Pager subsystems
US4095215A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 10, 1977 |
| Grant date | Jun 13, 1978 |
| Priority date | — |
| Expiry date | Mar 10, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B5/227
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A number of subsystems are disclosed for use in pagers in which the message transmitted, received and displayed is in alpha/numeric form. The subsystems include an encoder which displays the encoded message on an imprinted tape which is run continuously as an alarm when the memory of the encoder is overloaded. In a soft copy embodiment the encoder includes a keyboard and a dot matrix form of display both driven by a single logic circuit which cycles sequentially through all the alpha/numeric characters to provide simultaneously keyboard decoding and display activation. In another subsystem an end of message circuit is provided to sense the absence of transmitted characters by integration of the message signals, with a nonzero average indicating the end of the message. In a further subsystem, when FSK message signals are used, only one of the two tones is detected for message decoding. In a yet still further subsystem addressing of the pager is accomplished with a digital code and address decoding is accomplished with an improved bit recognition circuit utilizing a single comparator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.