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:
Dec. 10, 1985
Filed:
Feb. 14, 1983
Kazuo Yamada, Noda, JP;
Victor Company of Japan, Limited, Yokohama, JP;
Abstract
A capacitance detector for detecting the information recorded in the form of a series of microscopic pits on a capacitance disc record. The detector comprises, within an outer conductor, a dielectric support, an oscillator having a first line conductor on the support for generating microwave energy, a coaxial resonator having a second line conductor on the dielectric support, the second line conductor being coupled to the electrode of a capacitance detection stylus. Means are provided for inductively coupling the microwave energy from the oscillator to the resonator. This coupling means comprises a loop having a first section inductively coupled with said first line conductor and a second section inductively coupled with said second line conductor, and a capacitor connected from an intermediate point between the first and second sections to ground, so that the microwave energy coupled to the second line conductor is modulated in amplitude with capacitance variations corresponding to the microscopic pits. An amplitude demodulator is provided for demodulating the amplitude-modulated energy to derive a signal representing the capacitance variation on the record.