Sony Corporation

Yoshihisa Mori

Mitsuru Takashima

Kazuo Shimura

Hiroyuki Watanabe

Takeo Eguchi

Susumu Hoshimi

Shiro Yasuda

Shingo Tamura

Norio Mashimo

Hachisiro Kobayashi

Herein disclosed is a compact, highly reliable and inexpensive moving coil type cartridge comprising a ring-like magnet which is coaxially disposed with respect to a cantilever having a needle at its free end. A back-up first and a ring-like second auxiliary magnetic members are additionally provided at both sides of the ring magnet to attain the effective utilization of magnetic flux from the ring magnet.

Moving coil type cartridge mounted on cantilever within central opening

The present invention is directed to a pickup cartridge used for reproducing an information recorded on a record disc, the pickup cartridge having a magnet, a stylus which engages a spiral groove on the record disc, a pole piece for forming a path for a magnetic flux generated by the magnet and varied in response to the movement of the stylus and a wire coil wound on the pole piece for producing a signal voltage. The pole piece is made of magnetic material with electrical conductivity, such as permalloy, and is provided with an output electrode portion at one end. One end of the coil wire is connected electrically to the pole piece. The signal voltage is induced in the coil in response to variations in the magnetic flux passing through the pole piece and is fed to the output electrode portion at the end of the pole piece.

Pickup cartridge

A stereophonic pick-up cartridge which has a cantilever having a stylus on a free and thereof and an armature at the rear end thereof, a fixed support and a damper having a first plane surface abutting on the support and a second plane surface abutting on the armature. Grooves are formed in the second plane surface of the damper. The provision of the grooves results in improved isolation between the left and right channels during playback and results in an improved stereophonic pick-up cartridge.

Stereophonic pick-up cartridge

A record player for use with a stationary conventional record disc having a spiral sound groove with signals recorded therein includes a freely movable body which is placed on the record disc, a drive assembly for causing the movable body to effect random movements over the record disc, a pick-up or cartridge pivotally mounted at the underside of the movable body to pivot about a pivot axis for engaging the sound groove and reproducing the signals recorded therein while tracking the spiral sound groove as the movable body travels on the record disc, and a guide assembly for controlling the travel of the movable body relative to the record disc in response to pivotal movement of the pick-up. The guide assembly includes a guide wheel disposed in advance of the pivot axis so that the guide wheel provides a radial inward force to compensate for centrifugal forces acting on the movable body in moving in a generally circular path defined by turns of the spiral sound groove.

Phonograph record player

A record player for use with a stationary conventional record disc having a sprial sound groove with signals recorded therein includes a movable body which is placed on the record disc, a drive assembly for causing the movable body to travel over the record disc, a pick-up or cartridge pivotally mounted at the underside of the movable body for engaging the sound groove and reproducing the signals recorded therein while tracking the spiral sound groove as the movable body travels on the record disc, and an arrangement for controlling the travel on the movable body relative to the record disc in response to pivotal movement of the pick-up.

Record player for a stationary record disc

A gramophone record player comprises a movable body to be placed on a stationary gramophone or phonograph record, a drive in the movable body to drive the movable body on the record, a sound pick-up arranged to be energized by the sound groove of the record and mechanically connected to the movable body, and a gramophone record sound groove following guidance member coupled to the movable body in such a manner that the pick-up traces along the sound groove of the record.

Record player

An electrodynamic transducer comprising a source of magnetic flux and poles that define an annular gap in the flux path to obtain a radially oriented and uniformly distributed magnetic flux across the gap. Coils are mounted on a support that pivots universally about a center concentric with the gap. The coils are placed on the support so that pivotal movement of the latter causes a change in flux linkage with the coils. The coils are wound in such a manner that the electric potentials generated in diametrically opposite coils are added together. There may be sets of mutually perpendicular coils.

Electrodynamic transducer

A pickup cartridge having a vibrating member including a cantilever arm with a reproducing stylus and a permanent magnet, an elastromeric damping member formed into a come or the like shape for supporting the vibrating member as its fulcrum, and a holder supporting the damping member.

Growing community of inventors

Tokyo, Japan

Yoshihisa Mori