JPS6055881B2 - Cartridge output muting device in record player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device in a record player that prevents unpleasant noise from being generated by cartridge output when a turntable is rotating at a speed below a predetermined speed.

Some conventional record players were equipped with a cartridge output muting device that was linked to the arm lipter, but the purpose of such a device was to eliminate the noise generated when the tip of the cartridge stylus landed on the record surface. .

Therefore, if the turntable is started with the stylus placed on the surface of the disc, unpleasant noises may occur when the tip of the cartridge stylus traces the sound groove before the turntable rotates at the specified speed. , it is useless for the generation of unpleasant noise that occurs before the turntable stops when the turntable is stopped with the needle tip down during playback.

Moreover, when used for commercial purposes, accurate "cueing" is possible.
is required, and such a mechanism linked to an arm re-lifter is not practical due to its poor precision in ``heading''. The purpose of the present invention is to eliminate the drawbacks of the conventional device as described above, and to provide a record that does not generate unpleasant noise even when the turntable is started and stopped while the stylus tip is placed on the record surface. An object of the present invention is to provide a cartridge output muting device in a player.

In order to achieve the above object, in the present invention, the cartridge output is cut off while the turntable rotation speed does not reach a predetermined value, and when it is detected that the turntable rotation speed has reached the predetermined value, the cartridge output is stopped. A means for transmitting the information and a means for cutting off the cartridge output when detecting that the power to the turntable drive motor is disconnected are provided.

FIG. 1 is a diagram showing an embodiment of the present invention.

In the figure, 1 is a turntable drive motor, 2 is a rotation speed voltage converter, 3 is a voltage comparator, 4 is a cartridge output controller, 5 is a cartridge, and 6 is an output terminal to the outside (amplifier, loudspeaker, etc.) , 7 is a reference voltage, 8 is a DC power source for driving the turntable, 9 is a turntable driving motor switch, 10 and 11 are transistors, 12 is a DC power source,
13 and 14 are capacitors, and 15 is an inductance. When the switch 9 is turned on, a voltage is applied to the base of the transistor 11, so that the transistor 11 is turned off. On the other hand, at this time,
The output of voltage comparator 3 is (because the rotation speed of the turntable is still low and the output voltage of rotation speed voltage converter 2 is low)
It is configured to provide a constant positive DC voltage, and the transistor 10 is in a conductive state. Therefore, the output of the cartridge 5 does not appear at the output terminal 6. Eventually, the rotation speed of the turntable increases, and the output voltage of the rotation speed voltage converter 2 also increases, and when its value reaches the value of the reference voltage 7, the output voltage of the voltage comparator 3 becomes zero. Along with this, the transistor 10 of the cartridge output controller 4 is turned off (since the transistor 11 is already turned off as described above), and the signal from the cartridge 5 is transmitted to the output terminal 6. It is becoming more and more common. Next, when the power switch 9 of the turntable drive motor is turned off, the base of the traverse transistor 11 is grounded, so the transistor becomes conductive, and the output of the cartridge 5 no longer appears at the output terminal 6. Note that the part that detects when the turntable rotational speed reaches a predetermined speed can be the one that has been used in the past for controlling the servo motor for driving the turntable. As explained above, according to the present invention,
This eliminates the problem of reproducing unpleasant sounds due to fluctuations in the rise of the rotational speed when starting up the turntable, and reproduction of unpleasant sounds due to fluctuations in the fall of the rotational speed from the time when the drive power is turned off until the turntable is stopped.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Turntable drive motor, 2... Rotation speed voltage converter, 3... Voltage comparator, 4... Cartridge output controller, 5... Cartridge, 6... Output terminal, 9 ...Turntable drive motor switch.

Claims (1)

[Claims] 1. In a record player, means for transmitting the cartridge output when detecting that the turntable rotational speed has increased to a predetermined speed at startup, and means for cutting off the cartridge output when detecting disconnection of the turntable drive power source. A cartridge output muting device for a record player, characterized in that: