JPH0748271B2 - 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 that ensures tape operation during mode switching.

2. Description of the Related Art In recent years, along with a remarkable increase in demand for magnetic recording / reproducing devices, there is an increasing demand for cost reduction of the devices. At the same time, multi-functionalization of the device, such as still image, normal / reverse slow motion, forward / reverse fast-forward, and forward / reverse frame-feed modes, is possible. ing. Further, as the usability of the apparatus, it is required that the mode transition of each reproduction mode is quick. In order to speed up the mode transition, it is necessary to switch the forward / reverse playback mode while the pinch roller is being pressed against the capstan. Further, in order to reduce the cost of the device, there has been proposed a device that reduces the number of motors that drive the device. As a specific example, as shown in FIG. 6, there is a device that drives a capstan and a pair of a supply-side reel stand and a take-up reel stand with one motor.

In FIG. 6, reference numeral 51 is a first motor, which is a capstan DD motor and is integrally formed with the capstan 23. 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 25-b is attached to the center pulley 25 coaxially with the center pulley 25 by means of an elastic member through a friction member such as felt, and has a torque limiter function. When rotating torque is transmitted over a certain level, slippage occurs between the center pulley 25 and the center pulley gear 25-b, and the transmission torque is controlled. The rotational driving force of the center pulley gear 25-b is generated by the first idler arm 27 and the first rolling contact gear 28 attached thereto via the first reel stand relay gear 29 or 30 and the reel stand 31 or 32. The power is transmitted to and the reel base is driven 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 a-1) and the signal is reproduced in the normal direction. The pinch roller from the normal direction reproduction in FIG.
The first motor with the 45 crimped onto the capstan 23
FIG. 7 shows a diagram when the tape is transferred in the reverse direction by driving 51 in reverse. The reverse rotation of the first motor 51 (direction of arrow b-2) causes the capstan 23 to rotate in the reverse direction (arrow b-2).
At the same time, the magnetic tape 54 is transported in the opposite direction as indicated by arrow b-1. On the other hand, when the center pulley 25 connected by the timing belt 24 reversely rotates from the first motor 51, the first continuation gear 28 that contacts the center pulley gear 25-b rotates in the reverse direction, and the first reel stand. The mesh with the 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 b-4, meshes with the first reel stand relay gear 30, and moves the supply reel stand toward the arrow b. -Rotate in the -3 direction. And capstan
The magnetic tape transported by the reverse rotation of 23 starts to be wound around the supply-side tape reel 18. During this time, the reverse rotation of the capstan 23 causes the tape to move in the opposite direction,
The rolling contact gear 28 of is meshed with the first reel stand relay gear 30,
There is a time delay between the tape reel 18 being driven in reverse and the magnetic tape 54 being wound. During that time, the winding failure of the magnetic tape occurs and the tape sags. To that end, the magnetic tape 54 is, for a moment, a cylinder 20 with a rotating head.
The contact with the magnetic tape 54 is released, and the magnetic tape 54 becomes like the magnetic tape 54 shown in FIG. 7, and the signal recorded on the magnetic tape 54 cannot be read by the rotary head of the cylinder 20. 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 back tension releasing 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 (a-1). Usually VTR
In such a magnetic recording / reproducing apparatus, an appropriate tension is applied to the magnetic tape 54 so that the recording / reproducing of the signal between the magnetic tape 54 wound around the cylinder 20 and the rotary head of the cylinder 20 is surely performed. There is a back tension applying mechanism for giving. 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 includes a spring 63 attached to the tension arm 62 and a tension band rotatably attached to the tension arm 62.
Braking force is applied by 61. When the magnetic tape 54 travels in the forward direction and the tape tension exceeds a predetermined appropriate value, the magnetic tape 54 presses the tension post 60 due to the tension, and the tension arm 62 is rotated in the e1 direction, and the supply reel Since the tension band 61 wound around the table 32 is loosened, the braking force applied to the supply reel table 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 the appropriate value, the spring 63 causes the tension arm to move.
62 rotates in the e2 direction, and the tension of the tension band 61 wound around the supply-side reel stand 32 is strengthened, so that the braking force applied to the supply-side reel stand 32 by the tension band 61 increases. , The back tension of the magnetic tape 54 increases. That is, the back tension imparting mechanism is a tension servo system that automatically tries to approach the proper value when the back tension of the magnetic tape 54 increases or decreases from the proper value set by the spring 63. It is composed of an arm 62, a tension band 61, and the like. When the magnetic tape 54 is running in the reverse direction,
In order to wind the magnetic tape 54 transported by the capstan 23 in cooperation with the pinch roller 45 by the supply-side reel stand 32, the braking force applied to the supply-side reel stand 32 by the back tension applying mechanism described above. Must be released and the supply side reel base 32 must be rotatably moved.
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 main lever 65 and the release arm 6 when the magnetic tape is running in the forward direction.
4 is the positional relationship between the tension arm 62 and the tenth arm.
FIG. B shows respective positional relationships when the magnetic tape is running in the reverse direction. Before the magnetic tape shifts from running in the forward direction to running in the reverse direction, the braking force applied to the supply-side reel stand 32 as shown in FIG. 10B is released by the first motor 51. When the reverse traveling command is issued during the forward traveling shown in FIG. 8, the clutch mechanism (not shown) built in the gear B is activated and the forward rotation driving force of the first motor 51 is applied to the timing belt 24. , Center pulley 25, gear A69,
It is transmitted to gear C71 via gear B70. The positive rotational drive force of the first motor 51 transmitted to the gear C71 is transmitted to the main cam 68 meshing with each other, and the cam follower 67 mounted rotatably coaxially with the main cam 68 causes the main cam 68 to rotate. It is rotated in the c direction by the cam formed on the end face,
A main lever in which the rotational movement of the main cam 68 engages with the cam follower 67 by interposing the cam follower 67.
Converted to a linear motion of 65 in the c direction. The forward rotation of the first motor 51 is continued until the main lever 65 reaches a predetermined position (broken line in FIG. 10B) and a switch (not shown) is detected. At the same time, the first motor 51 is reversed. The reverse driving force of the first motor 51 follows the same system path as described above and the main lever 65
Is converted into a linear motion in the d direction. This first motor
The rotational driving force in the reverse direction of 51 is transmitted to the main lever 65 until the operation of the clutch mechanism (not shown) incorporated in the gear B70 is released again, and reaches the position shown in 10-b of FIG. Then, the cam portion 65-a of the main lever 65 pushes the pin 64-a planted in the release arm 64 in the d direction. The pressing force of the cam surface 65-a of the main lever 65 against the pin 64-a in the d direction acts as the turning force of the release arm 64 in the f direction to press the end surface 62-a of the tension arm 62 in the g direction. Then, the tension band 61 wound around the supply-side reel stand 32 can be released, and the supply-side reel stand 32 can be rotatably moved. As described above, in order to switch the magnetic tape 54 from running in the forward direction to running in the reverse direction, it is necessary to release the tension band 61 wound around the supply-side reel stand 32 as described above. In the present example in which the magnetic tape is transferred and wound, and the mode is changed, as described above, it takes a long time to switch the magnetic tape from the forward running to the reverse running, and not only the response is bad. , Gear A, Gear B, Gear C, to release the tension band wound around the supply side reel stand,
It requires a series of complicated configurations such as the main cam, cam follower arm, and main lever.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described conventional configuration, the capstan is rotated in the reverse direction from the normal reproduction mode in which the magnetic tape is transferred in the normal direction while the pinch roller is pressed against the capstan. There is a problem that a reproduction signal is lost when the transfer is performed and the mode is changed to the reverse reproduction mode. Particularly, during slow-motion reproduction and frame-by-frame reproduction, at the time of reversal from the forward direction to the reverse direction, a phenomenon in which a reproduced signal for at least several fields is completely lost occurs in a reproduced image, which is a great obstacle to tape editing work.

Further, as shown in FIGS. 8 to 10, it takes time to release the tension band wound around the supply-side reel stand, which makes it possible to switch the tape from the forward running to the backward running, and the response Not only was it bad, but there was the drawback that a complicated structure was required to realize the release of this tension band.

In view of the above problems, the present invention provides a conventional device shown in FIGS. 6 to 10 with a second motor, a second reel base drive mechanism, a reel base drive locking mechanism, and a back tension release mechanism. By mounting the magnetic tape, it not only completely eliminates the loss of the slack playback signal of the magnetic tape that occurs when the playback mode is switched from the forward playback mode to the reverse playback mode, but it also requires the back tension required for the above mode transition. By releasing the instantly with a simple configuration,
(EN) A magnetic recording / reproducing apparatus capable of shifting to a reverse reproduction mode with good response.

Means for Solving the Problems In order to solve the above problems, a magnetic recording / reproducing apparatus of the present invention cooperates with a pinch roller to transfer a magnetic tape in forward and reverse directions, and rotationally drives the capstan. A first motor, 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; a supply-side reel stand driven by the first motor; A first reel stand drive mechanism for transmitting a rotation drive force to the take-up reel stand, a second reel stand drive mechanism for transmitting a rotation drive force to the supply reel stand, and a second reel stand drive mechanism are provided. When transmitting the rotational drive force to the supply-side reel mount, the reel-base drive locking mechanism that locks and does not transmit the transmission of the rotational drive force to the supply-side reel mount by the first reel mount drive mechanism and the cap. Stan porcelain A back tension applying mechanism for applying a back tension to the magnetic tape when the air tape is transported in the forward direction, a back tension releasing mechanism for releasing the back tension applying mechanism when the magnetic tape is transported in the reverse direction by a capstan, and A second motor for driving the second reel base drive mechanism and the back tension release mechanism at substantially the same time via a still mode in which the capstan is stopped when the transfer direction is switched is provided.

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, before the capstan is reversed and the reverse reproduction is started, the first motor is once stopped to stop the capstan, and the one-still still mode is set. In this still mode, the supply side reel stand is driven by the second motor and the second reel stand drive mechanism. At this time, since the capstan is stopped, the magnetic tape is not sent out. Immediately after this, 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 defective winding of the tape, which has occurred in the conventional device, when the magnetic tape transits from the forward running to the backward running. In addition, since the second motor that drives and rotates the second reel base drive mechanism releases the tension band wound around the supply-side reel base, the rotation of the second motor is almost the same as the start of rotation. Since the brakes of the supply side reel stand can be realized at the same time, it is possible to shift to the reverse playback mode with good response.

Example A magnetic recording / reproducing apparatus according to an example of the present invention will be described below with reference to the drawings.

1 to 5 show an explanation of each operation of one embodiment of the present invention. In comparison with the conventional case, this embodiment further includes a second embodiment.
The reel base drive mechanism, the second motor, the reel base drive locking mechanism, and the back tension release mechanism of FIG. 1 are provided. In FIGS. 1 to 5, reference numeral 51 denotes the first motor, which is a capstan DD. It functions as a motor and is configured integrally with the capstan 23. Power from the first motor 51 arranged on the back surface of the chassis substrate 50 is generated by the timing belt 24.
Is transmitted to the center pulley 25. Center pulley
A center pulley gear 25-a is attached to the center pulley 25 coaxially with the center pulley 25 through a friction member such as felt by pressure contact with an elastic member.
The center pulley gear 25-a and a center pulley gear 25-a form a torque limiter, and cut off transmission of rotational torque above a certain level between the center pulley 25 and the center pulley gear 25-a. The rotational driving force of the center pulley gear 25-a is generated by the first idler arm 27-b and the first rolling contact gear 28 attached to the first idler arm 27-b.
Thus, power is transmitted to the pair of reel stands 31 or 32 through the first reel stand relay gear 29-b or 30-b to drive the reel stand. Center pulley 25, center pulley gear 2
5-a, the first idler arm 27-b, the first rolling gear 28, etc. 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. 2, the second pulley 5 has a gear
15 is press-fitted and integrated to rotate about the shaft 9 as a center of rotation to form a driving wheel member. The second pulley gear 14 is
It constitutes a driven wheel member, and is attached to the end surface of the gear 15 in 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. When the rotation torque exceeds a certain level, the second pulley gear 14 and the gear 15
Between the second center pulley 5 and the second pulley gear 14 limits the torque transmission between the second center pulley 5 and the second pulley gear 14 to form a torque limiter mechanism. The rotation driving force of the second pulley gear 14 is supplied by the second idler arm 6 and the second rolling contact gear 7 attached to the second idler arm 6 to the supply reel stand.
Drive 32. The torque limiter mechanism composed of the second center pulley 5, the second idler arm 6, and the second rolling gear 7 constitute a second reel base drive mechanism. The tension post 60, the tension arm 62 and the tension band 61 constitute a back tension applying mechanism. FIG. 1 shows that the magnetic tape 54 in the tape cassette 17 is pulled out to the outside of the tape cassette, the magnetic tape is attached to the rotary head of the cylinder 20, and the magnetic tape 54 is sandwiched between the capstan 23 and the pinch roller 45. While crimping
The figure shows a state in which the tape is transported in the forward direction (arrow a-1 direction) and the signal recorded on the magnetic tape is reproduced in the forward direction. At the same time as the magnetic tape is sent out by the capstan 23 (direction of arrow a-1), the first rolling gear 28
By meshing with the first reel stand relay gear 29-b,
The reel side 31 of the winding side is driven to wind the magnetic tape 54 on the tape reel 19. 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 capstan 23 is stopped at the same time when the first motor 51 is stopped, and the still mode is set. 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.
The second pulley gear 14 is moved while rolling to a position where it can be meshed with the supply-side reel stand 32. Thereby, the supply-side reel stand 32 is rotationally driven in the direction of arrow b-3.
As a result, the tape reel engaged with the supply-side reel stand 32
18 makes the magnetic tape 54 wind up. At this time, the capstan is stopped, so the tape is not delivered. The winding torque of the supply-side reel stand 32 for winding the tape reel 18 is set by the torque limiter value of the torque limiter portion formed between the second pulley 5 and the second pulley gear described above. If the winding torque required for winding the tape reel is larger than the set torque limiter value, slippage will occur between the second pulley 5 and the second pulley gear, and the tape tension will increase abnormally. There is no problem such as tape damage.

Next, FIG. 4 shows a state immediately after the supply-side reel base is driven by the second reel base drive mechanism as shown in FIG. In FIG. 4, the first motor 51 is reversely rotated,
The capstan 23 is rotated in the direction of arrow b-2, and the magnetic tape 54 is transported backward in the direction of arrow b-1. At this time, the transferred tape is wound around the tape reel 18 by the second reel base drive mechanism driven by the second motor 1 without causing slack in the tape. Simultaneously with the reverse rotation of the first motor 51, the first rolling gear 28 disengages from the first reel base relay gear 29-b and starts rotating in the direction of arrow b-4.

However, as shown in FIG. 4, the first rolling contact gear 28 is
When the gears 29-b and 30-b disengage from each other, the pin 35-a of the regulating arm 35 comes into contact with the end surface of the cam groove 34-a of the rolling contact regulating cam gear 34 when the gear 35-a is rotated substantially in the center. Abut and regulate arm 35
Also, the rotation of the first idler arm 27-b is locked.
After that, when the capstan 23 rotates in the direction of arrow b-2, it is held at the position shown in FIG. In this way, the first reel base drive mechanism is locked to transfer the rotational drive force to the supply-side reel base and becomes non-transmitted. During this time, the tape 54 fed by the reverse rotation of the capstan (direction of arrow b-2)
As described above, the tape is wound on the tape reel 18 by the second reel base driving mechanism driven by the second motor 1. 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. The rolling contact control cam gear 34 and the cam groove 34-a constitute the reel base drive locking mechanism of the present invention. The rolling contact control cam gear 34 is a magnetic tape.
In the operation mode in which 54 is stored in the cassette, the first reel base drive mechanism can drive the supply reel base to rotate the supply reel by a predetermined angle, and the magnetic tape can be wound on the supply tape reel. .

Next, by the rotation of the second motor 1, the tension band 61 wound around the supply-side reel stand 32 that operates at substantially the same time as the winding of the supply-side reel stand 32 by the second reel stand drive mechanism is released. The operation will be described. Reference numeral 80 denotes a balance leg gear that meshes with the second center pulley 5. As shown in the sectional view of FIG. 2B, the sleeve 81 is press-fitted into the ten-legged gear 80 so that the sleeve 81 rotates integrally about the shaft 84 as a rotation center.
It constitutes a driving wheel member. The rotating arm 82 constitutes a driven wheel member, and is coaxial with the balance gear 80 through a friction portion such as a felt 85, and is made of a sleeve by an elastic member such as a spring 86.
It is attached by pressure contact with the end face of 81. 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-a of the rotating arm 82 is coaxial with the rotating arm 82.
A release lever 83 that engages with a pin 83-b is rotatably mounted, and a pin 83-a provided on one end surface of the release lever 83 is inserted into a hole provided in the chassis substrate 50. It is configured to drive the tension arm. The rotational driving force of the second center pulley 5 is transmitted to the rotating arm 82 through the torque limiter mechanism including the ten-legged gear 80, the sleeve 81, the felt 85, the spring 86, etc., and the appropriate torque is transmitted to the pin 82 via the release lever 83. The portion 83-a rotates the tension arm 62 in the g direction to release the tension band 61 wound around the supply reel stand 32. Torque limiter mechanism consisting of a ten-legged gear 80, rotating arm 82
And the release lever 83 constitutes a back tension release mechanism.

The torque limiter force of the torque limiter is the first
As shown in the figure, the rotation torque of the tension post 60, which is biased by the spring 63, is set smaller than a value within a range in which the contact between the tension post 60 and the magnetic tape 54 does not come off, and As shown in FIG. 3, the tension arm 62 is rotated in the g direction to set the torque within a predetermined range at least capable of releasing the tension band 61 wound around the supply reel stand 32.

The operation of the back tension releasing mechanism will be described in accordance with the mode transition from the forward transfer to the reverse transfer of the tape.

The same system path as that described for the second reel base drive mechanism has already been followed, 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 4, and the second motor.
From the position shown in FIG. 1, the tension arm 62 shown in FIG. 3 supplies the tension band 61 to the tension band 61 through the center pulley 5, the balance gear 80, and the rotating arm 82. The reel base 32 can be moved to a position where the contact relationship can be released, and within a range where the contact between the tension post 60 and the magnetic tape 54 does not separate. After that, the rotational driving force of the second motor 1 is absorbed by the torque limiter mechanism including the ten-legged gear 80 and the like, so that the pin portion 83-a of the release lever 83 comes into contact with the end surface of the tension arm 62. The state shown in FIG. 2B continues. Then, the contact release of the tension band 61 to the supply-side reel stand is maintained. In this way, the back tension applying mechanism is released. The amount of change in the tape length generated by the rotation of the tension post rotated by the back tension release mechanism is the tape reel without causing the slack in the tape by the second reel base drive mechanism described above.
It is rolled up to 18.

The back tension releasing mechanism having the above torque limiter can release the back tension applying mechanism by minimizing the rotation of the tension post. Also, always maintain the contact relationship between the magnetic tape and the tension post,
Since the forward transfer → reverse transfer and the reverse transfer → forward transfer are performed, there is no problem of reproduction signal loss due to Roaki noise at the time of mode transition, and the mode transition time can be minimized.

By the operation shown in FIGS. 1 to 4, with the pinch roller 45 kept in pressure contact with the capstan 23, the magnetic tape can be transferred from the forward direction to the backward direction with good responsiveness without causing slack in the magnetic tape. It can be switched within 1 second.

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. 4, the capstan 23 is stopped to enter the still mode. 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 gear 7 as shown in FIG. Rotate to the position where the mesh is released. Simultaneously with this operation, the release lever 83 is rotated from the position shown in FIG. 4 in the direction as shown in FIG. 5 to release the second brake release mechanism, and the tension band 61 causes the supply reel to rotate. The braking force is applied again to the table 32 to establish the back tension applying mechanism when the magnetic tape is running in the forward direction. The supply-side reel stand 32 is released from the meshing relationship with the second reel stand drive mechanism by the above-mentioned operation. Therefore, depending on the winding amount of the magnetic tape around the tape reel 8, the magnetic tape 54 may be magnetically tensioned by the tape tension of the magnetic tape 54. The tape 54 is slightly rotated in the forward winding direction. However, the tension post 60
A spring 63 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 rotates while contacting the magnetic tape 54 in the direction 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 direction of arrow a-2 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 instantly switch from the forward transfer to the reverse transfer without causing the slack of the magnetic tape while the pinch roller is pressed against the capstan.

Conventionally, in a device that drives a capstan and a pair of reel bases with a single motor, the pinch roller is switched from the forward direction reproduction mode to the backward direction reproduction mode of the magnetic tape while the pinch roller is being pressed against the capstan. At times, the loss of the reproduced signal could not be completely eliminated. Therefore, it is necessary to release the tension band wound around the supply reel stand in order to enable the winding of the supply reel stand when traveling in the reverse direction with only one motor. Therefore, there is a drawback that the response of mode switching from the forward transfer to the reverse transfer is poor. In order to solve the above-mentioned problems, it is necessary to drive the capstan and the pair of reel bases by separate motors, and the motor for driving the reel base is of the same class as the motor driven by the capstan. Control was needed. Moreover, since the motor itself needs a motor having high-precision performance that does not adversely affect wow flutter and image jitter, which are important characteristics, the device is expensive. In addition, in order to switch forward / reverse with good response, it is necessary to cancel the tension band winding around the supply side reel base at the moment of shifting from the forward direction to the reverse direction. It is necessary to use another power source such as a rerenoid to operate the supply-side reel base at the same timing as the winding of the supply-side reel base, which is an apparatus that requires an expensive and complicated configuration. However, according to the present invention, a relatively inexpensive second motor (for example, a brushed motor with a core) can be provided to a conventional device that can be produced at a relatively low cost.
By attaching a reel base drive locking mechanism and a second reel base drive mechanism using this second motor as a power source and a back tension release mechanism, forward / reverse slow motion, forward / reverse frame feed, forward / reverse When switching between playback mode and forward / reverse fast-forward mode, the special playback function that can instantly obtain a playback image without loss of playback signal with high response without giving high tension to the magnetic tape or damaging the tape is easy. Can be given to

Further, when the torque limiter force of the torque limiter configured by the ten-legged gear of the back tension release mechanism shown in this embodiment is made larger than the turning torque of the spring-biased tension post 60, the pin of the release lever 83 is A member that abuts and locks the pin portion 83-a is installed on the chassis 50 so that the balance leg arm is not rotated too much at the portion 83-a and the abutment of the magnetic tape and the tension post is not separated. is necessary.

Further, the torque limiter mechanism constituted by a ten-legged gear and the like for establishing the back tension releasing mechanism shown in the present embodiment is constituted by the second center pulley gear 14 and the like for establishing the second reel base drive mechanism. Needless to say, a torque limiter mechanism used as a substitute can be used for rationalization.

As described above, according to the present invention, the capstan that cooperates with the pinch roller to transfer the magnetic tape in the forward and reverse directions, the first motor that rotationally drives the capstan, and the magnetic tape in the tape cassette. The rotation driving force is transmitted to the supply-side reel stand and the take-up reel stand that engage with the pair of tape reels wound around, and the supply-side reel stand and the take-up reel stand driven by the first motor. The first reel base drive mechanism, the second reel base drive mechanism that transmits the rotational drive force to the supply side reel base, and the second reel base drive mechanism when the rotary drive force is transmitted to the supply side reel base are No. 1 reel stand drive locking mechanism that locks transmission of rotational drive force to the supply side reel stand by the reel stand drive locking mechanism, and a magnetic tape during forward transfer of the magnetic tape by the capstan. Back to A back tension applying mechanism for applying a tension, a back tension releasing mechanism for releasing the back tension applying mechanism when the magnetic tape is transferred in the reverse direction by a capstan, and a still mode for stopping the capstan when switching the transfer direction of the magnetic tape. The second reel base drive mechanism and the second motor for driving the back tension release mechanism substantially at the same time through the second motor are provided to thereby provide the conventional magnetic recording / reproducing apparatus with the following problems. Completely eliminates the problems such as the loss of the playback signal due to the slack of the magnetic tape and the poor response of the mode transition, which occurred when shifting from the forward playback mode due to the forward transfer of the magnetic tape to the backward playback mode due to the backward transfer. Forward / reverse fast forward, forward / reverse slow motion, forward / reverse frame advance, forward / reverse playback mode. At the time of soil regeneration,
It is possible to obtain a reproduced image with no signal loss without damaging the magnetic tape, and at the same time, it is possible to obtain an excellent effect of speeding up the transition between the forward and reverse reproduction modes.

[Brief description of drawings]

1 to 5 are operation state diagrams of the magnetic recording / reproducing apparatus according to the embodiment of the present invention, and FIGS. 6 to 10 are operation state diagrams of the conventional magnetic recording / reproducing apparatus. 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-b ...... First idler arm, 54 ...... Magnetic tape, 34 ...... Rolling control cam gear, 35 ...... Regulation arm, 60 ...... Tension Posts, 62 ... Tension arms, 61 ... Tension bands, 82 ... Rotating arms, 83 ... Release levers.

Claims (1)

[Claims] 1. A capstan for moving a magnetic tape in forward and reverse directions in cooperation with a pinch roller, a first motor for driving the capstan to rotate, and a pair of magnetic tapes wound in a tape cassette. Of the supply-side reel base and the take-up reel base that engage with the tape reel, and the first drive motor that transmits the rotational driving force to the supply-side reel base and the take-up reel base driven by the first motor. A reel base drive mechanism, a second reel base drive mechanism for transmitting a rotational drive force to the supply side reel base, and a second reel base drive mechanism for transmitting the rotary drive force to the supply side reel base, A reel base drive locking mechanism that locks transmission of rotational drive force to the supply-side reel base by the first reel base drive mechanism so as not to transmit, and a magnetic tape is forwardly transferred by the capstan. , Magnetic A back tension applying mechanism for applying a back tension to the cap, a back tension releasing mechanism for releasing the back tension applying mechanism when the magnetic tape is transferred in the reverse direction by the capstan, and a capstan for switching the transfer direction of the magnetic tape. A magnetic recording / reproducing apparatus comprising: a second motor that drives the second reel base driving mechanism and the back tension releasing mechanism at substantially the same time through a still mode in which they are stopped.