JPS5857826B2 - record player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a record player, and particularly to a record player in which an arm lifter operates when the hand is removed from the operating means, and the arm lifter does not operate while the hand is touching the operating means.
Concerning improvements to record players.

The applicant has already compared the output of a detection means that outputs an output corresponding to the rotational position of the tone arm as a tone arm drive means of a record player with the output of a setting means for setting the tone arm at an appropriate position. When the comparison outputs of the two above match (when they reach zero), the horizontal movement of the tone arm is stopped, and when the tone arm is lowered by an arm lifter or the like, the operating means of the setting means is operated. The application was filed for a record player in which the tone arm, which is automatically brought to the set position, does not lower while the player is in the setting position, and when the user releases the operating means, the arm lifter operates and the tone arm lowers. .

However, with this configuration, if you release your hand before the tone arm reaches the set position, the arm lifter will operate at that position, lowering the tone arm, and starting the performance from a position other than the set position. There is a folk book.

The present invention aims to provide a record player that eliminates the above-mentioned drawbacks, and provides a record player having a tone arm drive device that lowers the tone arm after confirming whether it is in the set position. We aim to provide the following.

An example of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 is a partial sectional view showing the appearance of one embodiment of the present invention.

In this example, the tone arm 1 has a cartridge 1-1 having a stylus tip at its tip, and a weight 1-1 at its rear.
It has 2.

Further, a horizontal drive shaft 2 of the tone arm 1 is attached near the weight 1-2 of the tone arm 1.

This horizontal drive shaft 2 is connected to a brushless morph, for example, or a rotary disk 3a fitted to the horizontal drive shaft 2, as shown in FIG. , a stator consisting of a coil 3b wound around the disc 3a is provided as a horizontal drive unit 3.

Furthermore, a disk 4 is fitted onto the horizontal drive shaft 2 of the horizontal drive unit 3,
This is made to rotate together with the rotation of the tone arm 1.

Also, with the disc 4 in between, a light emitting element 5 and light receiving elements 6, 6'
etc. will be arranged.

The disk 4 is made of a polarizing plate, and as shown in FIG. 3, there is another polarizing plate between the disk 4 and the front surfaces of the light receiving elements 6, 6' so that their polarization axes are perpendicular to each other. 7 and 7' are arranged, respectively, so that the outputs from the light receiving elements 6 and 6' can be extracted differentially.

The outputs from the light receiving elements 6, 6' vary linearly in accordance with the rotation angle of the tone arm 1 at point A of the circuit shown in FIG. 4, which will be described later.

Further, the arm lifter 8 of the tone arm 1 is moved up and down by a cam 10 attached to the shaft of a vertical drive unit 9 consisting of a motor, etc., and the upper and lower limits are detected by a switch 1.
1 and 12 respectively.

In the above configuration, the light receiving elements 6 and 6' are connected in series as shown in FIG. , the movable contact piece of the variable resistor VR1 connected to the negative input terminal (→) of the comparison amplifier circuit A1 and further connected in parallel with the series circuit of the light receiving elements 6, 61 is connected to the positive input terminal (1) of the comparison amplifier circuit A1. ).

As shown in FIG. 1, the variable resistor VR1 described above is attached to the chassis of a record player or the like via a non-conductive material 13, and the knob 14 made of a conductive material for adjusting it is
It is electrically connected to a terminal 15 through its shaft.

As described above, the comparison amplifier circuit A1 is supplied with an output corresponding to the rotational position of the tone arm 1 and an output port of the variable resistor VR1 that determines where the position of the tone arm 1 is set. A cover corresponding to the deviation between the current rotational position of the arm 1 and the set position is provided.

As shown in FIG. 1, this output cover is supplied to the motor 3, etc. as a horizontal drive section of the tone arm 1 through the second contact 11b of the switch 11 operating at the upper limit position of the arm lifter 8 and the differential amplifier circuit A3. and drive these.

On the other hand, in order to obtain an output (speed control output) corresponding to the rotational speed of the tonearm 1, the output corresponding to the rotational position of the tonearm 1 is differentiated by a differentiating circuit consisting of a capacitor C1 and a resistor R1. The output is amplified by the amplifier circuit A2 to form a speed control output, which is applied to one input terminal of the differential amplifier circuit A3.

Thereby, the error output cover applied to the differential amplifier circuit A3 is made smaller than that of the comparison amplifier circuit A1.

In this way, since the speed control output is controlled by the error output cover, the speed of the tone arm 1 becomes slower as it approaches the set position, but on the other hand, the speed of the tone arm 1 decreases as it moves away from the set position. Movement speed becomes faster.

At the set position, the error output cover is 0■ (zero volt),
Since the speed signal output also becomes O■, the tone arm 1 stops.

In the present invention, furthermore, when a person touches the adjustment knob 14 of the variable resistor VRI, a signal component such as hum is transmitted through the output terminal 15 to the positive input terminal (for example, the positive input terminal) of the differential amplifier circuit A4. In addition to 1), a small voltage (-v) is applied to the negative input terminal (→) through resistors R2 and R3.

Therefore, when a person touches the knob 14, the hum component caused by the human body as shown in E of FIG. 5 is amplified and extracted by the differential amplifier circuit A4.

Also, if you hold the knob 14 with one hand and touch the ground line 0■ of the casing etc. with the other hand, the differential amplifier circuit A4
Since negative voltage ←V is applied to both input terminals (→ and (c) through resistors R2 and R3, respectively),
When the knob 14 becomes the same potential as the ground line O■, this potential is applied to the positive input terminal (A) of the differential amplifier circuit A4, and it becomes a positive input signal with respect to the negative input terminal (→), so the differential Since the output shown in FIG. 5 H' is obtained at the output terminal of the amplifier circuit A4, a voltage difference from the ground line is applied thereto.

The output voltage H or H' of the differential amplifier circuit A4 is passed through a rectifying and smoothing circuit consisting of a diode D1, a capacitor C2, and a resistor R4 to obtain an output as shown in Fig. 6, 8', To this output or 8', gate circuit G1
to one of the input terminals.

The other input terminals of this gate circuit G1 are connected to a terminal 16 and a switch S1.
added through.

When this switch S1 is in the closed state, the tone arm 1 is electrically cued to an appropriate position.

That is, by operating the variable resistor VRI, it is possible to cue to an appropriate position on the record.

On the other hand, if the switch S1 is open, the above-mentioned operation is not performed and the tone arm 1 can be manually operated in a normal state.

The gate circuit G1 outputs an output if the signal passing through the above-mentioned switch S1 and the rectified output or to the rectified output are simultaneously received.
The output is supplied to the set terminal S of the flip-flop circuit FF to set it.

Therefore, relay RL is turned on by the output of flip-flop circuit FF (via the OR circuit described below),
Relay contact I (, L-1 falls to one side, arm lifter 8
A positive voltage is applied to terminal 1 of the vertical drive or motor 9 that drives the
7→first contact 11a of upper limit switch 11→relay contact RL-1, and arm lifter 8 is raised.

When the arm lifter 8 reaches the upper limit value, the first contact 11a of the upper limit switch 11 is set to the "1 off" state, and at the same time, the second contact 11b of the upper limit switch 11 is set to the "on" state,
The error output cover of the comparison amplifier circuit A1 is provided to the differential amplifier circuit A3.

In this state, the tone arm 1 is in a free state, and by rotating the variable resistor VRI with the knob 14, the tone arm 1 can be brought to a desired setting position.

When the tip of the cartridge of tone arm 1 is brought to the desired position, if you release knob 14 of variable resistor VR1, it will be added to the error detection circuit DET that detects that the error voltage has become zero volts. The error output cover from the comparison amplifier circuit A1 is zero volts.

If the knob 14 is touched when such an output is obtained, the output of the first gate circuit G1 and the error detection circuit D
The second gate circuit G2 to which the output of ET is supplied outputs an output, and this output is supplied to the reset terminal H of the flip-flop circuit FF via the delay circuit DEL. will be reset.

However, while the knob 14 is touched, a reset command is issued, but the gate circuit G1 and flip-flop circuit F
Relay RL is controlled by OR circuit OR to which the output of F is supplied, horizontal drive section 3 is in a state where horizontal drive is possible, and tone arm 1 can be rotated by operating knob 14.

In addition, if the knob 14 is released before the output of the error detection circuit DET that detects the coincidence signal, that is, the zero volt signal is generated, the second gate]-circuit G2 is not activated and the flip-flop The circuit FF is not released (reset) and the tone arm 1 is not lowered.

Therefore, when the error detection circuit DET always outputs an output,
That is, when the tone arm 1 is stopped, turn the knob 14 again.
You can reliably lower the tip of the tone arm to the desired position on the record board by touching it with your hand or waiting for it to stop while touching it.

In the above configuration, if the gate circuit G2 is established and then released, the flip-flop circuit FF is reset and the relay RL is released.

At this time, a negative voltage is applied to arm lifter 1 from terminal 18.
2 to the vertical drive 9 through the lower limit switch contact 12 and the relay contact RL-1, the tonearm 1 is lowered, the second contact 111) of the upper limit switch 11 is made "off", and the horizontal drive 3 The supply of position control signals to is cut off.

At this time, a small amount of current is applied to the horizontal drive unit 3 from the terminal 19 through the variable resistor VR2 to apply a force to the tone arm 1 that generates a torque in the direction opposite to the direction toward the center of the record board. As a result, it operates as an inside force canceller.

Next, the drive of the vertical drive section 9 is cut off by the lower limit switch 12 in order for the tip of the cartridge of the tone arm 1 to start playing along the tone groove of the record board.

In the embodiment of the present invention described above, when the knob 14 is released,
In the case where the tone arm 1 is lowered, it is possible to prevent the tone arm 1 from lowering, and to provide another switch so that the tone arm 1 can be lowered by operating this switch.

In addition, although the above is a case where the operation is started by touching the knob 14, a sleeve is provided coaxially with the variable resistor VRI, and this sleeve is related to the knob, and the knob and sleeve are connected to the variable resistor VR, , 1 and can be connected to the terminal 15.

As described above, according to the present invention, even while playing a record, the horizontal rotation speed of the tone arm is constantly controlled.
The cartridge's low-frequency resonance is damped, and playback is stable, with no stylus skipping caused by low-frequency noise, etc., and when you touch the knob at the end of a record playback or in the middle, the tone arm returns to its original setting position. It is also possible to automatically move to the desired position and repeat.Also, as long as you keep touching the knob, the tone arm will not descend in principle, and even if you take your hand off in the middle of operation, the tone arm will remain at the set position. Since the stylus does not descend until it has moved all the way, even if you take your hand off the knob in a place where there is no record board, the stylus tip will descend and will not cause any damage.
It has many features such as being able to perform corrections such as bringing the tone arm to a predetermined position again.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the configuration of the tone arm of the present invention, with a part of the line in cross section; FIG. 2 is a plan view showing the internal structure of the horizontal drive unit of the present invention; FIG. FIG. 4 is a plan view of the angle detection disk, FIG. 4 is a circuit diagram of the present invention, and FIGS. 5 and 6 are waveform diagrams for explaining the present invention in detail. In the figure, 1 is a tone arm, 3 is a horizontal drive section, 9 is a vertical drive section, A1 is a comparison amplifier circuit, and A4 is a differential amplifier circuit.

Claims (1)

[Claims] 1. In a record player that brings the tone arm to a predetermined position by comparing the output of the tone arm rotation angle detection means and the output of the setting means for setting the tone arm to a predetermined position, The detection means for detecting that a hand is touching the setting means controls the vertical drive unit for moving the tone arm up and down to move upward so as not to lower the tone arm, and outputs the output from the rotation angle detection means. The vertical drive section is lowered by the output of an AND gate which is supplied with the output of the error detection means for detecting the comparison output of the setting means output of the tone arm and the output taken out while the setting means is not touched. (2) A record player characterized in that the tone arm is controlled to lower f.