JPS5820198B2 - MC type pickup cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a movin coil (
MC) Type Pick Amplifier Cartridge The object of the present invention is to provide a pickup amplifier cartridge that is easy to mass-produce coils, has a small effective mass of the vibration system, and is easy to use as a replaceable needle type.
An object of the present invention is to provide a C-type pickup cartridge.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is an exploded view of the vibration system, in which the holder 2 at the base end of the cantilever 1 is made of a non-magnetic material, and the outer circumference of the holder 2 is
Notches 2a at angular intervals of degrees.

2b is formed, and coils 30, 3□ bobbins 41, 4□ made of magnetic material and having an H-shaped cross section are attached thereto.

In this case, the coils 3□, 3□ can be mechanically wound in advance on the bobbins 40, 4□, and since they can be wound in alignment, mass production of coils with the same characteristics becomes possible.

It is attached to the holder 2 using adhesive or the like.

The excitation circuit that applies a magnetic field to the coils 30, 3□ is based on a magnet, and as shown in Figure 2, this is a yoke between magnets 51. 6 in between.

A wedge-shaped notch 6a is formed in the lower end surface of the yoke 6.

FIG. 3 shows the arrangement when the above configuration is assembled.

However, only one channel is shown. When the cantilever 1 is stationary, the yoke 6 of the excitation circuit is centered on the bobbin 41 of the holder 2.

7 is a damper, and 8 is a holder that holds the cantilever 1 with a wire.

In the above, when the cantilever 1 moves downward,
As shown in FIG. 4A, the bobbin 41 is tilted, so that the magnetic flux from the excitation circuit passes from the N pole of the magnet 5 to the bobbin 4 from one collar a to the winding center to the other collar C to the yoke. 6, and comes to enter the S pole of the magnet 51.

Therefore, a voltage having the polarity shown at the beginning of FIG. 4 is induced in the coil 51.

On the other hand, when the cantilever 1 moves upward, the bobbin 41 tilts as shown in FIG.
1 through the other collar C → center of winding → one collar a to reach the yoke 6, and enter the S pole of the magnet 5a.

Therefore, a voltage of the polarity shown at the beginning of FIG. 5 is now induced in the coil 5.

In the above, the holder 2 may be made of a non-magnetic material such as aluminum, but may also be made of a resin such as polyamide formed integrally with the suspension wire.

Also coil 3. , 32 do not necessarily have to be provided parallel to the cantilever 1, but may be provided at right angles.

From the above, according to the present invention, the two magnets of the excitation circuit have the same polarity facing each other, and the yoke is interposed between them, so that the magnetic flux can effectively reach the coil through the yoke, and moreover, the magnetic flux can be effectively transmitted from the yoke. Since the magnetic flux is the sum of the magnetic flux of each magnet, the magnetic flux density for the coil increases, improving power generation efficiency, and the magnet itself needs to be smaller to achieve the same magnetic flux density as before. As a result, the weight of the cartridge as a whole can be reduced, so that the effective mass can be reduced.

Furthermore, since the same coil can be mass-produced in advance, the cost is reduced.

Furthermore, since no structure is required on the record side of the cantilever, it is easy to use a replaceable needle type.

[Brief explanation of the drawing]

Figure 1 is an exploded perspective view of the vibration system, Figure 2 is an exploded perspective view of the excitation circuit, Figure 3 is a layout relationship diagram of the vibration system and excitation circuit, and Figure 4 is an exploded perspective view of the vibration system.
This figure and FIG. 5 are operation explanatory diagrams. 1...Cantilever, 2...Holder,
3□, 32...°° coil, 4□, 4□...
・Bobbin, 50,5□・・・Macnet, 6,9
...Yoke, 10...Coil.

Claims (1)

[Scope of Claims] 1. A coil is attached to the base end of the cantilever, and two magnets with a yoke sandwiched between them that protrude in the direction of the coil are placed close to the coil so that their magnetization direction is parallel to the cantilever. The two magnets are arranged so that the yoke sides of the two magnets have the same polarity, and the magnetic flux passing through the yoke side of the magnets passes through the yoke and reaches the coil. MC type pickup cartridge.