Nippon Gakki Seizo Kabushiki Kaisha

Kenshiro Aizawa

Hisashi Okada

Tsugio Ito

In a pickup cartridge of the moving magnet type, the components of movement of a cantilever in the vertical and horizontal directions are individually detected to produce two kinds of electromotive forces respectively proportional to the velocity of the detected vertical and horizontal components of movement. The sum and difference signals of the two kinds of electromotive forces are separately obtained for stereophonic reproduction of signals recorded on a recorded disk. The vibration system is given different vibration characteristics for vertical movements thereof than those for horizontal movements thereof, without sacrificing electrical output characteristics such as channel separation characteristic and low frequency response characteristic.

Pickup cartridge for reproducing signals recorded on a 45-45

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.

In a pickup cartridge of moving-coil type, the components of movement of a cantilever in the vertical and horizontal directions are individually detected to produce two kinds of electromotive forces respectively proportional to the velocity of the detected vertical and horizontal components of movement. The sum and difference signals of the two kinds of electromotive forces are separately obtained for stereophonic reproduction of signals recorded on a recorded disk. The vibration system is given different vibration characteristics for vertical movements thereof than those for horizontal movements thereof, without sacrificing electrical output characteristics such as channel separation characteristic and low frequency response characteristic. First and second coils are arranged so that the axis of the first coil is parallel to the record disk and the axis of the second coil is perpendicular to the record disk.

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Hamamatsu, Japan

Kenshiro Aizawa