Patent · US Expired

Device for setting and tone dialing a single telephone number

US5210790A · kind A · utility

5Cited by
10References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 5, 1991
Grant dateMay 11, 1993
Priority date—
Expiry dateFeb 5, 2011

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M1/2725
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A device for setting and tone dialing a single telephone number includes a telephone number setting device to generate a digital signal corresponding to the binary equivalent of the digits of the telephone number to be set. A tone generator receives the digital signal generated and groups the digital signal into a predetermined number of bit groups. Each of the bit groups corresponds to one of the digits of the telephone number. The bit groups are accessed one at a time and a dual tone multi-frequency signal corresponding to the digit represented by the accessed bit group is generated by the tone generator and is directed to the telephone instrument.

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