×

Fluorescent ink detector

  • US 7,438,378 B2
  • Filed: 08/30/2004
  • Issued: 10/21/2008
  • Est. Priority Date: 08/30/2004
  • Status: Expired due to Fees
First Claim
Patent Images

1. A fluorescent indicium printing device for printing and detecting a black fluorescent indicium comprising:

  • a print head configured to print the black fluorescent indicium using a black fluorescent ink, the ink including at least one black pigment and at least one fluorescent taggant;

    a first ink sensor located downstream from the print head for detecting the at least one fluorescent taggant in the printed black fluorescent indicium including;

    a first radiant energy source configured to radiate at a first excitation wavelength suitable for exciting the black fluorescent indicium; and

    a photodetector having a bandpass filter, wherein the photodetector is adapted to detect luminescent energy at a first excited luminescent wavelength from the black fluorescent indicium printed by the print head,a second ink sensor located downstream from the print head including an infrared detector for detecting the at least one black pigment in the black fluorescent indicium; and

    a controller for determining if the indicium comprises a particular black fluorescent ink based upon output of the first ink sensor and the second ink sensor.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×