JPS5841463A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To perform automatic reversing with a simple mechanism, by delivering the rotation of a rotor roated with a slip from the rotation of a synchronous motor to one of a pair of reel stands via a rotation delivering mechanism on an arm plate fitted to a shaking arm. CONSTITUTION:A coil housing 10 having a bearing 11 and a coil 12 is fixed to a base 8. A rotor disc 15 having a plurality of rotor magnets 16 is fixed to a capstan shaft 14 to form a synchronous motor. A rotor 17 inserted freely rotatably to a capstan shaft 14 rotates with a slip from the rotation of the rotor disc 15 in the same direction. A pinion 18 of the rotor 17 is latched to gears 22 and 23 fitted feely rotatably to a gear arm 21. The gear arm 21 is shaken on the operation mode and one of the gears 22 and 23 is interlocked with a gear of reel stand of supply or winding side. The rotation is controlled by controlling the direction and magnitude of the current to the coil 12. Thus, automatic reversing can be obtained with a simple and small sized mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording and reproducing apparatus, and more particularly to a mechanical part of an auto-reverse type cassette tape recorder using, for example, a micro cassette tape.

Recently, so-called microcassette tape recorders, which are miniaturized conventional cassette tapes, have become popular.

If such a microcassette tape recorder could be equipped with a so-called auto-reverse mechanism capable of reciprocating recording and playback, it would be possible to further expand its uses. However, since microcassettes are much smaller than conventional cassette tapes, and the tape recorder itself is also smaller, it is necessary to simplify the configuration of the auto-reverse mechanism and make it more compact.

Therefore, the main object of the present invention is to provide a magnetic recording/reproducing device having an auto-reverse mechanism that is relatively simply constructed.

To summarize this invention, a capstan shaft is provided so as to be in contact with the magnetic tape of a cassette, slip torque is extracted from the capstan shaft, and this slip torque is transmitted to either one of a pair of reel stands. The rotational force transmitting means is mounted on a swingable arm plate, and one of the pair of magnetic heads is selectively moved in accordance with the movement position of the arm plate, which moves in accordance with the rotation of the capstan shaft. The above objects and other objects and features of the present invention, which is adapted to be brought into contact with a magnetic tape, will become more apparent from the detailed description given below with reference to the drawings.

FIGS. 1 and 2 are external views showing the structure of a microcassette tape used in an embodiment of the present invention, in particular, FIG. 1 shows a plan view, and FIG. 2 shows a front view. First, number one! ! The cassette main body 1 is generally formed in the shape of a sealed case made of synthetic resin, and the magnetic tape 2 is housed inside the cassette main body 1. A magnetic tape 2 is wound around the supply tape hub 3 and is rotatably attached within the cassette body 1. A writing tape hub 4 is also attached to the cassette body 1. Two felt pads 5 are provided in the cassette body 1, and the felt pads 5 are provided in two places in the cassette body 1, and are used to attach the magnetic tape 2 to the magnetic head, which will be described later.
This is provided to maintain good contact between the magnetic head and the magnetic tape 2 by sandwiching and pressing them together. Further, a capstan hole 6 for inserting a capstan shaft is formed in the cassette body 1. Furthermore, two guide rollers 7.7 are rotatably held within the cassette body 1. This guide roller 7 is for regulating the running of the magnetic tape 2.

FIG. 3 is a vertical cross-sectional view showing the structure of a motor included in an embodiment of the present invention, and FIG.
Fig. 5 is a cross-sectional view taken along the line VI of Fig. 3.
FIG. 6 is a cross-sectional view along I-VI I, and FIGS.
The figures are views showing the mechanical parts of an embodiment of the present invention, in particular, Fig. 6 shows a state in which the motor is stopped, Fig. 7 shows a sectional view of the reel stand, and Fig. 8 shows a state in which the motor is stopped. It shows a state in which it is rotating in the normal direction, and FIG. 9 shows a state in which it is also rotating in the 1 return direction.

Next, the motor and drive mechanism will be explained with reference to FIGS. 3 to 9. First, referring to FIG. 3, a microcassette 9, that is, an assembly of the cassette body 1 or the tape guide row 57 described in FIGS. 1 and 2 above is mounted on the substrate 8. The coil housing 10 is made of an insulator such as plastic, and is integrally fixed to the substrate 8. A bearing 11 is integrally molded approximately at the center of the coil housing 10, and a coil 12 and a magnetic flux detection element 13 are provided around the bearing 11. The coil housing 10 is then fixed to the substrate 8 by screws.

A capstan portion for running the magnetic tape 2 at a constant speed is formed at one end of the capstan shaft 14.
This capstan shaft 14 is rotatably held relative to the bearing 11. Further, a rotor disk 15 and a rotor magnet 16 are coaxially and integrally fixed to the other end of the capstan shaft 14 to constitute a first rotor.

For example, a gear (not shown) is provided on the outer periphery of the rotor disk 15.
is formed so that a control signal for controlling the rotational speed can be obtained. That is, since the rotor disk 15 is made of an electromagnetic soft iron plate, its rotation speed can be detected by electromagnetic or optical methods. As shown in FIG. 5, the rotor magnet 16 is alternately magnetized with north and south poles at every mechanical angle of 4511, and the rotor disk 15 also serves as a magnetic circuit for the rotor magnet 16.

The second rotor 17 is formed into a disk shape using a material having an eddy current characteristic such as an electromagnetic soft iron plate or a material having a hysteresis characteristic such as a hard magnetic material. It also serves as a circuit. Further, the second rotor 17 is rotatably fitted to the capstan shaft 14, and a pinion 18 is fixed coaxially thereto. An attractive force due to magnetic force acts on the darkness between the rotor magnet 16 and the second circle 17. This suction force generates a frictional force at the contact portion between the end surface 141 of the stepped portion formed on the capstan shaft and the opposing end surface of the second rotor 17. The second rotor 17 includes a rotor disk 15 and a rotor magnet 16.
The first rotor 2 is rotatable individually with respect to the first rotor 2, and receives the frictional force at the end surface 141. Therefore, the rotational force of the first rotor is transferred to the rotational force of the second rotor 17 via the frictional force.

In the motor configured as described above, if the magnetic flux of the rotor magnet 16 is detected by the magnetic flux detection element 13 and a drive current is supplied to the coil 12 by the control circuit (not shown), it becomes a two-phase 81i synchronous motor, and the first The rotor rotates. The input to the coil 12 is controlled by comparing the external synchronization signal with the control ratio 8 detected by the rotor disk 15 (not shown, but detected by a known electromagnetic or optical method). , the rotation of the first rotor, that is, the capstan shaft 14, can be controlled to a desired rotation speed. In this way, it is possible to obtain synchronous rotational torque on the capstan shaft 14.

Note that when it is necessary to reverse the rotation direction, this can be done by a known method such as reversing the polarity of the magnetic flux detection element 13. ” Also, as described above, a magnetic circuit is configured by the spatial magnetic flux of the rotor magnet 16 passing through the second rotor 17. When the rotor magnet 16 rotates,
Torque in which eddy current torque, hysteresis torque, or both (the type of torque differs depending on the material of the disk constituting the second rotor 17) is generated in the second rotor 17, and the second rotor 17 Rotational torque is generated in the same direction as the rotation of the rotor magnet 16.

At the same time, the end surface 1 of the stepped portion of the capstan shaft 14 mentioned above
41 and the second rotor 17, the end surface 141
The rotational force from the first rotor is also IF! due to the vibration force generated in IF! It is added to the rotational force of the second rotor 17. In this way, the combined torque generated in the second rotor 17 can be extracted to the outside by the pinion 18 that is integrated with the second rotor 17.

In this way, the torque that can be extracted from the second rotor 17 is not utilized as a rotational force in the form of electromagnetic and mechanical losses in conventional rotors of this type. The rotational force obtained by the second rotor 17 is
Since it is possible to obtain a nearly constant torque regardless of the rotation speed, if used to drive the rotation of a magnetic tape reel, a nearly constant tape winding torque can be obtained without the need for a mechanical sliding mechanism. Stable and long-life characteristics can be obtained.

In FIG. 3, the upper substrate 19 holds the upper bearing 20 by caulking it in a constant manner. Further, the upper substrate 19 is screwed and fixed to the substrate 8 so as to be integral with it, but its illustration is omitted in No. 35A. The upper bearing 20 is configured to rotatably hold the capstan shaft 14. That is, coil housing 1
The capstan motor is configured by the assembly of pinion 18 and pinion 18, and is integrated so that it can rotate by itself. Furthermore, by holding the capstan shaft 14 by an upper bearing 20, the rotation accuracy and the capstan motor are improved. This contributes to improving the bending strength of the shaft 14.

The gear arm 21 is held so as to be able to swing around the portion of the upper base plate 19 that holds the upper bearing 20, that is, the capstan shaft 14, and its state is shown in FIG. 3 and 6, capstan shaft 1
A normal direction gear 22 and a rewinding direction gear 23 are rotatably held by gear pins 24 at two locations on both ends of the gear arm 21, which is made to be able to swing about 4. The normal direction gear 22 and the rewinding direction gear 23 are each meshed with the pinion 18.

The supply side reel stand 25 and the take-up side reel stand 26 are each rotatably held by a reel architrave 27 fixed to the substrate 8, and a sectional view thereof is shown in FIG. A reel portion 251 is provided at the tip of the supply reel stand 25 and meshes with the supply tape hub 3 to transmit rotational force.

A reel portion 261 is provided at the tip of the take-up reel stand 26 and is adapted to mesh with the take-up tape hub 4 to transmit rotational force. Further, both reel stands 25 and 26 each have a gear portion, which meshes with the normal direction gear 22 or the rewinding direction gear 23 to transmit rotational force. The gear arm 21 has a protrusion 211 at its center and engages with a notch 281 formed in the check plate 28. The check plate 28 is guided so as to be movable left and right by a guide pin 29, and can be moved left and right as the gear arm 21 swings.

As mentioned above, the capstan shaft 14 is controlled by the control circuit.
], it can be rotated in both directions, that is, in FIG. 6, clockwise (in the direction of arrow A) or counterclockwise (in the direction of arrow B) at a desired rotation speed. At this time, as mentioned above, pinion 1
8 also rotates in the same direction as the capstan shaft 14. When the pinion 18 rotates in the direction of arrow A, the gear arm 2
1 also swings in the direction of the arrow. This is two gears 2
This is due to the frictional force between the gear pin 24 and the pinion 18 and the two gears 22 and 23. If more rocking force is required, a means (
(not shown). By the way, when the capstan shaft 14 rotates in the direction of arrow A, the gear arm 21 also swings in the direction of arrow A, as described above, so that the normal direction gear 22 and one wheel of the rewind direction reel stand 26 mesh with each other. Thus, a gear train of pinion 18 - normal direction gear 22 - take-up side reel stand 26 is obtained. This state is shown in FIG. 8. When the pinion 18 rotates in the direction of the arrow B in the same manner, a gear train of the pinion 18 - the reverse direction gear - 23 - the supply side reel stand 25 is obtained, and this state is changed to IIP19. Shown in the figure.

In FIG. 8, when the capstan shaft and the pinion 18 rotate in the direction indicated by the arrow, the writing side reel stand 26 moves toward the direction indicated by the arrow C.
Rotate in the direction. Furthermore, by swinging the gear arm 21 in the direction of the arrow, the check plate 28 moves in the direction of the arrow. In FIG. 9, when the capstan shaft 14 and pinion 18 rotate in the direction of arrow B, the supply reel stand 25 rotates in the direction of arrow E. Furthermore, by swinging the gear arm 21 in the direction of arrow B, the check plate 28 moves in the direction of arrow F.

FIG. 10 is a plan view showing the magnetic tape running in the normal direction, and FIG. 11 is a plan view showing the magnetic tape running in the rewinding direction.

FIG. 10 corresponds to FIG. 8, and therefore, when the capstan shaft 14 rotates in the direction of the arrow, the writing-side reel stand 26 and the writing-side tape hub 4 that operates accordingly rotate in the direction of the arrow C. Further, FIG. 11 corresponds to FIG. 9, so when the capstan shaft 14 rotates in the direction of arrow B, the supply reel stand 25 and the supply tape hub 3 that operates accordingly rotate in the direction of arrow E. do.

3, FIG. 10, and FIG. 11, the pinch roller 30 has an outer peripheral portion made of a material such as silicone rubber, and the pinch roller 30 has an outer peripheral portion made of a material such as silicone rubber. It is rotatably held by 1. This pinch roller pin 31 is held by a pinch roller arm 32. Since the pinch roller 30 is pressed against the capstan shaft 14 by a controllable external force, the magnetic tape 2 runs at a constant speed in the direction of arrow G in FIG. You can get magnetic tape running to do it.

The normal direction erasing head 33 is for erasing recorded signals on the normal direction tracks on the magnetic tape 2. The normal direction recording/reproducing head 34 performs recording or reproduction on the normal direction track on the magnetic tape 2.

In FIG. 10, the normal direction erasing head 33 and the normal direction recording/reproducing head 34 are arranged at positions in contact with the magnetic tape 2, but this is because the pinch roller arm 30
Mechanism that operates I! 1 (not shown) and is moved by a mechanism that operates at the same time as 1 (not shown). In other words, w
In the state shown in Figure Ii10, both heads 33 and 34 come into contact with the magnetic tape 2 only when the magnetic tape is running in the normal direction during recording or reproduction. This mechanism will be explained in detail later.

Similarly, in FIG. 11, the magnetic tape 2 can run at a constant speed in the direction of arrow H, that is, the magnetic tape can run in the rewinding direction for recording or reproducing. The rewinding direction erasing head 35 is for erasing recorded signals of tracks on the magnetic tape 2 in the rewinding direction. The rewinding direction recording/reproducing head 36 is for recording or reproducing on the rewinding direction track on the magnetic tape 2.

In FIG. 11, the rewind direction erasing head 35 and the rewind direction recording/reproducing head 36 are arranged at positions where they contact the magnetic tape 2, but this is due to the mechanical part (not shown) in which the pinch roller 30 operates. ) is moved by a mechanism that operates simultaneously. Both heads 35 and 36 are designed to come into contact with the magnetic tape 2 only in the state shown in FIG. 11, that is, when the magnetic tape is running during recording or reproduction in the rewinding direction. do.

12 to 14 are plan views showing the moving mechanism of the magnetic head, and FIG. 12 shows a state in which the magnetic tape 2 is stopped, so each magnetic head is not in contact with the magnetic tape 2. This corresponds to Figure 6. FIG. 13 shows the running state of the magnetic tape 2 in the normal direction, and corresponds to FIGS. 8 and 10. The 14th factor indicates the running state of the magnetic tape 2 in the rewinding direction, and the 9th factor indicates the running state of the magnetic tape 2 in the rewinding direction.
This corresponds to FIG.

In FIG. 10, the gear arm 21 and check plate 28 are shown in FIGS. 6, 8, and 9.
This is explained in detail in the figures. That is, the capstan shaft 14 rotates in the direction of the arrow or in the direction of B (according to FIG. 6), and the check plate 28 moves in the direction of the arrow (FIG. 8) or in the direction of arrow F (FIG. 9). The head plate 37 includes a normal direction erasing head 331 a normal direction recording/reproducing head 34 . A rewinding direction recording/reproducing head 36 and a rewinding direction erasing head 35 are each provided integrally.

The head plate 37 is configured to be movable only in the direction of the arrow (■) by means of a guide portion (not shown). The normal direction check bin 38 and the rewinding direction check bin 39 are each provided at a predetermined position 1 on the head plate 37, and are arranged in a positional relationship to engage with the check plate 28. The drive arm 40 has a single-shape, and its center portion is rotatably formed by a fixed pin 41, and a drive pin 42 is provided at one end of the drive arm 40.

This drive pin 42 is engaged with a round hole formed in the head plate 37. Therefore, when the drive arm 40 is rotated in the direction of arrow J by the drive device W1 (not shown), the head plate 37 moves in the direction of arrow 1.

In FIG. 13, the magnetic tape 2 supplied by the supply tape hub 3 runs at a constant speed in the direction of arrow G as the capstan shaft 14 rotates in the direction of the arrow. At this time, the gear arm 21 also rotates in the direction of arrow A, and therefore the check plate 28 moves in the direction of arrow A. In this state, the drive arm 40
Move the head plate 37 with the arrow! When the normal direction check bin 38 is moved in this direction, the normal direction check bin 38 hits the check plate 28 and its movement is blocked.

Further, when the head plate 37 is advanced in the direction of the arrow 1, the head plate 37 rotates around the point where the normal direction check bin 37 hits the check plate 28. As a result, each of the normal direction erasing head 33 and the normal direction recording/reproducing head 34 comes into contact with the magnetic tape 2. When recording on the magnetic tape 2, the recording signal on the magnetic tape 2 is erased by the normal direction erasing head 33, and then the audio signal is recorded by the normal direction recording/reproducing head 34. Furthermore, when reproducing the recorded signal on the magnetic tape 2, the normal direction recording/reproducing head 34 reproduces the audio signal. As described above, in the magnetic recording/reproducing apparatus according to the embodiment of the present invention, the necessary magnetic head 33 is automatically adjusted according to the running direction of the magnetic tape 2.
and 34 or 35 and 36 to be brought into contact with the magnetic tape 2.

If the four magnetic heads 33, 34, 35 and 36 are in contact with the magnetic tape 2 at the same time regardless of the running direction, two unnecessary magnetic heads (in FIG. The rewind direction erasing head 35 and the rewind direction recording/reproducing head 36) adversely affect the running of the magnetic tape 2. That is, since the magnetic head contacts the magnetic tape 2 before the capstan shaft 14 contacts the magnetic tape 2, the running resistance of the magnetic tape increases. In the worst case, a situation occurs in which the magnetic tape 2 stops running. Also, when stopping magnetic tape running (when stopping recording or playback),
The pinch roller arm 32 rotates to break the contact between the capstan shaft 14 and the pinch row 530, and at the same time the head plate 37 moves in the direction opposite to the direction of arrow 1, so that the magnetic tape of the two magnetic heads 33, 34 is removed. 2, and the state shown in FIG. 12 is reached.
m can be attributed.

In FIG. 14, the capstan shaft 14 of the magnetic tape 2 supplied from the take-up tape hub 4 rotates in the direction of arrow B, so that the magnetic tape 2 runs at a constant speed in the direction of arrow H. At this time, gear arm 21 is also rotating in the direction of arrow B, and therefore check plate 28 is moving in the direction of arrow F. In this state, the drive arm 40
When the head plate 37 is moved in the direction of the arrow {circle around (2)}, the I# return direction check bin 39 hits the check plate 28 and its progress is blocked. Furthermore, when the head plate 37 moves in the direction of the arrow {circle around (2)}, the head plate 37 rotates around the point where the rewinding direction check bin 39 hits the check plate 28. As a result, only the backward erasing head 35 and the rewinding recording/reproducing head 36 come into contact with the magnetic tape 2, and the magnetic tape 2 runs at a constant speed in the direction of arrow H. That is, the magnetic head 35.3 is set in the opposite position to that shown in FIG. 13, and the necessary magnetic head 35.
6 is selected and brought into contact with the magnetic tape 2. Furthermore, when the magnetic tape 2 stops running, it is returned to the state shown in FIG. 12 described above.

In addition, although the above-mentioned embodiment explained the case where this invention was applied to a micro cassette, it goes without saying that this invention is not limited to this and can be applied to a so-called compact cassette.

As described above, according to the present invention, a capstan shaft is provided in contact with the magnetic tape of a cassette, slip torque is extracted from this capstan shaft, and rotational force is transmitted on an arm plate provided swingably. The slip torque is transmitted to either one of the pair of reel stands by a means, and the slip torque is selectively transmitted to one of the pair of magnetic heads in accordance with the movement position of the arm plate that moves in accordance with the rotation of the capstan shaft. Since one side was in contact with the magnetic tape,
The configuration can be made relatively simple, and the whole can be made smaller.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing the structure of a microcassette tape. FIG. 3 is a longitudinal sectional view showing the structure of a motor included in an embodiment of the present invention. FIG. 4 is a cross-sectional view taken along the line Vl--Vl in FIG. FIG. 5 is a cross-sectional view taken along line VII-Vll in FIG. 3. 6 to 9 are diagrams showing the mechanical parts of an embodiment of the present invention, in particular, FIG. 6 shows the motor in a stopped state, FIG. 7 shows a sectional view of the reel stand, and FIG. 9 shows a state in which the motor is rotating in the normal direction, and FIG. 9 shows a state in which the motor is also rotating in the rewinding direction. FIG. 10 is a plan view showing the magnetic tape running in the normal direction. FIG. 11 is a plan view showing the same case when traveling in the rewinding direction. 12 to 14 are diagrams showing the moving mechanism of the magnetic head. In particular, FIG. 12 shows the stopped state of the magnetic tape, and FIG. 13 shows the running state of the magnetic tape in the normal direction.
FIG. 14 shows the running state of the magnetic tape in the rewinding direction. In the figure, 2 is a magnetic tape, 12 is a coil, 13 is a magnetic flux detection element, 14 is a capstan shaft, 15 is a rotor disc, 16 is a rotor magnet, 17 is a rotor of 12, 18
21 is a gear arm, 22 is a normal direction gear, 23 is a rewinding direction gear, 25 is a supply side reel stand, 2
6 is the take-up side reel stand, 28 is the check plate, 281
30 is a notch, 30 is a pinch roller, 33 is a normal direction erasing head, 34 is a normal direction recording/reproducing head, 35 is a rewinding direction erasing head, 36 is a rewinding direction recording/reproducing head, 37 is a head plate, and 38 is a normal direction erasing head. A direction check bin, 39 is a rewinding direction check pin, 211 is a protrusion, and 281 is a notch. Representative Makoto Kuzuno (1 other person) Mei Town.弗Z-ku No. 4 ``Gento Kabuto S-kojii's/Z-tuo 15 boxes

Claims (1)

[Claims] (1) A capstan shaft that contacts the magnetic tape of a cassette, and by selecting the rotation direction of the capstan shaft,
An auto-reverse magnetic recording and reproducing device configured to run the magnetic tape in a desired direction, comprising: a motor for rotationally driving the capstan; a pair of reel stands; and a motor connected to the capstan shaft. means for extracting slip torque accompanying rotation of the capstan shaft; an arm plate provided swingably relative to the capstan shaft; and a means provided on the arm plate for extracting slip torque accompanying rotation of the capstan shaft a rotational force transmission means for transmitting rotational force based on the slip torque to either one of the pair of reel stands according to the direction; a pair of magnetic heads; and a magnetic tape sandwiched between the capstan shafts. The pair of magnetic heads are mounted so as to face each other, and one of the pair of magnetic heads is selected in accordance with the movement position of the arm plate that moves in accordance with the rotational direction of the capstan shaft. and a magnetic head mounting plate that is brought into contact with the magnetic tape. (2) The magnetic recording and reproducing device according to claim 111, wherein the means for extracting slip torque includes a pinion coaxially attached to the capstan shaft. (3) A first gear is coaxially formed on each of the pair of reel stands, and the rotational force transmission means is configured to
a pair of gears rotatably held by the arm plate and aligned with the pinion, and meshing with a gear on one of the pair of reel stands depending on the direction of rotation of the capstan shaft; The magnetic recording and reproducing I! according to claim 1, comprising a gear of 2! stomach. (4) The magnetic head mounting plate further includes a check plate that moves in the running direction of the magnetic tape in accordance with the sliding of the arm plate, and the magnetic head mounting plate engages with the moved check plate to connect the pair of magnetic tapes. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein either one of the heads is brought into contact with the magnetic tape. (5) The arm plate includes a protrusion, the check plate includes a notch that engages with the protrusion, and when the arm plate swings, the protrusion engages with the notch. 5. The magnetic recording and reproducing apparatus according to claim 4, wherein the check plate is moved in the running direction of the magnetic tape. (6) The magnetic head mounting plate has a first check whose substantially central portion is rotatable about a rotation axis and which engages with one end of the check plate when the check plate moves in one direction. 5. A magnetic recording and reproducing device according to claim 4, comprising a pin and a second check bin that engages the other end of the check plate when the check plate moves in the other direction.