Security system
US4970504A · kind A · utility
Inventor
Key dates
| Filing date | Dec 19, 1988 |
| Grant date | Nov 13, 1990 |
| Priority date | — |
| Expiry date | Dec 19, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C9/33
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A security system for controlling access to property having a user-operated keyboard to key in and reset a composite password code. An indicator visually displays at least one code symbol varying with time. A memory device stores a current composite password code including at least two code symbols so that upon entry of the keyed-in password code through the keyboard, one of the stored password code symbols is replaced directly by the time varying code symbol to form a regenerated, composite password code which is then compared with the keyed-in password code to grant access to the property when coincidence occurs between the keyed-in and the regenerated password codes. In response to non-coincidence, an alerting signal is generated to indicate the incorrect password condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.