JPS5862860A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To exactly execute recording and reproducing operations, by making an operation of a damping mechanism of a reel base gear correspond to switching of engagement of an idler gear, and running of a magnetic tape, by a control mechanism. CONSTITUTION:A titled device is provided with a feed side reel base gear 4a and a winding side reel base gear 3a, which have been provided on the same axis as the rotary axial core of a feed side reel base 4 and a winding side reel base 3, and an idler gear 17 selectively engaged with 2 gears 4a, 3a in a state engaged with an output shaft 7a of a forward and reverse rotation driving mechanism 7. Also, this device is provided with control mechanisms 39, 38 of 2 gears 4a, 3a, and a control mechanism 40 which sets said mechanisms 39, 38 to an operation state when engagement of the idler gear 17 and 2 gears 4a, 3a is switched, and sets them to a non-operation state when a tape of a cassette installed to a device body 1 is running.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording and reproducing apparatus, and more particularly to a magnetic recording and reproducing apparatus employing a cassette housed in a magnetic tape half called a general audio cassette or a compact cassette.

As is well known, a magnetic recording/reproducing device consists of a supply side reel unit, a take-up side reel stand, which is connected to and detached from a reel installed in a cassette F, and a normal reel stand for running the magnetic tape at a constant speed in the normal direction or the rewinding direction. It is equipped with a direction capstan shaft, a rewind direction capstan shaft, and a magnetic head, among which auto-reverse types are used, for example, in car stereos. In such a magnetic recording/reproducing device, it is desirable to simplify the II configuration and achieve miniaturization of the device while maintaining reliable operation.

However, in conventional devices of this type, each reel stand and middle spindle were driven by separate drive sources, and the movement of the head toward and away from the magnetic tape was switched using a plunger. In addition to the complexity of the structure of the drive system, in the case of a slip mechanism using a felt as a means of generating rotational force for the reel stand, there is a problem with reliability due to wear of the felt. This hindered the miniaturization and price reduction of equipment. In addition, as a way to reduce the problem of the drive source, there was also a type that used a drive source that rotated in one direction and transmitted power from this drive source to the reel stand and capstan shaft using a mechanical transmission mechanism. Even with this, a complicated mechanism was used to change the rotation direction of the reel stand, etc., and it was not sufficient to simplify the structure or miniaturize the device.

This invention has been made in view of the above circumstances, and is configured to transmit the output of the forward and reverse rotation drive 1islt to the supply side reel stand and the take-up side reel stand using an idler gear, and thereby It is an object of the present invention to provide a magnetic recording/reproducing device that can simplify the WII configuration of the entire device and achieve miniaturization of the device.

Next, embodiments of the present invention will be described with reference to FIGS. 1 to 12.

Figures 1 to 4 are partially cutaway plan views for explaining each operating state of the magnetic recording/reproducing device, Figures 5 to 7 are plan views for explaining the same states, and the laB diagram is for forward and reverse. A vertical cross-sectional view of the rotational drive mechanism, No. 9 TjIli is a cross-sectional view taken along the line I-I in FIG. 8, and FIG. 10 is a cross-sectional view taken along the line I-I in FIG. 8,
Figure 11 is a characteristic diagram of the forward/reverse rotating part of 1 mm. ! FIG. 12 is a bottom view of the capstan shaft drive system.

In FIGS. 1 to 7, (1) shows the main body of the magnetic recording and reproducing apparatus, and its substrate (2) includes a take-up side reel stand (8) and a supply side reel stand (4), as in the conventional case. and each capstan shaft in the normal direction and the rewinding direction (5), (6
) are provided facing each other. In the illustrated example,
Take-up side reel stand gear (3 &) on the take-up side reel stand (3)
However, a supply reel stand gear (4&) is also integrally formed on the supply side reel stand (4) coaxially with the respective rotation axes. And these two gears (3m), (4
m), the output shaft (No. 7) of the forward/reverse rotation drive S structure (7) is arranged.

As is clear from FIGS. 8 to 10, the forward/reverse rotation drive mechanism (7) has both the functions of a J synchronous motor and an eddy current motor, and has the functions of the substrate (2). ) is attached to the back of the

That is, the insulating coil housing (8) screwed onto the substrate (2) has a bearing (9) integrally in its center,
A required number of coils and magnetic flux detection elements (6) are provided around this bearing (9) in a predetermined positional relationship. Bearing (9
) is rotatably fitted into the output shaft (7&), and a tenth rotor (ro) consisting of a rotor disk (12m) and a rotor magnet (12b) is attached to the lower end of the output shaft (7&).
is fixed. The rotor disk (12a) is composed of an electromagnetic soft iron plate, and has a gear groove (not shown) around it.

), which make it possible to detect the rotational speed by electromagnetic or optical methods and to obtain a control signal for controlling the rotational speed. Also, as is clear from Figure 10, rotor magnets)
(12k) is alternately magnetized to M and S poles at every 45 degrees of mechanical angle, and the rotor disk (12m) also serves as the magnetic circuit of this rotor magnet (12b).

The motor described above operates as a so-called synchronous motor, and detects the magnetic flux of the rotor magnet (12b) using a magnetic flux detection element αυ, and a control circuit (not shown).

), if a driving current is supplied to the coil, the 10th motor rotates. In this case, if the input of the coil noise is controlled by comparing the external synchronization signal with the control signal detected from the rotor disc (12 m) by a known method, i.e. The rotation speed of the output shaft (7&) can be controlled to a desired value. Output shaft (7&)
In order to reverse the rotation direction of the magnetic flux detecting element (6), known means such as reversing the polarity of the magnetic flux detecting element (6) is employed.

Next, on the side is the 20th ta, which is made of a material with eddy current characteristics, such as an electromagnetic soft iron plate, or a material with hysteresis characteristics, such as an electromagnetic material, in the shape of a disk. At the same time, the rotor magnet (1211) facing the 10th rotor (b) (which also serves as the magnetic circuit for the spatial magnetic flux of QtP et al.) is a pinion, and is hollowed out with plastic or the like having a low coefficient of friction. It is shaped so as to be integrated with the 20th turret, and in its center,
It has a bearing part so that it can freely rotate with respect to the output shaft (7&). It is rotatably supported in contact with an end face (7b) of the useful part formed at the center of the output shaft (7&). Therefore, an attractive force due to magnetic force acts between the pinion or the 20th rotor and the rotor magnet (12b), and this attractive force causes the 20th rotor (b) to press against the end surface of the useful part (7b). It is pressed through the pinion, and a constant frictional force is generated between the contact parts.

In other words, if a driving current is supplied to the coil to rotate the 10th motor, the 20th motor will be induced by the rotating magnetic field and rotate at the same time as the 10th motor rotates. do.

The motor described above operates as a so-called Eddy current electric motor, and when the 10th motor (B) rotates, the 20th motor (To) generates Eddy current torque or hysteresis torque, or both. The applied torque (the type of torque differs depending on the material used to rotate the 20th motor (B)) is generated, and the torque in the same direction as the rotation direction of the 10th motor is generated at the 20th motor (to). Rotational torque is generated. Moreover, since an sm force is generated between the 20th point (to) and the end surface (7b) of the useful part of the output shaft (7 &) due to magnetic attraction, the 1
The rotational torque of the 0-ta (b) is transmitted to the 20-ta (b) via the output shaft (7&).

In this way, in the 20th ta (to), the 10th ta (wealth)
A composite torque of the rotational torque in the same direction as the rotational direction of , and the rotational torque of the 10th (b) transmitted through the frictional force with the stepped portion end surface (7b) acts.

The relationship between this composite torque and the relative rotational speed is shown in FIG. Here, the relative rotational speed refers to the 10th (b) and the 2nd
It means the difference from the rotation speed of 0-ta (to).

In FIG. 11, part 1 is a torque component based on frictional force, indicating that torque is generated regardless of the relative rotational speed. Part b is a torque component electromagnetically generated at the 20th motor, and shows that the generated torque increases in proportion to the relative rotational speed. As can be seen from this, almost constant torque can be obtained from the rotational force obtained by No. 20-T (B) regardless of the number of rotations, so this torque can be applied to the reel stand (3) and It is clear that if used to drive the rotation of the rewind side reel stand (4), a more or less constant tape winding torque can be obtained.

As mentioned above, this rotational force can be taken out through the pinion) and transmitted to the take-up reel stand (8) or the supply reel stand (4), and the magnetic tape is The winding torque can be kept constant. Therefore, a rack (E) is fixed to the base plate (2) so as to face the pinion (2) in a spaced manner.

As shown in Figures 1 to 4, the slide plate (
16) is provided, and an idler gear αη is rotatably supported on this slide plate). A guide 41111 (e) is provided between the slide plate 06) and the substrate (2). Specifically, this guide machine WI (E)
, is a pair of left and right arc-shaped guide holes (1B&) formed in the slide plate 06), and this pair of guide holes (
It consists of a pair of left and right protruding pins (18b) that protrude from the substrate (2) so as to fit into the base plate (18m). This guide mechanism (E) moves the idler gear αη between the pinion and
It is useful for swinging from side to side around the center while keeping the distance between the centers constant.

That is, as shown in FIG. 1, the idler gear (b) is located at the center between the take-up side reel stand gear (5a) and the supply side reel stand gear (4a).
It is arranged so that it meshes with both the and rack (b).
From this state, move the pinion (6) in the forward direction (
When the rack is rotated counterclockwise), the idler gear (b) rotates clockwise, kicks the rack (to), and swings toward the take-up side reel stand gear (31). In this case, a guide mechanism is provided in order to allow the oscillating pinion of the idler gear αη to remain in mesh with the oscillating pinion around the idler gear αη. The same applies when rotating the pinion) in the opposite direction (clockwise). This swing of the idler gear (b) is caused by the idler gear (b) being connected to the take-up side reel stand gear (5&).
It is necessary to do this between the position where it meshes with the supply side reel stand gear (4m) and the position where it meshes with the supply side reel stand gear (4m). In that case, it is desirable to obtain the most appropriate meshing state when the idler gear (b) is located at the left and right swing limit. For this purpose, the stopper mechanism (b) and plate link
and a cam plate ψυ are provided.

The stopper mechanism (to) includes a pair of left and right protruding pieces (19m) provided on the slide plate), and a locking piece provided on the base plate (2) opposite to these protruding pieces (19&). (19b), and when the corresponding protruding piece (19m) and the locking piece (+ on 19) come into contact with each other due to the swinging of the idler gear -qη in the forward or reverse direction, This idler gear (B) is at its swing limit and is set so as to mesh with the take-up side reel stand gear (5&) or the supply side reel stand gear (4&) in the most appropriate state. In addition, the plate link is swingably supported on the board (2) by a pin at its center (pin), and a locking pin (251L) is provided at the tip of the plate link.
is a long hole (2) formed in the slide plate CL6).
675 and the plate link (675 and 5b) which are engaged in a fit-like manner are provided with a pin (to) on one side of the support part by @kibin), and the said cam plate is attached to this pin (c). ) is opposed to the first cam part of vO. This first cam part) is
In the figure, it has two cam surfaces (25 & 1° (25b)) which face each other from the side and are symmetrical to each other. When the slide plate (with the idler gear (17)) swings to the left or right, the plate link connected to the slide plate (b) via the locking pin (25m) moves around the pin). Since it swings to the right or left in ) is followed, and even after the idler gear αη is separated from the rack, its oscillation continues.

Then, the most appropriate meshing state is set by the stopper 1lIW (b).

In addition, a positioning mechanism for the idler gear qη is provided between the plate link and the board (2).

This positioning mechanism has a pair of legs of a torsion spring (26m) hooked to the pin) facing the cut-and-raised piece (26b) of the plate link from both sides, and
A fixing piece (26s) provided at the bottom protrudes between the pair of legs. This positioning machine (Wt) always urges the plate link blade in the direction of restoring it to its original state, that is, the state shown in FIG. 1, when the plate link (2) swings from side to side. Therefore, the idler gear (b) is also always biased in the direction of restoring to the neutral position shown in FIG. is provided. This pinch roller (b) - is a support shaft protruding from one substrate (2).

The swing arm (b) is attached to the fourth part via the -,
The rotational support shafts of the pinch rollers are extended to the vicinity of the surface of the substrate (2). In the swing path around the support shafts -, - of these rotation support shafts -0@4, one end and the other end (to the stopper plate) are allowed to move in and out.

That is, this stopper plate (2) is held by a guide mechanism (2) so as to be slidable left and right on the board (2), and its longitudinal center portion is held by a locking pin (2) provided at the other end of the plate link (2). It is locked. Therefore, the stopper plate slides to the left or right in conjunction with the swinging of the plate link to the right or left, and selectively moves one end or the other end into or out of the swing path. let

Next, ■ and ee indicate the braking mechanism, and the braking mechanism corresponding to the take-up side reel table ear (5 &) is the opposite (
The bent part of the letter-shaped rocking piece (58m) is supported by a support shaft (381*) protruding from the base plate (21), and this rocking Igb
A rubber brake shoe (!58o) as an actuating part is provided at one end of the piece (38m), and a seal (384) is provided at the other end, and the brake shoe (580)
A spring (58.) is interposed between the swinging piece (58m) and the base plate (z), which always urges the reel base gear (58) in pressure contact with the take-up side reel table gear (5&). Supply side reel stand gear (4
The brake II mechanism corresponding to & is arranged symmetrically with respect to the brake mechanism. That is, (59m) is the rocking piece, (
59b) is the support shaft, (396) is the brake shoe, (5
91) is Mitsu, and (59・) is Spring.

- is a control m- for switching the operating state of the brakes am and 911. This control mechanism consists of the aforementioned cam plate (2), a cam plate drive boat 11) for moving the cam plate ψ0 in and out, and a manual mechanism for manually moving the cam plate ψ in and out. Become. In the illustrated example, a manual dial is shown as a manual dial.

The cam plate (2) is disposed above the plate link (2) so as to cover the plate link (2), and is held by a guide mechanism (2) so as to be slidable left and right on the base plate (2). In addition to this cam plate (b), in addition to the above-mentioned first cam part), there is also a
), two second cam parts (45&) corresponding to (59a)
, (45b). These second cam parts (45m)
, (45b) are three valleys 1. va, n and three mountains gX
ly, z alternately, and valleys t, m
.

When the above-mentioned Mitsuko (38a) and (39d) are made to follow n, the player shoes (38o) and (39o) are moved to the take-up side reel stand by the urging force of the springs (58・) and (39・).
The gear (6&) and the supply side reel stand gear (41) are pressed into operation, and the peak 'gLx e y
+ When Mitsuko (38a) and (39a) follow s, the brake shoes (58a) and (39o) move against the bias of the springs (38@) and (59@) to each gear. (3a
), (4m) and become inactive 6 In addition, the cam play F drive 1w14υ consists of a worm (b) that is linked to a motor that can rotate in forward and reverse directions, a worm wheel that meshes with this worm, and a worm wheel that meshes with this worm. It consists of a pinion integrally provided with the worm wheel and a rack ring formed at the rear end of the cam plate (b) and meshing with the pinion.

Roughly speaking, the cam plate position detection m structure includes vertical pieces (51&), (51b), (51o) provided at the rear end of the cam plate (2) in three upper and lower stages in a predetermined positional relationship. Corresponding to these, Mitsu F sweeteners (52m), (52b), and (52o) are provided on the substrate (2). Therefore, limit switches (52m), (52b), (52a)
) will be kicked by each vertical piece (51m), (51), '(Sls), thereby each limit switch (5
2&), (52b), and (52a) are switched individually,
Along with this operation, the cam plate drive machine WI鵠υ
is started or stopped.

Next, in FIGS. 5 to 7, FIG. 5 corresponds to FIG. 1, and FIG. 7 corresponds to FIG. 4 b6. In these,
- indicates a magnetic head, - indicates this magnetic head - and the head plate on which the erasing head (■) is attached. The head plate is arranged so as to cover the upper surface of the cam plate 〇, and is moved in a direction perpendicular to the sliding direction of the cam plate on the substrate (2) by guide rollers provided at each corner of the head plate. It is configured to be able to reciprocate. Also, a spring (b) is interposed between the head plate trout and the base plate (2) to constantly bias the head plate in the backward movement direction. Roughly, there are a pair of cut and raised pieces (58 &) on the left and right sides of the front edge of the head plate.
b) and (59a) and (59b) are provided, and these cut and raised pieces (58m), (58b) and (59m),
(59b), one spring is locked from the outside. And, for this spring 11), there is one pinch roller (c).

(c) Swinging arm 90. - is provided with spring receiving pieces -, -. In addition, (58a) and (59o) are springs, 11)
Cut and raised pieces supporting n, n, s, rs, m, taI
(respectively) 9 wheels on the support shaft, middle Yapstan shaft (5),
(6) This is a through hole to prevent the rotating support shaft 1@4 of the pinch roller 1g4 from interfering with the head plate. Further, a bulge is provided in the center of the head plate, and this bulge is made to follow the fifth cam portion provided on the cam plate stem υ. This fifth cam g- has two second cam parts (45a) and (45
b) Intermediate &: A shadow is formed and an intermediate step for cueing (69
m) and a final stage section (69b) for recording and reproduction.

That's all explained here! ! 1st part 5th part (c), 2nd part
The actuation timing of each element is determined by the force parts (45&), (45b) and the fifth cam part.

In Fig. 12, capstan shaft (5) I (6)
At the lower end of the board (2) is a pulley 4 on the back side of the board (2).

While the pulleys Q and G are fixed respectively, a pulley Q is also integrally provided in the 10th pulley (B) of the forward and reverse rotation drive mechanism (TE), and the pulley Q is connected between these three pulleys 4 to (C). The transmission belt (to) is hung. □ Next, the operation will be explained.

FIGS. 1 and 5 show how the cassette 0 is attached to and removed from the main body (1) of the magnetic recording/reproducing apparatus. That is, the idler gear 〇η meshes with both the pinion (141) and the rack (115) by the action of the positioning mechanism 11#4, and the idler gear 〇η meshes with both the pinion (141) and the rack (115), and the idler gear ) is held at a neutral position where it does not mesh with any of the rotation support shafts (2) and -.Therefore, the stopper plate ()M is also held at a position where it does not protrude into the swing path of either of the rotation support shafts (2), -. Further, the cam plate ψυ is held at the backward limit by a cam plate drive mechanism (6), and its first cam portion) is cut off from the bottom part of the plate link (a).

Furthermore, Mitsuko (38a) and (39a) of the braking mechanism-9-
are made to follow the first troughs l of the second cam parts (45m) and (45b), and the bottom of the head plate is made to follow the troughs of the fifth cam part. Therefore, the brakes man and - are activated to brake the take-up reel stand (8) and the supply reel stand (4), and the head plate or the magnetic head wheel is positioned at the backward limit.

FIG. 2 shows the state after the magnetic tape cassette 0 is installed and, for example, when the magnetic tape is rapidly forwarded in the normal direction. That is, in this case, as the pinion (pinion) rotates in the direction of the arrow by starting the forward/reverse rotation drive machine 11 (7), the idler gear -αη rotates and kicks the rack (b),
That is, it is fed by the rack (b) and swings in a direction approaching the take-up side reel stand gear (5a). Along with this, the plate link () swings clockwise against the bias of the positioning machine mH, and at the same time, the cam plate drive mechanism 6 starts and the cam plate () moves forward in the direction of arrow 1. Second cam part (45m) of cam plate ψυ, (45
When the imitation element (38 revision), (391) of the braking mechanism -9- is imitated on the first peak X of b), the first vertical piece (51 m) of this cam plate ψυ is In order to kick the limit switch (52a) corresponding to , the operation of the cam plate drive machine W (6) is stopped by the position detection signal.

Along with this, Mitsuko (foundation) of Plate Link) became the first
Since the idler gear αη moves away from the rack (E) and meshes with the take-up side reel stand gear (51), it continues to rotate in this state. Therefore, the take-up side reel table gear (5&) rotates in the direction of arrow O, and the magnetic tape is rapidly fed in the normal direction.

FIGS. 6 and 6 show the state when the magnetic tape is fast-forwarded in the normal direction, then stopped at a predetermined position, and then recorded and reproduced in the normal direction.

As shown in FIGS. 4 and 7. That is, when the cam plate ψυ is advanced by starting the cam plate drive mechanism (b), the brake *n is activated as shown in FIG.

- Mitsuko (58a) and (39a) are the second cam g (45a)
), (45b) and enter the operating state, the fast-forward rotation of the take-up reel stand (3) and the supply side reel stand (4) is stopped, and the cam continues to move. Plate 〇 moves forward, and as shown in Fig. 5, the above-mentioned Jinko (58a) and (39d) are made to follow the second peaks y of its second cam portions (45m, ) and (45b). The braking condition will be released. The cam platen υ continues to advance further after that, and as shown in FIGS.
5b) is made to imitate the fifth peak 2. Cam plate in this state? The υ position is the fifth limit switch (52o)
and the corresponding vertical piece (51e),
In response to the detection signal, the operation of the cam plate drive aim (b) is stopped, and the advancement of the cam platen υ is also stopped. This state [11'G;! The braking state for the take-up side reel stand gear (51) and the supply side reel stand gear (4&) is released.

On the other hand, during the above-mentioned series of extensions, the bottom of the head 6 plate is sequentially made to follow the final step (69b) of the fifth cam portion via the intermediate step (69&). Therefore, the magnetic head as well as the head plate are shown in Figures 6 and 7.
The head plate moves forward as shown by the arrow in the figure, and the magnetic head comes into contact with the magnetic tape.
As the head plate moves forward, the force of the spring provided on the head plate is applied to the pinch roller swing arm QO1.
energize the pinch roller ) and - while it is in contact with the spring receiver piece -1- of ). In this case, the support shaft () moves together with the head plate while being locked to one end edge of the square hole, but at this time, the rotating support shaft - swings in the unwinding direction pinch roller. One end of the stopper placee protrudes into the path and engages with its support shaft. ) It is blocked before it comes into contact with CEE.

Therefore, when the head play (b) reaches its travel limit, only the normal direction pinch roller (b) is elastically pressed against the capstan shaft (5). This state is shown in FIGS. 4 and 7. It will be done.

In the states shown in FIGS. 4 and 7, the magnetic tape is fed in the normal direction according to the rotational speed of the capstan shaft (5), and the take-up reel stand (8) and the supply reel stand (4) are The magnetic tape is rotated at the same speed as the winding speed and the unwinding speed, and the winding torque at that time is constant.

That is, the output of the forward/reverse rotation drive mechanism (7) taken out by the pinion Cl41 is the aforementioned composite torque, and this is because it is always constant as long as the rotational speed of the 10-th gear is constant.

Above, we have explained the case where the magnetic tape is fast forwarded in the normal direction and then steadily fed in the same direction. However, in this magnetic recording and reproducing device, there are fast forwarding in the normal direction, steady forwarding and stopping, and four return directions. Rapid forwarding, steady forwarding and stopping, is it magnetic? The beginning of the rad, etc. is performed in an arbitrary order. Therefore, as a countermeasure against this, it is desirable to adopt a structure in which, when moving from one operation to the next, the cam plate is temporarily returned to the retraction limit as shown in FIGS. 1 and 5. Although such a configuration can be easily adopted by using a micro combinator, for example, it is also necessary to take out the micro cassette a due to a power outage (ml) while the magnetic tape is running. In this case, as a manual machine W (b)! Turn the rotation dial to manually return the cam plate to its retraction limit, and then attach the capstan shaft (5) # (6) to the pinch roller).
, , ), and then remove the micro cassette C. Roughly, connect the idler gear αη, take-up reel stand gear (5 &), and supply side reel stand gear (4 &). This manual motor w- is also used when performing the meshing of the
From the state in which it is engaged with a), return the cam plate ψ0 to the backward limit ★ using the manual mum to brake this take-up side reel stand gear (5&), and then perform the same operation on the supply side reel stand gear (5&). 4&).

As is clear from the above description, according to the present invention, rotational force is selectively applied from the output shaft of the forward/reverse rotation drive mechanism to the supply side reel table gear and the take-up side reel table gear by the idler gear. Since the power is transmitted, there is no need to provide separate drive motors for each reel stand or separate transmission mechanisms as in the past. As a result, the drive system, and even the entire device, are simpler in configuration and smaller in size.
In addition to contributing to cost reduction, the operation of the braking mechanism for each gear is controlled by the control mechanism to change the engagement of the idler gear and run the magnetic tape, so that recording or reproducing operations can be performed reliably.

[Brief explanation of the drawing]

The drawings show a magnetic recording/reproducing device according to an embodiment of the present invention, and FIGS. 1 to 7 are partially cutaway plan views for explaining its operating state, and FIG. 8 is a forward/reverse rotation drive mechanism. FIG. 9 is a sectional view taken along the II=1 arrow in FIG. 8, and FIG. 10 is a sectional view taken along the arrow II=1 in FIG.
rXi is a characteristic diagram of the forward/reverse rotation drive mechanism, and FIG. 12 is a bottom view of the capstan shaft drive system. (1)...Magnetic recording and reproducing device main body, (2)...Substrate, (3)...Take-up side reel stand, (5a)...Take-up side reel stand gear, (4)...・Supply side reel stand, (4&
)...Supply side reel stand gear, (5), (6).
...Medium Yapustan axis, (7)...Forward/reverse rotation drive 411
If11, (7a) - Output shaft, C141... Pinion, (B)... Rack, (B) - Idler gear, @υ... One to cam drive - C3B), C, j 'l
') - Braking mechanism, (58m), (39m)... Rocking piece, (58a), (59c)... -7 Rake shoe - Control mechanism, ←000. cam plate drive mechanism,
Sakaki...Cam plate position detector W1 wheel...Magnetic head. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Shin Kuzuno (1 other person)

Claims (1)

[Claims] (1) The supply side reel stand gear and the take-up side reel stand gear, which are provided coaxially with the rotation axes of the supply side reel stand and the take-up side reel stand, are interlocked with the output shaft of the forward and reverse rotation drive mechanism. An idler gear that is selectively engaged with the two gears in the state, and braking of the two gears 4! ! Be prepared and
A magnetic recording device comprising: a control mechanism that activates the braking mechanism when switching the engagement between the idler gear and the two gears, and deactivates the braking mechanism when a tape is running on a cassette installed in the apparatus main body. playback device.