Admission control system having a transponder actuated by an inquiry signal
US4822990A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1986 |
| Grant date | Apr 18, 1989 |
| Priority date | — |
| Expiry date | Nov 20, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S283/904
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An admission control system including a portable medium which is equipped with a transponder that is actuated and powered by an inquiry radio wave and sends out an identifying code signal as a radio wave, a transmission device which is provided at a gateway to a place to which admittance is to be gained by only specific persons, and at the gateways to specific areas within the place, and so on, the transmission device transmits an inquiry radio wave, upon detecting the passage of the gateway by a person who carries the portable medium. The admission control system receives an identifying code signal from the portable medium that is transmitted in response to the inquiry radio wave, admits the bearer of the portable medium card to the place only when the identifying code coincides with the identifying code at the gate, and confirms the position of the person within the place.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.