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:
Jul. 13, 1999
Filed:
Jun. 24, 1997
Nobuhiro Ishikawa, Ibaraki, JP;
Motonori Ogihara, Ibaraki, JP;
Mitutoyo Corporation, Kanagawa, JP;
Abstract
The phase controlling circuit 1 controls the phase of the input sinusoidal signal S1 to generate first and second sinusoidal signal S1 and S2 which have different phases of 90.degree. shifted from each other. The signal generating circuits 2a and 2b square the first and second sinusoidal signal S1 and S2 to generate first and second squared sinusoidal signals S1.sup.2 and S2.sup.2, respectively. The squared sinusoidal signals S1.sup.2 and S2.sup.2 are added by the signal adding circuit 3, thereby generating the added output S3 which is an amplitude of the input sinusoidal signal S. The phase controlling circuit 1 comprises 90.degree. phase shift circuits 11 and 12 which have a common signal input terminal and the respective signal output terminals. The 90.degree. phase shift circuit is composed of an all-pass filter whose central frequency is set to be f0-.DELTA. f so as to generate the first sinusoidal signal. The second 90.degree. phase shift circuit is composed of an all-pass filter whose central frequency is set to be f0+.DELTA. f so as to generate the second sinusoidal signal.