JPS58218299A - Moving coil type pickup cartridge - Google Patents

Abstract

PURPOSE:To realize excellent performance and high productivity and to improve the distortion of a coil, by moving two moving coils in a magnetic field by the oscillation of a needle point to obtain a reproduction output, and by making a coil holder of an aluminum. CONSTITUTION:A coil holder 3 is coupled to one end of a cantilever 2 which is fixed with a needle point 1 on its another end to support it so that it can move freely with a supporting point near to the center of the coil holder 3, and moving coils 4 and 5 are fixed on its outer peripheral so that their wound coil plain surfaces are located in a surface perpendicular to the main axis of the cantilever. Magnetic gaps 21 and 22 are formed between a front yoke 20 and poles 18 and 19 which are arranged so that they face each other with the poles, which are inserted in the center holes of the coils 4 and 5, and the coils 4 and 5 in-between. A permanent magnet 24 between the front yoke 20 and a rear yoke 23 generates a magnetic field. If the coils 4 and 5 are moved in the magnetic field, a reproduction output is obtained. Thus, the excellent performance and high productivity are realized. Since the coil holder is made of an aluminum, the distortion of the coil becomes small.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention has a single stylus tip for tracing record grooves formed substantially at right angles to each other in which individual signals are recorded. A moving coil type pickup cartridge configured to move two moving coils disposed within a magnetic field in response to mechanical vibrations, thereby obtaining reproduction output from the two moving coils, which has a good frequency. The purpose is to provide a product that can obtain basic characteristics such as characteristics, and can be easily assembled and mass-produced easily. □ Furthermore, the objectives of the present invention are as follows.

(1) In particular, by effectively making the moving coil part smaller and lighter without impairing its performance, the effective mass of the resonator system can be reduced, resulting in wide-band reproduction characteristics with a high high-frequency reproduction limit frequency, To obtain a moving coil type pickup cartridge with low mechanical impedance.

(2) The output sensitivity-to-impedance ratio is greatly improved by the low inductance, low DC resistance centered coil and the high magnetic flux density magnetic circuit with high magnetic flux concentration.

To obtain a moving coil type pickup cartridge with low noise and high S/N ratio.

(3) With simple shaped coils and coil holders, etc.
To obtain a moving coil type pickup cartridge with high productivity and uniform quality.

(→ To obtain a moving coil type pickup cartridge in which crosstalk can be easily minimized by simple geometric arrangement of coils and magnetic poles.

(6) To obtain a moving coil type pickup cartridge with less leakage and leakage magnetic flux from a DC magnetic circuit, less attraction phenomenon caused by magnetic materials such as a turntable, and no adverse effects such as changes in stylus pressure.

(6) To make it possible to block the vibrator system and a part of the magnetic circuit, and to obtain a cartridge with a replaceable needle configuration.

Conventional structure and problems Generally speaking, as a moving coil type pickup cartridge,
The following two methods have been proposed.

(1) Japanese Utility Model Publication, Utility Model Publication 1987-1987
Moving coil type pickup cartridge disclosed in Publication No. 9◎ (2) Japanese Patent Application Publication No. 46-5577
A moving coil type pickup cartridge disclosed in the publication.

First, the first cartridge disclosed in the above-mentioned Japanese Utility Model Publication No. 40-19879 is as shown in FIGS. 1 to 3.
In the DC magnetic field generated between the yoke piece 102 and the magnetic pole piece 10 by the permanent magnet 101, two magnets are directly applied to the armature 104 placed at -'1.
,・ The needles 105 and 106 are wound so that they are at right angles to each other, and the output voltage corresponding to the movement of the needle tip 107 is the same as the above-mentioned 2.
However, this type of moving coil Kurt-Fusso has the following drawbacks.

(a) As shown in FIG. 3, it is necessary to wind two coils 105 and 106 around the armature 104, that is, the coil support frame, to which the cantilever 108 having the needle tip 107 is fixed, so the cantilever 108 etc. This makes coil winding work difficult and productivity is severely limited.
Also, the coil 106°106 wound around the armature 104
Since the damper 109 contacts the damper 109, the damping surface of the armature 104 by the damper 109 does not become a uniform plane, making it difficult to uniformly position and brake the armature 104.

(b) In order to increase the output sensitivity, the armature 104 interposed in the magnetic field is made of a magnetic material, but this increases the effective mass of the vibrator and increases the inductance of the coil, narrowing the reproduction frequency band. ,S/N
In order to suppress this, the number of turns of the coil is limited, and as a result, the ratio of output sensitivity to impedance cannot be made large, making it impossible to construct a cartridge with a high 87N ratio.

(c) Since a uniform DC magnetic field is generated between the magnetic pole piece 103 and the yoke piece 1020, and the armature 104 is inserted into the magnetic field, essentially one end of the yoke piece 102 is fixed to the armature 104. A hole 110 is required for the cantilever 108' to pass through, and the work of inserting the cantilever 108 into the hole 110 is required during assembly.This makes assembly of the cartridge difficult, and the needle exchange structure is also very difficult. This is difficult to achieve.

) Since the yoke piece 102 and the magnetic pole piece 103 are very close to the record surface, the yoke piece 102 and the magnetic pole piece 10
The force attracted to a magnetic body such as a turntable due to the leakage of the DC magnetic flux generated between the three positions increases, which tends to cause problems such as changes in stylus pressure. It also has various drawbacks, such as the fact that it easily attracts iron powder and the like, requiring protective measures such as a thin rubber film. As shown in FIGS. 4 and 6, the cartridge has an arc-shaped effective coil portion 111a, 112a of two sector-shaped coils 111, 112 formed at the tips of magnetic pole pieces 113, 114, and an arc-shaped air gap 116. Although this type of cartridge is a stereo electrodynamic transducer that is fitted into the cartridge and generates an output to a coil in response to the movement of the needle tip 116, this type of cartridge also has the following drawbacks. That is, (a) since the coils 111 and 112 are fan-shaped in which the effective coil portions 111a and 112a are lengthened in order to increase the output sensitivity, the ineffective coil portions are also inevitably lengthened, making the coils large. For this reason, the mass of the resonator increases, and if the effective mass cannot be reduced and the angular wave number at the high frequency reproduction limit decreases, the mechanical impedance increases and the reproduction frequency band becomes narrow. becomes worse. Furthermore, since the ineffective coil portion coupled to the coil holding member 117 is relatively long, the rigidity of that portion is reduced and harmful resonance is likely to occur. Furthermore, since the two coils are placed very close together, crosstalk problems are likely to occur.

(b) Also, since the coil is large, the winding length is long, and the direct current resistance increases, resulting in thermal noise and noise due to an increase in the equivalent input impedance of the connected amplifier input stage. increases.

EJ: Because the coil is fan-shaped and asymmetrical.

The coil is difficult to manufacture, and attachment to the coil holding member 117 is also very troublesome.

It includes various drawbacks such as.

Purpose of the Invention The present invention has been developed based on the prior art and has carried out further research and development in order to eliminate the drawbacks thereof, and has achieved an overall excellent performance and high productivity, that is, it can be manufactured at low cost. A moving coil type pickup cartridge is provided.

Structure of the Invention 1'1 16'J The present invention fixes two moving coils in the shape of a circular ring to a coil holder to which the other end of the cantilever is fixed. The coil holder is inserted into the gap and configured to obtain a redistribution force from the movable coil in accordance with the movement of the tip of the cantilever, and the coil holder is made of aluminum. By doing this, the coil holder becomes strong and unnecessary resonance can be sufficiently suppressed, and since aluminum is a non-magnetic material, there is no magnetic influence.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to FIG. 6 and subsequent drawings. The cartridge of this embodiment is a pickup cartridge for 45-45 stereo playback in which two or more independent signals are recorded in one sound groove, and two independent moving coils are operated in a DC magnetic field. It uses a moving coil type power generation system that vibrates to generate an output voltage.

First, regarding the first embodiment of the present invention/11ii, Figures 6 to 1
This will be explained using Figure 0. The structure of the pickup cartridge can be roughly divided into a vibration system and a power generation system, so the following explanation will be made according to these classifications as much as possible. First, let's start with the vibration system.The needle tip 1 is fixed to one end of the cantilever 2, and the other end of the cantilever 2 has an I''' made of synthetic resin.
J. A nearly disk-shaped coil holder 3 is coupled, and two independent circular ring-shaped coils 4.5 are attached to the outer periphery of the coil holder 3 so that the winding plane is located in a plane perpendicular to the main axis of the cantilever 2. is fixed (see Figure 9). - The two coils 4 and 6 are arranged in the plane so that the respective winding centers a and b and the main axis C of the cantilever 2 are approximately at the vertices of a right-angled isosceles triangle (see Fig. 8). . 4a and 6a indicate the output leads of the coil 4.6.

Further, to explain the vibration system in more detail using FIG. 10, a cylindrical protrusion 3a is integrally provided on the front surface of the coil holder 3, and the center hole of the cylindrical protrusion 3a is The other end of the cantilever 2 is press-fitted into the through hole 6 passing through in the thickness direction and fixed by adhesive.

Furthermore, arc-shaped notches 7°7 are provided symmetrically above the outer periphery of the coil holder 3, and the notches 7
7 is provided with a coil insertion groove 8.8, and a pre-wound circular ring-shaped coil 4.6 is inserted into this groove 8.8 and fixed by adhesive or the like.

As mentioned above, the coil holder 3 has a through hole 6 for coupling the cantilever 2 and a coil insertion groove 8.8 for fixing the coil 4.6, but this coil holder 3 is made of aluminum. be done. If the coil holder is made of aluminum in this way, the holder itself will be strong, and the movable coil 4.5 can be prevented from twisting and distortion can be reduced. Moreover, since aluminum is a non-magnetic material, it has no magnetic influence.

The coils 4 and 6 are formed into a circular ring shape using a self-welding wire or a coated conductor wire with a diameter of about 16μ to 40μ treated with adhesive and adhesive.

The coil holder 3 is made by winding it tightly, but in order to minimize the effective mass and direct current resistance of the tip 1, the diameter is small and the weight is reduced, and a notch is formed in the coil holder 3 so as to be as close as possible to the main axis C of the cantilever 2. Attach by forming a 7°7 and secure it firmly with epoxy adhesive or the like. If the coil is circular and small, the rigidity can be increased and unnecessary resonance will not occur.

As shown in FIG. 11, a coil support plate 9 having a circular lip 9a is provided integrally with the coil holder 3, and the coils 4 and 6 are installed so that the rib 9a is inserted into the center hole of the coils 4 and 6. If this is done, the coil 4.6 can be easily positioned with respect to the holder 3.

To explain the support structure for supporting such a vibration system, as shown in FIG. 9, a pipe-shaped cantilever 20 is press-fitted into a through hole 6 of a coil holder 3 and fixed with adhesive, and a thin metal wire 9 made of a synthetic resin filament or the like is attached to the rear end of the cantilever 20. One end of the support wire 10 is fixed using a connector 11, a slight gap 12 is provided, and the support pipe 1L is inserted into the pipe 13 under a pressure of 6! Fix it. And a circular ring-shaped damper made of viscoelastic material such as butyl rubber...
・j.

14 is held between the coil holder 3 and the support 16, and the support is inserted into the center hole 16 of the support 16.

The pipe 13 or the support line 10 fixed to the support pipe 13 is pulled behind the support 16 to optimally adjust the amount of compression of the damper 14, that is, the damping of the vibration system, and then the screw 17
tighten the pipe 13 and the support wire 10 to the support body 16.
The vibration system is supported on the support body 16 so as to be able to freely vibrate.

When the vibration system vibrates, the support wire 10 bends at and near the neck portion 10a located within the cavity 12, and this neck portion 1
The vibration system moves angularly in any direction using 0a as the fulcrum. At this time, the support line 10 is not moved in its longitudinal direction. The neck portion 10a is expected to substantially coincide with a plane passing through the center of the coil 4.6 in the thickness direction. The support pipe 13 and support line 10 protruding to the rear of the support body 15 adjust the amount of compression of the damper 14, and the screw 17
It may be cut and removed after it is tightened. Support pipe 1
The front end of the damper 3 passes through the center hole of the damper 14 and partially projects into the cavity 12. The prior art related to this vibration support structure is disclosed in Japanese Utility Model Publication No. 61-241, which was invented by the present inventor.In this embodiment, this prior art is utilized in an improved form. ing.

Next, a description will be given of a power generation system for outputting an electric signal corresponding to the vibration of the needle tip 1 from the two circular ring-shaped coils 4.5 as the vibration system vibrates. is made of a magnetic material, and cylindrical rod-shaped poles 18 and 19, which are inserted into the center holes of the two coils 4 and 6, are integrally formed on the front surface of the support 16. These poles 18.19 are the 8th
As shown in the figure, they are arranged along the central winding axes a and b of the coils 4 and 6. In FIG. 8, the poles 18.degree. 19 and the coils 4.6 are arranged concentrically. A front yoke 2o is arranged to face the poles 18, 19 and the coil 4.5, and the front yoke 2o and the pole 18
．． A magnetic gap 21, 22 is formed between the two.

A permanent magnet 24 is connected between the front yoke 20 and the rear yoke 23 which is integrally provided on the rear outer periphery of the support body 15.
The magnetic gap 2 is connected by this permanent magnet 24.
A magnetic field is generated at 1.22.

To explain in more detail, the lower end of the front yoke 20, that is, the part facing the poles 18 and 19 has two coils 4 and 6.
As shown in FIG. 8, magnetic pole faces 26 and 27 are formed facing each of the inverted V-shaped notches 26, which are substantially perpendicular to the two modulation axes of the record, H, and substantially perpendicular to each other. ing. On the other hand, as described above, the two protruding poles 18 and 19 with circular cross sections formed on the front surface of the support body 16 extending forward from the rear yoke 23 are arranged so as to penetrate approximately at the center of each coil 4°6. Therefore, independent magnetic gaps 21 and 22 are formed between the magnetic pole faces 26 and 27 forming the inverted V-shaped notch 26, respectively.

In this magnetic gap 21, 22, the coils 4 and 5 move in response to the mechanical movement of the stylus tip 1 as it traces the record groove, thereby cutting the DC magnetic flux.

Output voltages corresponding to the left and right channels are applied to each coil. That is, if the needle tip 1 is now vibrated in the direction along the left channel modulation axis in FIG. The portion 4b located in the coil 4 moves to cut the parallel DC magnetic flux, and an electrical output is induced in the coil 4. At this time, since only the portion 5b of the other coil 5 within the magnetic gap 22 rotates around the axis R, the portion 6b of the coil 5 does not cut the magnetic flux, and no output is obtained from the coil 6. I can't do it. Conversely, if the needle tip 1 vibrates in the direction along the right channel modulation axis R, no output is obtained from the coil 4, but an electrical output is induced in the coil 5. In this manner, the left channel signal and the right channel signal are separated and output from the coil 4.5 in response to the movement of the needle tip 1.

The power generation system and the vibration system are combined to form a unit as shown in FIG. 7. This unit is attached to the cart carriage main body 28 as shown in FIG. By connecting the lead wires to the four neutral force terminals 29 provided on the rear plate portion of the main body 28, the moving coil type pickup cartridge of this embodiment is completed. In FIG. 6, the plate 31 indicates a screw insertion recess for attaching the cartridge to the head shell (not shown).

The above is the explanation of the cartridge of this embodiment.

Further supplementary explanation will be provided. In general, the effective mass of the tone arm system including the cartridge (affects frequency characteristics)
The weight of the cartridge has a large influence on the performance, so the weight of the cartridge must not be unnecessarily large (if it is too large, the reproduction frequency band will be narrowed).
Since a sintered magnet is used, the weight is too large and the reproduction frequency band becomes narrow. In order to avoid this, in this embodiment, a rare earth cobalt magnet such as a samarium cobalt magnet, which is characterized by high coercive force and high (BH) maw, is used to obtain a strong gap magnetic field and to reduce the size and weight of the magnet. Of course, magnets made of other materials may be used without any problem.

Front yoke 20 constituting a magnetic circuit. The support body 16 with the rear yoke 23° and the poles 18 and 19 is made of a magnetic material such as electromagnetic pure iron, permendur, or ferrite, which has a high saturation magnetic flux density and high magnetic permeability, but the same material can be made of powder. In particular, the rear yoke 23 and the pole 18.1
By integrally molding and manufacturing the support body 16 having 9 by a sintering method, assembly precision can be significantly improved and the number of man-hours can be reduced. The same applies to the front yoke 20, but it goes without saying that it may be manufactured using other methods such as press working.

By the way, in the first embodiment described so far, the support body 16 for supporting the vibration system forms part of the magnetic line for generating a magnetic field in the magnetic gap between the poles 18 and 19 and the front yoke 20. Therefore, at least the portion of the support 16 that connects the poles 18, 19 and the rear yoke 23 must be made of a magnetic material. However, in the second embodiment shown in FIGS. Even if the support body 16 is made of a non-magnetic material such as synthetic resin, it does not interfere with the reproducing operation.

The second embodiment will be described with reference to FIGS. 12 and 13. The base 3 protrudes forward on the front side of the lower end of the rear yoke 23.
2 is integrally formed with the rear yoke 23 by a sintering method, and the base 3
Circular grooves 34 and 35 are provided on the circumference of the center through hole 33 of No. 2, and these holes 33. A cylindrical support 36 and ball bottles 37 and 38 made of a magnetic or non-magnetic material are respectively inserted and fixed into the grooves 34 and 35 to form one magnetic pole part. In this case, the support pipe 13 connected to the vibration system described above is inserted into the center hole 16 of the support 36, and after adjusting the amount of compression of the damper 14, it is fixed with screws 17 to assemble the vibration system. 36 is inserted into the hole 33 of the base 32 and fixed with the screw 39, making assembly easy.

By the way, in order to improve the separation characteristic between the left and right channel outputs, which is an important performance for a pick amplifier cartridge for playing stereo records, one important thing is the geometric arrangement of the oscillators. That is, as shown in FIG.
．． The line connecting the center of 6 and the stylus tip 1 must be configured so that they both coincide with the modulation axis of the record groove, the direction of the R axis.・Need to be placed. To explain the operation in this case, when the needle tip moves along the axis H due to 45° leftward modulation, the effective coil portion 4a of the coil 4 moves in parallel in the front-rear direction and generates an output voltage within the magnetic gap 21. However, since the coil 6 rotates around the axis R within the plane of the coil, no output voltage is generated. Therefore, good separation of left and right outputs is achieved. Further, when the needle tip makes a vertical modulation movement, an output is produced in the coil 4.5 in the same phase and at the same level. Furthermore, in the case of horizontal modulation, since the coils 4 and 6 move back and forth in opposite directions, they produce outputs of the same level with opposite phases, but horizontal modulation! One coil is reversed to obtain an in-phase signal for the control tone.
・Connect to the other coil so that it becomes the 1' phase.

Another important factor is the shape of the notch 26 of the leakage yoke 20. If the shape of the notch 26 is set so that the direction in which the density of magnetic flux generated between the pole 18° 19, which is a protruding magnetic pole, and the front yoke 20 is maximum coincides with the modulation axis direction of the record, the left and right channel When separated by 1'lE, channel separation can be improved. For example, by providing a recess 40 for separating the magnetic poles as shown by dotted lines in FIGS. 7 and 8, the magnetic flux component in the vertical direction (vertical direction in FIG. 8) can be adjusted to decrease. The maximum magnetic flux density direction, which is the vector sum of the vertical magnetic flux component and the horizontal magnetic flux component (horizontal direction in Figure 8), can be perfectly aligned with the modulation axis direction of the record, and the minimum crosstalk point can be realized. For easier understanding, this will be explained with reference to FIG. 18. As the opening width and depth of the recess 4o is increased, the magnetic flux component in the vertical direction will be reduced accordingly, and the coil 4 of the recess 40, The more the number of magnetic pole faces facing the side surface of 5 increases, the more the magnetic flux composition in the horizontal direction increases.

The direction of the maximum magnetic flux, which is the vector sum of the vertical component and the horizontal component, can be made to coincide with the modulation axis direction R of the record.

Next, another example of the support wire 10 portion forming the vibration fulcrum of the vibration system will be described with reference to FIGS. 14 and 16.
In the example shown in FIG. 4, the coil holder 3 and the support wire 10 are integrally molded into a synthetic resin 1, and the support pipe 13 is attached and fixed to the support wire 10. In the example shown in FIG. 15, a recess 41 is provided on the rear surface of the holder 3 in order to bring the flexible neck portion 10a, which serves as a vibration fulcrum, as close to the surface containing the coils 4 and 5 as possible, and the front end of the support pipe 13 is partially inserted into the recess 41. It's being invaded.

The latter structure is almost the same as the structure of the first embodiment shown in FIG.

Next, FIG. 16 shows a third embodiment of a moving coil type pick-up cartridge in which the needle can be replaced. In the cartridge of Conventional Example 1 explained at the beginning, as shown in FIG. However, since the yoke piece 102 requires a hole that passes through the cantilever 108, it is very difficult to replace the needle, and since the magnetic pole is close to the record surface, leakage magnetic flux attracts iron particles, so the magnetic pole coating is not necessary. A thin film is required. Furthermore, in the case of a turntable containing a magnetic material, the cartridge is likely to be attracted, causing problems such as changes in stylus pressure. However, according to the cartridge of this embodiment, there is no need for a hole that passes through the cantilever 2 at the tip of the yoke 20, and since it is open downward, the needle can be easily replaced, and the magnetic pole is separated from the record surface, so as mentioned above. There is no suction phenomenon, and there is no need for a dustproof thin film.

Therefore, to explain the structure in which the needle can be replaced using FIG. 16, when assembling the vibration system, the output lead wires 4a and 6a of the coil 4.6 are connected to the slit structure 4 provided on the outer periphery of the support 36.
A needle terminal portion 44 having four terminal pins 43 is fixed to the rear end portion of the support body 36, and the lead wires 4a, 5
Connect a to the terminal pin 43. This support 13 is the base 3
2 into the hole 33 (inserted. On the other hand, the cartridge main body 28
The terminal pin 43 is press-fitted into the terminal plate 46 formed in □
.

Four jacks 46 and a conductive foil 47 electrically connected to the jacks 46 are provided, and the conductive foil 47 and the output terminal 29 of the cartridge are connected by a lead wire 48.

In order to facilitate needle exchange, the support body 36 is integrated with a needle holder 49 made of synthetic resin, light alloy, etc., and this holder 49 is attached to the main body 28 with a fixing screw 6o.

When replacing the needle, the entire vibration system including the needle tip 1 can be easily replaced by loosening the fixing screw 5o and pulling out the support body 36 integrated with the needle holder 49 forward.

Note that the shape of the magnetic pole faces 26, 27 of the yoke 2o is in the form of an arc concentric with the center of the pole 18, 19 as shown in Fig. 17, which makes the effective coil portion relatively longer and increases the output voltage. It is also possible to have a structure that

Effects of the Invention 1.1 As explained above, in the movable coil type pickup cartridge sensor of the priming invention, the movable coil is independently formed into a simple circular ring shape, and the coil holder is fixed to the coil holder.

A magnetic gap is formed between a pole inserted into the center hole of the coil and a yoke opposed to the pole, and a DC magnetic field is generated within this magnetic gap. The above-mentioned coil is moved in the vibrator system to extract an output, and in particular, the coil holder is movably supported around its center as a fulcrum to reduce the effective mass of the vibrator system. By making the movable coil into a circular ring shape and generating a magnetic field in the radial direction of this coil, the objectives of 0) to (6) mentioned at the beginning are achieved, namely (1) to increase the high frequency reproduction limit frequency. To obtain a moving coil type pickup cartridge having high broadband reproduction characteristics and low high frequency mechanical impedance; @) To obtain a moving coil type pickup cartridge having a large output sensitivity to impedance ratio, low noise, and high S/N ratio; (3) Obtaining a moving coil pickup cartridge with high productivity and uniform quality; (4) A moving coil pickup cartridge that can easily minimize crosstalk due to the simple geometrical arrangement of coils and magnetic poles. (6) To obtain a moving coil type pickup cartridge with less leakage magnetic flux from a DC magnetic circuit, less attraction phenomenon due to magnetic materials such as a turntable, and no adverse effects such as changes in stylus pressure; (6) Vibrator. The system and some magnetic circuits can be made into blocks,
Excellent performance that can satisfy the need to obtain a moving coil type pickup cartridge that can be easily changed to a needle-replaceable configuration.

It is possible to provide an unprecedented moving coil type pickup cartridge that is easy to assemble, and from a performance standpoint, for example, it is possible to easily expand the playback frequency band without reducing the S/N ratio. From the viewpoint of ease of assembly, the moving coil can be manufactured separately from the coil holder, and since the coil is a simple circle, high-speed winding work is easy and quality can be easily maintained.

Automatic machinery can be introduced to perform mass production.

In this case, variations in the performance of the obtained car IJ can also be greatly reduced.

In addition, in the present invention, since the coil holder is made of aluminum, the holder itself has a strong anti-movable coil 4.
, 6 can be eliminated to reduce distortion.

Moreover, since aluminum is a non-magnetic material, there is no magnetic influence.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing an example of a conventional moving coil type pickup cartridge, Fig. 2 is a side sectional view of the same main part, and Fig.
4 is a side view showing another example of the conventional moving coil type pickup cartridge. FIG. 6 is a front view of the coil portion. FIG. 6 is a first embodiment of the present invention. FIG. 7 is a perspective view of the main parts, FIG. 8 is a front view of the main parts, FIG. 9 is a side sectional view of the main parts, and FIG. 10 is the vibration system of the moving coil type pickup cartridge in the example. FIG. 11 is a partially exploded perspective view showing another example of the same vibration system, FIGS. 2111! 3 is an exploded perspective view of the same essential parts, FIGS. 14 and 16 are side sectional views showing other examples of the vibration system support structure, and FIG. 16 is a side view of a moving coil type pickup cartridge in a third embodiment of the present invention. 17 is a front view of the fourth embodiment, and FIG. 18 is an explanatory diagram for explaining the principle of matching the maximum magnetic flux direction with the modulation axis direction of the record. Needle tip, 2...cantilever,
3... Coil holder, 4, 5... Moving coil, 18.19... Pole, 20...
... Yoke, 2i, 22 ... Magnetic gap,
24...Permanent magnet. Name of agent: Patent attorney Toshio Nakao and 1 other person'1
・ 11ゝ, ::1 □・":1 , -1 Figure 1 Figure 2 Figure 1 υ So Figure 3 Figure 4/13 Figure 5 Figure 6 1 '-. Figure 7 Figure 1O Figure 12 Figure 36 3q Figure 13 Figure 14 Figure 16 Factors Figure 17

Claims (1)

[Claims] (1) The other end of the cantilever with the needle tip fixed at one end is fixed to a coil holder, and this coil holder is movably supported by a supporting means with the center of the coil holder as a fulcrum, and the movable coil is attached to a circular ring. The two circular ring-shaped movable coils are arranged around the outer periphery of the coil holder so that the plane of the windings is substantially perpendicular to the axial direction of the cantilever, and the center of the windings is aligned with the cantilever. A magnetic gag is fixed so as to form a substantially right-angled isosceles triangle, and a pole is passed through the center hole of the circular ring-shaped moving coil, and a yoke is opposed to the pose with the moving coil in between. A permanent magnet is interposed in a line that magnetically connects the pole and yoke to generate a magnetic field in the magnetic gap, and the magnetic field is disposed within the magnetic gap in response to the mechanical vibration of the needle tip. A moving coil type pickup cartridge, characterized in that the moving coil is configured to obtain reproduction output from the moving coil, and the coil holder is made of aluminum.