Pager having receiving frame tuned by transducer
US4663624A · kind A · utility
6Cited by
2References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1985 |
| Grant date | May 5, 1987 |
| Priority date | — |
| Expiry date | Mar 21, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B3/1008
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pager is described for use in an electronic watch. The pager comprises a frame (1) for picking up a magnetic signal and a piezoelectric transducer (11) having a static capacitance on its terminals, for producing a sound. 11 To improve sensitivity of reception, a switching circuit (15) connects the transducer (11) in parallel with the frame (1) to tune it by means of the static capacitance to the frequency of the magnetic signal carrier wave. To increase the performance of the transducer (11 ) when it operates as a sound transmitter, the switching circuit (15) connects the frame (1) in series with the transducer (11).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.