The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 1976
Filed:
Sep. 18, 1974
Jerold Dennis Dwire, Byron, MN (US);
Townsend Henry Porter, Jr, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A frequency shift key modulator producing sine wave output signals of different frequencies for mark (1) and space (0) signal levels on an input 'send data' lead including a counter which divides the frequency of an input oscillator by different denominators for the mark and space signals and the output of which is synthesized to produce a stepped output approximating a sine wave and a final filter for smoothing the steps out of the output. In cases in which the mark and space output frequencies are approximately in the ratio of 1 to 2, a frequency divider is used for the mark output frequencies.