Moving magnet type stereo pickup

Claim 2

A moving-magnet-type stereo pickup comprising a cantilever arm carrying at one end a stylus, an armature attached to the other end of said cantilever arm, said armature comprising a flat permanent magnet which is magnetized in the direction of its thickness and longitudinally of the arm, said cantilever arm fixed to said armature so that the longitudinal direction of said cantilever arm crosses the plane of said armature at right angles, means for supporting the armature in such a manner that the center of vibration of the vibration system including said stylus, cantilever arm and armature lie substantially at the center of gravity of said armature, E-shaped magnetic pathforming means comprising core means for forming a plurality of magnetic paths in cooperation with said armature, said E-shaped magnetic core means mounted adjacent said armature and disposed relative to said armature so that the legs of said E-shaped magnetic core means are arranged one after another along an axis parallel to the north and south poles of said armature, and the center leg of said E-shaped magnetic core means is adjacent said armature, and windings wound on said E-shaped magnetic core means for detecting movement of said stylus in two direction normal to each other and the response of said windings being linear as a function of movement of said armature so that distortionless response is obtained.

Claim 3

A moving-magnet-type stereo pickup comprising a cantilever arm carrying at one end a stylus, an armature attached to the other end of said cantilever arm; said armature comprising a flat permanent magnet which is magnetized in the direction of its thickness and longitudinally of the arm, said cantilever arm fixed to said armature so that the longitudinal direction of said cantilever arm crosses the plane of said armature at right angles, means for supporting the armature in such a manner that the center of vibration of the vibration system including said stylus, cantilever arm and armature lie substantially at the center of gravity of said armature, E-shaped magnetic path-forming means comprising core means for forming a plurality of magnetic paths in cooperation with said armature, said E-shaped magnetic core means mounted adjacent said armature and disposed relative to said armature so that the legs of said E-shaped magnetic core means are arranged one after another along an axis parallel to the north and south poles of said armature, and the center leg of said E-shaped magnetic core means is adjacent said armature, and windings wound on said E-shaped magnetic core means for detecting movement of said stylus in two directions normal to each other and the response of said windings being linear as a function of movement of said armature so that distortionless response is obtained, wherein the cantilever arm is composed of a plurality of nested cylindrical members each having different lengths, the plurality of cylindrical members disposed around the outside of the cantilever arm along its base portion, and the smaller cylindrical members having lengths which are greater than the larger cylindrical members and said stylus mounted at the end of the arm at its smallest diameter.

Claim 4

A moving-magnet-type stereo pickup comprising a cantilever arm carrying at one end a stylus, an armature attached to the other end of said cantilever arm; said armature comprising a flat permanent magnet which is magnetized in the direction of its thickness and longitudinally of the arm, said cantilever arm fixed to said armature so that the longitudinal direction of said cantilever arm crosses the plane of said armature at right angles, means for supporting the armature in such a manner that the center of vibration of the vibration system including said stylus, cantilever arm and armature lie substantially at the center of gravity of said armature, E-shaped magnetic path-forming means comprising core means for forming a plurality of magnetic paths in cooperation with said armature, said E-shaped magnetic core means mounted adjacent said armature and disposed relative to said armature so that the legs of said E-shaped magnetic core means are arranged one after another along an axis parallel to the north and south poles of said armature, and the center leg of said E-shaped magnetic core means is adjacent said armature, and windings wound on said E-shaped magnetic core means for detecting movement of said stylus in two directions normal to each other and the response of said windings being linear as a function of movement of said armature so that distortionless response is obtained, wherein the cantilever arm is composed of a plurality of nested cylindrical members each having different lengths, the plurality of cylindrical members disposed around the outside of the cantilever arm along its base portion, and the smaller cylindrical members having lengths which are greater than the larger cylindrical members and said stylus mounted at the end of the arm at its smallest diameter.

Claim 5

A moving-magnet-type stereo pickup as claimed in claim 2 in which said windings are wound on the center leg of said E-shaped magnetic core means.

Claim 6

A moving-magnet-type stereo pickup as claimed in claim 2 in which said windings are wound on both outside legs of said E-shaped magnetic core means.

Claim 7

A moving-magneT-type stereo pickup as claimed in claim 2 wherein the armature is square.

Claim 8

A moving-magnet-type stereo pickup as claimed in claim 2 wherein the armature is circular.

Claim 9

A moving-magnet-type stereo pickup as claimed in claim 2 wherein the armature is cross-shaped.

Claim 10

A moving-magnet-type stereo pickup as claimed in claim 2 wherein the armature is polygonal-shaped.

Claim 11

A moving-magnet-type stereo pickup as claimed in claim 2 wherein said magnetic path forming means comprise a pair of magnetic detectors, each disposed adjacent the armature.

Claim 12

A moving-magnet-type stereo pickup as claimed in claim 2 wherein said magnetic path forming means consist of two pairs of magnetic detecting means mounted adjacent the armature and windings on each pair of the detecting means connected together so that their outputs add together.

Claim 13

A moving-magnet-type stereo pickup as claimed in claim 2 comprising a first support means for supporting said vibration system, a pin attached to said first support means, and a second support means formed with a hole into which said pin is inserted to support said stereo pickup.