JPS6238781B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reel stand drive control device for a magnetic recording/reproducing device such as a tape recorder or a microcassette recorder. The object of the present invention is to provide a reel stand drive control device with good operability by combining it with a signal processing control circuit and the like.

In tape recorders, especially in-vehicle tape recorders, operability is important, and if playback, fast-forwarding, and rewinding are performed with light operating force, for example, by remote control, the device can be made with good operability. In that case, if the operation is performed by mechanical means (manual lever), a certain amount of operating force is required and it is difficult to achieve remote control operation.

On the other hand, if the operation is performed by electrical means, it is possible to achieve remote control operation, but there is a drawback that the configuration becomes more complicated.

The present invention aims to eliminate these drawbacks, and an embodiment applied to a microcassette tape recorder will be described below with reference to the drawings.

The configuration of the reel stand drive control device in the case of auto-reverse tape running, which is an example, is shown in FIG.
and will be explained in FIG. The capstan shafts 1a, 1b are inserted into holes 2a, 2b formed on both sides of the microcassette body 2. The above capstan shafts 1a and 1b have a capstan
Flywheels 3a, 3b and capstan drive gears 4a, 4b are fixed or held, respectively. A yoke 13 is attached to the reel shafts 5a and 5b.
a, 13b and non-magnetic spacers 14a, 14
Reel driven gears 6a and 6b, which are reel driven members, are rotatably held via b. Idler gears 7a and 7b are always connected to the capstan drive gears 4a and 4b and the reel driven gears 6a and 6b so as to mesh and transmit the transmission. An endless belt 12 is stretched between the capstan flywheels 3a, 3b, a motor pulley 9 attached to a motor 8 serving as a drive source, and an intermediate pulley 11 fixed to an intermediate pulley shaft 10. The above reel shaft 5a
As shown in FIG. 2, is fixedly supported by a yoke 13a fixed in a hole of the substrate A via a non-magnetic spacer 14a. The reel driven gear 6a is rotatably held in the yoke 13a. Further, a reel stand 15 is rotatably held on the reel shaft 5a. A permanent magnet 16 which is monopole magnetized in the vertical direction is fixed to the reel stand 15 so as to face the yoke 13a with a gap therebetween. A felt 17 serving as friction means is fixed to the lower surface of the permanent magnet 16 on the reel driven gear 6a side. In addition, felt 1
7 may be fixed to the upper surface of the reel driven gear 6a, or may be interposed between the permanent magnet 16 and the reel driven gear 6a. Further, when the reel stand and the reel driven member face each other, a felt may be interposed between them. Board A has core 18
is arranged, and a coil 19 is wound around this winding core 18. This coil 19 and yoke 13a constitute an electromagnet. When a current is passed through the coil 19, a magnetic path is formed from the substrate A to the yoke 13 to the permanent magnet 16. Further, the reel shaft 5b side is similarly configured.

Next, the operation of the above embodiment will be explained with reference to FIGS. 1 to 3. The rotational force of the motor 8 is transmitted to the endless belt 12 via the motor pulley 9, causing the capstan flywheels 3a, 3b and the intermediate pulley 11 to rotate. When the capstan flywheel 3a rotates, the capstan drive gear 4a rotates, the idler gear 7a meshing with the capstan drive gear 4a rotates, and the reel driven gear 6a meshing with the idler gear 7a rotates. . Similarly, when the capstan flywheel 3b rotates, the capstan drive gear 4b
rotates, the idler gear 7b meshing with the capstan drive gear 4b rotates, and the reel driven gear 6b meshing with the idler gear 7b.
rotates. During regenerative forward rotation, as shown in FIG. 3, a current (positive current) is passed through the coil 19 on the reel shaft 5a side, which is the winding side. When current flows through the coil 19, magnetic flux is generated, and an attractive force is generated between the yoke 13, which is a magnetic material, and the permanent magnet 16. Note that even when no current is passed through the coil 19, the yoke 13
A magnetic attraction force is exerted between the magnet 16 and the permanent magnet 16, and by passing current through the coil 19, the polarity of the magnetic pole surface portion 13a of the yoke 13 is changed relative to the polarity of the opposing surface of the permanent magnet 16. The magnets are magnetized so that they have different polarities, generating an attractive force. Due to this attractive force, the permanent magnet 16 is absorbed by the yoke 13 side, and the reel stand 15 is moved by the felt 17 which is a friction means.
The reel driven gear 6a is pressed through the reel drive gear 6a, and the rotation of the reel driven gear 6a
5. Note that the rotational force of the reel stand 15 is determined by the above-mentioned pressing force and the coefficient of friction at the contact surface between the felt 17 and the reel driven gear 6a. Also, the reel shaft 5 which is the supply side at this time
The movement of the reel stand in b is the reel axis 5a during replay reversal.
Since the operation is the same as that of the reel stand 17, the operation will be explained with reference to FIG. 2, which shows the state of the reel shaft 5a at the time of reproduction reversal. As shown in FIG. 2, a current in the opposite direction to the current during regenerative normal rotation is passed through the coil 19 on the side of the reel shaft 5a, which is the supply side, and the yoke 1, which is a magnetic material,
3 and the permanent magnet 16.
(This current is called reverse current) In other words, yoke 1
The polarity of the magnetic pole surface portion 13a on the permanent magnet 16 side of No. 3 is
It is magnetized to have the same polarity as the polarity of the facing permanent magnet 16 surface, thereby generating a repulsive force. Therefore, the reel stand 15 and the felt 17 are separated from the contact surface of the reel driven gear 6a, and the rotation of the reel driven gear is not transmitted to the reel stand 15. In this case, the reel stand 15 works as a supply reel, so the repulsive force generated between the coil magnetic flux and the permanent magnet magnetic flux causes the retaining ring 20 and the reel stand 15 to
A frictional force acts between the two, and this frictional force acts as a back tension. Similarly, when reproducing and reversing, a reverse current is applied to the coil 19 on the reel shaft 5a side to separate the reel stand 15 (felt 17) from the reel driven gear 6a, and a positive current is applied to the coil on the reel shaft 5b side to reel the reel. Only the reel stand on the reel shaft 5b side, which is the reel side, is rotated. In addition, during rightward fast forwarding, the same operation as during normal playback rotation is performed, and the tape is wound even when the speed of the motor 8 is increased. Note that the actually required winding force during playback and the winding force during fast forwarding are different, and if you match the winding force during playback, the winding force during fast forwarding may be insufficient and winding may not be possible halfway through. be.
This means that if the cue function is requested,
This is even more of a problem. On the other hand, if the winding force is adjusted to the winding force during fast forwarding, slippage occurs during tape running, which adversely affects rotational unevenness during playback. Therefore, in order to make the winding force during right fast forwarding larger than the winding force during play, the current flowing through the coil 19 is increased by the coil current control means 21 during rightward fast forwarding, and the coil 19 and the permanent magnet 16 are increased. Increase the suction force generated by Therefore, the frictional force between the reel driven gear 6a and the felt 17 increases, and the winding force of the reel stand 15 increases. It should be noted that the coil current control means 21 also performs switching between the above-mentioned forward current and reverse current.
Further, when fast forwarding to the left (when rewinding), the same operation as that during reversal of reproduction is performed, and the tape is wound even when the speed of the motor 8 is increased. In this case as well, if the winding force during left fast forwarding is to be made larger than the winding force during playback, the coil current is switched in two stages by the coil current control means 21.
The coil current control means 21 will be explained with reference to FIG. The coil current control means 21 is a drive circuit 22
and a coil current control means 23. The drive circuit 22 is for switching the direction of the current flowing through the coil 19 depending on the operation signal X for feeding the tape to the right or to the left. The coil current control circuit 23 also controls the coil 19
This is for switching and supplying the magnitude of the current to be applied to the reproducing or fast-forwarding operation signal Y.

In this example, a gear part is used as the reel driven member, but if the drive system is not of a gear transmission type, the present invention is not limited to this, and a configuration in which the driven member is directly driven by an endless belt may also be used. Construction of the invention is possible.

The operation of this embodiment is controlled by logic circuit means, including playback (bidirectional), fast forwarding (bidirectional),
An operating signal for remote control operation of the stop is sent in pulses to control the reel stand drive controller.

As mentioned above, the present invention controls the transmission of rotation from the drive source to the reel stand by electrical means,
According to the present invention, the following effects can be obtained.

(a) When combined with a signal processing control circuit, operations can be easily switched by remote control, resulting in a device with good operability.

(b) Since the switching mechanism is performed by electrical means rather than mechanical means, the configuration is simple and does not require much accuracy of parts, so miniaturization is possible.

(c) The drive of the reel stand is switched by applying a positive current and a reverse current to the coil and pressing and separating the reel stand and the reel driven member, so when no current is flowing, the spring The switching operation is more reliable than when they are spaced apart.

(d) By changing the magnitude of the coil current in stages, the magnitude of the reel winding force during playback and the magnitude of the reel winding force during fast forward/rewind (right fast forward/left fast forward) can be changed. This makes it possible to improve rotational unevenness characteristics and tape winding. This is particularly effective when a function for finding the beginning of a song is required.

(e) A magnetic yoke is implanted on the substrate to which the coil is fixed, a reel driven member is rotatably supported on the yoke, and a reel shaft is implanted on the yoke via a non-magnetic spacer, A reel stand supported rotatably and axially movably on the reel shaft is prevented from coming off by a retaining ring provided on the reel shaft, and a permanent magnet fixed to the reel stand is placed face-to-face with the yoke. The overall structure can be made thin. By passing current through the coil in the forward and reverse directions, power can be transmitted and back tension can be applied.

Therefore, if the reel stand drive control device of the present invention is used particularly in an ultra-small microcassette recorder, the device can be made with good operability.

[Brief explanation of the drawing]

Fig. 1 is a schematic layout diagram of a reel stand drive control device of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, Fig. 2 is a sectional view of the main parts of the same apparatus when the reel stand is separated, and Fig. 3 is a FIG. 4 is a cross-sectional view of the main part of the device when the reel stand is pressed, and FIG. 4 is a block diagram of the main part. 5a, 5b... Reel shaft, 15... Reel stand,
8... Drive source (motor), 6a, 6b... Reel driven gear, 13... Yoke, 16... Permanent magnet, 17... Felt, 19... Coil, 21...
... Coil current control means, 22 ... Drive circuit, 23
...Coil current control circuit.

Claims (1)

[Claims] 1. A yoke that is a magnetic material embedded in a substrate, a reel driven member that is rotatably supported by this yoke and is connected to a drive source and rotationally driven, and a reel driven member that is connected to the yoke with a non-magnetic spacer interposed therebetween. a reel stand that is rotatably and movably supported in the axial direction on a reel shaft planted on the reel shaft and is prevented from coming off by a retaining ring provided on the reel shaft; a permanent magnet; a friction means disposed between the reel driven member and the reel stand or the permanent magnet and the reel driven member; a coil fixed to the substrate and forming an electromagnet together with the yoke; a coil current control means for controlling the current to the coil, and generating an attractive force and a repulsive force between the permanent magnet and the yoke by passing a forward and reverse current through the coil;
A reel stand drive control device for a magnetic recording and reproducing apparatus, characterized in that driving of the reel stand is switched by pressing or separating the reel stand and the reel driven member.