JPS6125044Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electronically controlled record player in which a tone arm is operated by a motor such as a linear motor.

Generally, in an electronically controlled player, a predetermined stylus pressure is set by a direct current flowing through a vertical drive motor for vertical operation of the tone arm, and horizontal balance adjustment (zero balance adjustment) of the tone arm is performed. This is accomplished by adjusting the movement of a counterweight that is movably disposed along the axial direction on the rear end side. Therefore,
When adjusting the horizontal balance of the tone arm by replacing the pick-up cartridge, first set the DC current for setting the stylus force supplied to the vertical drive motor to zero, and then move the counterweight horizontally. A balance adjustment must be made. If you adjust the horizontal balance without reducing the DC current for setting the stylus pressure to zero, you will not be able to obtain the desired stylus pressure during performance, causing problems such as distortion in the reproduced sound. .

In view of these points, the present invention provides an electronically controlled record player that allows horizontal balance adjustment to be carried out with simple operations and allows for a wide range of horizontal balance adjustment. It is something.

An embodiment of the electronically controlled record player of the present invention will be described below with reference to the drawings.

1 shows the tone arm of the record player,
It is mounted by a bearing mechanism 2 so as to be movable in vertical and horizontal directions. A pickup cartridge 7 is attached to a cartridge shell 3 provided at the tip of the tone arm 1, which is equipped with a playback needle 6 for tracing the sound groove of a record 5 placed on a turntable 4. There is.
Further, a counterweight 8 for horizontal balance adjustment is attached to the rear end of the tone arm 1 so as to be movable along the axial direction of the tone arm 1.

Also, 9 is a coil for applying needle pressure (vertical drive coil)
A vertical drive motor comprising 9a is shown for driving and operating the tone arm 1 in the vertical direction. Then, the stylus pressure is adjusted by the direct current flowing through the stylus pressure applying coil 9a. Further, a signal corresponding to the vertical operation speed of the tone arm 1 obtained by a vertical speed detector 10 having a vertical speed detection coil 10a is supplied to the vertical drive motor 9 as a control signal. Then, the reproduction needle 6 of this tone arm 1
When tracing the sound groove of the record 5, a predetermined stylus pressure is always applied to the record 5.

Further, reference numeral 11 denotes a horizontal drive motor having a horizontal drive coil 11a for horizontally driving the tone arm 1, and driving the tone arm 1 in the horizontal direction. The horizontal drive motor 11 includes a tone arm 1 which is provided with a horizontal speed detector 12 having a horizontal speed detection coil 12a.
A signal corresponding to the horizontal operation speed of the tone arm 1 is supplied as a control signal to keep the horizontal operation speed of the tone arm 1 constant.

Reference numeral 13 denotes an armrest, and a support shaft 13a of the armrest 13 is provided to pass approximately through the center of a cylindrical armrest base 15 that is fixed to the top panel 14a of the player body 14. A collar-shaped protrusion 13b for locking a spring is fixed at a predetermined position at the lower end of this support shaft 13a, and a spring 16 is disposed in a compressed state between this protrusion 13b and the armrest base 15. has been done. In this way, the armrest 13 has this support shaft 13a.
The spring 16 is rotatable around the center.
The upper end of the armrest base 15 and the armrest 1 due to being pressed vertically due to the restoring force of
3, the rotational position can be stably maintained by a predetermined frictional force between the rotational position and the rotational position.

Further, a switch operation piece 17 is disposed at the lower end of the support shaft 13a of the armrest 13 so as to protrude in parallel with the rotating surface of the earth clamper 13c of the armrest 13. Further, 18 indicates a micro switch, and 18a is an actuator of this micro switch 18. In this case, when the armrest 13 is at the normal rotational position a where the tone arm 1 can be placed, as shown in FIG. , micro switch 1
The actuator 18a of No. 8 is not pressed and the micro switch 18 remains off. On the other hand, when the rotational position of the armrest 13 is set to a position a' which is rotated 90 degrees clockwise from the position a shown in FIG. Since the operation piece 17 presses the actuator 18a of the microswitch 18, the microswitch 18 is turned on and continues to maintain this state.

The microswitch 18 is turned on and off to control the supply of power to the stylus pressure applying coil 9a.

That is, in FIG. 3, reference numeral 19 indicates a power supply terminal to which a positive DC voltage is supplied, and this power supply terminal 19 is grounded via a variable resistor 20 for voltage adjustment. is connected to the movable contact 21a of the changeover switch 21, one fixed contact 21b of this changeover switch 21 is electrically floating, and the other fixed contact of this changeover switch 21 is connected to the resistor 22, the current amplifier 23, and the needle. It is grounded through a series circuit of the pressure applying coil 9a. In this case, the drive current supplied to the stylus pressure applying coil 9a is controlled in the current amplifier 23, and when the playback stylus 6 of the tone arm 1 traces the sound groove of the record 5, a predetermined stylus pressure is applied to the record. It is being added to the list. In this case, the movable contact 21a of the changeover switch 21 is connected to one of the fixed contacts 2
1b, from the power supply terminal 19,
No drive current is supplied to the stylus pressure applying coil 9a. Further, when the movable contact 21a of the changeover switch 21 is connected to the other fixed contact 21b, a driving current is supplied from the power supply terminal 19 to the stylus pressure applying coil 9a as usual.

Further, one end of the vertical speed detection coil 10a is grounded, and the other end is connected to the input side of the current amplifier 23 via a series circuit of a current amplifier 24 and a resistor 25. The vertical operation speed detection signal obtained by the vertical speed detection coil 10a is supplied as a control signal to the stylus pressure application coil 9a. Also, the other end of this vertical speed detection coil 10a is connected to the movable contact 26a of the changeover switch 26,
One fixed contact 26b of this changeover switch 26 is grounded, and the other fixed contact 26c is electrically floating. In this case, when the movable contact 26a of the changeover switch 26 is connected to one fixed contact 26b, the other end (output end) of the vertical speed detection coil 10a is grounded, so that the vertical speed is connected to the stylus pressure applying coil 9a. No control signal is supplied from the detection coil 10a. Also, this changeover switch 26
When the movable contact 26a is connected to the other fixed contact 26c, this vertical speed detection coil 10a
The signal obtained is supplied to the stylus pressure applying coil 9a as a control signal. In addition, the other fixed contact 21c of the changeover switch 21 is connected to a resistor 27 and a current amplifier 2.
8 and the horizontal speed detection coil 11a through a series circuit. In this case, the current amplifier 28 controls the drive current supplied to the horizontal drive coil 11a to a predetermined value, so that the tone arm 1 is driven horizontally at a predetermined speed. Also, one end of the horizontal speed detection coil 12a is grounded, and the other end is connected to the current amplifier 29 and resistor 30.
It is connected to the input side of the current amplifier 28 through a series circuit of. This horizontal speed detection coil 12a
A signal obtained in the horizontal drive coil 11a is supplied as a control signal to the horizontal drive coil 11a.

Further, the power terminal 19 is connected to the movable contact 33a of the changeover switch 33 through a series circuit of the resistor 31 and the light emitting diode 32, and the changeover switch 33
One fixed contact 31b of the changeover switch 33 is grounded, and the other fixed contact 33c of the changeover switch 33 is placed in an electrically floating state. In this case, when the movable contact 33a of the changeover switch 33 is connected to one fixed contact 33b, a current flows through the light emitting diode 32, and the light emitting diode 32 emits light.
Further, when the movable contact 33a of the changeover switch 33 is connected to the other fixed contact 33b, no current flows through the light emitting diode 32.
This light emitting diode 32 does not emit light.

In addition, the power supply terminal 19 is connected to the movable contact 34a of the changeover switch 34, and one fixed contact 34b of the changeover switch 34 is used to control the operation of a system control circuit (not shown) having program control functions such as vertical and horizontal drive motors. , a control signal output terminal 35 for outputting a control signal for controlling non-operation, and the other fixed contact 34 of this changeover switch 34.
Let c be electrically floating. In this case, when the movable contact 34a of the changeover switch 34 is connected to one fixed contact 34b, a DC voltage of a predetermined value is obtained at the control signal output terminal 35. This DC voltage is then supplied as a control signal to the system control circuit to stop the operation of the system control circuit. In addition, the changeover switch 34
When the movable contact 34a is connected to the other fixed contact 34c, no predetermined DC voltage is obtained at the control signal output terminal 35, and the system control circuit described above operates normally.

In addition, the positive DC voltage supplied to the power supply terminal 19 is connected to the changeover switch 2 via the micro switch 18.
1, 26, 33 and 34 as a control signal. That is, when this micro switch 18 is in the off state, the changeover switches 21, 26, etc.
Movable contacts 21a, 26a, 33 and 34, respectively.
33a and 34a are the other fixed contacts 21
c, 26c, 33c and 34c, and when this micro switch 18 is in the on state (during horizontal balance adjustment), the movable contacts 21a of these changeover switches 21, 26, 33 and 34 , 26a, 33a, and 34a, respectively, are connected to fixed contacts 21b, 26b, 33b, and 34b.

According to this example, during normal times (other than during horizontal balance adjustment), the rotational position of the armrest 13 is maintained at a position a where the tone arm 1 can be placed, as shown in FIG. 2A. At this time, micro switch 1
8 remains off, and a drive current is supplied from the power supply terminal 19 to the stylus pressure application coil 9a, and a signal corresponding to the vertical operation speed obtained is supplied to the vertical speed detection coil 10a as a control signal. ,
When the playback stylus 6 of the tone arm 1 traces the sound groove of the record 5, a predetermined stylus pressure is applied. On the other hand, when adjusting the horizontal balance, the armrest 13 is rotated 90 degrees clockwise and its rotational position is set to the position shown in Figure 2B.
Let it be a′. At this time, the micro switch 18 is turned on and can be maintained in that state, so no drive current is supplied from the power supply terminal 19 to the stylus pressure application coil 9a, and the vertical speed detection coil 10
No control signal is supplied from a. Therefore, horizontal balance adjustment becomes possible. Note that at this time, a current flows through the light emitting diode 32, and the light emitting diode 32 emits light.

As described above, according to the present invention, if the rotational position of the armrest 13 is set to the predetermined position a', no driving current is supplied to the vertical drive motor 9. When adjusting the horizontal balance, the horizontal balance can be adjusted by simply rotating the armrest 13 to the predetermined position a'.

At this time, the direction of the armrest 13 is approximately tangential to the circumference of the record 5 as shown in FIG. It is convenient to have a wide range of

Furthermore, in this example, the light emitting diode 32 is turned on during the horizontal balance adjustment, so it is possible to visually confirm whether or not the horizontal balance adjustment is possible.

Furthermore, since the operation of the system control circuit is stopped during this horizontal balance adjustment, malfunctions can be completely prevented.

In the above-mentioned embodiment, the light emitting diode 32 continues to light up during horizontal balance adjustment, but for example, during horizontal balance adjustment, an oscillation circuit such as an astable multivibrator is driven, It is also possible to make the light emitting diode blink based on the output signal.

Furthermore, in an electronically controlled record player equipped with an electrical inside hose canceller, it is necessary to reduce the current supplied to the inside hose canceler application coil to zero during horizontal balance adjustment, but in this case as well, Micro switch 1
It is sufficient to provide a changeover switch which is controlled by 8, and to configure the changeover switch so that no current is supplied to the inside hose canceller application coil during horizontal balance adjustment.

Note that the present invention is not limited to the above-described embodiments, and it goes without saying that various other configurations may be adopted without departing from the gist of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the electronically controlled record player of the present invention, and FIGS. 2A and B
3 is a plan view showing essential parts of an embodiment of the present invention, and FIG. 3 is a connection diagram showing an example of the drive circuit of the present invention. 1 is a tone arm, 4 is a turntable, 5 is a record, 6 is a playback stylus, 7 is a pick-up cartridge, 8 is a counterweight, 9 is a vertical drive motor, 9a is a coil for applying stylus pressure, 10 is a vertical speed detection 10a is a vertical speed detection coil, 13 is an armrest, 13a is a support shaft, 13b is a protrusion, 1
5 is an armrest base, 16 is a spring, 17 is a switch operation piece, 18 is a micro switch, 18a is an actuator, 19 is a power terminal, 21, 26, 3
3 and 34 are changeover switches, 23 and 24 are current amplifiers, and 32 is a light emitting diode.

Claims (1)

[Scope of utility model registration request] In an electronically controlled record player in which the tone arm is operated by a motor, the armrest is rotatably provided, and a switch is provided that is controlled to turn on and off according to the rotational position of the armrest, so that the rotational position of the armrest can be adjusted to one position. An electronically controlled record player characterized in that when the switch is set to the 1 position, the switch is in one state so that no drive current is supplied to the motor.