master document and scanned image enhancement. Lexmark International, September 7, 2010: US07791756 (1 worldwide citation)

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, rathe ...


6
James Thomas Beegle, Chengwu Cui, Adam Christopher Kelty, Charles Brandon Langrel, Joshua Tyler Strow: Image scanning apparatus and methods. Lexmark International, July 24, 2012: US08228571 (1 worldwide citation)

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 ...


7
Chengwu Cui, Charles Brandon Langrel: Detachable transparent plate for scan head assembly. Lexmark International, January 3, 2012: US08089663 (1 worldwide citation)

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 ...


8
Eugene David Allen, Chengwu Cui, Joshua Tyler Strow: Illumination assembly for a scanner with thermally conductive heat sink. Lexmark International, Justin M Tromp, December 17, 2013: US08610969 (1 worldwide citation)

An illumination assembly for a scanner according to one example embodiment includes a scan head frame. A thermally conductive heat sink component has an elongated base portion that is mounted along a longitudinal edge of the scan head frame and a protruding portion having a generally L-shaped struct ...


9
Chengwu Cui, David Keith Jackson, Joshua Tyler Strow: Linear light diffusing structure for document scanners. Lexmark International, John Victor Pezdek, December 4, 2012: US08322872 (1 worldwide citation)

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. T ...


10
Chengwu Cui, Larry L Kiser: Estimating light output of a lamp in a scanner. Lexmark International, March 22, 2011: US07911654 (1 worldwide citation)

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 ti ...