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:
Apr. 21, 1981
Filed:
Aug. 29, 1978
Shuichi Obata, Kyoto, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A pick-up assembly carried by a tone arm itself or a cartridge adapted to be connected to the tone arm includes a vibrating section and a magnetic circuit section. The vibrating section has a cantilever having one end carrying a stylus and the other end mounted in a support ring. A pair of ring-shaped moving coils are mounted on the support ring in such a manner that the longitudinal axes of the coils are in parallel and equidistantly spaced relation to the longitudinal axis of the support ring so that the coils are angularly spaced at right angles to each other about the longitudinal axis of the support ring. The magnetic circuit section has a permanent magnet sandwiched between front and rear yokes of magnetic material. The front yoke has a pair of leg portions extending downwardly for positioning the coils in spaced relationship between the leg portions while the rear yoke has a cylindrical support member carrying the support ring in such a manner as to allow the vibrating section to flex angularly and a pair of poles of magnetic material rigidly connected to the cylindrical support member and the rear yoke. Free end portions of the poles remote from the rear yoke are coaxially inserted into the coils respectively for forming a magnetic field between each pole and its corresponding leg portion. A recess in the front yoke improves the separation between the audio channels.