JPS6120044B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tone arm brake device for stabilizing the movement of a tone arm of a record player.

2. Description of the Related Art Some conventional record players have been designed to mechanically brake the tone arm to stabilize its movement when the tone arm is lead-in or lead-out.

However, this method has various defects such as a complicated structure, high cost, and easy failure.

The present invention was invented to correct the above-mentioned defects, and it is possible to apply an electric braking force when the tone arm is moved.
It is an object of the present invention to provide a tone arm brake device that has a simple structure, is low in cost, and has fewer problems such as failure.

First, to help understand the device according to the present invention,
The overall structure of the record player will be explained from pages 3 to 19 of this specification with reference to FIGS. Refer to and explain. Further, FIG. 14 shows the features of the present invention.

Next, the overall structure of a record player will be explained. The tone arm drive mechanism in this record player includes a horizontal drive motor for leading in and leading out (returning) the tone arm, and a motor for moving the tone arm down and up. Consists of vertical drive motor. Note that the horizontal drive motor and the vertical drive motor are associated with a horizontal position detector and a vertical position detector, respectively, for detecting the horizontal and vertical positions of the tone arm. Further, the control circuit for driving the horizontal drive motor and the vertical drive motor includes a horizontal control circuit, a vertical control circuit, a system control circuit, and the like.

First, the horizontal drive motor and vertical drive motor will be explained with reference to FIGS. 1 to 4.

First, a vertical arm shaft 3 is supported on a top panel 1 of a record player via a bearing block 2 so as to be rotatable about its axis. The tone arm 4 is attached to the upper end of the arm shaft 3 via a fulcrum mechanism 5, and is configured to be freely rotatable in the horizontal direction and vertical direction (vertical direction) around a vertical axis and a horizontal axis that are orthogonal to each other. has been done. However, when the tone arm 4 rotates in the horizontal direction, the arm shaft 3 is rotated together with the tone arm 4. Furthermore, tone arm 4
A regeneration needle 8 is attached to the tip of the needle via a head shell 6 and a cartridge 7, and a weight 9 is attached to the other end.

And the horizontal drive motor 1 of this tone arm 4
1 is arranged on one side of the arm shaft 3 and is curved in an arc shape with the arm shaft 3 as the center in the horizontal plane; The coil 13 is configured to rotate integrally with the arm shaft 3 and parallel to the permanent magnet 12 inside. The permanent magnet 12 is attached via a fixed arm 14 to a mounting base 15 fixed to a part of the bearing block 2 by adhesive or the like, and the coil 13 is attached via a rotating arm 16 to a mounting base 15 fixed to a part of the bearing block 2. It is wound around a bobbin 17 fixed to a part of the arm shaft 3. The mounting base 15 is curved into an arc shape together with the permanent magnet 12 and has a substantially U-shaped cross section, and a horizontal rod 18, which is also curved in an arc shape, is installed between the rising portions at both ends of the mounting base 15. There is. The bobbin 17 is configured to be horizontally rotated along the outer periphery of the horizontal rod 18. The permanent magnet 12 is magnetized in its upper and lower thickness directions, and the magnetic flux generated therefrom is vertical, and a closed magnetic path is formed by the horizontal rod 18 and the mounting base 15. Further, the direction of the current in the coil 13 is perpendicular to the direction of the magnetic flux generated from the permanent magnet 12.

Therefore, according to this horizontal drive motor 11, by passing current through the coil 13 in the direction a or a' in FIG. Accordingly, it is possible to obtain a driving force in the b direction or b' direction in FIG.
is configured to be rotationally driven in the lead-in direction or the lead-out direction. However, in this case, the driving force is varied depending on the strength of the current flowing through the coil 13, but a constant driving force is obtained for a constant voltage.

Note that the vertical drive motor 20 of the tone arm 4 is
In principle, this motor is completely similar to the horizontal drive motor 11, but is arranged vertically. That is, a pair of permanent magnets 23 are attached by adhesive or the like in parallel to each other on the inner surface of a rectangular and vertical mounting base 22 fixed to a part of the arm shaft 3 via a rotating arm 21. It is being The permanent magnet 23 is curved in an arc shape in a vertical plane with the horizontal axis of the fulcrum mechanism 5 as the center. Further, a rectangular and horizontal mounting base 24 fixed to the tone arm 4 is disposed around the outer periphery of the mounting base 22, and is located at the center of the mounting base 22 at an intermediate position between the two permanent magnets 23. A coil 26 wound around a bobbin 25 is attached. Furthermore, this bobbin 2
5 is configured to be rotated in the vertical direction along the outer periphery of a vertical rod 27 fixed vertically to the center of the mounting base 22. Both permanent magnets 23 are magnetized in their left and right thickness directions, and the magnetic flux generated from them is horizontal, and a closed magnetic path is formed by the vertical rod 27 and the mounting base 22. The direction of the current in the coil 26 is perpendicular to the direction of the magnetic flux generated from the permanent magnets 12, and depending on the direction of the current flowing through the coil 26, the direction shown in FIG.
The tone arm driving force in the direction or c′ direction can be obtained,
The tone arm 4 is configured to be rotationally driven in the down direction or up direction by this driving force. Note that the weight 9 is attached to the tone arm 4 via the mount 24.

Next, the horizontal position detector 29 of the tone arm 4 will be explained with reference to FIGS. 2 and 5 to 8.

This horizontal position detection device 29 is a movable slit plate 3
0, a fixed slit plate 31, three sets of light emitting elements 32a, 32b, 32c such as lamps, and light receiving elements 33a, 3 such as photodiodes.
3b and 33c. The movable slit plate 30 has a substantially fan-shaped configuration and is horizontally attached to the lower end of the arm shaft 3 via a mounting plate 34. In addition, the fixed slit plate 3
1 is constituted by a fan plate having, for example, approximately 1/3 the size of the movable slit plate 30, and is arranged in parallel with, for example, very close to the lower part of the movable slit plate 30. And movable slit plate 3
0 is inserted into a horizontal slit 36 formed in the holder 35 that holds the light emitting elements 32a, 32b, 32c and the light receiving elements 33a, 33b, 33c, and the fixed slit plate 31 is inserted through this slit 36.
For example, it is attached to the inner surface of the lower side of 6 by adhesive or the like. Note that the holder 35 is attached to the mounting arm 37.
The bearing block 2 is fixedly attached to the lower end portion of the bearing block 2 through a screw.

A slit row 39 consisting of a large number of slits 38 is formed along the periphery of the movable slit plate 30 in an arc shape centered on the arm shaft 3, and at a position inside the movable slit plate 30 there is also an arm shaft. A long hole 40 having an arc shape centered at 3 is formed. Further, the fixed slit plate 31 has the slits 38 at two locations facing the slit row 39 and spaced apart in the arc direction.
Several slits 41, 42 of the same width and pitch as
Two sets of small arc-shaped slit rows 43,
44 is formed, and a slit 45 is formed at a position opposite to the elongated hole 40. However, above 2
The interval between the two slit rows 43 and 44 is approximately nλ±1/
There is a relationship of 4λ. Note that λ is the slit interval of one wavelength. The light emitting elements 32a, 32b, 32 are arranged on the upper side of the slit rows 43, 44 and the slit 45, respectively.
c is arranged, and the light receiving elements 33a, 3 are arranged on the lower side.
3b and 33c are arranged. Note that these light emitting elements 32a, 32b, 32c and light receiving element 33
a, 33b, 33c are, for example, the bearing block 2.
It is wired to a printed circuit board 46 attached to the lower end of the .

However, according to the lever horizontal position detector 29, the movable slit plate 30 is rotated in the horizontal direction together with the arm shaft 3 when the tone arm 4 is horizontally rotated, and the movable slit plate 30 and the fixed slit plate 31 at this time are rotated horizontally together with the arm shaft 3. By detecting the position relative to the tone arm 4, the horizontal position of the tone arm 4 is detected. However, in this case, the horizontal position detector 29 is configured to also be used to control the moving speed of the tone arm 4.

That is, as shown in FIG. 5, for example, when the slit 45 overlaps the elongated hole 40, light from the light emitting element 32b facing them passes through the slit 45 and the elongated hole 40 and reaches the light receiving element 33b. The light is received, and at this position, the tone arm 4 is subjected to position control and stopped. This position becomes the armrest position of the tone arm 4, and the tone arm 4 is placed on the arm rest 48 formed on the upper panel 1 as shown in FIGS. 1 and 2. Also, a record disc 50 with the tone arm 4 placed on the turntable 49 from the armrest position.
When moving horizontally to the upper position side, slit row 4
In connection with the movement of the slit row 39 with respect to 3 and 44, the light emitting elements 32a and 3 facing these
The light from 2c is intermittently received by the light receiving elements 33a, 33c, and both of the light receiving elements 33a, 33c
A frequency signal is obtained from the tone arm 4, and the speed control of the tone arm 4, etc. is performed based on this signal. At this time, both light receiving elements 33a,
The frequency signal obtained from 33c has a phase difference of nλ±1/4λ, and this phase difference is used to determine the forward or reverse direction of horizontal movement of the tone arm 4, that is, the lead-in/lead-out. It is composed of

Note that the vertical position detector 52 of the tone arm 4
As shown in FIGS. 1, 2, and 9, it is composed of, for example, a coil 53 and a rod-shaped dust core 54 that can be inserted into and taken out from the coil 53 at will. The coil 53 is inserted into an insulating tube 55 and attached vertically downward to one end of the tone arm 4, and the dust core 54 is disposed at the center of the lower side of the coil 53, and is attached to one end of the tone arm 4 in a vertical manner. 21 in a vertical manner.

This vertical position detector 52 detects the inductance of the coil 53 caused by a change in magnetic permeability of the coil 53 caused by a change in the position of the dust core 54 with respect to the coil 53 when the tone arm 4 moves in the vertical direction. The vertical position of the tone arm 4, ie, the position of the tone arm 4 such as arm down or arm up, is detected by detecting changes in the tone arm 4.

Further, as shown in FIGS. 1, 2, and 10, a track distance sensor 57 is provided at the tip of the head shell 6 near the needle tip. This inter-track sensor 57 is composed of a light emitting element 59, such as a lamp, which is attached to a holder 58 which is attached to the head shell 6 and has a substantially inverted T shape, and a light receiving element 60, such as a photodiode. When the tone arm 4 reaches the top of the record 50 during lead-in, the light from the light emitting element 59 is reflected on the record 50, and the reflected light is detected by the light receiving element 60. ing. However, in this case, the light receiving element 60 is located at the outer peripheral part 50a and the inter-track part 50b of the record 50.
and the sound groove portion 50c (the reflected light is strong in the outer circumferential portion and between songs, and the reflected light is weak in the sound groove portion). The resulting signal and the horizontal position detector 2 corresponding to the signal
The horizontal position control of the tone arm 4 is performed based on the detection signal 9. The detection position based on the reflected light is approximately the same as the position of the playback needle 8 of the cartridge 7 or a position slightly ahead of the lead-in direction of the tone arm 4.

The lead-out position of the tone arm 4 can be detected by detecting that the moving speed of the tone arm suddenly increases near the end of the record 50 where the sound groove disappears, that is, from the slit rows 43 and 44 in the horizontal position detector 29. This is done by taking advantage of the fact that the signal frequency becomes higher.

In this record player, the vertical control system of the tone arm 4 is configured to perform controls related to zero balance, application of stylus pressure, low frequency resonance control, up-down of the tone arm 4, etc.
Further, the horizontal control system of the tone arm 4 controls the lead-in and lead-out of the tone arm 4, the speed of movement of the tone arm 4 at that time, the control of the stop position, etc.

The horizontal control system of the tone arm 4 will be mainly described.

FIG. 11 is a block diagram showing the circuit configuration of the horizontal control system and the vertical control system.

First, the circuit configuration of the horizontal control system HC will be described.
It is now being supplied to Note that the counter circuit 70 does not always count the above output signals, but its counting operation is performed based on a control signal supplied from a system control circuit (hereinafter simply referred to as a system controller) SC. .

This system controller SC is, for example, a minicomputer called a microprocessor, and is configured to supply control signals to each circuit block of the horizontal control system HC and the vertical control system VC, which will be described later, based on a pre-installed program. It's summery. The D/A converter 73 converts the pulse signal supplied from the counter circuit 71 into an analog signal, and then supplies the analog signal to the position control circuit 74 at the next stage.

The position control circuit 74 is for stopping the tone arm 4 at a predetermined position, and is operated by the control signal supplied from the system controller SC and the output signal of the D/A converter 73. There is. Incidentally, when the record player is in the playing state, in other words when the tone arm 4 is on the record disc 50, the voltage level of the output signal obtained from the position control circuit 74 is approximately zero level. The horizontal drive circuit 75 drives the horizontal drive motor 11 in a lead-in direction or a lead-out direction based on output signals supplied from a position control circuit 74, a forward/reverse sorting circuit 77, and a lateral balance circuit 78, which will be described later. ing.

On the other hand, the amplifying circuit 72 is connected to the light receiving element 33 described above.
The output signals of a and 33c are amplified to a predetermined voltage level and supplied to a speed control circuit 79 at the next stage. The speed control circuit 79 is configured to control the speed of the horizontal drive motor 11 using a so-called sampling peak hold operation. Incidentally, two output signals having mutually opposite phases are obtained from this speed control circuit 79. Both of these output signals are supplied to the forward/reverse sorting circuit 77 at the next stage, and one of the output signals is also supplied to the lead-out detection circuit 80.

The forward/reverse sorting circuit 77 is configured to be able to determine the horizontal movement direction of the horizontal drive motor 11 based on a control signal supplied from the system controller SC.
The polarity of the output signal of the forward/reverse sorting circuit 77 is changed based on a control signal supplied from the system controller SC.

The lead-out detection circuit 80 detects that the play has ended based on a change in the voltage level of the output signal obtained from the speed control detection circuit 79,
It is designed to supply a readout detection signal to the system controller SC.

The forward/reverse direction malfunction prevention circuit 81 prevents the tone arm 4 from moving, for example, in the lead-in direction, when a disturbance occurs that forces the tone arm 4 to move manually or the like in the lead-out direction. Movement in the out direction can be detected. At the same time that the tone arm 4 moves in the lead-out direction, an output signal is supplied to the horizontal drive circuit 75 in order to move the tone arm 4 again in the lead-in direction. That is, when the tone arm 4 is forcibly moved in the lead-out direction, the horizontal drive motor 1
1 in the lead-in direction suddenly increases, and as a result, the horizontal drive motor 1
1's rotational torque also increases, and the tone arm 4 begins to move in the lead-in direction again.

The lateral balance circuit 78 is for compensating the lateral balance of the regeneration needle 8.
The current flowing through the horizontal drive motor 11 can be controlled by adjusting the bias voltage of the horizontal drive circuit 75.

The brake circuit 82 is for electrically applying a brake when the tone arm 4 moves in the lead-in direction or the lead-out direction. For example, the frictional resistance between the arm shaft 3 of the tone arm 4 and the bearing block 2 is extremely small. Therefore, when the horizontal drive motor 11 is energized, the tone arm 4 may move horizontally. Therefore, the horizontal drive motor 1 is connected to the brake circuit 82.
1 is supplied with a current in the opposite direction, and an electrical brake is applied to prevent the tone arm 4 from moving widely.

The sound groove identification circuit 83 determines whether the tone arm 4 is on the outer circumferential portion 50a and the inter-song portion 50b of the record 50 or not based on the voltage level of the output signal of the light receiving element 60 of the song inter-song sensor 57 described above.
The output signal is supplied to the system controller SC.

The start position control circuit 84 is connected to the light receiving element 33b.
Based on the voltage level of the output signal, it is determined whether or not the tone arm 4 is placed on the armrest 48, and the output signal is supplied to the system controller SC.

The horizontal control system HC is constructed as described above, whereas the vertical control system VC, which controls the vertical movement of the tone arm 4, is constructed as described below.

The oscillation circuit 85 is configured so that its oscillation frequency changes in response to changes in the inductance of the coil 26 described above. 86 is a frequency discrimination circuit;
Reference numeral 87 denotes a detection circuit, and the voltage level of the output signal obtained from this detection circuit 87 changes in accordance with the frequency change of the oscillation frequency. The vertical drive circuit 88 is for driving the vertical drive motor 20, and is for driving the vertical drive motor 20.
The amount of current supplied to the detector circuit 87 changes depending on the voltage level of the output signal of the detection circuit 87. Note that the output signal obtained from this vertical drive circuit 88 is supplied to the vertical drive motor 20 and also to the inside force cancellation circuit 89 at the same time.

The inside force canceling circuit 89 is for canceling the frictional force called the inside force or skating force that occurs between the sound shock of the record 50 and the stylus tip when the record is played. and a vertical drive motor 20
A current proportional to the current flowing through the horizontal drive motor 11 is supplied to the horizontal drive motor 11.

Next, details of the tone arm brake device for a record player according to the present invention will be explained with reference to FIG. Note that in the circuit diagram of FIG. 12, the effects of each circuit component such as a resistor and a capacitor on the circuit are omitted for convenience of explanation. Further, each resistor is labeled with the symbol R, and each capacitor is labeled with the symbol C.

Furthermore, in FIG. 12, earth line E is the reference line of this horizontal control system HC, and +V power supply and -V power supply are determined for this earth line E, the former being, for example, about +12V, and the latter, for example, - It is about 12V.

First, the lead-in operation of the tone arm 4 will be explained.

Regarding this lead-in, there are two ways to start, one is to start with the tone arm 4 correctly placed on the armrest 48, and the other is to start with the tone arm 4 not correctly placed on the armrest 48. However, here we will explain the start operation in the former state.

First, in the above state, turn on the start switch (not shown)
When turned on, power supply voltage is supplied to each circuit. In this case, if the tone arm 4 is correctly moved back onto the armrest 48,
The slit 45 and the long hole 40 overlap each other in a predetermined state. Therefore, the light emitted from the light emitting element 32b is received by the light receiving element 33b. Therefore, the start position control circuit 84 is supplied with a relatively high level voltage from the light receiving element 33b.

Note that the light receiving element 33b and the start position control circuit 84 are connected as shown in FIG. That is, resistors R ₁ and R ₂ are connected in series between the +V power line and the -V power line, and the light receiving element 33 is connected between the midpoint and the base of the transistor TR ₁ .
A photodiode is connected as b.
Therefore, when the photodiode 33b receives light, the base current is supplied to the transistor _TR1 .
This transistor _TR1 is turned on and its collector voltage drops. and transistor TR ₂
is a PNP transistor, so the transistor
If the collector voltage of TR ₁ decreases, the transistor
The base-emitter voltage of TR ₂ becomes high and this transistor TR ₂ is turned on.

Therefore, the collector voltage of the transistor _TR2 becomes high, so that the transistor _TR3 constituting the Schmitt circuit is turned on and the transistor _TR4 is turned off. As a result, the collector voltage of the transistor _TR4 becomes high, so the diode _D1 is turned on, and the voltage level of the output signal of the start position control circuit 84 becomes "1". That is, when the tone arm 4 is placed on the armrest 48, the voltage level of the input terminal _T1 of the system controller SC becomes "1", and the tone arm 4 is placed on the armrest 48 based on the presence or absence of this voltage. to identify whether it is placed on the

On the other hand, output signals obtained from the light receiving elements 33a and 33c are supplied to amplification circuits 71 and 72 and a counter circuit 70. The amplification circuit 71 amplifies the output signal and supplies it to the system controller SC. Further, the amplification circuit 72 amplifies the output signal and supplies it to input terminals T ₂ and T ₃ of the speed control circuit 79 shown in FIG. Next, to describe the circuit operation of the speed control circuit 79, a differentiated signal _V1 as shown in FIG. 13A is generated by a differentiating circuit composed of a capacitor _C1 and a resistor _R3 , ₁ , the transistor _TR5 is momentarily turned on every time interval t. This results in a capacitor through resistor R ₄
Since the charge stored in C ₂ is instantaneously discharged via the transistor TR ₅ every time interval t, the base voltage of the transistor TR ₆ becomes the sawtooth wave voltage V ₂ as shown in FIG. 13B. Become.

By the way, the transistor TR ₆ and the transistor TR ₇ constitute a differential amplifier. Therefore,
The base voltage Va of the transistor _TR7 is the 13th B
At the voltage level shown by the dotted line in the figure, the collector voltage of the transistor TR ₆ becomes an intermittent sawtooth wave voltage V ₃ with a phase inversion with respect to the sawtooth wave voltage V ₂ as shown in FIG. 13C. The base of the next stage PNP transistor _TR8 is this transistor.
Since it is connected to the collector of TR ₆ , the transistor TR ₈ is intermittently turned on based on the sawtooth voltage V ₃ .

Note that the collector of the transistor TR ₆ is connected to the -V power supply via the resistors R ₅ and R ₆ connected in series, and the midpoint thereof is connected to the waveform shaping circuit 79a and the resistor.
Integrating circuit 79 composed of R ₇ and capacitor C ₃
connected to b. Therefore, the voltage waveform at the midpoint between the resistors R ₅ and R ₆ becomes a pulse-like waveform V ₄ as shown in FIG. 13D by the operation of the waveform shaping circuit 79a.

On the other hand, when the input terminal _T3 is supplied with an output signal from the light receiving element 33c, based on the action of a differentiating circuit constituted by a capacitor _C4 and a resistor _R8 ,
The base voltage of transistor TR ₁₁ becomes the differentiated signal V ₅ as shown in FIG. 13F. And the collector voltage V ₆ of the transistor TR ₁₁ is the 13th G
As shown in the figure, the signal _V5 is phase-inverted. This signal V ₆ is then fed via the capacitor C ₅ to the base of the transistor TR ₁₀ . Therefore, the transistor _TR10 is turned on every time interval t in response to the rising edge of the signal _V6 .

Here, the waveform of the emitter voltage of transistor _TR10 will be described. First, from time _t0 to _t1 , the voltage level at the midpoint between resistors _R5 and _R6 becomes high, so a charging current flows through capacitor _C3 . The potential across the capacitor _C3 , in other words, the emitter voltage of the transistor _TR10 gradually increases. Transistor TR ₁₀ is therefore turned off and diode D ₂ is turned on. Therefore, at the same time that capacitor C ₃ is charged, capacitor C ₆ is also charged. However, when comparing the quantities of capacitors C ₃ and C ₆ , the capacitance value of capacitor C ₆ is smaller and the charging time is shorter. Therefore this capacitor
The potential difference across _C6 , in other words the collector voltage of transistor _TR10 , becomes high level within a short time. The potential difference across capacitor _C6 is then supplied as a bias voltage to the gate of the next stage field effect transistor, that is, FET.
FET turns on.

Then, at time _t1 , the voltage level at the midpoint between resistors _R5 and _R6 drops rapidly. At the same time, the charge charged in the capacitor _C3 is discharged to the -V power supply via the resistors _R7 and _R6 , and in synchronization with this, the base of the transistor _TR10 is charged as shown in Fig. 13G. Voltage V ₆ is supplied. When the collector voltage of the transistor _TR10 is at a higher level than its emitter voltage, the transistor _TR10 momentarily turns on in synchronization with the rising edge of the voltage _V6 . As a result, the charge stored in the capacitor _C6 is discharged to the capacitor _C3 via the transistor _TR10 .

Then the emitter voltage of transistor TR ₁₀ is
Based on the charging and discharging action of the capacitor _C3 , a voltage waveform _V7 as shown in FIG. 13E is obtained. At the rising edge of this voltage waveform _V7 , the transistor _TR9 is turned on, so that the capacitor _C3 is completely discharged. Therefore the transistor
The overall level of the emitter voltage of TR ₁₀ does not gradually increase, and this transistor TR ₉
The collector voltage of is also held at a substantially constant voltage level.

In other words, the gate voltage of the FET is held at a substantially constant voltage level, and the voltage level _V8 at the source of the FET is increased by a predetermined voltage level from -12V as shown in Figure 13H. Become. Further, the voltage level _V9 at the drain of the FET is lowered by a predetermined voltage level from +12V as shown in FIG. 13I.

In this way, two control signals with mutually different polarities are obtained from the FET forming the output stage of the speed control circuit 79. When the drain voltage level falls below +12V, the transistor _TR12 of the forward/reverse separation circuit 77 is turned on, and its collector voltage becomes high level. Further, as the voltage level of the source becomes higher than -12V, the transistor TR ₁₃ of the forward/reverse separation circuit 77
turns on.

On the other hand, when the tone arm 4 moves in the lead-in direction, the voltage level of the output signal of the α circuit ₁₀₅ becomes " ₁ " based on the control signal supplied from the system controller SC via the terminal T11, and the voltage level of the output signal of the α circuit 105 becomes "1". β circuit 10 based on the control signal supplied via
The voltage level of the output signal No. 6 becomes "0". Therefore, the transistor _TR14a is switched on based on the output signal of the α circuit 105, so that the anode of the diode _D3 is shunted to the -V power supply. Therefore, the output signal of the forward/reverse separation circuit 77 is not supplied to the drive circuit 75.

However, the transistor TR ₁₄ b is connected to the β circuit 106
It is switched to the off state based on the output signal of.
Since the transistor TR ₁₃ has already been turned on, it turns on the diode _D4 . As a result, the voltage level at the movable terminal of the variable resistor VR ₁ constituting the lateral balance circuit 78 decreases. Therefore, in the horizontal drive circuit 75, the differential amplifier composed of transistors TR ₁₅ and TR ₁₆ does not operate, and the collector voltage of transistor TR ₁₅ does not drop. Therefore, the NPN transistor TR ₁₇ is in the off state and this transistor is removed from the +V supply.
Coil 13 of horizontal drive motor 11 via TR ₁₇
The current flowing through is interrupted.

However, as the voltage level of the movable terminal of the variable resistor VR ₁ decreases, the differential amplifier composed of the NPN transistors TR ₁₈ and TR ₁₉ operates. That is, since the transistor _TR18 is turned on, its collector voltage becomes high level. This means, in other words, that the voltage level of transistor TR ₂₀ is at a high level, so that this transistor TR ₂₀ is switched on.

As a result, a current path is formed from the earth line E to the coil 13 to the transistor TR ₂₀ to the -V power supply, and a forward current _I1 flows as shown in FIG. Then, rotational torque is generated from the horizontal drive motor 11 based on the amount of forward current _I1 , and the tone arm 4 is driven to a lead-in operation.

However, the tone arm 4 is mechanically adapted to rotate with extremely low friction. Therefore, there is a possibility that the initial driving force of the horizontal drive motor 11 will cause the tone arm 4 to be moved by a wide range to the lead-in operation.
Therefore, when the output signal of the α circuit 105 becomes "1", the brake circuit 82 is operated to apply a brake to the horizontal drive motor 11.

That is, when the output signal of the α circuit 105 becomes "1", the transistor TR ₂₅ of the brake circuit 82 is turned on. As a result, the collector voltage of transistor TR ₂₅ decreases, so the NPN transistor
TR ₂₆ turns on. Note that at this time, the transistor TR ₂₈ is in an off state. Therefore, +V power →
A current path is formed from transistor TR ₂₆ → coil 13 → earth line E, and brake current I ₂ flows as shown in FIG. The polarities of forward current I ₁ and brake current I ₂ are opposite to each other,
Moreover, since the absolute value of the amount of current is |I ₁ |> |I ₂ |, the tone arm 4 is braked by this brake current I ₂ and is not moved rapidly. It will slowly move to the lead-in movement.

When the tip of the tone arm 4, which has been moved in this way for the lead-in operation, reaches above the outer periphery 50a of the record 50, the tone arm 4 is position controlled at that position and then lowered to start playing. is started.

Although a detailed explanation will be omitted during play, the transistor TR ₁₇ is turned on and the lateral balance current I ₃ flows through the coil 13, and the brake current also flows through the coil 13.
I ₂ also flows through the coil 13. Then, the transistor TR29 is turned on by the output from the inside force cancellation circuit 89, and the current I ₄ is caused to flow through the coil 13, and lateral balance and inside force cancellation are performed by the current amounts of these I ₃ , I ₂ and I ₄ . ing. Then, when the tone arm reaches the record end, a lead-out is performed.

That is, first, when the record ends and the playback needle 8 reaches the end of the tone groove, the moving speed of the tone arm 4 increases. As a result, the voltage level of the output signal obtained from speed control circuit 79 decreases. On the other hand, the first stage of the readout detection circuit 80 includes NPN transistors TR ₃₀ and TR ₃₁ forming a differential amplifier. Then, when the voltage level of the output signal of the speed control circuit 79 decreases, the transistor TR ₃₀ is turned on. Therefore, the collector voltage of the transistor TR ₃₀ becomes high, and based on this, the next stage transistor TR ₃₂ is turned on. Then, when the collector voltage of the transistor _TR32 decreases, the transistor _TR33 forming the Schmitt circuit turns on, and based on this, the transistor _TR34 turns off. Therefore, the resistor R ₁₁ connected between the emitter of the transistor TR ₃₄ and the −V power supply,
The voltage level at the midpoint of _R12 becomes -12V.

The output signal of the readout detection circuit 80 is then supplied to the input terminal _T6 of the system controller SC as shown in FIG. As a result, by the operation of the system controller SC, a control signal is first supplied to the vertical drive circuit 88, and the tone arm 4 is raised by the vertical drive motor 20.

Note that the moving speed of the tone arm 4 during play becomes faster during each song interval 50b of the record 50, and the lead-out detection circuit 8 increases each time.
0 operates as described above, and the tone arm 4 may be raised unexpectedly. So Cisco SC
A gate circuit 110 is provided at the terminal T ₇ of the counter circuit 70 , and the on/off control of the gate circuit 110 is performed in accordance with the output signal of the counter circuit 70 .
In other words, the gate circuit is turned on only when the counter circuit 70 counts the output signals 93 of the light receiving elements 33a and 33c up to the end of the record, and is normally kept off. As a result, even if the tone arm 4 moves at high speed between each song, the gate circuit is in the OFF state, so the output signal of the lead-out detection circuit 80 is not supplied to the system controller SC, and the tone arm 4 moves at a high speed between each song. There is no chance of an accidental increase in the space 50b.

After the tone arm 4 is turned up, the voltage level of the control signal supplied from the system controller SC to the α circuit and the β circuit is changed, the level of the output signal of the α circuit becomes “0”, and the level of the output signal of the β circuit becomes “0”. The level becomes "1". As a result, the transistor TR ₁₄ of the forward/reverse sorting circuit 77 is turned off, and the transistor TR ₁₅ is turned on. The voltage level of the output signal obtained from the speed control circuit 79 is supplied to the horizontal drive circuit 75 via the forward/reverse separation circuit 77. As a result, the base voltage of the transistor TR ₁₅ of the horizontal drive circuit 75 becomes high level, so that
This transistor TR ₁₅ is turned on. Then, the transistor TR ₁₇ is also turned on, and a current I ₃ as shown in FIG. 12 flows through the coil 13.
As a result, the tone arm 4 is moved in the lead-out direction, and lead-out is performed.

On the other hand, as the voltage level of the β circuit becomes "1", the transistor of the brake circuit 82
TR ₂₇ turns on. This results in a transistor
Since TR ₂₈ is also turned on, earth line E→
A current path from the coil 13 to the transistor TR ₂₆ to the power source is formed, and a brake current _I5 flows in the opposite direction to the current _I3 . The polarities of the reverse current I ₃ and the brake current I ₅ are opposite to each other, and the absolute value of the current amount is |I ₃ |> |I ₅ |, so this brake current I ₅ , the tone arm 4 will not be moved rapidly with the brake applied, but will be moved slowly.

As described above, the tone arm 4 is read out, and when the tone arm 4 approaches the armrest 48, the elongated hole 40 and the slit 45 overlap again. Therefore, the voltage level of the output signal obtained from the light receiving element 33b increases, and this change in voltage level is detected by the start position control circuit 84. and start position control circuit 8
The voltage level of the output signal No. 4 also changes, and as a result, a control signal is supplied from the system controller SC to the vertical drive circuit 88. As a result, the tone arm 4 is lowered onto the armrest 48 by the vertical drive motor 20. This is detected by the vertical position detector 52, the vertical control system VC becomes inactive, and the tone arm 4 is stopped on the armrest 48.

In the circuit diagram of FIG. 12, detailed explanations of components not directly related to the present invention, such as the position control circuit 74 and the forward/reverse direction malfunction prevention circuit 81, will be omitted.

Next, only the features of the present invention are extracted from FIG. 12, and the configuration thereof will be explained with reference to FIG. 14. That is, one end of the motor coil 13 is connected to the ground, which is an intermediate potential, and the first transistor TR ₁₇
One electrode (collector) of is connected to the other end of the coil 13. Further, the other electrode (emitter) of the first transistor is connected to the +V power supply, which is the first power supply. A second transistor that constitutes the horizontal drive circuit 75 together with the first transistor TR ₁₇
One electrode (collector) of the TR ₂₀ is connected to the other end of the coil 13, and the other electrode (emitter) is connected to a -V power source, which is a second power source. The brake circuit 82 has one electrode (collector) of the third transistor TR ₂₆ connected to the other end of the coil 13, and the other electrode (emitter) connected to the first power supply (+V).
Further, one electrode (collector) of the fourth transistor _TR28 is connected to the other end of the coil 13, and the other electrode (emitter) is connected to the second power source (-V). Note that the first and second transistors are system controllers.
The output of the SC is passed through the forward/reverse separation circuit, and the third and fourth transistors of the brake circuit are connected to the system controller.
Each is controlled as follows by the output of SC.

In other words, during lead-in of the tone arm, the second transistor is connected by the first output of the system controller SC.
TR ₂₆ turns on, forward current I ₁ is supplied to the coil 13, and at the same time, the third transistor TR ₂₆
is turned on, and the brake current I ₂ is supplied to the coil 13. Also, during readout of the tone arm, the first transistor TR ₁₇ is turned on by the second output from the system controller SC, and a current I ₃ in the opposite direction is sent to the coil 13.
At the same time, the fourth transistor TR ₂₈ is turned on and a brake current I ₅ is supplied to the coil 13.

Therefore, according to the present invention, a current in the opposite direction to the current that drives the tone arm is always supplied to the coil during lead-in and lead-out, which prevents a failure from occurring in contrast to a configuration in which a mechanical brake is applied to the tone arm. It is possible to provide a tone arm brake device that is difficult to use and highly reliable. In addition, by applying the above-mentioned brake current, it is possible to eliminate the negative effects caused by the phase delay of the servo circuit at the time of starting the motor, such as excessive movement of the tone arm and delay in stabilizing the control, and also to reduce the dynamism of the servo circuit. You can take a wide range of honey cleanses.

Furthermore, according to the present invention, since the tone arm is simultaneously driven and braked by a combination of two out of at least four transistors, only one motor coil is required, and the drive circuit is reduced accordingly. This has the advantage that not only the brake circuit but also the structure of the motor can be simplified, and in addition to being highly reliable, an inexpensive tone arm brake device can be obtained.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention,
Fig. 1 is a side view of the tone arm portion, Fig. 2 is a plan view of the same as above, Fig. 3 is a sectional view taken along the - line in Fig. 2,
Figure 4 is a sectional view taken along the - line in Figure 2, and Figure 5 is a cross-sectional view of Figure 1.
6 is a plan view showing the structure of the movable slit plate of the horizontal position detector, Fig. 7 is a plan view showing the structure of the fixed slit plate same as above, and Fig. 8 is a plan view showing the structure of the movable slit plate of the horizontal position detector. FIG. 9 is a perspective view of the vertical position detector, FIG. 10 is a perspective view of the inter-track sensor, and FIG. 11 is the vertical control system VC. and horizontal control system HC
Block diagram showing the circuit configuration of
Fig. 2 is a circuit diagram of the horizontal control system HC, Figs. 13A to 13I are waveform diagrams for explaining the circuit operation of the horizontal control system HC, and Fig. 14 is a circuit showing characteristic parts of the brake device according to the present invention. It is a diagram. In addition, in the symbols used in the drawings, 4
is a tone arm, 11 is a horizontal drive motor, 13 is a coil, 75 is a horizontal drive circuit, 77 is a forward/reverse separation circuit, 82 is a brake circuit, Sc is a system control circuit, +V is the first power supply, -V is the second power supply Power supply, TR ₁₇ is the first transistor, TR ₂₀ is the second transistor, TR ₂₆ is the third transistor,
TR ₂₈ is the fourth transistor, I ₁ , I ₂ , I ₃ , I ₄ , I ₅ are currents.

Claims (1)

[Claims] 1. A motor having a coil and driving the tone arm in a horizontal direction relative to the record surface, a forward/reverse separation circuit for separating the lead-in/lead-out direction of the tone arm, a drive circuit for the motor, and a brake circuit for the motor. and a system control circuit, the coil has one end connected to an intermediate potential point, and the drive circuit has one electrode connected to the other end of the coil and the other electrode connected to a first power source. The brake circuit includes a first transistor having one electrode connected to the other end of the coil and a second transistor having one electrode connected to the other end of the coil and the other electrode connected to a second power source. a third transistor connected to the other end and having the other electrode connected to the first power source; and a third transistor having one electrode connected to the other end of the coil and the other electrode connected to the second power source. The second and third transistors are made conductive by the first output of the system control circuit when the tone arm is lead-in, and the second and third transistors of the system control circuit are made conductive when the tone arm is lead-out. According to the output of
and a fourth transistor are made conductive, and the conduction of the second and first transistors causes currents to flow in the third and fourth transistors in a direction opposite to the direction of current flowing through the coil, respectively.
A tone arm brake device for a record player, in which a braking force is applied to the tone arm moved in a predetermined direction by supplying power to the coil through conduction of the transistor.