Issued Patents All Time
Showing 76–84 of 84 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4591707 | Printed security with hallmarks | Gerhard Stenzel | 1986-05-27 |
| 4533244 | Process for authenticity determination of security documents with security features in the form of luminescing substances | Gerhard Schwenk, Gerhard Stenzel | 1985-08-06 |
| 4516031 | Method of determining the degree of wear of bank-notes and a device for carrying out this method | Walter Renz, Gerhard Stenzel | 1985-05-07 |
| 4463970 | Security paper having camouflage materials to protect its authenticity features | Gerhard Schwenk, Gerhard Stenzel | 1984-08-07 |
| 4452843 | Security paper | Gerhard Schwenk, Gerhard Stenzel | 1984-06-05 |
| 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 | Gerhard Stenzel | 1984-05-29 |
| 4451530 | Security paper with authenticity features in the form of luminescing substances | Gerhard Schwenk, Gerhard Stenzel | 1984-05-29 |
| 4446204 | Security paper with authenticity features | Gerhard Schwenk, Gerhard Stenzel | 1984-05-01 |
| 4442170 | Security document with security features in the form of luminescing substances | Gerhard Schwenk, Gerhard Stenzel | 1984-04-10 |