Patent · US Expired

Automatic telephone answering apparatus

US4445148A · kind A · utility

1Cited by
4References
14Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 17, 1981
Grant dateApr 24, 1984
Priority date
Expiry dateDec 17, 2001

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M1/6515
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

For switching over from playback of the owner's announcement text to recording a message from a caller, a pause of defined length is present on the announcement tape between the first and second (or end) parts thereof. This pause is recorded and on every run of the announcement tape through the apparatus the reading, recorded for the length, undergoes comparison with the pause of the announcement tape being transported. When the two values are the same, switch over takes place. In this way, it is possible to make certain of switch over without being dependent on the tape speed, and the circuit system may be made very much less complex.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.