JPS6038763B2 - Pickup Cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pickup cartridge, and the non-oscillation frequency can be adjusted arbitrarily by providing an elastic member that can arbitrarily adjust the elastic force to a rigid body that brakes the rotation of the pickup arm. As a result, records can be reproduced with high accuracy, and by providing a member that can switch the rigid body between braking and non-braking states, the desired resonance frequency can be easily set without using special measuring equipment. The purpose is to provide pickup cartridges.

In general, the resonant frequency fo of a pickup arm (hereinafter referred to as arm) is expressed as The frequency is set at an appropriate frequency so that it does not follow very low frequencies such as curvature, and can reproduce relatively high-pitched audio signals without cutting them.

Therefore, in order to reliably reproduce the audio signal,
It is common practice to apply a brake to the arm. Conventionally, as shown in FIG. 1A, a brake 2 is provided at the base of an arm 1, and the brake 2 is submerged in a viscous agent 3 filled in a container to brake the arm 1. There is something to brake.

However, since the vibration of the arm 1 is damped at its base, if the arm 1 vibrates within the range of the broken line shown in A in the same figure, the damping effect is small and the braking cannot be done reliably. there were. Also, as shown in the equivalent schematic diagram and equivalent circuit diagram in B and C of the same figure, respectively, the braking amount R is
When is large, (pickup output i,): (vibration source output io), which makes it easy to detect unnecessary signals in the ultra-low frequency band such as warpage of the record, and also prevents the cantilever from warping due to warpage of the record. Since the vertical angle changes greatly, the linearity of the output tends to change, which has the disadvantage that the original audio signal in the audible band is modulated. In addition, as another method of applying braking to the arm, conventionally, as shown in FIG. 2A, a cartridge 4 is used.
}There is a device in which a support 5 provided with a brush 5' is provided so as to be rotatable in the vertical direction, and the arm 1 is braked by rotating the rotation shaft of the support 5 via a viscous agent.

As shown in the equivalent schematic diagram and equivalent circuit diagram in FIG. The effect of cutting and damping near the resonant frequency fo is better than that shown in FIG. 1A. However, this device cannot adjust the frequency itself of the resonant frequency fo, and when the resonant frequency is low, it detects ultra-low frequency components such as warpage of the record, and when the resonant frequency fo is high, it detects the original low frequency component. This results in the inconvenience of cutting off the area signal. The resonant frequency is generally determined by the combination of the low-frequency conformance of the vibrator and the effective mass of the arm, and the above-mentioned disadvantages can be avoided when arbitrarily combining vibrators and arms that have different characteristics. This is likely to occur, but in cases where the mechanical impedance is particularly low in the low range, the conformance in the vicinity is generally large, and therefore the resonant frequency fo becomes too low in the neck direction. Therefore, when attempting to reduce the mass of the arm in order to eliminate the above-mentioned disadvantages, the rigidity of the arm is likely to be sacrificed, resulting in drawbacks such as high-order split vibration of the arm occurring in the audible band castle. . In this way, since conventional pickup cartridges are simply provided with a brake at the base of the arm or a brake means at the tip of the arm, the equivalent elasticity S of the cantilever and armature itself can be adjusted as desired. First, for this reason, the resonant frequency fo itself cannot be adjusted, and when arms, cartridges, etc. are used in any combination, problems tend to occur.

The present invention eliminates the above-mentioned drawbacks, and one embodiment thereof will be described with reference to FIG. 3 and subsequent figures.

FIG. 3 shows a perspective view of an embodiment of a pickup cartridge according to the present invention. In the figure, 6 is an L-shaped support,
It is fixed to the upper surface of the cartridge body 7 with screws or the like. Reference numeral 10 denotes a pulley with a hole bored in the center, and as shown in FIG. 4, flanges 10a and 10b are provided at both ends. is rotatably supported by a free iron.

Reference numeral 8 denotes a brake lever, which has a hole bored at one end, a felt 11 pasted on the lower surface of the end, and a flange 10a of the pulley 10.
, 108 so as to be rotatable.

Note that a viscous agent is applied to the surface of the pulley 10 facing the lever 8. 12 is a U-shaped guide rail, and the supporting body 6
is fixed to the side surface of the cartridge body 7 in parallel with the upper surface of the cartridge body 7.

Reference numeral 13 denotes a leaf spring support, to which a leaf spring 14 biased in the direction of the arrow is fixed, as shown in FIG. The configuration is fixed to .

The felt 11 provided at the tip of the lever 8 is brought into contact with a record (not shown) with a predetermined pressure by the downward pressure of the tip 14a of the leaf spring 14. Reference numeral 16 denotes a stopper, which is protruded from the lower side of the support 6, and when the cartridge 6 is raised above the record, the lever 8
is constructed so that it does not rotate unnecessarily.

Here, when applying braking, the pulley 10 is fixed to the support body 6 by tightening the screw 9. As a result, the lever 8 is fixed to the screw 9 (
It rotates using a pulley 10) as a fulcrum and is braked by a viscous agent. When the brake is released, the screw 9 is loosened to allow the pulley 10 to rotate freely. Thereby, the lever 8 rotates integrally with the pulley 10 regardless of the viscous agent. Note that a leaf spring 14 is in pressure contact with the upper surface of the lever 8, but the leaf spring 14 has only an elastic resistance and has nothing to do with braking (viscous resistance). Figure 6 shows the lever 8 and leaf spring 1 shown in Figure 3.
Fig. 4 is an equivalent schematic diagram of Fig. 4, in which the same components as in Fig. 3 are given the same reference numerals.

Here, cantilever 17 and bar 8 are placed on the record.
are supported in parallel, the elasticity S of the vibration system is expressed as the sum of the stiffness Sc at the base of the cantilever 17 and the effective stiffness SR seen from the contact point on the record by the bar 8 (Sc + SR). As a result, the resonant frequency of the arm becomes a hindrance. On the other hand, if the stiffness of the leaf spring 14 is SP, the distance from the fulcrum (screw) 9 to the felt 11 of the lever 18 is s, and the distance from the fulcrum 9 to the tip 14a of the leaf spring m4 is s, then the stiffness is SR is represented by the SR:SPX dispute.

Therefore, by appropriately displacing the position of the tip 14a of the leaf spring 14 to vary the distance, the stiffness SR can be freely varied and the resonant frequency So can be freely adjusted.

In this way, the pickup force of the present invention is as follows:
The rigid lever 8 is placed in parallel with the cantilever 17 in contact with the record, and the pressure force of the lever 8 on the record can be adjusted by the leaf spring 14. Since the value of the effective stiffness SR can be freely adjusted and the value of the resonance frequency itself can be varied compared to conventional pickup cartridges as shown in FIG. 1A and FIG. 2A, different types of Appropriate resonant frequencies can be set for each arm and vibrator having the characteristics, and these can be freely combined and used,
It has the feature of high versatility.

Next, a method of adjusting the resonance frequency fo will be explained.

A test record is prepared in which signals with a frequency of about 5 Hz to 30 Hz are sequentially stored at the same relatively high level for a predetermined period of time at intervals of IHz to 2 Hz.

First, loosen the screw 9 and remove the lever 8 in Figures 3 and 4.
is set so that it rotates integrally with the pulley 10 (non-braking). Next, the leaf spring 14 of the leaf spring support 13 is set at an appropriate position, the screw 15 of the support 13 is tightened, and the test record is traced. Here, when tracing the groove near the resonance frequency fo' in this cartridge, the arm vibrates relatively largely as a whole, which can be easily confirmed with the naked eye. The frequency at which this arm vibrates strongly is the leaf spring 1
4 is set at the above position, the resonance frequency of this cartridge is . Next, temporarily interrupt the tracing, and if the desired resonance frequency (generally set to about 10Hz to 15Hz) is higher than the resonance frequency at the time of the above measurement, loosen the screw 15 of the leaf spring support 13. Move the support 13 toward the tip of the lever 8 in the direction of arrow b in FIG. The levers 8 are respectively displaced toward the base side.

Trace the test record again, and set the plate spring support 13 so that the entire arm vibrates greatly due to the resonance frequency of the kiln.
, and tighten the screws 15 to fix the support body 13 to the rail 12. Finally, the screw 9 is tightened to apply braking so that the lever 8 rotates through the viscous agent. In this way, the desired resonance frequency fo can be set by simply observing the vibration of the arm with the naked eye and appropriately displacing the position of the support 13 without using any special measuring instrument. Next, other embodiments of the elastic member of the cartridge of the present invention will be described with reference to FIGS. 7 to 12.

In FIG. 7, the same components as in FIG. 3 are given the same reference numerals.
The explanation will be omitted.

In the same figure, reference numeral 18 denotes a lever that does not have elasticity, for example, and is attached to a support (not shown) similar to the support 6 in FIG.
, ) is rotatably supported. 20 is arrow C
One end of the spring is fixed to the support body, and the end of the spring is fixed to the lever bar 18.

Reference numeral 21 denotes a shank member, which is slidably inserted and supported by the lever 18, and its tip is supported by the upper surface of the lever bar 8.

The lever 8 is pressed against the record by a lever 18 and a sliding member 21, and when adjusting the resonance frequency, the sliding member 21
Slide it appropriately. In this case, if the contact point between the lever 8 (fulcrum ○) and the sliding member 21 is displaced from point A to point B, the stiffness of the mustard bar 18 at point B is 0, A/
The stiffness seen from the contact point of lever 8 with the record is OB/OA×0, A/○,
It increases at the rate of B. In this manner, the stiffness of this embodiment can be varied over a wider range than that of the embodiment shown in FIG. Conversely, if the stiffness is to be reduced, the sliding portion village 21 is displaced in the opposite direction to the above. In FIG. 8, the lever 22 is rotatably supported around a fulcrum 23, biased in the direction of arrow C by a telescoping spring 24, and inserted through the sliding member 21. As shown in FIG.

This embodiment can also obtain the same effects as the embodiment shown in FIG. In FIG. 9, reference numeral 25 denotes a leaf spring, the end of which is opposite to the fulcrum (screw) 9 of the lever 8 is fixed to a suitable member (fulcrum ○), and the sliding member 21 is inserted through the leaf spring.

For example, if the contact point between the lever 8 and the sliding part 21 is displaced from point A to point B, the stiffness of the leaf spring 25 seen from point B increases at a ratio of (0'A/○'B)3. death,
The stiffness seen from the contact point of lever 8 with the record increases at the ratio of (OB/OA) x〇A/〇B)3,
The stiffness can be varied over a wider range than those shown in FIGS. 7 and 8. In Fig. 10, reference numeral 26 is a leaf spring, and the lever 8 is connected to Oribe on the same side as the fulcrum 9 with a suitable member (the fulcrum).
The sliding member 21 is inserted through the sliding member 21 .

Similar to the above embodiment, when the contact point is displaced from point A to point B, the stiffness seen from the contact point of lever 8 with the record is (OA/OB) x (〇'A/0''B) 3
increases at the rate of Although this ratio is smaller than that of the embodiment shown in FIG. 9, it is sufficiently practical. 1st
In Figure 1, a leaf spring 8'' is integrally fixed to a fulcrum 9' in a direction perpendicular to the ladder bar 8'.

The sliding member 21 is slidably inserted and supported by the guide rail 12', and the leaf spring 8'' is biased in the direction of arrow e at the tip of the sliding member 21. This is also the same as in the above embodiment. Similarly, the stiffness can be varied over a wide range. In FIG. 12, the sliding member 21' is provided with a slit 27.
The leaf spring 8'' is held between the slits 27.

The rest of the structure is the same as that shown in FIG. 11, and the effect is also the same as that shown in FIG. In addition, in Fig. 4, the lever 8 and the pulley 10' are used only when the brake is released.
If a screw or the like is provided to fix the lever 8 and the pulley 10, the lever 8 and the pulley 10 can be reliably rotated together when the brake is released.

In addition, in FIG. 4, a viscous agent is applied between the screw 9 and the pulley 10, and a loose iron is used without applying the viscous agent between the lever 8 and the pulley 10, so that when braking, the lever 8 and the pulley 10 They may be fixed with screws or the like so that they rotate together.

Furthermore, the pulleys may have the same multi-axis structure, and the degree of braking may be adjusted by appropriately selecting the amount and type of viscous agent and the circumferential length of the shaft.

Furthermore, the lever 8 may be constructed in the same manner as the support 5 provided with the brush 5' as shown in FIG. 2A. As described above, the pickup cartridge of the present invention has an elastic member near the stylus tip that has an elastic force in a direction perpendicular to the record surface and can arbitrarily adjust the elastic force as a rigid body that brakes the rotation of the pickup arm. By adjusting the elastic force of the elastic member, the effective stiffness seen from the contact point on the record surface can be varied, thereby allowing the resonance frequency of the pickup arm to be arbitrarily selected. Optimal resonance frequencies can be set for each vibrator and arm, each with different characteristics, and these can be used in any combination, making it possible to prevent audio signals from being modulated by unnecessary ultra-low frequency components such as the warping of a record. Even if the conformance of the resonator is increased, the low-frequency mechanical impedance of the resonator can be reduced, so the tracing ability can be improved. Since we have added a mechanism to selectively switch the resonance frequency to the state of Finally, if you apply braking when the desired resonance frequency is obtained, you can simply observe the vibration of the arm with the naked eye and change the position of the elastic body as appropriate, without using any special measuring equipment. It has features such as being able to easily set a desired resonance frequency just by pressing the button.

[Brief explanation of the drawing]

1A to 2C are front views, equivalent schematic diagrams, and equivalent circuit diagrams of respective examples of conventional pickup cartridges, and FIG. 3 is an implementation of the pickup cartridge according to the present invention. The perspective view of the example, FIGS. 4 and 5 are a longitudinal cross-sectional view of the lever rotation part of the cartridge shown in FIG. 3, and a front view of the vicinity of the leaf spring, respectively, and FIG. 6 shows the operation of the cartridge shown in FIG. Equivalent schematic diagrams for explanation, Figures 7 to 1
FIG. 2 is a front view of other embodiments of the elastic portion of the cartridge of the present invention. 6... Support body, 7... Cartridge body, 8...
Brake lever, 9, 15...screw, 10...pulley, 1
DESCRIPTION OF SYMBOLS 1... Felt, 12... Guide rail, 13... Leaf spring supporter, 14, 25, 26... Leaf spring, 14a... Tip part, 17... Cantilever, 18, 22... Lever, 20...
・Spring, spring, 21... Numitsuki parts, 24... Telescopic spring. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12

Claims (1)

[Scope of Claims] 1. A rigid body that brakes the rotational displacement of the pick-up arm in a direction perpendicular to the record surface is provided in the vicinity of the stylus tip of the cartridge body, etc., so as to be in contact with the record surface and to be freely displaceable in the direction perpendicular to the record surface. In the pick-up cartridge according to the present invention, an elastic member having an elastic force in a direction perpendicular to the record surface and capable of arbitrarily adjusting the elastic force is provided in the vicinity of the stylus tip in contact with the rigid body. Pickup cart storage. 2. The rigid body is a lever-shaped body having one end in contact with the record surface and the other end rotatably perpendicular to the record surface and supported near the stylus tip, and the elastic member has one end in contact with the record surface. 2. The pick-up cartridge according to claim 1, further comprising a plate spring supported near the needle tip so as to be freely displaceable in the longitudinal direction of the rigid body and having its other end abutted against the rigid body. 3. The rigid body is a lever-shaped body having one end in contact with the record surface and the other end supported near the needle tip so as to be rotatable in a direction perpendicular to the record surface, and the elastic member has one end in contact with the record surface. A pick-up car according to claim 1, characterized in that the pick-up car is made of a member fixed near the tip of the needle, the other end of which abuts against the rigid body, and the point of contact with the rigid body can be displaced in the longitudinal direction of the rigid body. Tori Tsuji. 4. A pick-up cartridge in which a rigid body for braking the rotational displacement of the pick-up arm in a direction perpendicular to the record surface is provided near the stylus of the cartridge body, etc., in contact with the record surface so as to be freely displaceable in the direction perpendicular to the record surface. An elastic member having an elastic force in a direction perpendicular to the record surface and capable of arbitrarily adjusting the elastic force is provided in the vicinity of the stylus tip in contact with the rigid body, and further, the rigid body is braked or unbraked. A pick-up cartridge characterized by being provided with a member that selectively switches to one of the following states. 5 The rigid body has one end in contact with the record surface, the other end near the stylus tip, and one end is a sliding shaft;
It consists of a lever-shaped body that is rotatably supported on a concentric rotating shaft with the other end being a viscous shaft, and when braking,
The sliding shaft is fixed and the rigid body is rotated separately from the viscous shaft, and when braking is not applied, the sliding shaft is rotated to rotate the rigid body integrally with the viscous shaft. 5. A pick-up cartridge according to claim 4, characterized in that: