Operator responsive keyless entry system with variable random codes
US5055701A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 15, 1989 |
| Grant date | Oct 8, 1991 |
| Priority date | — |
| Expiry date | Aug 15, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C2009/00793
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A keyless entry system for providing controlled access is provided. This system includes a portable transmitter carried by an authorized person and a control system for controlling a locking mechanism. When locking or unlocking, the portable transmitter outputs an input signal to the control system. Upon receiving the input signal, the control system generates a request code signal for output to the portable transmitter. The request code signal generally includes a sequence of random code and an identification code. The control system further generates a particular code signal into which the random code is converted according to information indicated by a specific code stored in the control system. Simultaneously, in the portable transmitter, the random code is converted in the same manner by a user particular code signal equal to the particular code and is transmitted to the control system. The control system compares the particuar code signal with the user particular code signal to activate the locking mechanism to lock or unlock a door when the two particular code signals are coincident with each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.