Issued Patents All Time
Showing 51–54 of 54 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4451521 | Security paper with authenticity features in the form of substances luminescing only in the invisible region of the optical spectrum and process for testing the same | Wittich Kaule | 1984-05-29 |
| 4451530 | Security paper with authenticity features in the form of luminescing substances | Wittich Kaule, Gerhard Schwenk | 1984-05-29 |
| 4446204 | Security paper with authenticity features | Wittich Kaule, Gerhard Schwenk | 1984-05-01 |
| 4442170 | Security document with security features in the form of luminescing substances | Wittich Kaule, Gerhard Schwenk | 1984-04-10 |