JP2548334B2 - Magnetic recording / reproducing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus having an improved mechanical response speed during mode transition.

2. Description of the Related Art In recent years, a magnetic recording / reproducing apparatus is required to have a multi-function, for example, a special reproduction function capable of obtaining a reproduced image with less noise in still, forward / reverse slow motion, forward / reverse fast-forward mode, and forward / reverse frame-feed mode. On the other hand, it is also required that the mode transition between the respective reproduction modes be quick as the usability of the apparatus. In order to speed up the mode transition, it is necessary to switch the forward / reverse reproduction mode while the pinch roller is kept in pressure contact with the capstan. In addition, there is a demand for cost reduction of the device, and in response to this, there is a device in which the number of motors driving the device is reduced. As a specific example, as shown in FIG. 6, there is a device that drives a capstan and a pair of supply-side reel base and take-up reel base with one motor.

In FIG. 6, reference numeral 51 is a first motor, which is integrally formed with the capstan 23 and is a so-called capstan direct drive motor. The power from the first motor 51 arranged on the back surface of the chassis substrate 50 is transmitted to the center pulley 25 by the timing belt 24. A center pulley gear 25b is coaxially attached to the center pulley 25 by an elastic member via a friction member such as a felt, and is attached to the center pulley 25 with a torque limiter function to be integrated with the center pulley 25. When rotating torque is transmitted over a certain level, slippage occurs between the center pulley 25 and the center pulley gear 25b to control the transmission torque. The rotational driving force of the center pulley gear 25b is generated by the first idler arm 27 and the first rolling contact gear 28 attached to the first idler arm 27, and the power is applied to the reel stand 31 or 32 via the first reel stand relay gear 29 or 30. To drive the reel base to rotate.

FIG. 6 shows a state in which the magnetic tape 54 in the tape cassette 17 is pulled out of the tape cassette, the magnetic tape 54 is attached to the cylinder 20 and the magnetic tape 54 is interposed between the capstan 23 and the pinch roller 45. FIG. 11 is a diagram when the tape is transferred in the normal direction (arrow a1) and the signal is reproduced in the normal direction.

Next, FIG. 7 shows that when the pinch roller 45 is pressed against the capstan 23 and the first motor 51 is reversely driven to transfer the tape in the reverse direction from the time of the normal direction reproduction of FIG. FIG. The reverse rotation of the first motor 51 (direction of arrow b2) causes the capstan 23 to rotate in the reverse direction (arrow b2), and at the same time, the magnetic tape 54 is transferred in the reverse direction as indicated by the arrow b1. On the other hand, when the center pulley 25 connected by the timing belt 24 is rotated in the reverse direction by the first motor 51, the first rolling gear 28 rollingly contacted with the center pulley gear 25b is rotated in the reverse direction, and the first rolling gear 28 is rotated.
The mesh with the reel stand relay gear 29 is disengaged. Then, together with the first idler arm 27, it starts rotating coaxially with the center pulley in the direction of arrow b4, meshes with the first reel stand relay gear 30, and moves the supply reel stand in the direction of arrow b3. Rotate. Then, the magnetic tape transferred by the reverse rotation of the capstan 23 starts to be wound around the supply-side tape reel 18.

During this time, the reverse rotation of the capstan 23 causes the first rolling gear 28 to mesh with the first reel stand relay gear 30 from the moment the tape is transferred in the reverse direction, and the tape reel 18 is driven to rotate in the reverse direction to cause magnetic force. There is a time delay between winding the tape 54. During that time, the winding failure of the magnetic tape occurs and the tape sags. Therefore, the magnetic tape 54 is momentarily released from contact with the cylinder 20 having the rotary head, and becomes like the magnetic tape 54 shown in FIG. 7, and the signal recorded on the magnetic tape 54 is transferred to the cylinder 20. It becomes impossible to read with the rotary head. Therefore, it becomes impossible to reproduce the recording signal in the slack section of the magnetic tape, and noise is generated on the reproduction screen of the television.

Next, a brake release mechanism that releases the back tension applying mechanism when the magnetic tape is running in the reverse direction to establish the supply side reel base drive mechanism by the first motor will be described.

FIG. 8 shows a back tension applying mechanism when the magnetic tape 54 is running in the forward direction a1. Normally, a magnetic recording / reproducing apparatus such as a VTR is equipped with a magnetic tape so that signals can be surely recorded / reproduced between the magnetic tape 54 wound around the cylinder 20 and the rotary head of the cylinder 20.
There is a back tensioning mechanism for giving 54 a proper tension. When traveling in the forward direction, the magnetic tape 54
Tension post 60 planted on tension arm 62 rotatably mounted on shaft 72 planted on chassis substrate 50.
Run while touching. On the other hand, the supply side reel stand 32
A braking force is applied by the spring 63 attached to the tension arm 62 and the tension band 61 rotatably attached to the tension arm 62. Magnetic tape 54
When the tape tension increases above an appropriate value during normal running of the tape, the magnetic tape 54 presses the tension post 60 due to the tension, the tension arm 62 is rotated in the e1 direction, and the tape is wound around the supply-side reel stand 32. Since the tension of the tension band 61 is loosened, the braking force applied to the supply reel stand 32 by the tension band 61 is reduced, and the back tension of the magnetic tape 54 is reduced. Conversely, when the magnetic tape 54 travels in the forward direction and the tape tension decreases below an appropriate value, the tension arm 62 rotates in the e2 direction due to the force of the spring 63, and the tension wound around the supply reel stand 32 is increased. Because the tension of the band 61 becomes stronger,
The tension band 61 increases the braking force applied to the supply-side reel stand 32, and the back tension of the magnetic tape 54 increases. In other words, the back tension applying mechanism is a magnetic tape that has a proper value set by the spring 63.
It is a tension servo system that automatically tries to approach an appropriate value when the back tension of 54 increases or decreases.

When the magnetic tape 54 is traveling in the reverse direction, in order to wind up the magnetic tape 54 transported in the reverse direction by the capstan 23 in cooperation with the pinch roller 45 by the supply-side reel stand 32, the above-mentioned back tension applying mechanism is used. Release the braking force applied to the supply-side reel stand 32 to
It is necessary to make 32 rotatable. FIG. 9 shows the brake release state when the magnetic tape 54 is running in the reverse direction.

Next, referring to FIGS. 9 and 10, a method of releasing the braking force applied to the supply reel stand when the magnetic tape is running in the forward direction will be described. FIG. 10A shows the positional relationship between the main lever 65, the release arm 64, and the tension arm 62 when the magnetic tape is running in the forward direction, and FIG. It is a positional relationship. Before the magnetic tape moves from the forward running to the backward running, the first motor 51 releases the braking force applied to the supply reel stand 32 as shown in FIG. 10 (a). When a reverse traveling command is issued during the forward traveling shown in FIG. 8, the clutch mechanism (not shown) built in the gear B70 is actuated and the forward rotation driving force of the first motor 51 is applied to the timing belt 24. Then, it is transmitted to the gear C71 via the center pulley 25, the gear A69, and the gear B70. Gear C
The forward rotational driving force of the first motor 51 transmitted to the 71 is transmitted to the main cam 68 meshing with each other, and
A cam follower mounted coaxially with the 68 so that it can rotate.
67 is rotated in the c direction by a cam formed on the end surface of the main cam 68, and the rotational movement of the main cam 68 is in the c direction of the main lever 65 that engages with the cam follower 67 by interposing the cam follower 67. Is converted into a linear motion of.
This forward rotation of the first motor 51 is performed by the main lever
The process continues until 65 reaches a predetermined position (broken line in FIG. 10 (a)) and a switch (not shown) is detected, and the first motor 51 reverses at the same time as the detection by the switch.

The reverse driving force of the first motor 51 is converted into a linear movement of the main lever 65 in the d direction by following the same path as described above. The rotational driving force of the first motor 51 in the reverse direction is transmitted to the main lever 65 until the operation of the clutch mechanism (not shown) built in the gear B70 is released again, and as shown in FIG. The position shown is reached and the main lever 65
The cam portion 65a of the above pushes the pin 64a implanted in the release arm 64 in the d direction. The pressing force of the cam surface 65a of the main lever 65 against the pin 64a in the d direction acts as the turning force of the release arm 64 in the f direction to press the end surface 62a of the tension arm 62 in the g direction, and the supply side reel stand. By releasing the tension band 61 wound around 32, the supply-side reel stand 32 can be freely rotated.

In this way, in order to switch the magnetic tape 54 from the forward running to the backward running, as described above, the supply reel stand 32
It is necessary to release the tension band 61 that is wound around, and in the above configuration in which the magnetic tape is transferred and wound up and the mode is changed by the only motor 51, the tension band It is necessary to release the magnetic tape, and it takes a long time to switch the magnetic tape from running in the forward direction to running in the reverse direction. As a result, the slack of the tape occurs as shown in FIG. 7, and a reproduced image cannot be obtained. Was becoming. In addition, in order to release the tension band wound around the supply side reel stand, gear A69, gear
B70, gear C71, main cam 68, cam follower arm 67, main lever 65, release arm 64 required a series of complicated configurations.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As described above, in the magnetic recording / reproducing apparatus shown in FIG. 6, the capstan is moved from the normal reproduction mode in which the pinch roller is pressed in the capstan and the magnetic tape is transferred in the normal direction. Reverse rotation to transfer the magnetic tape in the reverse direction,
When the mode is changed to the reverse direction reproduction mode, there is a problem that it takes time to change the mode and a reproduction signal is lost. Especially during slow-motion playback and frame-by-frame playback, a phenomenon in which the playback signal for at least several fields is completely lost when reversing from the forward direction to the reverse direction occurs in the playback image, which is a major obstacle to tape editing work. Was there.

Further, as shown in FIGS. 8 to 10, it takes time to release the tension band wound around the supply-side reel base for enabling the tape to be switched from the forward running to the backward running, Not only was the response unsatisfactory, but it also had the drawback of requiring a complicated structure to release the tension band.

In view of the above-mentioned problems, the present invention provides a second motor, a second reel base drive mechanism, and a second brake release mechanism so as to shift the magnetic tape from the normal direction reproduction mode to the reverse direction reproduction mode. In addition to completely eliminating the loss of the playback signal due to the slack of the magnetic tape, the release of the brake of the supply side reel stand required for the mode transition described above can be quickly realized with a simple structure, and the reverse direction with good response can be achieved. It is intended to provide a magnetic recording / reproducing device capable of shifting to a reproducing mode.

Means for Solving the Problems In order to solve the above problems, the magnetic recording / reproducing apparatus of the present invention, in a state in which a magnetic tape is wound around a cylinder by a loading post, cooperates with a pinch roller to run the magnetic tape in a forward direction. And a first motor that drives the capstan to rotate, a supply-side reel stand that engages with a pair of tape reels around which a magnetic tape in a tape cassette is wound, and a take-up reel. Side reel stand, a first reel stand drive mechanism for transmitting a rotational driving force to the take-up reel stand by a first motor when the magnetic tape is running in the forward direction, and a magnetic tape when the magnetic tape is running in the forward direction. A back tension applying mechanism for applying a back tension to the second reel, and a second tension transferring mechanism for transmitting a rotational driving force to the supply reel stage when the magnetic tape is running in the reverse direction. A reel base drive mechanism, a second motor that rotationally drives the second reel base drive mechanism, and the back tension applying mechanism is released when the magnetic tape is running in the reverse direction to establish a second reel base drive mechanism. It is equipped with a brake release mechanism.

With the above-described structure, the present invention drives the take-up reel stand by the first reel stand drive mechanism in the forward play mode in which the magnetic tape is forward-moved in the state where the pinch roller is pressed against the capstan. . Then, when the capstan is reversed to shift to the reverse reproduction, the first motor is temporarily stopped to stop the capstan, and the momentary still mode is set. In the still mode, the supply side reel base is driven to be wound by the second motor and the second reel base drive mechanism. At this time, since the capstan is stopped, the magnetic tape is not sent out. After that moment, the capstan is rotated in the reverse direction to transfer the magnetic tape in the reverse direction. After that, the magnetic tape is wound around the supply-side reel stand by the second reel stand drive mechanism. In this way,
It is possible to eliminate the slack of the tape due to the poor winding of the tape, which occurs in the conventional device, when the magnetic tape transits from the forward running to the backward running. Also, the second
Since the second motor for driving and rotating the reel base drive mechanism releases the tension band wound around the supply side reel base, the supply side is synchronized with the rotation start of the second motor. Since the brake of the reel stand can be released quickly, it is possible to shift to the reverse playback mode with good response.

Example Hereinafter, regarding the magnetic recording and reproducing apparatus of the example of the present invention,
This will be described with reference to the drawings.

1 to 5 show an explanation of each operation of the embodiment of the present invention. In FIGS. 1 to 5, reference numeral 51 denotes a first motor, which is a so-called capstan DD motor integrally formed with the capstan 23. Chassis board
The power from the first motor arranged on the back surface of 50 is transmitted to the center pulley 25 by the timing belt 24. A center pulley gear 25b is attached to the center pulley 25 coaxially by pressure contact with an elastic member via a friction member such as felt. The center pulley 25 and the center pulley gear 25b are a torque limiter. The transmission of rotational torque above a certain level is cut off between the center pulley 25 and the center pulley gear 25b. The rotational driving force of the center pulley gear 25b is generated by the first idler arm 27 and the first rolling gear 28 attached to the first idler arm 27 through the first reel stand relay gear 29 to the take-up reel stand 31. To drive the reel base. The center pulley 25, the center pulley gear 25b,
First idler arm 27, first rolling gear 28 and first
The reel stand relay gear 29 and the take-up side reel stand 31 constitute a first reel drive mechanism.

Reference numeral 1 is a second motor, which is attached to the rear of the chassis via a mounting bracket 11. The rotational driving force decelerated by the worm 2 is transmitted to the second pulley 5 via the timing belt 4 arranged on the rear surface of the chassis. As shown in the sectional view of FIG.
A gear 15 is press-fitted into and integrated with and rotates about the shaft 9 as a rotation center to form a driving wheel member. The second pulley gear 14 constitutes a driven wheel member, and is attached to the end surface of the gear 15 under pressure contact with an elastic member such as a spring 13 coaxially with the second pulley via a friction member such as a felt 43. ing. When the rotation torque exceeds a certain level, the second pulley gear 14
Occurs between the second pulley 5 and the second pulley gear 14, and a torque is limited between the second pulley 5 and the second pulley gear 14 to form a torque limiter mechanism. Second pulley gear 14
The rotational driving force of the drive drive the supply-side reel stand 32 by the second idler arm 6 and the second rolling gear 7 attached thereto. The torque limiter mechanism composed of the second pulley 5, the second idler arm 6, the second rolling gear 7, and the supply-side reel stand 32 constitute a second reel stand drive mechanism.

In Fig. 1, the magnetic tape 54 in the tape cassette 17 is pulled out to the outside of the tape cassette, and the magnetic tape is placed in the cylinder.
The tape is transferred in the forward direction (arrow a1) while being attached to the rotary head of 20 and holding the magnetic tape 54 between the capstan 23 and the magnetic tape 54, and recorded on the magnetic tape. It is a state diagram at the time of carrying out the normal direction reproduction of the generated signal. At the same time as the magnetic tape is fed by the capstan 23 (in the direction of arrow a1), the first rolling gear 28 meshes with the first reel base relay gear 29 to drive the reel base 31 on the take-up side and The tape 54 is wound around the tape reel 19. A magnetic tape pulled out from the tape reel 18 by the capstan 23 and the pinch roller 45.
54 is a cylinder via the post 92a inside the tape cassette and the post 92b inside the tape cassette, then the tension post 60, the P1 post 91, the full width erasing head 90, and the S side tape post.
Has 20 tape paths.

The transition of the operation mode from the forward transfer to the reverse transfer of the tape will be described below.

In FIG. 3, the first motor 51 is stopped and at the same time the capstan 23 is stopped to set the still mode. Next, in this still mode, the second motor 1 is rotationally driven to move the second rolling gear 7 from the position shown in FIG. 1 to the position where it can be meshed with the supply reel stand 32. The second pulley gear 14 is moved while rolling. Thereby, the supply-side reel stand 32 is rotationally driven in the direction of arrow b3. This causes the tape reel 18 engaged with the supply-side reel stand 32 to wind up the magnetic tape 54. At this time, the capstan is stopped, so the tape is not delivered. Supply side reel stand 32 that winds the tape reel 18
The winding torque is set by the torque limiter value of the torque limiter portion formed between the second pulley 5 and the second pulley gear 14 described above. When the winding torque required for winding the tape reel is larger than the torque limiter value set above, slippage occurs between the second pulley 5 and the second pulley gear 14, so that the tape tension is increased. There is no problem such as abnormally high cost or tape damage.

Next, FIG. 4 shows the state immediately after the second reel base drive mechanism drives the supply reel base as shown in FIG. In FIG. 4, the first motor 51 is rotated in the reverse direction, the capstan 23 is rotated in the direction indicated by the arrow b2, and the magnetic tape 54 is transferred in the direction indicated by the arrow b1. This time,
The transferred tape is transferred to the tape reel 18 by the second reel base drive mechanism driven by the second motor 1.
In addition, the tape is taken up without slack. First
Simultaneously with the reverse rotation of the motor 51 of the
Is disengaged from the reel stand relay gear 29 and starts rotating in the direction of arrow b4. After that, when the capstan 23 rotates in the direction of the arrow b2, it is held at the position shown in FIG. In this way, the first reel base drive mechanism is locked in a state in which the rotational drive force cannot be transmitted to the supply reel base. During this time,
The magnetic tape 54 sent by the reverse rotation of the capstan (direction of arrow b2) is wound on the tape reel 18 by the second reel base drive mechanism driven by the second motor 1 as described above. By the operation shown in FIGS. 1 to 4, the magnetic tape can be switched from the forward transfer to the reverse transfer without causing the slack of the magnetic tape while the pinch roller 45 is pressed against the capstan 23.

Next, the tension band 61 wound around the supply-side reel base 32 is released in synchronization with the winding of the supply-side reel base 32 by the second reel-base drive mechanism by the rotation of the second motor 1. The operation of will be described. Reference numeral 80 is a balance gear that meshes with the second pulley 5. Figure 2 (a)
As shown in the cross-sectional view of FIG.
The shaft that was pressed into and integrated with the chassis 50 was planted in the chassis 50.
The second driving wheel member is configured by rotating around 84 as the center of rotation. The rotating arm 82 constitutes a driven wheel member, and the felt 85
It is attached to the end surface of the sleeve 81 by pressure contact with an elastic member such as a spring 86 coaxially with the balancer 80 via a friction member such as. When the rotational torque is equal to or higher than a certain level, slippage occurs between the sleeve 81 and the rotating arm 82, and torque transmission is limited between the balance gear 80 and the rotating arm 82. Thus, the torque limiter mechanism is constructed. The opening 82 of the rotating arm 82 is coaxial with the rotating arm 82.
A release lever 83 that engages with a and a pin 83b is rotatably mounted, and a pin 83a provided on one end surface of the release lever 83 is inserted into a hole 50a provided in the chassis substrate 50. Has become.

The rotational driving force of the second pulley 5 is transmitted to the rotating arm 82 through the torque limit mechanism constituted by the ten-legged gear 80, the sleeve 81, the felt 85, the spring 86, and the like, and the pin portion is released via the release lever 83. 83a rotates the tension arm 62 in the g direction to release the tension band 61 wound around the supply reel stand 32. The torque limiter mechanism composed of the ten-legged gear 80, the rotating arm 82, the release lever 83, and the hole 50a of the chassis board are the second.
Constitutes the brake release mechanism of. The operation of releasing the brake will be described according to the mode transition from the forward transfer to the reverse transfer of the tape.

The same route as that of the second reel base driving mechanism has already been described, and in FIG. 3, the first motor 51 is stopped and at the same time the capstan 23 is stopped to set the still mode. Next, in this still mode, the second motor 1 is rotationally driven to drive the worm 2, the timing belt.
3, the tension arm 62 shown in FIG. 3 supplies the tension band 61 to the supply side through the pin portion 83a of the release lever 83 from the position shown in FIG. Move from the reel stand 32 to a position where it can be released. Since the rotation driving force of the second motor 1 thereafter is absorbed by the torque limiter mechanism including the ten-legged gear 80 and the like, the pin portion 83a of the release lever 83 abuts the end surface 50b of the hole 50a of the chassis substrate 50. The state is continuously ensured, and the brake release state of the supply-side reel stand 32 is reliably continued while the second motor 1 is rotating. In order to realize the above brake release, the tension post 60 is rotated in the direction of arrow g from the position shown in FIG.
Brought to the position shown. The reduced length of the tape path generated by the rotation of the tension post is wound on the tape reel 18 by the second reel base drive mechanism described above without causing slack in the tape. By the operation shown in FIGS. 1 to 4, the pinch roller 45 is kept in pressure contact with the capstan 23, and the magnetic tape is responsive from the forward transfer to the reverse transfer without sagging. It can be switched within 1 second.

At this time, the magnetic tape 54 sent out in the opposite direction by the capstan 23 and the pinch roller 45 is the cylinder 2
0, S side tape post 21a, full width erasing head 90, P1 post 91,
It is wound around the tape reel 18 via the tension post 60, the tape cassette post 92a, and the tape cassette post 92b. At this time, since it passes through the tension post 60 implanted in the tension arm 62 released by the second brake release mechanism, the P1 post 91 is different from the magnetic tape 54.
Does not touch.

Next, the operation of switching the magnetic tape shown in FIG. 4 in the reverse direction to the still mode will be described. In FIG.
The capstan 23 is stopped and the still mode is set. In the meantime, the second motor 1 is rotated in the reverse direction to move the second idler arm 6 from the position shown in FIG. 4 to the second reel contact gear 7 as shown in FIG. Rotate to the position where the mesh is released. At the same time as this operation, the release lever 83
4 is rotated from the position shown in FIG. 4 in the h direction as shown in FIG. 5 to release the second brake releasing mechanism, and the tension band 61 applies the braking force again to the supply reel stand 32. , Establishes a back tension applying mechanism when the magnetic tape is running in the forward direction. Supply side reel stand 32
Since the meshing relationship with the second reel base drive mechanism is released by the above operation, the magnetic tape 54 may move in the forward direction due to the tape tension of the magnetic tape 54 depending on the winding amount of the magnetic tape around the tape reel 8. Slightly rotate in the direction in which it is wound up. However, tension post 60
Is biased by a spring 63 so as to rotate in the direction of coming into contact with the tape. Therefore, the tension post 60 is rotated from the position shown in FIG. 4 to the position shown in FIG. This prevents the occurrence of slack in the magnetic tape. After that, the rotation of the second motor 1 is stopped and the still mode is continued.

Next, in order to shift to the forward reproduction mode, the capstan may be rotated in the a2 direction as shown in FIG. Further, when the reverse reproduction mode is switched to the forward reproduction mode, the still mode described above can be instantaneously passed to switch the reproduction mode in a short time of about 1 second or less.

In this way, it is possible to instantaneously switch from the forward direction transfer to the reverse direction transfer without causing the slack of the magnetic tape while the pinch roller is pressed against the capstan.

With conventional equipment, one motor, one capstan and one
In a device that drives a pair of reel bases, when the pinch roller is pressed against the capstan and the magnetic tape is switched from the forward playback mode to the backward playback mode, the only motor is the first Since it was necessary to release the tension band wound around the side reel stand, the response of the mode switching from the forward transfer to the reverse transfer was poor, and the reproduction signal was lost. On the other hand, there was a device in which the capstan and the pair of reel bases were driven by different motors, but in this way, the motor that drives the reel base is the same as the motor that the capstan drives. High-precision control was required, and the motor itself needed an expensive motor that did not adversely affect important characteristics such as wah and jitter. In order to switch between forward and reverse with better response, it is necessary to release the brake on the supply reel base instantly when the mode is switched from the forward direction to the reverse direction.For example, another power source such as a solenoid is used. Therefore, it is necessary to operate the supply-side reel base at the same timing as the winding of the supply-side reel base, which is an expensive and complicated device.

However, according to the present invention, a relatively inexpensive second motor (for example, a brushed motor with a core),
It is only necessary to provide a second reel base drive mechanism and a second brake release mechanism, which use this second motor as a power source, and forward / reverse slow motion, forward / reverse frame feed, forward / reverse playback mode, forward / reverse fast feed. When switching modes, it is possible to easily realize a special playback mechanism that can instantly obtain a playback image without loss of the playback signal with good response without giving high tension to the magnetic tape or damaging the tape. is there.

Further, the torque limiter mechanism, which is composed of a ten-legged gear and the like, which constitutes the second brake release mechanism shown in the present embodiment, and the torque, which is constituted by the second center pulley gear 14 and the like, which constitutes the second reel base drive mechanism. It is also possible to substitute a limiter mechanism.

As described above, according to the present invention, the capstan that cooperates with the pinch roller in a state where the magnetic tape is wound around the cylinder by the loading post to perform the forward running and the backward running of the magnetic tape, A first motor that rotationally drives the capstan, a supply-side reel stand and a take-up reel stand that engage with a pair of tape reels around which a magnetic tape in a tape cassette is wound, and a forward direction of the magnetic tape. A first reel stand drive mechanism for transmitting a rotational drive force to the take-up reel stand by a first motor during running; and a back tension applying mechanism for applying back tension to the magnetic tape when the magnetic tape runs in the forward direction. A second reel stand drive mechanism for transmitting a rotational driving force to the supply side reel stand when the magnetic tape is running in the reverse direction; and a second reel stand drive. A configuration including a second motor that rotationally drives a moving mechanism, and a second brake release mechanism that releases the back tension applying mechanism to establish a second reel base drive mechanism when the magnetic tape is running in the reverse direction. By doing so, it is possible to quickly perform the transition from the forward reproduction mode by the forward transfer of the magnetic tape to the backward reproduction mode by the backward transfer, and therefore, the slack of the magnetic tape does not occur, An excellent magnetic recording / reproducing apparatus capable of obtaining a reproduced image with no signal loss without damaging the magnetic tape during the reproduction in the forward / reverse fast-forward, forward / reverse slow motion, forward / reverse frame feed, and the forward / reverse reproduction mode. It can be realized.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the magnetic recording / reproducing apparatus of the present invention, FIG. 2 (a) is a cross-sectional view of an essential part showing a second reel base drive mechanism of the present embodiment, and (a) is A sectional view of an essential part showing a brake releasing mechanism of the present embodiment, (c) a plan view of an essential part showing the mechanism of (a) and (a), and FIGS. 3 to 5 show the operation of the same embodiment of the present invention. 6 is a plan view showing the operation of the conventional magnetic recording / reproducing apparatus, and FIGS. 10 (a) and 10 (a) are schematic views showing the brake release mechanism of the conventional magnetic recording / reproducing apparatus. FIG. 1 ... second motor, 5 ... second center pulley,
6 ... second idler arm, 7 ... second rolling gear,
14 …… Second center pulley gear, 17 …… Tape cassette, 18,19 …… Tape reel, 23 …… Capstan, 51
...... First motor, 31,32 …… Reel stand, 27 …… First
Idler arm, 54 ... magnetic tape.

Claims (1)

(57) [Claims] 1. A capstan for running a magnetic tape in a forward direction and a backward direction in cooperation with a pinch roller while the magnetic tape is wound around a cylinder by a loading post,
A first motor that rotationally drives the capstan, a supply-side reel stand and a take-up reel stand that engage with a pair of tape reels around which a magnetic tape in a tape cassette is wound, and a forward direction of the magnetic tape. A first reel stand drive mechanism for transmitting a rotational drive force to the take-up reel stand by a first motor during running; and a back tension applying mechanism for applying back tension to the magnetic tape when the magnetic tape runs in the forward direction. A second reel base drive mechanism that transmits a rotational drive force to the supply-side reel base when the magnetic tape is running in the reverse direction; a second motor that rotationally drives the second reel base drive mechanism; And a brake release mechanism for releasing the back tension applying mechanism when the tape is running in the reverse direction to establish the operation by the second reel base drive mechanism. Magnetic recording and reproducing apparatus characterized by operating the second reel table driving mechanism and the brake release mechanism in the second motor.