Patents by Inventor Zhi-guo Chang

Zhi-guo Chang 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).

  • Methods and systems for encoding and decoding data in 2D symbology
    Patent number: 7028911
    Abstract: Methods and systems for encoding and decoding a 2D symbol is disclosed. According to one aspect of the 2D symbol, the following characteristics are realized: 1) variable symbol widths and height; 2) variable print resolution, 3) multiple damage protection levels; 4) large information storage; 5) high redundancy; 6) readable by line based scanning devices; 7) recognizable by either contact scanning or non-contact scanning devices. In addition, a set of positioning lines are attached 2D symbol for guiding scanning devices to decode the 2D symbol with proper resolution.
    Type: Grant
    Filed: August 5, 2003
    Date of Patent: April 18, 2006
    Assignee: Shenzhen Syscan Technology Co. Limited
    Inventors: Wai Cheung, Zhi-guo Chang, Shillin Ding, Ying-feng Lv
  • Guiding a scanning device to decode 2D symbols
    Patent number: 6802450
    Abstract: To facilitate the decoding of a 2D symbol (e.g., PDF417), a plurality of positioning lines are attached to the 2D symbol. Depending on implementation, these substantially parallel positioning lines may be provided on at least one side of the symbol or superimposed on the symbol. A scanning device is provided to capture an image of the symbol together with these positioning lines that are then detected to determine an orientation of the 2D symbol. In some cases, these positioning lines are used to correct images with distortion.
    Type: Grant
    Filed: August 5, 2003
    Date of Patent: October 12, 2004
    Assignees: Shenzhen Syscan Technology Co. LTD, Syscan, Inc.
    Inventors: Wai Cheung, Zhi-guo Chang, Shillin Ding, Ying-feng Lv
  • Methods and systems for encoding and decoding data in 2D symbology
    Publication number: 20040026510
    Abstract: Methods and systems for encoding and decoding a 2D symbol is disclosed. According to one aspect of the 2D symbol, the following characteristics are realized: 1) variable symbol widths and height; 2) variable print resolution, 3) multiple damage protection levels; 4) large information storage; 5) high redundancy; 6) readable by line based scanning devices; 7) recognizable by either contact scanning or non-contact scanning devices. In addition, a set of positioning lines are attached 2D symbol for guiding scanning devices to decode the 2D symbol with proper resolution.
    Type: Application
    Filed: August 5, 2003
    Publication date: February 12, 2004
    Applicants: ShenZhen SYSCAN Technology Co., Limited., SYSCAN Inc.
    Inventors: Wai Cheung, Zhi-Guo Chang, Shillin Ding, Ying-Feng Lv
  • Guiding a scanning device to decode 2D symbols
    Publication number: 20040026511
    Abstract: To facilitate the decoding of a 2D symbol (e.g., PDF417), a plurality of positioning lines are attached to the 2D symbol. Depending on implementation, these substantially parallel positioning lines may be provided on at least one side of the symbol or superimposed on the symbol. A scanning device is provided to capture an image of the symbol together with these positioning lines that are then detected to determine an orientation of the 2D symbol. In some cases, these positioning lines are used to correct images with distortion.
    Type: Application
    Filed: August 5, 2003
    Publication date: February 12, 2004
    Applicants: ShenZhen SYSCAN Technology Co., Limited., SYSCAN Inc.
    Inventors: Wai Cheung, Zhi-Guo Chang, Shillin Ding, Ying-Feng Lv