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.

Date of Patent:
Jul. 28, 1981

Filed:

Jan. 08, 1979
Applicant:
Inventors:

Tsugio Ito, Hamamatsu, JP;

Kenshiro Aizawa, Hamamatsu, JP;

Hisashi Okada, Hamamatsu, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
369139 ; 369147 ;
Abstract

A moving coil type pickup cartridge comprises at least two movement-electromagnetism conversion systems functioning in push-pull mode, each system being arranged by a coil supported on a plate and inserted in an air gap between two opposing magnet blocks each constituted by side-to-side two magnets so as to provide opposite magnetic poles facing each other with the air gap intervening therebetween. A linear movement of the coil is allowed in the air gap in the directions of cutting the magnetic fluxes in the magnetic fields produced between the opposing magnet blocks. This arrangement provides a high density of magnetic fluxes and a high output voltage and improves the quality of signals reproduced. This effect is promoted further by yoke plates of a material of high magnetic permeability arranged to straddle the open magnet poles of the side-to-side magnets, thereby inhibiting leak of magnetic fluxes from these open poles. Vertical compliance of the vibration system can be made small during tracing a warped record disk by the use of an asymmetrically shaped armature. Good contact of damper to armature can be secured by fitting the armature into the damper. This cartridge may be made integral with head shell.


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