JPS5915459Y2 - printed coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to printed coils for mechanical-to-electrical conversion.

For example, in a conventional MC (moving coil) type cartridge, a coil is attached to the cantilever, but since this coil is generally a wire-wound coil, its weight increases, which adversely affects the movement of the cantilever. In addition, it requires a large magnetic circuit and requires a fairly sophisticated winding technology, which is not very desirable in terms of mass production.

Therefore, in order to solve the above problem, a printed coil in which a coil is formed using a conductive film on an insulating substrate has been proposed.

However, since the insulating substrate in this printed coil is made of an ultra-thin sheet of resin such as polyamide, it has poor heat resistance and wrinkles occur when the conductor is plated. Because of the absorption, it is not possible to use an ultrasonic bonder, making it difficult to draw out lead wires, and furthermore, there are drawbacks such as performance deterioration due to resonance and deformation of the substrate itself.

The present invention has been developed in view of this point, and attempts to solve the above-mentioned problems by using a substrate in which an insulating film is formed on a thin sheet of non-magnetic metal.

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

FIG. 1 shows a cross section of the printed coil, where 1 is the substrate, 2.
2' is a coil made of a conductor.

This substrate 1 is composed of a thin metal sheet 110 made of a non-magnetic metal such as aluminum or beryllium, and an insulating layer 12, 12' made of an insulating film is formed on the front and back sides of the thin metal sheet 110 made of a non-magnetic metal such as aluminum or beryllium. It is formed on the insulating layer 12, 12' by plating, photoetching, or the like.

Next, an embodiment of the MC type cartridge as a print coil will be described with reference to FIG. 2 and subsequent figures.

Figure 2 shows a surface view of the printed coil. A hole 1a for fixing the cantilever is formed in the center of the substrate 1, a semicircular coil 2 is placed on the right side of the hole 1a, and a semicircular coil 2 is placed on the left side of the hole 1a. A semicircular coil 3 is formed, which is wound in the opposite direction to the coil 2 .

Then, the winding centers 2 a and 3 a of both coils 2 and 3 are connected, and output is taken out from their outer winding ends 2 b and 3 b.

Figure 3 shows the back side from the front side with the coils 2 and 3 in the front view of Figure 2 removed, and the pattern on the front side is rotated 90 degrees to the left as it is, and the corresponding pattern is shown. Coils 2' and 3' are printed.

In the above, if the area outside the two-dot chain line in FIGS. 2 and 3 is located within the magnetic gap, and the magnetic field is configured to flow perpendicularly to the plane of the paper toward the back, the printed coil
When the coils 2 and 3 move in the direction of the arrow, an electromotive force is generated in the direction of the arrow, and this electromotive force is caused by the connection of the winding centers 2a and 3a,
The added state appears between the winding outer ends 2b and 3b.

Furthermore, when moving in the L' direction, an electromotive force is generated in the direction opposite to the arrow.

As described above, if the L and L' vibrations occur in the forward directions, an electromotive force corresponding to the vibrations can be obtained.

Note that when vibrating in the R and R' force directions, the upper and lower parts of the coils 2 and 3 cut the magnetic flux, producing an electromotive force, but this electromotive force is canceled out, so the outer end 2b, No output appears between 3b.

On the other hand, since the coil on the back side has a pattern with an angle difference of 90 degrees, the electromotive force when vibrating in the R and R' force directions is added and output is output at the outer winding ends 2'b and 3'b. The electromotive force when L and L' vibrate in the forward direction cancel each other out.

Therefore, L and L' forward vibrations occur only at the outer ends 2b and 3b of the coils 2 and 3 on the front surface, and R and R' force direction vibrations occur only at the outer ends 2'b of the coils 2' and 3' on the back surface. , 3'b, respectively, and no crosstalk occurs between the front and back coils.

Note that although the above is a case in which a magnetic field is applied to the outside portion of the coil, the same effect occurs even if a magnetic field is applied to the inside portion of the dashed-dotted line.

Further, the coils may be connected on one side by connecting the outer ends of the windings to each other and outputting the output from the center of the windings.

Figure 4 shows the above-mentioned printed coil A connected to the canchiever B.
The cartridge is shown when attached to the coil to apply a magnetic field to the outside of the coil.

As described above, in the present invention, the printed coil substrate used in the MC type cartridge is constructed by forming an insulating layer on the surface of a non-magnetic thin metal sheet.

Therefore, since the substrate is heat resistant, it is easy to form a conductor thereon by plating or photo-etching, and since it is rigid, it is also easy to draw out lead wires.

Furthermore, the coil itself does not deform, and its resonant frequency can be increased to an acceptable level.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the printed coil, FIG. 2 is a plan view, FIG. 3 is a view showing the back side from the front side, and FIG. 4 is a view when it is used in a cartridge. 1...Substrate, 11...Metal sheet, 1
2,12'...Insulating layer.

Claims (1)

[Scope of utility model registration request] A printed coil is a coil made of conductive material that is printed on a substrate with an insulating layer formed on the surface of a non-magnetic thin metal sheet.