Device for recognizing latent information
US5218644A · kind A · utility
Inventor
Key dates
| Filing date | Mar 21, 1991 |
| Grant date | Jun 8, 1993 |
| Priority date | — |
| Expiry date | Mar 21, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C9/257
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A device for recognizing latent information including an asymmetrical reading head in the form of a truncated cone which is inclined (oblique). The image of the latent information furnished by the reading head is deformed or "warped" with respect to the image which would be furnished by a perfectly symmetrical reading head (a right truncated cone). Hence, different categories of users of an installation can be provided with device having different reading heads furnishing each user with a proper image for the information he is permitted to access so as to prevent access to non-permitted information, each category of users having access to a part of the information corresponding to the specific image furnished by the proper reading head of his device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.