JPS5822804B2 - record player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a record player, and more particularly to a turntable section of a record player.

If the turntable in a record player has a large moment of inertia within the allowable range of the phono motor's torque, it will be easier to rotate at a constant rate regardless of external conditions, and vibrations of the phono motor can be effectively blocked.

This moment of inertia is '! It is proportional to the amount and proportional to the square of the distance between the point of mass application and the center of rotation.

In a turntable, the moment of inertia is increased by increasing the mass of the outer periphery, but in order to increase the mass of the outer periphery and lower the center of gravity, for example, the outer periphery is shaped to protrude downward. are commonly used.

In a record player using a turntable having such a shape, a space is formed between the back surface of the turntable and the top surface of the player board, and as the turntable rotates in this space, air vibrations are generated. .

This air vibration is also generated by the vibration of the player case and the transmission of vibration through the air, and is transmitted to the cartridge via the turntable, rubber sheet, and record, and has a negative impact on S/N characteristics and sound quality. ing.

Therefore, an object of the present invention is to provide a record player that improves S/N characteristics, sound quality, etc. by absorbing air vibrations generated in the space between the back surface of the turntable and the top surface of the player board. That's true.

The record player according to the present invention is characterized in that it has a turntable with a sound absorbing material provided on the back side through a vibration isolating material, and the vibration isolating material and the sound absorbing material absorb air vibrations generated in the space. There is.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a record player according to the present invention.

In the figure, a tone arm 1 has a cartridge 2 at its tip and a counterweight 3 at its rear end, and is rotatably supported by an arm holder 6 attached to a player case 5 via an arm base 4. has been done.

A player board 7 is firmly attached to the player case 5 with screws, etc., and a motor 9 that drives a turntable 8 is fixed to the player case 5 through a support member 10 at approximately the center of the player board 7. .

The motor 9 has its rotating shaft fitted into the center hole of the turntable 8 as a turntable shaft 11 so as to directly drive the turntable 8.

It goes without saying that the motor 9 may be directly fixed to the player case 5 and only the turntable shaft 11 may have a structure in which the player board 7 also protrudes.

A rubber sheet 13 is placed on the turntable 8 to securely hold the record disc 12 and to absorb minute vibrations of the turntable 8.

Note that 14 is a dust cover.

Further, a sound absorbing material 15 such as styrofoam, glass fiber, or rock wool is provided on the back surface of the turntable 8.

This sound absorbing material 15 is for absorbing air vibrations generated when the turntable 80 rotates in the space existing between the back surface of the turntable 8 and the upper surface of the player board 7.

Therefore, in order to absorb the air vibrations that were conventionally transmitted to the cartridge 2 via the turntable 8, rubber sheet 13, and record disc 12 before being transmitted to the turntable 8, the S/N characteristics or sound quality etc. can be improved. becomes possible.

Furthermore, as shown in FIG. 2, by providing a vibration isolating material 16 such as vibration isolating rubber between the back surface of the turntable 8 and the sound absorbing material 15, this vibration isolating material 16 prevents the turntable 8 from resonating. Therefore, the vibration generated within the space can be suppressed to a smaller level, and the vibration-proofing effect can be further improved.

Therefore, according to the record player of the present invention, the turntable has a sound absorbing material provided on the back surface through the vibration isolating material, and the vibration isolating material and the sound absorbing material allow the space between the back surface of the turntable and the player board to be Since the air vibration generated due to the rotation of the turntable is absorbed and the air vibration is not transmitted to the cartridge via the turntable, rubber sheet, and record, the S/
N characteristics or sound quality are improved.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a record player according to the present invention;
FIG. 2 is a sectional view of another embodiment of the turntable in FIG. 1. Explanation of symbols of main parts, 1...Tone arm, 2
... Cartridge, 5 ... Player case, 7 ... Player board, 8 ... Turntable, 9 ... Motor, 15 ...・・・
・Sound absorbing material, 16... Vibration isolating material.

Claims (1)

[Claims] 1. A record player characterized by having a turntable with a sound absorbing material provided on the back side through a vibration isolating material.