JPH05962Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a head shell for attaching a phono cartridge that is attached to the tip of a rotary arm for record playback in order to attach the phono cartridge to the arm. .

[Prior Art] A phono pickup installed in a record player generally includes an arm, a headshell provided at the tip of the arm, and a phono cartridge attached to the headshell.

Rotating arms are often used, but when using a rotating arm, a side focus is placed on the cantilever that supports the stylus when the stylus of the phono cartridge traces the sound groove of the record. works, and this side force has various effects on the reproduced sound.

Typical phono pickups used in record playback devices are shown in FIGS. 3 and 4. Figure 3 shows an example in which a linear arm 1 is used as a rotatable arm. In the figure, 2 is a support device that rotatably supports the arm, and 3 is a support device for adjusting the arm's weight balance and stylus pressure. The arm 1 is supported by a support device 2 so as to rotate around a rotation center axis P. 4 is a head shell attached to the tip of the arm 1; 5 is a phono cartridge attached to the head shell 4; the head shell 4 is detachably attached to the arm 1, or is integrally fixed to the arm. The phono cartridge 5 has a suitable power generation mechanism built into the cartridge body, and a needle S is attached to the tip of a cantilever 6 connected to the movable side of the power generation mechanism.

Figure 4 shows an example in which an offset arm 1' is used as a rotary arm, the tip of which is bent into a dogleg shape to give an offset angle θ _0f.The other points are the same as the example in Figure 3. It is similar to

Figure 6 shows the positional relationship between the turntable T of the record player, the rotation center axis P of the arm, the motion center Q of the cantilever, and the needle S when a linear arm as shown in Figure 3 is used. Using this diagram, we will explain why side forces occur when using a straight arm.

In Fig. 6, when the needle S traces the sound groove of the record on the turntable T, a tensile force F acts on the needle tip in the tangential direction of the sound groove, and the direction of this force F is the rotation center axis P of the arm. If the direction does not match the direction of the straight line connecting the center of motion Q of the cantilever 6, a component force Fi1 of the tensile force F is generated, and this component force becomes the side force. In a rotary arm, no matter how the position of the arm's rotation center axis is set, the direction of the tensile force F is in the straight line connecting the arm's rotation center axis P, the motion center Q of the cantilever 6, and the needle S. Only one point coincides with the direction, and at other points the tensile force F
The direction of the rotation center axis P of the arm and the cantilever 6
does not coincide with the direction of the straight line connecting the center of motion Q and the needle S. A deviation in this direction is called a tracking error, and as is clear from FIG.
It becomes larger as it is located further forward than A.

When the rotation center axis of the arm is at point P in Fig. 6, the component force Fi1 of the tensile force F is an inside force directed inward in the radial direction of the turntable T at any position on the arc O-A. becomes. Furthermore, when the rotation center axis of the arm is set at point P' shown in Fig. 6, the component force of the tensile force F becomes an outside force directed outward in the radial direction of the turntable T.
The component of the tensile force F that occurs when the rotation center axis of the arm is set between points P and P' is the
Centering on the point that touches -O', the area outside it is an inside force, and the area inside it is an outside force.

On the other hand, in the offset arm shown in Fig. 4, in order to reduce tracking errors, the arm has an offset angle θ _0f , and the tip of the needle S is shifted a certain distance forward from the center O of the turntable. It is installed (with a so-called overhang). This type of arm creates an inside force for two reasons. One is the inside force Fi1 caused by the above-mentioned tracking error, and the other is the inside force Fi2 caused by having the offset angle θ _0f .
It is.

That is, as shown in Fig. 7, when the arm has an offset angle, the tensile force F does not pass through the fulcrum P of the arm, so an inside force Fi2 is generated, and this inside force Fi2 causes the entire pick-up to move inward. Try to rotate it. However, since the stylus is actually restrained by the sound groove g of the record, only the motion center Q of the cantilever 6 and the arm 1' are located at Q1 and 1, respectively, as shown in FIG.
It rotates in the direction of A', and one direction S moves inside the sound groove g.
With a slight displacement in the direction 2, the cantilever 6 is bent to the side opposite to the center of the record with respect to the cartridge. In this case, the center of motion Q1 of the cantilever and the position S2 of the needle tip are determined by the mechanical impedance of the cantilever support system and the inside force Fi2. In this inside force Fi2, the needle is displaced to the position S2 as shown in FIG.
When it comes to be located above 2, it becomes zero.

[Problem to be solved by the invention] As mentioned above, when either of the arms shown in Fig. 3 or 4 is used, it is unavoidable that side forces occur, and especially when the arm shown in Fig. 4 is In the set arm, inside force Fi2 occurs even if there is no tracking error. This inside force causes the following problems.

When the offset arm 1' is used, the center of motion of the cantilever and the position of the needle tip (relative to the fixed side of the power generating mechanism in the cartridge body) are displaced by the inside force Fi2, but as this displacement becomes large, the cartridge The operating range of the vibration system enters the nonlinear region of the magnetic circuit and the cantilever support system (composed of an elastic body generally called a damper), which causes distortion.

In addition, the tensile force F that causes side force is determined by three factors: the shape of the stylus tip, the friction coefficient of the record, and the rate of change in the shape of the sound groove.Of these, the shape of the sound groove naturally changes from moment to moment. , the tensile force F also changes from moment to moment. Tensile force F
When changes from moment to moment, inside force Fi2
The arm always undergoes displacement vibration due to the inside force Fi2. As a result, the cartridge output will be modulated by the inside force Fi2, causing dynamic distortion that is most detrimental to sound quality.

Further, the arm 1 is vibrated not only by the inside force Fi2 but also by the vibration of the needle S transmitted through the mechanical impedance at the Q point. As a result, the arm resonates and the reproduced sound deteriorates or is colored, making it impossible to correctly reproduce the sound recorded on the record.

An object of the present invention is to provide a head shell for mounting a phono cartridge that can reduce distortion of reproduced sound caused by side forces and distortion of reproduced sound due to arm resonance.

[Means for solving the problem] The present invention provides a rotary arm 1 for record playback,
This is an improved version of the head shell for attaching a phono cartridge, which is attached to the tip of the nuclear arm in order to attach the phono cartridge 5 to the phono cartridge 1'.

The headshell according to the present invention has a frame 10 fixed to the tip of the arm, and cartridge attachment parts 14a and 14b to which the phono cartridge is removably attached. The rotation center axis P of
A base 14 is rotatably supported by the frame 10 via a rotation shaft 13 arranged parallel to the cartridge mounting portion 14a of the base.
14b is configured such that the phono cartridge 5 can be mounted with the center of motion Q of the cantilever of the cartridge 5 substantially aligned with the center of rotation YY of the base 14.

In this specification, the term "head shell" refers to a portion provided at the tip of an arm to support a cartridge, and includes both head shells that are detachably attached to the arm and head shells that are integrally attached to the arm.

[Operation] When a phono cartridge is attached to the above head shell and a record is played back, the head shell tries to rotate until the side force becomes zero, and the axis of rotation P of the arm, the center of motion Q of the cantilever, and the needle S are Automatically tries to align itself. In reality, there is bending resistance of the lead wire connecting the cartridge and head shell, frictional resistance of the rotation axis of the base, etc., so the rotation axis P of the arm, the center of motion Q of the cantilever, and the needle S are automatically aligned. Although it may not always be in a straight line,
If regeneration is started after setting the rotation center axis P of the arm, the motion center Q of the cantilever, and the needle S to be positioned almost in a straight line, as shown in Fig. 5, this state will be maintained during use. It is automatically maintained and can be reproduced in a practically satisfactory state.

As mentioned above, when the phono cartridge is attached to the base that is rotatably supported by the frame,
When the side force acts on the cantilever of the cartridge, the cartridge rotates together with the base, so the displacement of the cantilever due to the side force (displacement relative to the fixed side of the power generating mechanism within the cartridge body) can be reduced. Therefore, the side force acting on the cantilever can prevent the operating range of the cartridge vibration system from entering the non-linear region of the magnetic circuit and the cantilever support system, thereby suppressing the occurrence of distortion.

Furthermore, if the head shell is configured as described above, the horizontal rotational force generated by the vibration of the cantilever is used to rotate the cartridge and base, and the vibration of the cantilever is hardly transmitted to the arm, so the arm It is possible to prevent the reproduced sound from deteriorating due to resonance.

In the present invention, the center of motion of the cantilever and the center of rotation of the base are supposed to almost coincide, but it is preferable that the center of motion of the cantilever and the center of rotation of the base coincide, but it is preferable that the center of motion of the cantilever and the center of rotation of the base coincide, but they may not deviate slightly. The idea is that there is no problem.

In order to achieve the purpose of the present invention, when a force is applied from the horizontal direction to the tip of the cantilever of the cartridge with the cartridge attached to the base, that force is transmitted to the base and the base rotates. You just have to be able to do it. Therefore, the center of motion of the cantilever and the center of rotation of the base do not necessarily have to exactly coincide, and may be slightly different from each other.

However, if there is a deviation between the center of motion of the cantilever and the center of rotation of the base, it becomes difficult to move the base sensitively to the force acting on the cantilever. Therefore, it is preferable that the cartridge attachment portion of the base is configured so as to minimize the deviation between the center of motion of the cantilever and the center of rotation of the base.

[Embodiments] Examples of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show a headshell 4 according to an embodiment of the present invention, in which numeral 10 denotes a substantially L-shaped frame fixed to the tip of the arm;
1 is a male coupling part fixed to one end of the frame 10, and the coupling part 11 is attached to an arm (FIGS. 1 and 2).
Not shown in the figure. ) is inserted into the female joint provided at the tip of the arm, and is tightened and fixed to the arm by a well-known locking mechanism.

A predetermined number (usually four) of terminal fittings 12 are provided in the coupling portion 11, and one end 12a of each terminal fitting 12 is provided.
is exposed on the outer end surface of the connector 11, and the other end 12b is formed into a pin shape, and the pin-shaped end portion 12b protrudes from the frame side end surface of the male coupling portion 11.

When the frame 10 is attached to an arm, a plate-shaped base 1
4 is rotatably supported.

In this embodiment, the lower end of the rotation shaft 13 is connected to the base 1.
The shaft fixing member 14c is fixed to the shaft fixing member 14c fixed to the shaft fixing member 14c by suitable means such as screw connection. The rotation shaft 13 is rotatably supported by a pair of bearings 16 and 17 held in a bearing holding cylinder 15, and the bearing holding cylinder 15 is fitted into a hole 10a provided in the frame 10. A screw 15 is attached to the outer periphery of the bearing holding cylinder 15.
a is provided, and a cap nut 1 is attached to the screw 15a.
8 are screwed together, and the bearing retainer cylinder 15 is fixed to the frame 10 by tightening the nut 18.

Reference numeral 19 denotes a stop ring attached to the upper end of the rotating shaft 13 in order to prevent the rotating shaft 13 from coming off.

The base 14 has a contact surface 14a against which the cartridge 5 is brought into contact, and a long hole 14b provided through the base.
b constitutes a cartridge attachment part. The elongated hole 14b aligns the motion center Q of the cantilever 6 of the phono cartridge 5 with the rotation center Y of the base 14.
The phono cartridge is provided with an appropriate length in the front and rear so that the phono cartridge can be installed in a state substantially aligned with -Y.

The phono cartridge 5 has a groove (or hole) 5a on its side surface into which a mounting screw 20 is fitted, and the tip of the mounting screw 20 inserted into the groove 5a is inserted into a long hole 14b constituting a cartridge mounting portion. The nut 21 is screwed onto the mounting screw 20 to fix the phono cartridge 5 to the base 14.

The cartridge 5 is provided with pin-shaped output terminals 5b, and a contact 25a provided at one end of a lead wire 25 having sufficient flexibility is connected to each output terminal 5b. A contact 25b is provided at the other end of each lead wire 25, and the contact 25b is connected to the pin-shaped end 12b of the terminal fitting 12 of the head shell.
It is connected to the.

As described above, when the rotatable base 14 is provided on the head shell 4 provided at the tip of the arm and the phono cartridge 5 is attached to the base, the horizontal rotational force generated by the vibration of the cantilever 6 is applied to the cartridge 5. Just try to rotate it.
Almost no signal is transmitted to the arm. That is, by rotatably supporting the cartridge 5 with respect to the shell 4, it is possible to break the connection between the vibration system of the cartridge and the vibration system of the arm, thereby preventing the vibration of the cantilever 6 from being transmitted to the arm. This makes it possible to suppress deterioration of reproduced sound due to arm resonance.

Furthermore, since the cartridge 5 can rotate together with the base 14 when the cantilever 6 receives a side force, the rotation of the cantilever 6 is suppressed and the operating range of the vibration system of the cartridge is reduced to the non-linear region of the magnetic circuit and the support system of the cantilever. It is possible to prevent this from occurring, and the occurrence of distortion can be suppressed.

In the above embodiment, a head shell is detachably attached to the tip of the arm.
Of course, the present invention can be similarly applied to a head shell that is integrally attached to an arm.

[Effects of the invention] As described above, according to the invention, a base having a cartridge attachment part is rotatably supported on a frame fixed to the tip of an arm, and a phonograph is attached to the cartridge attachment part of the base. Since the cartridge is attached, when the side force acts on the cantilever of the cartridge, the cartridge can be rotated together with the base, and the displacement of the center of motion of the cantilever and the position of the needle tip due to the side force can be reduced. Therefore, the side force acting on the cantilever can prevent the operating range of the cartridge vibration system from entering the non-linear region of the magnetic circuit and the cantilever support system, thereby suppressing the occurrence of distortion in reproduced sound.

Furthermore, according to the present invention, by rotatably supporting the base on the frame, it is possible to break the coupling between the cartridge vibration system and the arm vibration system against horizontal vibration, and the cantilever vibration is reduced. Since it is possible to ensure that almost no signal is transmitted to the arm, there is an advantage that deterioration of reproduced sound due to resonance of the arm can be significantly reduced.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view of an embodiment of the present invention, Fig. 2 is a top view of Fig. 2, and Figs. 3 and 4 show linear and offset rotating arms, respectively. FIG. 5 is a top view showing a phono pick-up using a phono pick-up, and FIG. 5 shows a state in which the direction of the head is adjusted so that the axis of rotation of the arm, the center of motion of the cantilever, and the tip of the needle are located almost in a straight line in the embodiment of the present invention. FIG. 6 is an explanatory diagram illustrating the side force generation mechanism when a linear arm is used, and FIGS. 7 and 8 are side force generation mechanisms when an offset arm is used. It is an explanatory diagram. 1,1'...Arm, 4...Head shell, 5
...Fronocart cartridge, 6...Cantilever,
S... Needle, 10... Frame, 11... Male coupling part, 13... Rotating shaft, 15... Bearing holding cylinder, 18
... Cap nut, P ... Arm rotation center axis, Y-
Y... Center of rotation of the base, Q... Center of motion of the cantilever.

Claims (1)

[Scope of Claim for Utility Model Registration] In a phono cartridge mounting head shell that is attached to the tip of the rotary arm 1, 1' for record playback in order to attach the phono cartridge 5, the head shell is fixed to the tip of the arm. frame 10
and cartridge mounting portions 14a and 14b to which the phono cartridge is removably mounted, and arranged parallel to the rotation center axis P of the arm when the frame 10 is fixed to the tip of the arm. a base 14 rotatably supported by the frame 10 via a rotation shaft 13; A head shell for attaching a phono cartridge, characterized in that it is configured such that the cartridge can be attached in a state substantially aligned with Y-Y.