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:
Aug. 16, 1977
Filed:
Oct. 18, 1976
Eugene R Keeler, Fountain Valley, CA (US);
Michael R Harrison, Westminster, CA (US);
Other;
Abstract
Timing apparatus is provided for use in calibrating a wristwatch whose timing accuracy depends on the oscillation frequency of an electrical oscillator in the wristwatch. Electrical energy radiated from the wristwatch is picked up and in response there is produced a first periodic signal whose fundamental frequency depends on the oscillation frequency. In response to the first periodic signal there is produced a second periodic signal. The first and second periodic signals have the same fundamental frequency, but a frequency-dependent phase-shifting circuit causes a phase shift to be defined between the first and second periodic signals. The amount of this phase shift depends on the frequency difference between the equal fundamental frequencies and a predetermined standard frequency. An indicator is provided, and a phase-difference detecting circuit arrangement causes the indicator to display an indication of said frequency difference.