JPS6146911B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a record player equipped with an insulator for vibration isolation, and particularly to a record player with a simple configuration that greatly improves the vibration isolation effect, prevents howling, and improves low frequency characteristics and S/ The purpose of this is to improve characteristics such as N, wow, and flutter.

In general, record players with poor anti-vibration effects suffer from howling, which has become a problem. This howling is a type of oscillation phenomenon that occurs when, for example, the acoustic output from the playback speakers of a record player is fed back to the pickup. Sound pressure can be generated by being transmitted to a record player through the floor or rack, or by sound pressure from a speaker directly vibrating the player's cabinet, dust cover, pickup, etc. and,
Needless to say, when this howling occurs, a needle skipping phenomenon occurs and normal record playback is no longer possible, but even if no howling occurs, the frequency characteristics of the pickup output may change due to external vibrations, or partial resonance may occur. However, there is a problem in that reproduced sound quality is adversely affected due to an increase in cross-modulation distortion, deterioration in transient phenomena, etc., and the S/N ratio is deteriorated.

Therefore, various insulators have been developed and provided by combining rubber, springs, etc., but most of these have only a single function and can be used while attached to the record player.
In particular, a serious problem occurs when the tone arm, cartridge, etc. of an armless type record player are replaced. In other words, even with the included single-function insulator, it is no longer possible to fully demonstrate the vibration-proofing effect of a record player whose tone arm or cartridge has been replaced, and it is susceptible to howling and needle skipping, and the low-frequency characteristics and S/ There was also a drawback that characteristics such as N, wow and flutter were also deteriorated.

The present invention eliminates such conventional drawbacks, and the present invention will be described below with reference to drawings of embodiments.

1 and 2 show an example of the configuration of a record player according to the present invention. In the figures, 1 is a record player main body, 2 is a turntable rotatably mounted on this record player main body 1, and 3 is a turntable mounted on this record player main body 1. A record disc mounted on a turntable 2; 4 an arm base attached to the record player body 1; 5 a pick-up arm rotatably attached to the arm base 4; 6 a tip of the pick-up arm 5; The attached head shell 7 is a cartridge supported by the head shell 6, and 8 is an insulator for vibration isolation attached to the record player main body 1. Here, the above-mentioned insulator 8 utilizes the non-linearity of the spring 9 as shown in FIG. 2, and by changing the length l of the spring 9, the compliance can be freely adjusted as shown in FIG. 3. A configuration that allows settings is used. In this way, if you use an insulator 8 whose compliance can be changed freely, the insulator 8
Since the resonant frequency and Q characteristics can be set freely, it goes without saying that it is possible to prevent howling and needle skipping phenomena of record players, and it also greatly improves characteristics such as low frequency characteristics, S/N, wow and flutter. can be improved.

Here, the pick-up resonance frequency far and Q
is expressed by the following formula, Q=1/R ₁・mt/C _c where mt: Tone arm effective yield [Kg] C _c : Cartridge compliance [m/
N] R ₁ : Cartridge and pick-up equivalent resistance [N·sec/m] The transfer characteristic is shown in curve A in FIG.

On the other hand, the resonant frequencies _p and Q of the record player are expressed by the following equations, However, M: Record player weight [Kg] C: Insulator compliance [m/
N] R ₂ : Insulator equivalent resistance [N·sec/m] Its transfer characteristic is shown in curve B in FIG.

Now, as shown in Fig. 6, in the transfer characteristics of a record player (curve B) and the transfer characteristic of a pickup (curve A), their resonant frequencies _p , ar
If they match at 8Hz, each Q
Although it is about 8 dB, the overall characteristics become as shown in curve C in Figure 6, and Q ₁ becomes as high as 20 dB. Howling and needle skipping are likely to occur at this frequency, and the low-frequency characteristics and S /N, wow/fluttering, and other characteristics are also adversely affected.

On the other hand, as shown in FIG. 7, even if the pick-up transfer characteristic (curve A) is the same, if the compliance of the insulator 8 is changed and the record player's transfer characteristic is set as shown in curve D of FIG. , the resonant frequency of the record player
Since the resonant frequency ar of the pickup with _p of 15 Hz is 8 Hz, the overall characteristic becomes as shown by curve E in FIG. 7, and _Q2 is improved by 10 dB. still,
As shown in FIG. 8, the insulator 8 can also be made by utilizing the non-linearity of the rubber 10, and by changing its length l, it can achieve compliance as shown in FIG. 9 and as shown in FIG. 10. You may use one in which the resistance component can be set freely, or you may use one in which only the resistance component can be set freely. In this way, the insulator 8 configured to be able to adjust mechanical impedance, such as a compliance type, a resistance adjustment type, a combination adjustment type of compliance and resistance, etc., is specifically a bolt inserted into the rubber 16 as shown in FIG. 11. Nut 19 at the bottom end of 18
By attaching the nut 19 and adjusting the height of the nut 19, the bolt 18 is fitted into the rubber 16.
The length l of the spring 17 positioned within the support plate 15 is varied to set the compliance as shown in FIG. 12. Also,
As shown in FIG. 13, a support plate 15 is attached to the lower end of the bolt 18, a spring 17 and a rubber 16 are arranged on the support plate 15, and the spring 17 and the rubber 16 are tightened by a nut 20 provided on the bolt 18. A device in which the length l is changed and the compliance and resistance components are set as shown in FIGS. 14 and 15 is used. Further, as shown in FIG. 16, a bolt 18 is taken out from the record player's cabinet 21, and a leg 2 is attached to the lower end of this bolt 18.
2 and the support plate 15 provided on this bolt 18.
A base 23 for mounting a motor and an arm is supported between the rubber 16 and a spring 17, and the lengths of the rubber 16 and spring 17 are changed by a nut 24 provided on the bolt 18. A floating type device with compliance settings as shown in Figure 17 is used.

This type of floating type is the most distinctive feature of the present invention, and it goes without saying that it has an anti-vibration effect against vibrations from the floor. It also has an anti-vibration effect against the vibration of the cabinet 21 caused by sound. In addition, as shown in FIG.
At the same time, insert the spring 17 into the spring 1.
7 is supported by the nut 24 provided on the bolt 25 and the support plate 15, and the rubber 16 and the spring 17
The floating type supports a base 23 on which a motor and an arm are attached, and the length l of the spring 17 is changed by the nut 24, and the compliance is set as shown in Fig. 19. is used.

This embodiment has a feature that as the nut 24 is screwed onto the bolt 25, the compliance changes as shown in FIG. 19 depending on the point where the nut 24 contacts the rubber 16.

As described above, according to the present invention, since the mechanical impedance of the insulator provided in the record player body can be freely set, it is possible to prevent howling and needle skipping even in the insulator itself. Moreover, since the insulator can freely set its mechanical impedance such as compliance and resistance, even if the one installed in the record player is converted, the low frequency characteristics,
It has the advantage that characteristics such as S/N, wow and flutter can be maintained well, and the vibration damping effect can be greatly improved. Further, by movably providing a base for attaching a motor and an arm to the record player main body, and providing the above-mentioned insulator on this base, vibrations caused by direct sound from the speaker can be very effectively damped.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an example of the configuration of a record player of the present invention, Fig. 2 is a schematic diagram of an insulator in the record player, Fig. 3 is a characteristic diagram of the insulator, Figs. 4, 5, and 6. 7 is a characteristic curve diagram of the same record player, FIG. 8 is a schematic diagram showing another example of an insulator used in the record player of the present invention, FIG. 9 and FIG.
Figure 0 is the characteristic diagram of the insulator, Figure 11,
13, 16, and 18 are specific configuration diagrams showing an example of an insulator used in the record player of the present invention, and FIGS. 12, 14, and 15.
17 and 19 are characteristic diagrams of the insulator. 1...Record player body, 2...Turntable, 4...Arm base, 5...Pickup arm, 7...Cartridge, 8...Insulator.

Claims (1)

[Scope of Claims] 1. A record player comprising a base movably provided within the main body of the record player to which a motor and an arm are attached, and an insulator configured to be able to change the mechanical impedance that supports the base, and by this insulator. A record player characterized in that transmission characteristics such as resonance frequency and Q can be set to appropriate values. 2. The record player according to claim 1, characterized in that a compliance adjustment type insulator is used as the insulator. 3. The record player according to claim 1, characterized in that the insulator is of a combined compliance and resistance adjustment type.