Optical watermark

Number of patents in Portfolio can not be more than 2000

United States of America Patent

PATENT NO 7366301
APP PUB NO 20020054680A1
SERIAL NO

09810971

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ATTORNEY / AGENT: (SPONSORED)

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Abstract

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A multiple-layered watermark is generated to be placed on document, to protect against counterfeiting and forgery. Hidden information embedded into each of the watermark's layers is only detectable by using a corresponding decoder. Because of the multiple-layered structure, it is difficult to reverse engineer the optical watermark. The generalized watermark structure significantly increases the 'key space' of the decoder.

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Patent Owner(s)

Patent OwnerAddress
TRUSTCOPY PTE LTDSINGAPORE 119631

International Classification(s)

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  • 2001 Application Filing Year
  • G09C Class
  • 13 Applications Filed
  • 4 Patents Issued To-Date
  • 30.77 % Issued To-Date
Click to zoom InYear of Issuance% of Matters IssuedCumulative IssuancesYearly Issuances200120022003200420052006200720080255075100

Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Huang, Sheng Singapore, SG 96 969
Wu, Jian Kang Singapore, SG 4 263

Cited Art Landscape

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Patent Citation Ranking

  • 19 Citation Count
  • G09C Class
  • 50 % this patent is cited more than
  • 17 Age
Citation count rangeNumber of patents cited in rangeNumber of patents cited in various citation count ranges1113021 - 3091 - 100100 +00.20.40.60.811.21.41.61.822.22.42.62.833.2

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