JPS6059655B2 - record player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a linear tracking type record player using a linear motor.

In linear tracking type record players,
During the performance of a record, the tone arm is rotated by the spiral sound groove of the record and is angularly displaced with respect to the tangential direction of the record.

When this angle of deviation exceeds a predetermined value, the tone arm is moved linearly so as to make this angle of deviation zero. Since the rotation and linear movement of the tone arm are repeated alternately, the tone arm ends up performing a reciprocal movement in the angular direction. If this movement is performed too intermittently, faithful reproduction will no longer occur. Therefore, it is desirable that this rotation and linear movement be repeated very precisely and smoothly. Further, in a type of tone arm in which the stylus pressure of the record stylus is applied using a counterweight, the axis of rotation of the arm does not coincide with the center of gravity of the tone arm.

Therefore, when the tone arm moves linearly, the tone arm receives a rotational moment and rotates. Therefore, something other than the actual deflection angle is added and detected, making linear movement even more unstable. The present invention was made in view of these problems, and it detects the deviation angle of the tone arm with respect to the tangential direction of the record, and adjusts the tone in the radial direction of the record to compensate for this angular deviation. A record player whose arm is moved in a straight line by a linear motor is provided with means for detecting the rotational speed of the tonearm, and means for braking the rotation of the tonearm based on the detection output of the detection means. The present invention relates to a record player characterized in that the tone arm can be smoothly moved in a straight line.

Therefore, according to the present invention, the rotation of the tone arm is damped by motional flexback, and the deviation angle is extremely small, allowing smooth linear movement of the tone arm. It is possible to suppress the rotational vibration of arm rotation, and in particular, it is possible to lower the low-frequency resonance peak.The present invention will be explained below with reference to the illustrated embodiments.FIG. 1 is a plan view of this record player. , the top plate 1 of this player's cabinet
A large circular opening 2 is formed in the opening 2.
A turntable 3 is arranged. The turntable 3 is rotatably supported by a spindle 4 and is configured to be rotationally driven by a motor (not shown). Furthermore, a tone arm 5 is disposed on the top plate 1 of the cabinet. This tone arm 5 is fixed to a rectangular parallelepiped case 6. This case 6 is related to the horizontal rotation axis 7, and this horizontal rotation axis 7
is configured to move linearly from side to side in FIG. Therefore, the tone arm 5 is configured to move over the record 8 on the turntable 3 while maintaining an attitude substantially tangential to the sound groove of the record 8. For this reason, the cartridge 9 attached to the tip of the tone arm 5 performs linear tracking on the record 8. Furthermore, tone arm 5
is divided into two parts by the case 6, and the tone arm 5 is fixed to the front side of the case 6. An extension 10 of the tone arm 5 is fixed to the back side of the case 6. A counterweight 11 is attached to this extension portion 10. Next, the mechanism for linearly driving the tone arm 5 will be explained with reference to FIGS. 2 to 4. The vertically disposed horizontal rotation shaft 7 passes through the sleeve 12 as shown in FIG. At the same time, it is rotatably supported by this sleeve 12 by a pair of upper and lower bearings 13.

The sleeve 12 is integrally formed with the carriage 14.
It is inserted into the through hole 16 of the boss 15. This sleeve 12 is fixed to the sleeve 12 by a set screw 17. Therefore, by warming this set screw 17, the sleeve 12 can be moved in the height direction, thereby increasing the tone. The height of arm 5 is adjusted. A carriage 14 supporting the horizontal rotating shaft 7 is supported by a pair of rails 18 and 19 so as to be movable in the longitudinal direction thereof.

That is, a pair of support plates 20 are provided on the lower surface of the gear rigid 14.
and one support block 21 are attached. A pair of support plates 20 are arranged apart from each other in the length direction of the rail 18, and each of these support plates 20 holds a slide bearing 22, and these bearings 22 are fitted into the rail 18. has been done. Further, a groove 23 is formed in the support block 21, and the rail 19 is received in this groove 23. Then, the roller 24 is placed on the support shaft 25 so as to contact the upper surface of the rail 19.
It is supported by the support block 21 by. Therefore, the carriage 14 has a pair of slide bearings 22 and rollers 2.
4, it is supported by a pair of rails 18, 19 at three points a. Note that these pair of rails 18,1
9 are held by U-shaped holding plates 26 and 27 at both longitudinal ends thereof, as shown in FIG. A linear motor 28 is disposed below the rail 18 in parallel with the rail 18, as shown in FIG.

This linear motor 28 is composed of a pair of magnets 29 that are arranged in parallel and facing each other, and a coil 30 that is arranged between these magnets 29. The magnet 29 is connected to the holding plate 2 through a mounting plate 31 which also serves as a yoke.
It is held at 6,27. Also, the coil 30 is the bobbin 3
It is wrapped in 2. This bobbin 32 is integrally formed with a protruding piece 33 that protrudes upward.
The coil 30 is connected to the support plate 20 by. Furthermore, a through hole 34 is formed in the center of the bobbin 32, and a yoke 35 passes through this through hole 34. Both ends of this yoke 35 are also held by the holding plates 26 and 27. Therefore, when current flows through the coil 30, the coil 30 receives a force in the longitudinal direction of the rail 18, and this force is transmitted to the carriage 14 via the protruding piece 33 of the bobbin 32 and the support plate 20, and thereby The carriage 14 is configured to move along rails 18 and 19. A linear movement detector 36 is disposed below the rail 19.

This detector 36 is composed of a single magnet 37 and a coil 38. The magnet 37 is held on the holding plates 26 and 27 by a mounting plate 39 which also serves as a yoke (see FIG. 2). Further, the coil 38 is wound around a bobbin 40 as shown in FIG. 3, and a projecting piece 41 of this bobbin 40 is attached to the support block 21. Further, a yoke 43 is disposed passing through the through hole 42 of the bobbin 40, and both ends of the yoke 43 are held by the holding plates 26 and 27. Therefore, carriage 1
When the coil 4 moves, the coil 38 also moves, and at this time, a current flows through the coil 38 because it interlinks with the magnetic flux formed by the magnet 37.
In this way, the linear motor 28 and the linear movement detector 36 are arranged below the rails 18 and 19, respectively, and since the motor 28 and the detector 36 are arranged apart from each other, the detector 36 is not affected by the leakage magnetic flux of the magnet 29 of the motor 28, and the noise of the linear motor 28 is not detected. Therefore, when motional feedback of the motor 28 is performed by the detector 36 as described later, the horizontal linear movement of the tone arm 5 can be performed very smoothly. Next, the mechanism for driving and detecting the vertical rotation of the tone arm 5 for raising and lowering the tone arm 5 will be described. The upper end of the horizontal rotation shaft 7 has an inverted U-shaped cross section as shown in FIG. It is fixed to the bottom of the connecting plate 44 that forms the structure.

A vertical rotating shaft 45 arranged horizontally is attached to the upwardly extending portion of the connecting plate 44, and both ends of this shaft 45 pass through the side wall of the case 6. As a result, the case 6 and the tone arm 5 fixed to the case 6 are rotatably supported by the horizontal rotation shaft 7 via the vertical rotation shaft 45. The rotation of the tone arm 5 about the shaft 45 causes the record stylus of the cartridge 9 to come into contact with or separate from the record 8. Inside the case 6, as shown in FIG. 3, a vertical rotation drive motor 46 and a vertical rotation detector 47 are arranged.

The motor 46 is arranged on the tip side of the tone arm 5 with respect to the axis of the horizontal rotation shaft 7. The motor 46 is comprised of a pair of magnets 48 (see FIG. 2) and a coil 49 disposed between these magnets 48. A pair of magnets 48 are fixed to the inner sides of opposing side walls of the case 6, respectively. Therefore, the side wall of this case 6 also serves as a yoke. Further, the coil 49 is wound around the outer circumference of a rectangular cylindrical bobbin 50, and the bobbin 50 is fixed to the connecting plate 44. And this bobbin 5
A yoke 52 is inserted into the through hole 51 at the center of 0 so as to extend vertically. The yoke 52 is fixed to the bottom of the case 6, and its upper end is in contact with the lid 53 of the case 6. The vertical rotation detector 47 also has the same configuration as the vertical rotation drive motor 46.

That is, the pair of magnets 54 of this detector 47 are fixed to the inside of the side wall of the case 6 so as to face each other. A coil 56 wound around a bobbin 55 is arranged between these magnets 54. The bobbin 55 wound with the coil 56 is fixed to the connecting plate 44. A yoke 58 vertically passes through the through hole 57 of the bobbin 55.
is fixed to the bottom of the case 6, and this yoke 5
The upper end of 8 is in contact with the lid 53. Therefore, the motor 46
When a current is applied to the coil 49, the magnet 48 receives force, and the case 6 and tone arm 5 are
Rotate around the center. Along with this rotation, a current flows through the coil 56 of the detector 47, and the vertical rotation of the tone arm 5 is detected. If the detection output of the detector 47 is fed back to the motor 46, vibrations when the tone arm 5 is raised or lowered are prevented. Next, we will discuss the horizontal rotation drive motor and the horizontal rotation detector arranged at the bottom of the horizontal rotation shaft 7. As shown in FIG. 4, a connecting plate 59 is fixed to the horizontal rotation shaft 7. .

Bobbins 60 and 61 are attached to both ends of this connecting plate 59, and coils 62 and 63 are wound around these bobbins 60 and 61, respectively. A pair of magnets 64 are arranged above and below the coil 62, and a pair of magnets 65 are arranged above and below the coil 63.
Note that these magnets 64 and 65 are arranged inside the upper and lower walls of the case 66. The case 66 is fixed to the sleeve 12 and also serves as a yoke. Additionally, a pair of yokes 6 are provided between both side walls of the case 66.
7 and 68 are arranged to extend horizontally and pass through through holes 69 and 70 of the bobbins 60 and 61, respectively. The coil 63 and magnet 65 constitute a horizontal rotation drive motor 71, and the coil 62
and the magnet 64 constitute a detector 72.

Therefore, when the horizontal rotating shaft 7 rotates due to vibration or the like, the coil 62 wound around the bobbin 60 moves, and since the coil 62 is disposed between the pair of magnets 64, This causes current to flow through the coil 62. Therefore, horizontal rotation is detected by this current. In response to the detection by the detector 72, a current is caused to flow through the coil 63 of the motor 71. When a current is passed through the coil 63, the bobbin 6 around which the coil 63 is wound
1 receives a force, this force is transmitted to the horizontal rotating shaft 7 via the connecting plate 59, and this shaft 7 is braked. Note that since the horizontal rotation drive motor 71 and the horizontal rotation detector 72 are arranged between the horizontal movement linear motor 28 and the linear movement detector 36 as shown in FIG. The drive mechanism does not become long in the height direction, and there is sufficient height adjustment allowance. That is, by loosening the setscrew 17, the case 66 housing the motor 71 and the detector 72 together with the sleeve 12 can be moved between the pair of rails 18 and 19 and below the rails 18 and 19, respectively. It can freely move in the height direction between the gaps formed between the detectors 36 (see FIG. 3). Also carriage 1
4, the center of gravity of the assembly is located between the pair of rails 18, 19, and in the plan view as shown in FIG. Since the carriage 14 is disposed inside the triangle thus formed, the horizontal movement of the carriage 14 is very stable, and moreover, the carriage 14 can be moved in a very stable manner. Le 18,1
Nothing unnatural is added to 9.

Next, a device for detecting the deflection angle of the tone arm 5 will be described. As shown in FIGS. 4 to 6, a holding plate 73 is fixed to the lower end of the horizontal rotating shaft 7. As shown in FIGS. This holding plate 73
There is a shutter 74 at the tip of the . Fixed and installed. On the other hand, a holding plate 75 is attached to the bottom of one end of the case 66 . The tip of this holding plate 75 is bent into a U-shape, and a pair of light receiving elements 76 and 77 are attached to the upper part of the tip, and a light emitting element 78 is attached to the lower part of the tip. ing. The shutter 74 is arranged between the light receiving elements 76, 77 and the light emitting element 78. Therefore, as the horizontal rotation shaft 7 rotates, the shutter 74 opens the light emitting element 78, the light receiving element 76,
77, and the amount of light received by the light receiving elements 76 and 77 changes. This allows the angle of deviation of rotation of the horizontal rotating shaft 7 to be known. Next, the mechanism for detecting the movement of the carriage 14 by gravity due to the inclination of the player will be described. As shown in FIG. Fixed location.

Both ends of this slit plate 79 are supported by arms 81 on a frame 80 held by holding plates 26 and 27. This slit plate 79 is opaque, and as shown in FIG. Transparent slit portions 82 are formed at a constant pitch.
4 is provided with an arm 83 that projects laterally, as shown in FIG. A pair of protruding pieces 84 and 85 that protrude downward are further connected to the arm 83, and a light emitting element 86 and a light receiving element 87 are supported on these protruding pieces 84 and 85, respectively. And these light emitting elements 8
The slit plate 79 is arranged between the light receiving element 6 and the light receiving element 87. Therefore, the carriage 14 is moved to the rail 1 by gravity.
8 and 19, the light emitting element 8
6 and the light receiving element 87 move relative to the slit plate 79, and the light receiving element 87 thereby generates a sinusoidal output. Next, the operation of this record player with the above configuration will be explained using automatic performance as an example. The automatic performance operation is started from a state where the tone arm 5 is in the armrest position as shown by the chain line in FIG.

When the linear motor 28 is driven by an instruction from an operating means (not shown) or a system controller, the tone arm 5 is linearly moved to the left in FIG. That is, in FIGS. 2 and 3, when current is supplied to the coil 30, the carriage 14 is moved along the rails 18 and 19 by the driving force of the linear motor 28. Moreover, this carriage 14 has a sleeve 12 and a horizontal rotation shaft 7.
Since the tone arm 5 is supported through the case 6, the tone arm 5 is linearly moved in a direction perpendicular to its length. Moreover, since the linear motor 28 is under motion feedback control by a linear movement detector 36 (see FIGS. 2 and 3), linear movement is performed smoothly.

That is, as shown in FIG. 8, the voltage of the detection output generated in the coil 38 of the linear movement detector 36 is supplied to one input terminal of an operational amplifier 88. Since the voltage applied to the coil 30 of the linear motor 28 is fed back to the other input terminal of the operational amplifier 88, the two input voltages are compared in the amplifier 88. Transistors 89 and 9 correspond to the positive or negative output of this amplifier 88.
0 selectively becomes 0N, current flows through the drive coil 30 in the forward or reverse direction, and the linear motor 28 generates a driving force such that the output of the speed detection coil 38 becomes zero. . Furthermore, as mentioned above, the linear motor 28
When the tone arm 5 is moved horizontally by the above-mentioned motion amplifier 88, in reality, a direct current bias voltage is applied to the above-mentioned one input terminal of the operational amplifier 88 in a manner superimposed on the detection output of the coil 38, and the above-mentioned motion arm 5 is moved horizontally. Eidback control is performed. This allows the tone arm to move linearly very smoothly. As the tone arm 5 moves, when the record stylus of the cartridge 9 reaches the top of the sound groove on the outermost circumference of the record 8, this is detected by a record size detecting means (not shown), and the operational amplifier 88 The DC bias voltage is no longer applied to the input, the driving of the linear motor 28 is stopped, and the tone arm 5 moves downward.

That is, current is supplied to the coil 49 of the vertical rotation drive motor 46 shown in FIGS. 2 and 3, and this motor 46
is driven. Accordingly, the case 6 supporting the magnet 48 and yoke 52 of the motor 46 rotates counterclockwise in FIG. 3 about the vertical rotation shaft 45. Along with this, the tone arm 5 fixed to the case 6 is also rotated in the same direction, and the record stylus at the tip of the arm 5 comes into contact with the record disc 8, and the record performance is started. Moreover, when the tone arm 5 vertically rotates, it is subjected to motional feedback control such that the detection output of the speed detection coil 56 of the vertical rotation detector 47 is always constant by the circuit shown in FIG. Furthermore, vertical rotation of the tone arm 5 is also performed very smoothly. Note that this circuit also has substantially the same configuration as the circuit shown in FIG. That is, as shown in FIG.
It consists of an operational amplifier 91 that compares the voltage applied to the coil 56 with the output voltage of the coil 56, and a pair of transistors 92 and 93 that are selectively turned ON by the output of the operational amplifier 91. When the tone arm 5 is vertically rotated, a DC bias voltage is superimposed on the output of the coil 56 of the detector 47, so that a constant driving force is obtained from the motor 46. Next, we will discuss the operation of the tone arm 5 while playing a record.Since the tone groove of the record 8 is formed in a spiral shape toward the center, the record needle moves toward the record 8 as the record 8 rotates. gradually move toward the center of

For this reason, the tone arm 5 rotates clockwise about the horizontal rotation axis 7 in FIG. 1, albeit by a small angle. Then, the tone arm 5 is connected to the case 6 and the horizontal rotation shaft 7.
The holding plate 73 connected via the holder also rotates in the same direction. For this purpose, the shutter 74 held at the tip of the holding plate 73 moves in the radial direction around the horizontal rotation axis 7,
It is deviated with respect to the light emitting element 78 and light receiving elements 76 and 77 shown in FIGS. 5 and 6. For this reason, the amounts of light received by the two light receiving elements 76 and 77 are not equal. When there is a difference in the amount of light received by these two light receiving elements 76, 77, an output corresponding to the difference in the amount of light received by these two light receiving elements 76, 77 is extracted from the operational amplifier 94, as shown in FIG. The output of is supplied to the one input side of the operational amplifier 88. That is, since a bias voltage is applied to one input terminal of the operational amplifier 88, the linear motor 28 is driven by this.
As a result, the tone arm 5 is moved toward the center of the record 8 via the carriage 14. That is, in this record player, when the tone arm 5 is angularly displaced due to the rotation of the record 8, this causes the light receiving elements 76, 7 to shift.
7, and along with this detection, the linear motor 2
8 moves the carriage 14 so as to eliminate the deflection angle of the tone arm 5. That is, in this record player, the tone arm 5 moves in an angular direction like an inchworm. Furthermore, in this record player, a bias voltage corresponding to the deflection angle of the tone arm 5 is applied to the above-mentioned one input terminal of the operational amplifier 88 of the drive circuit of the linear motor 28 so as to be superimposed on the output of the coil 38.

Therefore, the compensation of the deflection angle of the tone arm 5 becomes very smooth. That is, since the drive of the linear motor 28 that compensates for the deflection angle of the tone arm 5 receives motional feedback due to the detection of the coil 38, the deflection angle error is very small, and the inchworm movement in the above-mentioned angular direction is It is done finely and yet smoothly. Furthermore, since the drive circuit for compensation of the deflection angle and this motional feedback circuit are also used as those for the linear drive, the structure becomes very simple. Furthermore, in this record player, regarding the horizontal rotation of the tone arm 5, a horizontal rotation drive motor 71 and a horizontal rotation detector 72 shown in FIG.
Motional feedback control is performed by this, and thereby rotational vibration of the tone arm 5 in the horizontal direction is suppressed, and the deviation angle detection described above is performed stably. In other words, especially in a tone arm in which the stylus pressure of the record stylus is applied by the counterweight 11,
The center of gravity of the tone arm 5 is aligned with the axis of the horizontal rotating shaft 7, and is biased toward the tip side, as shown at 95 in FIG. Due to this deviation of the center of gravity, the tone arm 5 is subjected to a swinging motion when the tone arm 5 is moved horizontally. In other words, rotation about the center of gravity 95 occurs. Therefore, something other than the actual offset position is additionally detected, making the horizontal feed extremely unstable. Therefore, as shown in FIGS. 4 and 10, the detection output of the coil 62 of the detector 72 and the voltage applied to the coil 63 of the horizontal rotation drive motor 71 are compared using an operational amplifier 96. Either of the two transistors 97, 98 is selectively driven by the output.

As a result, a current in the forward or reverse direction flows through the drive coil 363, and the motor 11 generates a driving force such that the output of the detection coil 62 becomes zero. This force is the tone arm 5
The rotation of the tone arm 5 around the horizontal axis of rotation 7 is thereby braked, which eliminates the wobbling of the tone arm 5 that performs linear tracking, and enables accurate and smooth linear movement in the horizontal direction. . Further, by performing motional feedback on the horizontal rotation of the tone arm 5, low-frequency resonance of the tone arm 5 is significantly reduced, and crosstalk is also improved.

In other words, as shown in Figure 11A, if motional feedback in the horizontal rotation direction is not performed, a peak will appear in the output of the cartridge at the low resonance frequency, and a cross between the left and right channels will occur during stereo performance. The peak of the talk appears. However, if horizontal rotation motion feedback control is performed, the output of the cartridge becomes flat at the low resonant frequency, as shown in Figure 11B, and the crosstalk is also improved. The operation of preventing the tone arm 5 from moving when the tone arm 5 is at rest will be explained.

In the middle of a song or when a certain song ends, the tone arm 5 is rotated clockwise in FIG. 3 about the vertical rotation axis 45 by the vertical rotation drive motor 46 based on a command from an operating means not shown. When the record needle is rotated to , the record needle leaves the record and the record playing is interrupted. The upward movement of the tone arm 5 at this time is detected, for example, by a pair of detection means 99 and 100 shown in FIG. These detection means may be constituted by a magnet 99 and a Hall element 100, for example. When this Hall element 100 detects the up movement of the tone arm 5, the electronic switch 1
01 becomes 0FF, and the electronic switch 102 becomes 0.
Become N.

Therefore, the output of the deviation angle detector 103 is transmitted to the position servo circuit 10.
4, and the output of the position detector 105 is instead applied to the position servo circuit 104, whereby the horizontal drive linear motor 28 generates a driving force to prevent the tone arm 5 from moving. Note that this deviation angle detector 103
is composed of the shutter 7, light receiving elements 76, 77, and a light emitting element 78. Further, the position detector 105 is composed of the slit plate 79, a light emitting element 86, and a light receiving element 87. Further, the position servo circuit 104 is shown in FIG. The reason why the horizontal drive linear motor 28 is driven in accordance with the upward movement of the tone arm 5 is as follows.

That is, in a linear tracking arm using a linear motor, if the player is tilted, the tone arm 5 will drift along the rails 18 and 19. Furthermore, since the movable part of arm 5, that is, the part supported by carriage 14, is quite heavy, if a soft insulator is used to prevent howling, movement of tone arm 5 may cause the player to tilt, causing arm 5 to tilt. Trying to flow. When the tone arm 5 moves due to the tilt of the player, the light emitting element 8 attached to the carriage 14
6 and the light receiving element 87 start moving relative to the slit plate 79 (see FIG. 3).

Since the slit plate 79 has slit portions 82 formed at a constant pitch as shown in FIG. 13A, the output of the light receiving element 87 is as shown in FIG. 13B. This output is amplified by the operational amplifier 106 shown in FIG. 7, and compared with the reference voltage given by the variable resistor 107, and the amplitude is changed to form a sinusoidal waveform as shown in FIG. 13C. is obtained. The sinusoidal output of the amplifier 106 is superimposed on the output of the coil 38 and applied to one input terminal of an operational amplifier 88 shown in FIG. That is, as shown in FIG.
2, the maximum output is on the positive side, and the light receiving element 87
If the pitch is shifted, the output becomes maximum on the negative side, and if it is further shifted by 1/4 pitch with respect to the slit 82, the output becomes zero. Since this output voltage is applied as a bias voltage to the motion feedback circuit of the linear motor 28 shown in FIG. The carriage 14 comes to rest at a position where the longitudinal components of the rails 18 and 19 are balanced. That is, when the player is horizontal, the longitudinal component of the gravity applied to the carriage 14 on the rails 18 and 19 is zero, so
The tone arm 5 is Al, a2... in Fig. 14.
Equilibrium occurs at the point of...

Further, when the player is tilted upward to the right as shown in FIG. 15A, the linear motor 28 generates a force in the opposite direction and the same magnitude as the component force Wqsinθ in the length direction of the rails 18 and 19. The tone arm 5 is balanced at the points Bl, b2, . . . . Furthermore, if the record player is tilted upward to the left as shown in Figure 15B, Cl, C2...
Equilibrium occurs at the point. In this way, the tone arm 5 becomes balanced during one pitch of the slit 82, and the flow stops.
FIG. 16 is a block diagram of a modification of the stopper of the tone arm 5.

This block diagram is based on the block diagram shown in FIG.
1 and 102, it is constructed in a simplified form. According to this configuration, the servo that always makes the deflection angle of the tone arm 5 zero and the servo that stops the tone arm 5 from drifting are performed at the same time. In this case, Dl, d2..., El, e2... in Fig. 14
It is sufficient to obtain the force exceeding the peak of . from a servo system (see FIG. 8) that makes the deflection angle of the tone arm 5 zero.
If the two servos are always applied in this way, the tone arm 5 will be moved in steps at the pitch of the slits 82, but if the pitch of the slits 82 is made fine, for example, about 100 μm, the tone arm 5 will be moved in steps.
If you use the motion feedback of the linear drive to make linear movement smooth, there will be no practical problem.
There will be no effect on record playback. As described above, in this record player, when the tone arm 5 is moved up in the middle of playing a record and then paused, the tone arm 5 does not drift along the rails 18 and 19.

In other words, in the arm-up position, the tone arm 5
is stationary. Therefore, in this state, when the vertical rotation drive motor 46 is driven by a command not shown in the figure to perform an arm-down operation, the record stylus at the tip of the tone arm 5 comes into contact with the record disc 8 again, and the record playing resumes. be done. As the record is played, the tone arm 5 moves toward the center of the record 8 in the length direction of the rails 18 and 19. When the record stylus moves to the final groove position of the record disc 8 as shown by the dotted line in FIG. 1 and the record playing ends, this is detected by a sensor not shown. Upon detection by this sensor, the vertical rotation drive motor 46 is again driven, and the tone arm 5 is moved up. Thereafter, the tone arm 5 is further driven by the linear motor 28 to the right armrest position (indicated by a chain line) in FIG. As a result, the tone arm 5 is held at the armrest position and is ready for the next record performance. As described above, the present invention provides a tone arm that is linearly driven by a linear motor so as to compensate for angular deviation, and further includes tone arm rotation speed detection means and means for braking the rotation of the tone arm. By these means, motional feedback control is performed on the rotation of the tone arm.

Therefore, according to the present invention, the linear movement of the tone arm becomes extremely smooth, and rotational vibration in the rotation direction of the tone arm can be effectively prevented. Therefore, it is possible to lower the peak level of the cartridge output and crosstalk, especially at low resonance frequencies, to obtain flat characteristics, thereby enabling more faithful reproduction.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which FIG. 1 is a plan view of a record player of this embodiment, FIG. 2 is a perspective view of main parts of the tone arm drive mechanism, and FIG. A vertical cross-sectional view along lines ■~■ in the figure, Figure 4 is a ■~■ line in Figure 2.
5 is a perspective view of the main part of the tone arm deflection angle detection mechanism, FIG. 6 is a side view of the same, FIG. 7 is a perspective view of the main part of the mechanism for detecting the movement of the carriage, and FIG. The figure shows a circuit diagram of the motional feedback circuit for linear drive of the tonearm, Figure 9 is a circuit diagram of the motional feedback circuit for vertical rotation of the tonearm, and Figure 10 shows the circuit diagram of the motional feedback circuit for horizontal rotation of the tonearm. A circuit diagram of the null feedback circuit, Fig. 11A is a graph of the low-frequency resonance characteristics of a conventional record player, Fig. 11B is a graph of the low-frequency resonance characteristics of the record player of this embodiment, and Fig. 12 is a flow of the tone arm. A block diagram of the stop circuit, Fig. 13A is a front view of the slit plate, Fig. 13B is a diagram of the output waveform of the light receiving element, Fig. 13C is a diagram of the same waveform that has been amplified and changed to the reference level, and Fig. 14 is the Waveform diagram expanded from the waveform shown in Figure 13C, 1st
Figure 5A is a side view of the main part when the record player is tilted upward to the right, Figure 15B is a side view of the main part when the record player is tilted upward to the left, and Figure 16 is a side view of the main part when the record player is tilted upward to the left. FIG. 7 is a block diagram of a modified example.

Claims (1)

[Claims] 1. In a record player that detects the deviation angle of the tone arm with respect to the tangential direction of the record, and moves the tone arm linearly in the radial direction of the record using a linear motor to compensate for this angular deviation, the tone The tone arm is characterized by being provided with arm rotation speed detection means and means for braking the rotation of the tone arm based on the detection output of the detection means, thereby smoothly moving the tone arm in a straight line. record player.