Secure entry system with acoustically coupled telephone interface
US5245652A · kind A · utility
88Cited by
50References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1991 |
| Grant date | Sep 14, 1993 |
| Priority date | — |
| Expiry date | Dec 5, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T70/7028
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A comprehensive real estate lockbox system is disclosed which provides a variety of operational features. One of these includes a reader key that can retrieve access data from a system lockbox. The reader key is provided with an audible tone generator which can be selectively enabled by the user. The tone generator can be used to download data from the reader key over telephone lines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.