Time validation system
US7296162B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 26, 2002 |
| Grant date | Nov 13, 2007 |
| Priority date | — |
| Expiry date | Jul 14, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/601
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for time validation comprises a terminal (1) with means (7,7′) for tuning in to a number of different carrier frequencies (a-e), an authorisation device (6), e.g. a smart card, capable of communicating with the terminal (1) and means (2,5) to transmit time stamps, using a modulated signal having a carrier frequency, to the terminal (1). The authorisation device (6) comprises means (8) for selecting a carrier frequency to tune in to for retrieving a time stamp. A terminal (1) and authorisation device (6) are provided for use in the system. A computer program is suitable for loading into a programmable device, e.g. a smart card, to use it as an authorisation device (6) for use in such a system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.