JPS5918918B2 - Pickup Cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a so-called moving magnet type pickup cartridge, and particularly to a pickup cartridge that is most suitable as a structure using a flat armature magnetized in the thickness direction.

Traditionally, this type of pickup cartridge (hereinafter referred to as
The cartridge shown in FIGS. 1 and 2 is known as a cartridge (simply referred to as a "cartridge").

The cartridge shown in FIG. 1 has a cantilever 2 with a tone needle 1 attached to one end, and a flat armature 3 magnetized in the thickness direction extending perpendicularly to the axial direction of the cantilever 2 at the other end. The flat armature 3 is supported in the yoke 4 so as to be able to tilt and vibrate in the front-rear direction (direction of arrow A) about the fulcrum 5.
When the magnetic flux is tilted to one side due to vibration, the direction of the magnetic flux flowing through the yoke 4 is switched, and a voltage is induced in the wire ring 6 wound around the yoke 4. It is something.

However, in the configuration shown in FIG. 1, when the flat armature 3 vibrates, the magnetic pole portion of the flat armature 3 moves only a small amount with respect to the yoke 4, and moreover, this Since the dimension of the yoke 40 facing the wire ring 6 is long, as shown in the figure, in addition to the effective magnetic flux φ interlinking with the wire ring 6, there is also a large amount of invalid magnetic flux φB that does not interlink with the wire ring 6, which makes it difficult to obtain good sensitivity. difficult to obtain.

On the other hand, in the cartridge shown in FIG. 2, a yoke I having a substantially E-shaped cross section is arranged so that its central magnetic pole P1 faces the periphery of the flat armature 30 when it is stationary at an appropriate distance. When the armature 3 undergoes tilt vibration (the state in which the armature is tilted to one side due to vibration is shown by a virtual line), its peripheral edge approaches the front magnetic pole P2 of the yoke J.
By approaching the rear magnetic pole P3, the direction of the magnetic flux flowing through the portion of the yoke 70 around which the wire ring 6 is wound is switched, and a voltage is induced in the wire ring 6.

In the configuration shown in FIG. 2, when the flat armature 3 is tilted, one of the peripheral magnetic poles approaches the central magnetic pole P1 while losing its magnetic balance, while the other magnetic pole approaches the central magnetic pole P1 on the front side or the rear side. Side magnetic pole P2. Since the amount of change in the distance between contact and separation from P3 was small, it could not be said that the power generation efficiency was high.

Furthermore, in the configuration shown in FIGS. 1 and 2 above, the wire ring 6 and the yoke 4 or 7 around which it is wound are each configured to independently detect vibrations in one direction. For 2-channel stereo use, the L channel (
left channel), and R channel (right channel)
For each purpose, two sets of the same configuration are required, and in addition, due to the structure of the magnetic pole surfaces, the yokes 4 and 7 are made of a magnetic material such as Beaumalloy bent in a U-shape in the thickness direction. This may lead to deterioration of magnetic properties.

Therefore, these conventional configurations are not preferable in terms of ease of manufacturing the yoke, ease of assembling the yoke, and variations in manufacturing and characteristics.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cartridge that has high power generation efficiency, excellent electromagnetic characteristics, has a simple structure, and can be easily manufactured.

Hereinafter, the present invention will be described in detail using examples with reference to FIG. 3 and subsequent figures.

FIG. 3 is a perspective view showing one embodiment of the present invention, and FIG. 4 is a front view thereof.

In the figure, a circular plate-shaped flat armature 3 magnetized in the thickness direction is attached to the other end of a cantilever 2 with a front needle 1 attached to one end, with the front being the N pole and extending perpendicularly to the axial direction of the cantilever 2. A suitable damper (not shown) is installed so that the flat armature 3 can be tilted and vibrated about the center in the thickness direction on its central axis as a fulcrum.
The device is supported through the device and biased to stand still at a predetermined position.

Furthermore, the flat armature 3 is placed on a plane that is the same as or parallel to the extending plane of the flat armature 3 in this biased stationary position.
A yoke 8 having three thinner legs 8-1, 8-2, 8-3 is positioned above the flat armature 3 (
The tip magnetic pole surfaces of the leg portions 8-1 and 8-2 on both sides of the yoke 80 are arranged to face the left and right side surfaces of the peripheral edge of the flat armature 30, respectively, with an appropriate distance therebetween,
The tip magnetic pole surface of the central leg 8-3 is arranged to face the upper side surface with an appropriate distance therebetween, and each of the legs 8-1.
At 8-2 and 8-3, wire rings L1 and R1 are wound around both side legs 8-1 and 8-2, respectively, and wire rings L2 and R2 are both wound around the center leg 8-3.

As described later, the wire rings L1 and R2 and R1 and R2 cancel induced signals other than induced signals corresponding to a predetermined tilt vibration of the armature 3 based on the vibration of the front needle 1, and correspond to the predetermined tilt vibration. Connect the induced signals so that they add up.
An L-side line ring and an R-side line ring R are used to extract L channel and R channel signals corresponding to the vibration of the front needle 1, respectively.

Next, the principle of power generation in the above configuration will be explained in detail.

That is, from the state shown in FIG. 4, the front needle 1 is displaced as shown in FIG.
45 in the direction perpendicular to the reference plane (record surface)
If it is tilted in the Y' direction forming an angle of .degree., the ON pole of the flat armature 3 approaches the tip magnetic pole surface of the left leg 8-1 of the yoke 8, and the center leg 8-3 and the right leg 8- Since the S pole approaches the tip magnetic pole surface of each of the yoke 8, the magnetic flux φ0. φl.

φ2 occurs.

(However, φθ + φ1 + φ2) Therefore, the wire L1 wound around the left leg 8-1, and the wire L wrapped around the center leg 8-3.
2 are induced with voltages of the polarities shown in the drawings, and if these wire rings Ll t R2 are connected as shown in the figure so that the induced voltages are added to form the L side wire ring μ, the X-X of the flat armature 3 A voltage proportional to the change in magnetic flux caused by the tilted vibration centered around the break can be extracted from the L side track ring.

On the other hand, voltages of the polarities shown are induced in the wire ring R1 wound around the right leg 8-2 of the yoke l and the wire R2 wound around the center leg 8-3, respectively. By connecting R2 as shown in the figure so that the induced voltage is canceled out to form the R side race ring R, the voltage will not be applied to the R side race wheel R due to the tilt vibration of the flat armature 3 centered on x-xi. Not induced.

In this case, the relationship between the turns ratio of the coils R1 and R2 is such that if the respective numbers of turns are NR1 and 2, then dφ2 dφ1 is set so that the voltage induced in the coil R1 is equal to the voltage induced in the coil R2. It goes without saying that the settings should be made to satisfy the following relationship: NR1--Nl-dt dt.

In addition, contrary to the above, the flat armature 3 is tilted in the X' force direction from the state shown in FIG. If it is biased, the N pole of the flat armature 3 is the yoke 8.
The S pole approaches the tip magnetic pole surface of the right leg 8-2, and the S pole approaches the tip magnetic pole surfaces of the left leg 8-1 and the center leg 8-3, causing magnetic flux φ in the direction shown.

', φ1', φ2' occur, and in this case, as mentioned above, the wire ring R
When 1 and R2 and Ll and R2 are connected, the wire ring R1
, R2 are added, and the voltages induced in the coils Ll J R
The voltage induced in 2 is canceled out, and as a result, a voltage proportional to the change in magnetic flux due to the tilt vibration about the flat armature 30Y-Y" line is induced on the R side line, and this -Y" line as the axis, no voltage is induced in the L side line axis direction.

In this case, the turns ratio of the wires L1 and R2 is also the same as that of the wires R1 and R2.
Of course, this is set in the same way as the turns ratio of 2.

The cartridge having the above structure based on such a power generation principle has various advantages in terms of performance and manufacturing.

That is, in the above description, the three legs 8-1, 8-2, 8 of the yoke l extending around the periphery of the flat armature 30
The thickness 11 of -3 is set thinner than the thickness R2 of the flat armature 3, which is magnetized in the thickness direction as shown in the side view of FIG. In comparison, less reactive magnetic flux is generated, and even a slight displacement of the flat armature 3 generates a magnetic potential difference between the 8 legs of the yoke, so power generation efficiency is high.

Moreover, in this case, the interval between the flat armature 3 and the leg portions 8-1.8-2.8-3 of the yoke I can be easily set to be narrow due to the structure, so that the power generation efficiency can be further improved.

Furthermore, since the power generation efficiency is good, the thickness of the flat armature 3 can be made thinner, and the outer shape can be made smaller, so the weight of the vibration system can be reduced, and frequency characteristics and mechanical impedance characteristics can be improved.

In addition, since the configuration does not include a yoke below the flat armature 3 (on the record surface side), the distance a between the lower side of the power generator and the record surface can be widened as shown in FIG.
Therefore, it is easy to design the vertical tracking angle β, and it is also easy to reduce the length of the cantilever 2 to reduce the weight of the vibration system.

Furthermore, a wire ring L2.
By appropriately setting the number of turns of R2, it is possible to improve the value of crosstalk between the L and R channels, and it can also be arbitrarily selected within a certain range.

Since the magnetic path in the yoke 8 can be set short and bending of the yoke is not required, magnetic loss is small.

In particular, since the above configuration does not require bending, the yoke portion can be easily laminated, that is, formed into a layered structure, and the frequency characteristics of the magnetic circuit can be easily improved.

In addition, since the yoke 1 is not present below the flat armature 3, when attaching and detaching the vibration system, it is possible to attach and detach from the bottom instead of from the front as in the conventional case. It can be simplified.

In addition, the wire ring L of the leg part 8-1.8-2.8-3 of the yoke base
l t R2t R1t Since the interval between the parts where R2 is wound can be widened, the winding work can be simplified.

Furthermore, conventionally, two-channel stereo cartridges required two sets of yokes, one for the L channel and one for the L channel, but with the above configuration, only one set of yokes 8 is required. This is advantageous in manufacturing the yoke l and assembling the cartridge, and reduces manufacturing costs.

In addition, there are various effects resulting from being small, lightweight, and having a simple structure.

In the above embodiment, three legs 8-1, 8-2, 8 which are thinner than the armature 3 (thickness and magnetization direction dimension) are used.
-3 is disposed in a direction perpendicular to the magnetization direction of the armature 3. This means that the tips of the three legs face the periphery of the armature 30 and the distance between the three legs is As long as they are connected magnetically, the yoke 9 may have a shape as shown in FIG. 8 (or the yoke 10 may have a shape as shown in FIG. 9).

In addition, in the same embodiment, a circular plate-shaped flat armature 3 was used, but as shown in FIG. It is also possible to provide a yoke 12 with three leg portions 12-1, 12-2, and 12-3 facing each other in terms of planes.

In this case, it is preferable that the opposing magnetic pole surfaces of the legs 12-1, 12-2, 12-3 be longer than the armature 11.

In addition, the shape of the armature is not limited to a circle;
It may be square as shown in the figure, approximately semicircular as shown in the figure, approximately triangular as shown in the figure C, or approximately convex as shown in the figure d.

In addition, the present invention can be implemented with various modifications without changing the gist thereof.

As detailed above, according to the present invention, power generation efficiency is high;
It is possible to provide a cartridge that has excellent electromagnetic characteristics, has a simple structure, and can be easily manufactured.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an example of a conventional pickup cartridge, FIG. 2 is a schematic configuration diagram of another example of a conventional pickup cartridge, and FIG. 3 is a perspective view showing a schematic configuration of an embodiment of the present invention. , FIG. 4 is a front view of the same embodiment, and FIGS. 5 and 6 are diagrams for explaining the power generation principle of the same embodiment.
FIG. 7 is a schematic configuration diagram showing a side view of the same embodiment, FIGS. 8 to 10 are perspective views showing schematic configurations of different embodiments of the present invention, and FIGS. 11a, b, c, and d are respectively It is a figure which shows the modification of the armature in this invention. 1... Front needle, 2... Cantilever, 3
, 11... Armature, 8, 9, 10, 12
...York, 8-1.8-2, 8-3, 12-
1.12-2゜12-3... Legs, L...
...L side track wheel, R...R side track wheel, Ll, R2,
R1, R2... Line wheels.

Claims (1)

[Claims] 1 A tone needle is attached to one end of the cantilever, and an armature magnetized in the axial direction of this cantilever is attached to the other end, and this armature is supported so as to be able to tilt and vibrate and to be biased and stationary at one position. , a yoke having three legs facing each other from three sides is provided on the peripheral side surface of the armature in the biased stationary position, and the legs on one side and the other side of the three legs are each provided with a yoke having three legs facing each other from three sides. The coils A1 and B1 are wound separately, and the coils A2 and B2 are wound together on the central leg, so that the coils A1 and A2 and A2 and B
2 and 2 are connected, respectively, with the same polarity for the induced signal due to the magnetic flux passing through both in series, and with opposite polarity for the induced signal due to the magnetic flux passing through both in parallel, and based on the vibration given to the tone needle ( The induced signal other than the induced signal corresponding to the predetermined tilt vibration of the armature is canceled out, and the induced signal corresponding to the predetermined tilt vibration is added. A pink amplifier cartridge that is characterized by the ability to obtain a corresponding signal.