JPS6020164Y2 - Pickup Cartridge - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a pickup cartridge, and particularly to improvements in its vibration system.

As is well known, a pickup cartridge used for playing disc records is equipped with a movable member linked to a cantilever as its vibration system, and the vibration generated when the record stylus traces the sound groove is transmitted to the movable member. A reproduced output is obtained by changing the amount of electrostatic or electromagnetic coupling with a fixed member.

Figure 1 shows a conventionally known vibration system for such a pickup cartridge, with a cantilever 1
The movable member 12 is supported by fitting on the proximal end of the movable member 12, and
A tension member 15 fixed by a holder member 14 is stretched through a damper member 13 for making the cantilever 11 swingable.

Incidentally, in this case, since it is required to reduce the mass of the vibration system as much as possible, the thickness of the movable member 12 must also be reduced.

However, if it is made too thin, the tension from the tension member 15 is applied to the movable member 12 as lateral pressure via the damper member 13, causing the movable member 12 to deform as shown by the broken line in FIG. Become.

For this reason, in order to reduce the thickness of the movable member 12 and to overcome the limit of reducing the weight of the vibration system, the movable member 12
Efforts have been made to reduce the weight and prevent deformation by changing the materials of the parts.

In other words, the material for the movable part 12 is required to have as low a density as possible and a high Young's modulus.

However, in reality, there is a limit to changing the material, and the vibration system is on the verge of being insufficiently damped, resulting in undesirable peaking in the high range as shown in Figure 3. Ta.

Therefore, this invention was made in view of the above points, and it is an object of the present invention to provide an extremely good pickup cartridge equipped with an improved vibration system that can simplify and reliably eliminate the above-mentioned conventional problems. It is intended to.

That is, the pickup cartridge according to this invention includes a cantilever with a record stylus attached to its tip, a movable member having a pot-shaped part fitted to the base end of the cantilever, and a flange-shaped part on the back side of the movable member. It has a lateral pressure blocking member formed of a rigid body that is disposed coaxially with the extension axis of the cantilever with one end surface in contact with the cantilever, and a hollow portion that contacts the outer diameter portion and the other end surface of the lateral pressure blocking member. a flexible damper member disposed coaxially with the extension axis of the cantilever with one end surface in contact with the rear surface of the brim portion of the movable member; and the other end surface of the damper member. A holder member disposed coaxially with the extended axis of the cantilever with one end surface in contact with the cantilever, and a central axis portion of the lateral pressure blocking member, the damper member, and the holder member inserted into It is characterized by comprising a tension member, one end of which is engaged with the proximal end of the cantilever, and the other end of which is engaged with the holder member.

An embodiment of this invention will be described in detail below with reference to the drawings.

That is, as shown in FIG. 4, a thin rubber tube-shaped cantilever 21 made of light metal or the like has a record stylus 22 attached to its small-diameter tip, and a central guide hole 231 is formed on the outer periphery of the large-diameter proximal end of the cantilever 21. A movable member 23 having a flange-shaped portion 232 and a movable member 23 fitted with the movable member 23 is disposed coaxially with the extension axis of the cantilever 21 with one end surface in contact with the back surface of the flange-shaped portion 232 of the movable member 23. A rigid body! It has a ring-shaped lateral pressure blocking member 25 and a cavity 251 that comes into contact with the outer diameter part and the other end surface of this lateral pressure blocking member 25, and one end surface is on the back surface of the brim-shaped portion 232 of the movable member 23. A damper member 26 made of flexible material such as rubber is disposed coaxially with the extension axis of the cantilever 21 in a state of contact, and a state in which one end surface is in contact with the other end surface of this damper member 26. The holder member 27 is disposed coaxially with the extension axis of the cantilever 21, and the central axis portions of the lateral pressure blocking member 25, the damper member 26, and the holder member 27 are inserted into the holder member 27. The tension member 24 has one end fixed to the proximal end of the cantilever 21 and the other end fixed to the holder member 27 with a screw 28.

In the above description, the movable member 23 is formed as a movable electrode when configuring a capacitor-type pickup cartridge, for example, and the output is derived from between fixed electrodes (not shown) disposed opposite to the movable electrode. Take.

Figures 5a and 5b show different shapes of the lateral pressure blocking member 25 described above, in which figure a is a simple cylinder, and figure b is a cone.

1. In the pickup cartridge in which the vibration system is configured as described above, the tension member 24 that applies tension to the cantilever 21 has a lateral pressure blocking member 25 made of a rigid body, and a damper unit that substantially surrounds the lateral pressure blocking member 25. Since they are connected via the member 26, the fulcrum is within the lateral pressure blocking member 25, and the lateral pressure on the movable member 23 is removed.

As a result, the movable member 23 is substantially
4, it is possible to make the plate thickness much thinner than the conventional limit due to the lateral pressure, without causing deformation, and as a result, the effective mass of the vibration system can be effectively reduced. This can be reduced to

Figure 6 shows the frequency characteristics of a pickup cartridge equipped with such an improved vibration system.
It can be seen that it is possible to reduce the high-frequency peaks to 2 dB or less so that they do not cause any problems in practice, and that it is possible to eliminate the problem of insufficient braking in the past.

Also, a side pressure prevention member 2 made of a rigid body is provided at the rear of the movable member 23.
5 has the advantage of suppressing the resonance of the movable member 23 and at the same time preventing the application of more tension than necessary.

It goes without saying that this invention is not limited to the embodiments described above and illustrated, and that various modifications and adaptations can be made without departing from the gist of this invention.

For example, when applied to an MC (moving coil) type pickup cartridge, the movable member may be a thin substrate with a coil printed on it.

Therefore, as detailed above, according to this invention, the lateral pressure blocking member made of a rigid body and the damper member surrounding the lateral pressure blocking member are inserted into the proximal end of the cantilever that supports the movable member, and the tension member is tensioned. By configuring the vibration system as described above, the side pressure of the tension member is not applied to the movable member, and the plate thickness of the movable member can be made far thinner than the conventional limit, thereby reducing the effective mass of the vibration system. It becomes possible to provide an extremely good pickup cartridge that is equipped with an improved vibration system that can easily and reliably eliminate the conventional drawbacks.

[Brief Description of the Drawings] Fig. 1 is a side sectional view showing the vibration system of a conventional pink-up cartridge, Fig. 2 is a partial sectional view showing the deformed state of the movable member used in Figs. Fig. 1 is a curve diagram showing the frequency characteristics of the cartridge, Fig. 4 is a side sectional view showing the vibration system of the pickup cartridge according to this invention, and Fig. 5 is a curve diagram showing the frequency characteristics of the cartridge.
Figures a and b are perspective views showing different shapes of the side pressure blocking member used in Figure 4, and Figure 6 is a curve diagram showing the frequency characteristics of the cartridge according to Figure 4. 21... Cantilever, 22... Record needle, 23... Movable member, 24...
Tension member, 25... Side pressure prevention member, 26
・・・・・・Damper 1 member, 27 ・・・Holder 1 member, 28 ・・・Screw.

Claims (1)

[Scope of utility model registration request] A cantilever with a record stylus attached to its tip, a movable member having a collar fitted to the base end of the cantilever, and one end surface of the movable member in contact with the back surface of the collar. A lateral pressure blocking member formed of a rigid body disposed coaxially with the extension axis of the cantilever, and a cavity portion that abuts the outer diameter portion and the other end surface of the lateral pressure blocking member, and one end surface is connected to the movable member. a flexible damper member disposed coaxially with the extension axis of the cantilever while in contact with the back surface of the flange-like portion of the cantilever, and a state in which one end surface is in contact with the other end surface of the damper member; The holder member is disposed coaxially with the extension axis of the cantilever, and the central axis portions of the lateral pressure blocking member, the damper member, and the holder member are inserted into each other, and one end is A pickup cartridge characterized in that the pickup cartridge further comprises a tension member that is attached to the base end of the cantilever and whose other end is attached to the holder member.