JPS6133319B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a moving coil type pick-up cartridge, and aims to improve crosstalk and output, as well as improve assembly efficiency and facilitate mass production. .

Regarding moving coil type pick-up cartridges, various shapes and structures have been proposed and commercialized. The main thing is as shown in Fig. 1, a pair of coils 1 and 2 are connected to a rectangular armature 3 made of magnetic material at a angle of 45 mm with respect to the horizontal plane.
゜, one with a coil body wound so that the coils cross each other at 90 degrees, a coil with a pair of coils 1 and 2 wound longitudinally under the above conditions around a cross-shaped armature 3a as shown in Fig. 2. There are those that have a body, and those that have a coil body in which a pair of coils 1 and 2 are wound in the width direction under the above conditions around each arm of a cross-shaped armature 3a as shown in FIG. In any of the above coil bodies, a needle lever 5 having a regenerated needle 4 at its tip is fixed to the armature around which the coil is wound. As shown in FIG. 4, the armature is formed between a front yoke 7 fixed to the N pole of the permanent magnet 6 and a pole piece 9 fixed to the S pole of the permanent magnet 6 via a rear yoke 8. The needle lever 5 is inserted into the magnetic gap 10
is inserted through a through hole 11 provided in the front yoke, and the armature is vibably attached to the pole piece 9 via a rubber damper 12 by, for example, a support wire 13, a stopper 14, and a set screw 15.

This type of moving coil type pick-up cartridge has advantages such as stable characteristics and excellent sound quality, but on the other hand, it is very troublesome to assemble and in particular cannot easily wind the coil.
When the output voltage is low and a step-up transformer is required,
Disadvantages such as the inability to easily replace the needle and poor crosstalk characteristics have hindered its widespread use. Among these drawbacks, the low output voltage is not a major drawback, as the performance of amplifiers has significantly improved in recent years, and it has become possible to reproduce satisfactorily even with low output voltages, and needle replacement is also easier than before. Various proposals have been made,
In fact, some moving coil type cartridges that allow for needle exchange are on the market, so it will only be a matter of time before this problem is solved. However, poor ease of assembly and poor crosstalk characteristics are considered to be drawbacks that cannot be solved by moving coil type cartridges, and no proposal has yet been made that can solve the above two drawbacks at the same time.

To further address the above two drawbacks, in the structure shown in FIGS. 1 to 3 above, a pair of coils must be wound around the armature to which the needle lever 5 is fixed, so it is very difficult to wind the coil. It requires a lot of time and a high degree of skill to work, and is not easy to assemble.The above pair of coils are wound on a common armature, although their shapes are different, such as square or cross. , the coils influence each other during power generation, resulting in worsening crosstalk.

The present invention is the result of further research and development after identifying the advantages and limitations of the conventional technology described above.The present invention has excellent assembly ease and crosstalk characteristics, and enables high output voltage and easy needle replacement. The present invention provides a moving coil type pick-up cartridge that can be used.

The present invention will be described below with reference to drawings of embodiments shown in FIG. 5 and subsequent figures.

5 to 10 show a stereo pickup cartridge according to the first embodiment, and the basic structure of the cartridge of the first embodiment is clearly shown in FIGS. 5 to 7. be done. first,
As is clear from these drawings, the structures of the vibration support system A and the magnetic field generation system B of the regeneration needle of this cartridge are relatively similar to those of the conventional system shown in FIG. There is a big difference in the coil part, and in order to take full advantage of the new structure of the output coil part, the above-mentioned vibration support system A and magnetic field generation system B
It can be seen that improvements have been made to the.

Therefore, the explanation will focus on the output coil portion shown in FIG. 7. In FIG. 7, reference numeral 21 denotes a disk-shaped movable body made of a non-magnetic material, such as synthetic resin, and a protrusion 22 for supporting the needle lever is integrally provided at the center of the front surface of this movable body 21. A center hole 23 is provided in the movable body 21 including the protrusion 22. The other end of a needle lever 25 with a regenerating needle 24 attached to one end is press-fitted into the center hole of the protrusion 22, so that the needle lever 25 extends vertically at the center of the front surface of the movable body 21. .

On the other hand, above the outer periphery of the movable body 21, H-shaped coil winding frames 28 and 29 around which a pair of output coils 26 and 27 are wound are fixedly attached. In other words, the H-shaped coil winding frames 28 and 29 are made of a highly magnetic material (although they may be made of a non-magnetic material, of course).
The output coils 26 and 27 are wound in advance, and the two legs 28 of each of the coil winding frames 28 and 29 are
A, 29a are holes 30 provided on the outer periphery of the movable body 21,
31 to install the coil. Regarding the installation positions of the coils 26 and 27, when the reproduction needle 24 traces the sound groove of the stereo code, the maximum sensitivity axes of the left and right channel signals recorded on both walls of the sound groove of the record, i.e. The coils 26, 27 are arranged so that the a-a' line and the b-b' line shown in FIG. The location is being set. As is clear from the figure, the coils 26 and 27 are wound in parallel to the two axes of maximum sensitivity. The two maximum sensitivity axes mentioned above correspond to the direction in which the playback needle 24 swings the most in response to the left and right channel signals of the stereo record, and is generally said to be in the direction tilted at 45 degrees with respect to the record surface. In reality, depending on the storage method of stereo records, the angle may not be 45 degrees, so we used the expression maximum sensitivity axis. In this embodiment, the coils 26, 27 and their winding frame 2
8 and 29 are arranged at right angles to the central axis of the needle lever 25.

Next, the vibration support system of the needle lever 25 having the power generation system will be explained using FIG. 5. The needle lever 25 is formed of a pipe, and the needle lever 2
One end of a support wire 33 made of high quality piano wire or the like is fixed to the rear end of the support wire 33 by a first stopper 32. The support wire 33 is led out from the center of the rear surface of the movable body 21 through the center hole 23, and is inserted into the center hole of a second stopper 34, which is connected to the first stopper 34. They are crimped and fixed at predetermined intervals. The rear surface of the first stopper 32 is substantially aligned with the center plane of the movable body 21 in the thickness direction as shown in the figure, while the front surface of the second stopper 34 is spaced apart from the rear surface of the movable body 21. And the first above
A vibration fulcrum of the vibrating portion, such as the regeneration needle 24, is formed in the support line portion located between the stopper 32 and the second stopper 34. The second stopper 34
is inserted into the center hole of the cylindrical body 36 via a ring-shaped damper 35 made of an elastic material such as plastic rubber placed on the rear side of the movable body 21, and the second stopper 34 is inserted from the rear of the cylindrical body 36. The screw hole 3 provided in the outer peripheral surface of the cylinder 36 is pulled under a constant load.
By screwing the fixing screw 38 into the damper 35, each component is integrated with the damper 35 being compressed by a predetermined amount, and a vibration support system for the regeneration needle 24 and the like is completed.

Next, the magnetic field generation system will be explained with reference to FIGS. 5 and 6. 39 is a permanent magnet that serves as a magnetic field generation source, and is magnetized in N and S directions in the front and rear directions. Front pole piece 40 is on the side,
Further, an L-shaped rear pole piece 41 is attached to the rear S pole side. And the above front pole piece 4
Front end surfaces 41a of the rear pole pieces 41 are arranged parallel to the rear surface 40a, facing the lower end of the rear surface 40a at a predetermined interval to form a magnetic gap. Further, recesses 42 and 43 are formed on the lower surfaces of the pole piece 40 and the rear pole piece 41, and the recess 43 of the rear pole piece 41
The cylindrical body 36 of the vibration support system is fitted therein, and the recess 43 of the front pole piece 40 is used to prevent the needle lever 25 from coming into contact with the pole piece 40 during vibration. When the cylindrical body 36 is fitted into the recess 43 of the rear pole piece 41, as shown in FIG. , 41a. In the figure, the movable body 21 is shown to be partially inserted between the opposing surfaces, but it is not necessary to do so, and the coil 2
It is sufficient if only 6 and 27 are placed between the opposing surfaces. Furthermore, the coils 26, 27 are positioned at right angles to the facing surfaces 40a, 14a, and therefore the magnetic gap is located at right angles to the winding direction of the coils 26, 27. A uniform magnetic field parallel to line 33 is generated.

The basic structure of the cartridge of this embodiment has been described above. Next, the power generation principle of this cartridge will be explained. Assume now that the playback needle 24 is tracing the V-shaped sound groove 44a of the stereo record 44 as shown in FIG. Considering the case where the vibration is swung in the line direction, in the above-mentioned vibration support structure, the point 45, which is a part of the support line 33 in FIG. Since it can be equivalently considered that the movable body 21 is vibrated around the intersection point, the vibration of the regeneration needle 24 causes the movable body 21 to oscillate in the bb' line direction with its center as a fixed fulcrum. It can be thought of as a thing. The coil 26 is caused by the swinging of the movable body 21 in the b-b' line direction.
is assumed to be a back-and-forth motion, but in this case, the winding start end and winding end of the coil 26 simultaneously approach the pole piece 40, that is, the N pole, and approach the pole piece 41, that is, the S pole, so the movement of the coil 26 is caused by magnetic force. This does not cut the magnetic flux in the gap, and no output comes out from the coil 26. However, on the other hand, since the coil 27 rotates around the a-a' line, which is substantially perpendicular to the b-b' line, as a fixed center axis, the winding start end and the winding end of the coil 27 are fixed at one end. When one approaches the pole piece 40, the north pole, the other moves to approach the pole piece 41, the south pole, cutting the magnetic flux in the magnetic gap, so that an alternating current is induced in the coil 27. Therefore, if the regeneration needle 24 is swung in the bb' line direction, an output will be obtained only from the coil 27, and conversely, if the regeneration needle 24 is swung in the aa' line direction, an output will be obtained only from the coil 26.

The basic structure and power generation principle of the cartridge of this embodiment are as explained above, and as is clear from these, the coils 26 and 27 for the left and right channels of this cartridge are provided magnetically completely independently. Since there is no magnetic coupling path between the two coils, there is no mutual influence during power generation, and crosstalk characteristics can be significantly improved. Moreover, since the coils 26 and 27 are prepared separately and attached to the movable body 21, the coil windings are installed with the needle lever attached to the armature as shown in FIGS. 1 to 3. Compared to conventional methods, the ease of assembly and productivity are greatly improved, and the work does not require a high degree of skill.

In the above embodiment, the output coils 26 and 27 are wound around winding frames 28 and 29 made of a highly magnetic material, but this is to increase the output voltage, and the winding frames made of a non-magnetic material are used. Coil 26,2
7, or even if air-core coils 26 and 27 are used without using a winding frame, the power generation operation is performed in the same way. Even if a winding frame made of magnetic material is not used, the drop in output voltage can be covered to some extent by increasing the number of turns of the coil, and it is better not to use a winding frame made of magnetic material in order to reduce the mass of the vibrating part. It is. In connection with this, in the above embodiment, the movable body 21 is made into a disc shape, but this is because the damper 35 is in contact with the movable body 21, and whether it is triangular, square, or spherical, Rather than holding back, it seems better to make the shape symmetrical in order to make the vibration of the regeneration needle 24 uniform. Furthermore, if the coils 26 and 27 are wound around respective winding frames and attached to the movable body 21 as in the above embodiment, at least two man-hours are required. If the coils 26 and 27 are wound on both sides of the winding frame 44 so as to meet the above-mentioned conditions, the installation of the coils 26 and 27 will be completed by simply attaching one winding frame 44 to the movable body, and the work will only require one man-hour. It's convenient. Even if the winding frame 44 shown in FIG. 8 is made of a highly magnetic material, no magnetic coupling will occur between the coils 26 and 27.
There is no problem of crosstalk occurring.

Next, as is clear from the basic structural diagrams of this cartridge shown in FIGS. 5 and 6, the vibration system and magnetic field generation system of this cartridge can be completely separated. This means that needle replacement can be done easily. The structure of this needle exchange will be explained using FIGS. 9 to 11. In the figures, 45 is a synthetic resin cartridge body that houses the above-mentioned magnetic field generation system inside;
Reference numeral 6 denotes a needle support made of synthetic resin that is fitted and locked onto the cartridge main body 45. That is, recesses 47 are formed on both sides of the cartridge main body 45, and the needle support 46 is coupled to the cartridge main body 45 by inserting and locking the protrusions 48 provided on the opposing inner walls of the needle support 46 into the recesses 47. do. A cylindrical body 36 for supporting vibrations of the regenerated needle 24 and the like is engaged with a recess 49 provided on the upper surface of the needle support 46 and is firmly fixed by adhesive or the like.
The lead wires 26a and 27a of 6 and 27 are respectively connected to four output terminal pins 50 fixed to the rear surface of the needle support 46, as shown in FIG. In this way, since only the magnetic field generation system is attached to the cartridge body 45 side, and the vibration system, power generation system, and its electric circuit system are attached to the needle support 46 side, needle replacement can be easily performed. Note that the recesses 51 and 5 provided on both sides of the cartridge body 46
1 is for inserting a mounting screw when attaching the cartridge to the head shell.

Next, FIGS. 12 to 14 show a stereo pickup cartridge according to the second embodiment. Since the basic structure is almost the same as that of the first embodiment described above, the same components are designated by the same numbers. As shown in FIG. 14, each pair of output coils 26 and 27 is constructed by connecting two coils 26a, 26b, 27a, and 27b to increase the output voltage. They differ in some respects. In contrast to the first embodiment in which a pair of coils is provided in the upper half of the movable body 21, in the second embodiment, a pair of four coils is provided around the entire outer circumference of the movable body. Therefore, in order to efficiently and fully insert all four coils into the magnetic gap formed between the pole pieces 40 and 41, a ring-shaped auxiliary pole piece 52 is attached to the front of the outer circumference of the cylinder body 36. 36 is fitted into the lower surface recess 43 of the rear pole piece 41, the rear surface of the auxiliary pole piece 52 contacts the front end surface 41a of the rear pole 41, and the front surface of the auxiliary pole piece 52 and the rear surface of the front pole piece 40 40a to generate a uniform magnetic field. It goes without saying that the cartridge may be constructed by removing the auxiliary pole piece 52. The output coil is installed using the same concept as shown in Figure 8.
If the process is carried out as shown in Fig. 5, the number of work steps will be reduced.

By the way, one of the features of the present invention is the ease of assembling the coil part as mentioned above.
The structure using a letter-shaped coil winding frame has some difficulties in actually putting it on a mass production line in terms of workability of the winding frame, ease of assembling the winding frame to a movable body, ease of winding the coil, etc. It seems like you have it. Therefore, the present inventor takes the above points into consideration and discloses a cost-effective structure of the coil portion from FIG. 16 onwards.

In FIG. 16, a groove 53 is provided on the outer periphery of the movable body 21 along its axial direction and approximately coincides with the maximum sensitivity axis of the stereo record, while a coil winding frame 54
is a protrusion 5 formed into a flat plate and provided on one side thereof.
4a (see FIGS. 17a and b) has an output coil 26,
27, and the coil winding frame 54
One end of the movable body 21 is press-fitted into the groove 53 of the movable body 21 and fixed. According to this, the winding frame 54 is created, the movable body 2
The preparation of the winding frame attachment part 1 is very simple, and the precision thereof can be improved, and the characteristics of the cartridge can be improved.

In FIG. 18, the groove 53 provided in the movable body 21 is not a continuous groove, but has two grooves 53a and 53b, and by press-fitting the projections 55a and 55b of the coil winding frame 54 therein, the looseness of the winding frame 54 can be prevented. completely prevented.

The groove 53 provided in the movable body 21 may be formed by two opposing protrusions 56, 56 which are protruded from the outer peripheral surface of the movable body 21, as shown in FIG. This also applies to the grooves 53a and 53b.

Furthermore, the structure shown in FIG. 20 is effective for increasing the efficiency of the coil winding work. That is, an output coil is formed by forming a thin conductive film 58 in a spiral pattern on a flat coil winding frame 57 by photoetching or the like. One lead portion 59a of this coil is drawn out from the outer peripheral end of the conductor film 58, and the other lead portion 59b is drawn out from the outer peripheral end of the conductor film 58.
Its circumferential end is electrically connected to a conductive film 61 on the ground via a through hole 60 and drawn out from the end of the conductive film 61.

Furthermore, the structure shown in FIG. 21 is effective in reducing the number of parts. That is, a cement wire is used as a wire material for forming a coil, and the cement wire is wound into a coil shape to form a cylindrical plate-shaped coil body 62. Since the coil wire material of this coil body 62 is cement wire, it hardens into the shape shown in the figure and has the functions of both a coil and a winding frame at the same time. Therefore, this coil body 62 may be press-fitted into the groove 53 of the movable body 21 instead of the coil winding frame 54 shown in FIG.

The above is an explanation of the embodiment of the coil portion, and FIGS. 22 and 23 show an example of an output extraction structure suitable for needle exchange. That is, numeral 63 is a needle holder corresponding to the cylinder 36 in the above embodiment (for example, see FIG. 5), and a vibration system is attached to this holder 63 in the same manner as in the cylinder 36 described above. A plurality of output lead wires 64 are buried in this holder 63, one end of which is connected to the output coils 26, 27.
The other end protrudes from the rear surface of the holder 63 and is bent to provide elasticity. On the other hand, an output terminal plate 6 is provided at the rear of the cartridge body 65.
A plurality of output terminal pins 67 are implanted in this terminal plate 66, and a conductor film 68 is formed to be electrically connected to the output terminal pins 67. Then, insert the mounting screw 69 into the through hole 70 provided in the holder 63, and screw this screw 69 into the pole piece 41.
When the holder 63 is screwed into the holder 63 as shown in FIG. 22, the other end of the output lead wire 64 is elastically pressed against the conductive film 68 and the two are brought into good electrical contact. Since the output lead wire 64 can be easily formed when the needle holder 63 is formed, and the conductor film 68 can be easily formed when the terminal plate 66 is formed, an increase in man-hours can be kept to a minimum and an excellent output extraction structure for needle exchange can be provided.

As explained above, the movable coil type pick-up cartridge of the present invention has a movable body made of non-magnetic material and a separate output coil provided on the outer periphery of the movable body.
A pair of coil winding frames are installed with protruding parts, the winding direction of the coil is parallel to the maximum sensitivity axis of the stereo record, and the coil winding frame is placed inside a magnetic gap, and the playback unit is attached to the movable body. The above-mentioned coils are made to vibrate by the vibration caused by the sound groove tracing of the needle, and the output is taken out only from the coils that rotate around their central axis, and the pair of output coils are magnetically Since it is in a non-coupled state, crosstalk characteristics can be greatly improved, and the effective mass of the vibrator can be reduced, among other advantages. In addition, since the coil part can be pre-wound separately from the movable body, it is easy to assemble and has good productivity, and automatic machines can be easily introduced for mass production. be.

[Brief explanation of the drawing]

1 to 3 are front views showing the coil portion of a conventional moving coil type pickup cartridge, FIG. 4 is a structural diagram of the same cartridge, and FIG. 5 is a moving coil type pickup cartridge according to the first embodiment of the present invention. 6 is an exploded perspective view of the same cartridge, FIG. 7 is a front view showing the coil portion of the same cartridge, FIG. 8 is a front view showing another example of the same coil portion, 9 is an overall structural diagram of the same cartridge, FIG. 10 is a front view thereof, FIG. 11 is an exploded perspective view thereof, and FIG. 12 is a basic structural diagram of a moving coil type pick-up cartridge according to a second embodiment of the present invention. , FIG. 13 is an exploded perspective view of the same cartridge, FIG. 14 is a front view showing the coil portion of the same cartridge, FIG. 15 is a front view showing another example of the same coil portion, and FIG. 16 is the same as FIG. 17a and 17b are cross-sectional views thereof, FIG. 18 is an exploded perspective view showing a modification of the coil portion shown in FIG. 16, and FIG. 19 is an exploded perspective view showing another example of the coil portion of the cartridge shown in FIG. A 20th perspective view showing another example of a movable body
21 is a perspective view showing still another example of the coil portion, FIG. 22 is a side sectional view showing an application example of the cartridge shown in FIG. 6, and FIG. 23 is an exploded perspective view of the same. 21... Movable body, 24... Regeneration needle, 25... Needle lever, 26, 27... Output coil, 33... Support line, 35... Damper, 36... Cylindrical body, 39...
...Permanent magnet, 40,40...Pole piece, a-
a' line, b-b' line...maximum sensitivity axis, 53, 53a,
53b... Groove, 54, 57... Coil winding frame, 58
...Conductor film, 62...Coil body made of cement wire.

Claims (1)

[Scope of Claims] 1. A magnetic structure having opposing surfaces defining a magnetic gap and including a permanent magnet for generating a magnetic field in the magnetic gap, and a needle lever having a regeneration needle at one end and the other end fixed to the front surface. a movable body, a support line drawn out from the rear surface of the movable body in its axial direction,
an attachment member for attaching an end of the support wire to the magnetic structure so as to compress a braking member made of an elastic material disposed between the rear surface of the movable body and the magnetic structure; The body is made of a non-magnetic material, and on its outer periphery, a pair of coil winding frames provided separately from the movable body are arranged so that their center lines approximately coincide with the two maximum sensitivity axes of the stereo record. An output coil is wound around each of the pair of coil winding frames substantially parallel to the maximum sensitivity axis, and the coil winding frame is mounted with these coils wound thereon so as to protrude from the outer periphery of the movable body. A moving coil type pick-up cartridge consisting of the above-mentioned magnetic gap. 2. A groove is provided on the outer periphery of the movable body along its axial direction, and the output coil is wound around the outer periphery of a protrusion provided on one surface of a flat coil winding frame, Claim 1, wherein one end of the coil winding frame is press-fitted into a groove of the movable body and fixed.
The moving coil type pick-up cartridge described in Section 1. 3. The movable coil type pickup cartridge according to claim 1, wherein the output coil is formed by forming the coil winding frame into a flat plate and forming a thin conductive film in a spiral pattern on at least one surface thereof. . 4. The movable coil type pick-up cartridge according to claim 1, wherein the coil is formed into a cylindrical plate shape using cement wire, and is also provided with a coil winding frame. 5 Attach the support wire drawn out from the movable body to a needle holder, and attach this needle holder to the magnetic structure in a detachable manner, and also include an output lead part embedded in the needle holder and connected to an output coil at one end. an end protrudes outside the needle holder, a conductive film electrically connected to an output terminal pin fixed to the cartridge body is formed on one side of the cartridge body, and the needle holder is attached to a magnetic structure. Claim 1, wherein the other end of the output lead portion and the conductor film are in contact with each other when attached.
The moving coil type pickup cartridge according to item 1, 2, 3, or 4.