Slideshow TechConnect Summit 2007

1. Anti-Counterfeiting Filters for Currencies, IDs and Goods TechConnect Summit 2007 Presented by Thomas Martinuzzo, Jr. Eng. Project Leader, Business Development May 2007

2. Counterfeited and pirated goods trade worldwide represents an impact close to 1 trillon dollars annually Anti-Counterfeiting Filters for Currencies, IDs and Goods The challenge

5. The polymer circle is non iridescent, meaning its color is invariable as a function of the observation angle. On the other hand, the interference filter shows a colors shift when the device is tilted. Anti-Counterfeiting Filters for Currencies, IDs and Goods The demonstration Increasing angle of incidence Close to normal incidence Around 60°

6. The polymer acts as a color reference . The user consequently knows what color to expect from the interference filter . Therefore one does not simply rely on the color shift which can be reproduced by buying color shifting ink for example. Using the device in transmission offers a simple and quick method of verification which has to date not been exploited. The patterning of the polymer and filter offers another level of protection by using a known logo, in this case the logo of Univalor . Note that the colors obtained at high angle of incidence almost match the colors of the actual logo of Univalor : Anti-Counterfeiting Filters for Currencies, IDs and Goods How it works?

7. The principle behind the matching colors is based on the metameric effect in witch two objects having different reflection or transmission spectra still show the same color for a specific illuminant (light source). Comparison of the polymer’s and filter’s transmission spectra In order to ensure a metameric match under as many illuminants as possible, the spectra must intersect as many times as possible. The ideal case would be to identical spectra . As we can see in the example of the Univalor logo, the polymer and filter are very similar at normal incidence . Anti-Counterfeiting Filters for Currencies, IDs and Goods Design consideration Transmission Wavelength [nm]

8. In reflection the interference filter shows a yellowish color, the complementary color of that obtained in transmission. In order for metamerism to be observed at normal incidence, the control on the thickness of the individual layers of the interference filter must be very accurate . A slight shift and the match will occur at a higher angle (if the layers are too thick). Increased fabrication complexity = more difficult to reproduce Anti-Counterfeiting Filters for Currencies, IDs and Goods Design consideration