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Multiple Signatures from Fluorescent Dyes for Security Printing

Sorrento, 26-28 September 2001

Wendell M. Smith, Technology Transfer Group

Technology Transfer Group was formed in 1995 and is in the business of licensing technology in security printing fields. We represent 5 manufacturers of OVD's and other security technologies. I am pleased to return to this podium after several years away; I presented a speech to this group in Seville Spain on the subject of NovaVision, a high speed hologram application system.

The technology I am describing today comes from Boston University's Photonics Laboratories, Boston MA. This laboratory has been active in the photonics field, the interaction of optical, electronic, and digital sciences, for many years. One special area of study has been research in fluorescence. Fluorescence is the emission of light energy of longer wavelength when an object is illuminated with light energy of shorter wavelengths. This study has created a new range of fluorescent dye materials that can be "designed" and later measured in several "signature" characteristics to achieve truly secure printed objects.

The title of my speech is: Multiple Signatures from Fluorescent Dyes for Security Printing. The work is primarily that of Doctor Guilford Jones chemical engineer at the photonics laboratory of Boston University. The work is being commercialized by a newly formed company called PhotoSecure Inc. also of Boston. (operating from the new photonics laboratory business incubator).

The study of fluorescence over the past 15 years has led to the development of new ways to create and apply fluorescent dyes with controlled "signatures": The dyes are customized and printed as patches on a variety of surfaces. They each have signature elements that undeniably identify the patch as authentic.

Stroboscopic activation then measures features such as image, color and time has brought about a whole range of customized dyes that can be printed as security devices to verify a printed document or package. The patch is irradiated with short wave length energy (such as ultraviolet energy) with a stroboscope and the specific signature characteristics of the resulting fluorescence are carefully monitored.

Unique characteristics of the emitted light are studied; image, color, and time are precisely measured by special optical reading devices.

After the excitation flash, the PhotoSecure dye is monitored for several changing characteristics of image, color, and time.

A Unique Signature can be achieved as different dye formulas change their fluorescence characteristics in different repeatable ways.monitored and recorded at time of manufacture.

The dye is created and modified during manufacture in unique ways such that only that one particular image will produce the anticipated signature characteristics. These dyes have been developed to the stage that they can be printed with a conventional inkjet printer. This allows one to digitally encode uniquely identifiable covert or overt marks. It can be changed periodically making counterfeiting a very short term value or an entirely fruitless task

A small change in the dye formula changes the fluorescence characteristics in noticeable, measurable ways. The characteristics or signature can be monitored in effectively three dimensions by the special reading devices.

The inventions combined in this project include; SmartDYE suitable for films, plastics, fabrics, labels, many kinds of printing elements; Systems Engineering: creating detectors, scanners, and printers. The result is; Diverse signatures or characteristics of printed marks incorporating image, color, and time dependent variables.

The System Operation includes three steps: Detect and Capture, Process and Validate, and, Analyze and Report.

Step One: Detect and Capture: A strobe flash of known wavelength returns fluoresced light from a coded mark. The sensor receives the signal and then it is Filtered and Detected. The final part of step one is that a signal is sent forward with either "mark present" Yes, or, "mark absent", No mode determination.

Step Two: Process and Validate: The Yes condition moves forward to Image Processing Algorithms and in parallel, Signal Processing Algorithms. In the first case, Data Reduction determines 2/d 3/d bar code recognition. In the second, the fluorescence signature analysis is made. Now we have the possibility to verify both bar code validity and signature validity.

Step Three: Analyze and Report: The two possible modes from step two, "valid", or invalid" are followed by Display of failure data or Display of authenticity data. This information is sent to Data Storage and analysis for inventory control and for the management information technology department to use throughout the item's manufacturing, transport, and sale.

PhotoSecure Inc. is a photonics enabled information company. It provides invisible Ink and Hand Held Readers, as well as consultation on systems for specific applications. The Chairman is John Marenghi, the President and CEO is David Phillips who is here today, the Chief Technology Officer is Guilford Jones, Sr. Chemist is Ding Yan, and Technical Services Manager is Kevin Mills

How it all works: PhotoSecure will supply proprietary luminescent inks; work with printing partners; work with customer's own printing vendors, provide custom-made hand held and fixed position detectors.

The competitive advantages: Proprietary luminescent dyes: there are a very large number of these possible with unique spectral signatures. Detector systems that: authenticate, trace and track the signature of the printed marks.

PhotoSecure's first customer, a manufacturer of sporting goods, will use two detector systems with a the value of $10,000. Invisible bar codes will be placed on 25 million boxes per year. They are paying about two cents per box or one-half million dollars per year. Four marks will be printed on each box.

The result will be that the manufacturer can verify that the manufactured goods are indeed the original goods tracked all the way through their information technology system. They will be able to follow goods diverted from approved channels, and the data will link to a specific box from a specific factory and specific day of manufacture.

The application or printing of dyes: Standard inkjet printers work well with the new dyes.Digital printing enables a clean, inexpensive, database driven printing opportunity. Digital printing allows one-to-one personalization, bar coding, numbering, personal name or logo. New tests will be made with dry digital foil imprinting.

Ink Jet printer and hand held verifier held by David Walsh.

There have been no modifications required to the printer itself.

A Yes / No Authenticator determines the existence and the signature elements of the mark. A photo of one of the reading devices used to identify the existence of the mark and the unique dye used.

A Variable Data Scanner determines numerical or bar code information. This device determines the unique number or bar code data imbedded in the printed mark.

Digital Foil Imprinter: Here is a dry digital printer that may be useful in this project in the future. It is a thermal transfer printer placing 300 dpi foil dots in onto pens or any cylindrical object. This same print engine is being tested for several security print applications.

Digitally transferred hologram tickets: A sample of digital foil printing showing how a foil, even an embossed hologram foil, can be printed, by thermal transfer methods with numerical or bar code dropouts.

Variable Shape Algorithm dropout or positive hologram foil shapes can be printed by the digital imprinter. A dropout number created as the image is printed provides a unique patch by patch identity.

Telephone card: A sample of a hologram "stamped" telephone card.

Shaped Hologram and Unique Number: This photo shows a plastic card with a shaped wallpaper hologram unique to this card alone. It is amazing that the fine lines of the previously embossed hologram survive the bit-by-bit transfer process.


This new fluorescent dye technology provides a low-cost, easy to apply security printing opportunity. It combines all of the appropriate features; an absolutely unique signature, easy to print, overt or covert with unique machine readable data.

I am grateful to Guilford Jones and to PhotoSecure for the information provided in this report. Also to Steve Aroneo of Impress Systems for details of the digital thermal transfer foil printer. I am pleased to answer any questions now or later and to describe this process any time during the Conference.

Finally, I am particularly pleased to provide you with just one inspirational photo from New York. This was passed to me on email as I was writing the final version of this speech from my office near NYC, near enough to see the Twin Towers by binoculars. We are very pleased to have the support of so many people around the world. These firemen and other volunteers represent the spirit of America.

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