JPH01220164A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To instantly give a brake to various members at the time of a mode shifting by setting up a rachet and a slide plate with a pin which moves along a cam groove to enable the pin to move rapidly. CONSTITUTION:At the stopping time, the pin 110 is in a position of A of the 3rd cam groove 108. When a fast forward/rewinding signal is received, a drive motor 5 rotates clockwise, and then a rotational shaft 135 to be rotated by a pulley 11 also rotates clockwise. On the other hand, since a 2nd cam gear 47 rotates anticlockwise, the pin 110 moves in the direction of B, so as to move the slide plate 109 to the right. When the pin 110 arrives in the position of B, the pin 110 is released from the cam surface to move together with the rachet 130 and the slide plate 109 in the direction of C by a spring 133. However, a braking plate 134 is brought into contact on its opposite side surface to a slant surface with the rotational shaft 135, so as to regulate the movement of the rachet 130 to the left, thus performing the fast forward/rewinding operation under these conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording/reproducing device that can quickly achieve stop mode and still mode.

(Prior Art) In a VTR, which is known as a type of magnetic recording and reproducing device, braking force is instantaneously applied to the reel stand or capstan motor when transitioning from fast forward 7 rewind mode to stop mode, or from playback mode to steel mode. It is desirable that unnecessary tape feeding, etc., be prevented from being transferred instantaneously by being given this.For this reason, Japanese Patent Laid-Open No. 62-18644 discloses an example in which the rotation of a rotating shaft interlocked with a drive motor is utilized. According to this embodiment, when the tape moves from fast-forward mode to stop mode, a slight rotation of the rotating shaft causes the ratchet to release the stop on the rotating shaft, and the interlocking brake controls the reel. However, when the cam shifts to stop mode, the ratchet moves again in the direction to release the brake by following the cam groove, so the tape running stops. It is necessary to wait a certain period of time until the capstan motor stops completely (that is, until the capstan motor stops rotating completely) before shifting to stop mode.

[Problems to be solved by the present invention]

As mentioned above, in the prior art, when converting from fast forward/rewind to stop, or from playback to still,
Since it takes a relatively long time, the problem to be solved is to further shorten this time.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a rotating shaft rotated by a drive motor, a cam gear rotated by an output from the rotating shaft, and one end of which is inserted into a cam groove formed on the surface of the cam gear. It has a pin, a slide plate that supports the pin, a control plate that operates in conjunction with the slide plate and operates the main brake, a ratchet that is pivotally supported on the slide plate that receives the biasing force of a spring, and a brake plate provided on the ratchet. The present invention provides a magnetic recording and reproducing device characterized in that the engagement between the brake plate and the rotating shaft is released by rotation of the rotating shaft in one direction, and the ratchet instantly returns to its original position due to the biasing force of a spring.

According to the present invention, the engagement between the brake plate and the rotating shaft is released at least when converting from the fast forward 7 rewind mode to the stop mode and when converting from the playback mode to the steel mode. Further, according to the present invention, the pin is located at the center of the cam groove during the fast forward 7 rewind mode and the playback mode, and is maintained in that position by engagement between the brake plate and the rotating shaft. Furthermore, according to the present invention, the cam groove is composed of an outer circumferential wall, an inner semicircular wall, and a partial wall extending toward the center of the pair, so that the rotating shaft and the brake plate are connected to each other. When disengaged, the pin moves toward the circumferential wall.

[Effect]

According to the present invention, it is possible to instantaneously apply the brake in response to a stop command from a fast-forwarding state and shift to a stop mode while maintaining that state. That is, the motor starts at the same time as the stop command, and the ratchet is released by the slight rotation at the start of the start, and the brake is applied. Furthermore, the cam rotates due to the continuous rotation of the motor from startup, and the cam slide plate that moves the ratchet then follows another cam groove, thereby entering the stop mode while the brake remains in the applied state. Can be migrated. Therefore, since the capstan motor completely stops during this transition period, the time required for mode transition can be shortened.

〔Example〕

) is shown in the attached figure. Figure 1 shows the VT with the case removed.
The top view of the R mechanism is shown, and FIG. 2 shows its bottom view. VT
R1 has a cassette loading mechanism 2 that loads and discharges a tape cassette, a tape loading mechanism 3 that winds or returns the tape to a cylinder, and a tape running mechanism 4 that feeds the tape.

The cassette loading mechanism 2 has a worm wheel 7 that is provided on the shaft of a drive motor 5 and meshes with a rotatable worm 6 that is directly connected to the motor.The worm wheel 7 is connected to a rack 9 via a pinion 8. do. Rack 9
is connected to the mechanism described later (see Figure 32.33), and the first
As shown in the figure, when the rack 9 is moved upward, a cassette is mounted on the chassis, and when the rack 9 is moved downward, it is possible to eject the cart. The worm wheel 7 has a toothless portion 10, and when the toothless portion IO faces the worm 6, that is,
When no power is transmitted from the worm 6 to the worm wheel 9, the tape loading mechanism 3 is operated to transmit the rotational torque of the drive motor 5 only to the tape loading mechanism 3 via the pulley 11 and the reduction gear train 49.

The cassette loading mechanism shown in FIGS. 32 and 33 is used. Inverted-shaped grooves 156 and 157 are bored in the side plates 155 on both sides of the chassis.

A pair of spaced apart pins 159,160 extending laterally from the cassette holder 158 are inserted into the grooves 156,157. The cassette holder 158 will move according to the trajectory defined by the grooves 156, 157. A rack holder 161 is arranged apart from one side plate 155, and pins 162 and 163 fixed to the rack holder 161 are inserted into elongated holes 164 and 165 of the rack 9 to smooth the movement of the rack 9 in the front-back direction. The teeth 166 of the rack 9 mesh with a first gear 167 rotatably supported on the holder 161. A second gear 168 is disposed coaxially with the first gear 167 via a one-way clutch (not shown). 1st
Place the pin 169 on the gear 167 and attach it to the holder 16.
1 into the arc-shaped groove 170, and when installing the cassette pin 16.
9 in the center direction of the end of the groove 170 to create a locked state. Second gear 168 is connected to fourth gear 172 via third gear 171 .

The fourth gear 172 has an arcuate groove 173, and this gear 1
A sector gear 174 is arranged concentrically with 72, and an arm 174a of this sector gear 174 is connected to one end of a lever 175 pivotally supported by a pin 160 via an elongated pin 176. The gear 172 is provided with a through hole 200, and the fan-shaped gear 17
A protruding piece 201 fixed to the gear 172 protrudes from the through hole 200#-, and the protruding piece 201 and the pin 177 fixed to the gear 172 are connected by a spring 178. Note that this spring 178 is inserted into the groove 173.

The fan-shaped gear 174 is biased counterclockwise by the biasing force of the spring 178, and the end 202 of the through hole 200 and the protrusion 20
1 come into contact with each other to prevent rotation of the fan-shaped gear 174, and as a result, the gear 172 and the fan-shaped gear 174 can rotate together. This fan-shaped gear 174 is transmitted to an output gear 180 via an intermediate gear 179, and the rotation of this output gear 180 is transmitted to the gear on the other side plate side, so that the gears on both side plates rotate at the same time.

A similar cassette holder transfer mechanism is provided on the other side plate side. The rotation of the fourth gear 172 is transmitted to the sector gear 174 via the projection 201, and the rotation of the sector arm 174 rotates the arm 174a, causing the pin 160 to move along the groove 157 via the lever 175. move it. pin 159
．． The movement of 160 is caused by the groove 156 of the cassette holder 158.
．． Make a movement along 157. When the cassette loading is completed, the biasing force of the spring 178 allows the cassette to be pressed to a predetermined position on the chassis.

When a cassette is inserted, the drive motor 5 advances the rack 9 and rotates the gears 167.168.171.172. The clockwise rotation of the gear 172 is transmitted to the fan-shaped gear 174 via the pin 177, and the cassette holder 158
The arm 174a is rotated clockwise to move it backward. Eventually, as the holder 158 descends,
Pin 169 enters radially into the end of groove 170 to create a locked condition. Motor 5 is stopped at the same time.

At this point, the cassette is pressed against the chassis. At this time, pin 177 moves away from one end of 1173. Note that the reverse driving force from the fourth gear 172 is transmitted to the gear 16.
7. It is not transmitted to the rack 9 due to the clutch between 168 and 168.

Incidentally, to eject the cassette, the rack 9 is moved forward and the gear 172 is
counterclockwise, and the cassette holder 158 is returned to its original position by the biasing force of the spring 178.

The rotational torque of the drive motor 5 is applied via a motor pulley and a belt to a pulley 11 including a pulley on the motor side and a pulley on the worm 141 side, a worm 141 that receives rotational torque from the pulley 11 using a belt, and meshes with the worm. Worm wheel 142, the worm wheel 14
The small gear 143 is
The signal is transmitted to the first cam gear 12 (see FIG. 2) having a cam groove that meshes with the cam groove, and the rack 15 is reciprocated by swinging the follower 14 following the cam groove 13. U7ri15
The movement rotates the gear 16, opens the pair of links 17, and moves the tape drawer 18 through the guide hole 19 drilled in the chassis.
, the tape is wound around the cylinder 20, and the tape is returned to the cassette by a reverse motion. 21 indicates a tape tension lever.

The tape running mechanism 4 includes a capstan 22, a capstan motor 23, an idler mechanism 24, and a supply reel stand 25 (
SI7-reel stand), take-up reel stand 26 (TIJ-
When the T-reel stand 26 is rotated,
For example, the tape is fed to enable reproduction of magnetic recording, and the rotation of the S-reel base 25 is, for example, to feed the tape to enable fast reversal of the tape.

The basic configuration of an example of the present invention has been briefly described above, and the details thereof will be described below.

Components between the drive motor 5 and the rank 9 that constitute the cassette loading mechanism 2 are shown in FIG. The worm wheel 7 has an identical and integrally molded spur gear 27 and a cam surface 28 with a groove 45 (see Figures 4-11). Spur gear 27 integrated with worm wheel 7
is connected to a rack 9 via a pinion 8, and causes the rack 9 to reciprocate in accordance with the direction of rotation of the worm wheel 7. A first slide plate 30 that is rotatable about a pin 37 with respect to a shaft 29 that rotatably supports the worm wheel 7.
has a downward projecting piece 31 and an upward pin 32. The spring 33 is engaged with the protruding piece 31. Pin 32 is on cam surface 2
The projecting piece 31 faces a horizontal piece 36 of a second slide plate 35 that is slidable along the back surface of a base 34 fixed to the chassis. Second slide plate 3
5 has a pair of elongated holes 35a, 35b, and the pins 34a, 34b planted in the base 34 fit into these elongated holes 35a, 35b.
, and guides the movement of the second slide plate 35. The protruding piece 39 of the first control plate 38 is attached to the second slide plate 35.
A link 44, which has a downwardly facing part 40 facing the cam surface 28 and an upwardly facing part 42 facing the protrusion 41 of the cam surface 28 and receives the biasing force of a spring 43, is rotatably supported.

FIG. 4 shows the relative relationship of the above-mentioned parts when the cassette is being ejected. The worm 6 and the worm wheel 7 mesh near the toothless portion 10, the protruding piece 39 of the first control plate 38 comes into contact with the downwardly facing portion 40 of the link 44, and the pin 32 remains in the illustrated position. When the cassette is inserted and the drive motor 5 is rotated in the direction shown by the arrow in FIG. 5, and the worm wheel 7 is rotated clockwise via the worm 6, the spur gear 27
The pinion 8 rotates and the rack 9 moves rearward (see Fig. 5). The state shown in FIG. 5 is the same as the state shown in FIG. 4 except for the rotation of the worm wheel 7. When the worm wheel 7 further rotates in the clockwise direction, the pin 32 will eventually come to the front of the groove 45 and the worm wheel 7 will mesh with the worm 6 just before the toothless portion 10 of the worm wheel 7. When the pin 32 enters the groove 45 from the state shown in FIG. 6 to the state shown in FIG. The plate 30 rotates clockwise around the pin 37. As a result, the worm wheel 7 is forcibly rotated clockwise following the movement of the first slide plate 3°, the toothless portion 10 faces the worm 6, and the meshing between them is released, so that the worm wheel 7 Torque transmission between the worm wheel 7 and the worm wheel 7 is eliminated. The protruding piece 31 of the first slide plate 30 comes into contact with the piece 36 of the second slide Fi35. In this state, the cassette is placed in a predetermined position. Once this cassette loading is complete, the tape loading operation continues.

FIG. 8 shows a state in which tape loading has started.

The first cam gear 12 and the second cam gear 47 are rotated from the drive motor 5 via the pulley 11 and the reduction gear train 49, but the fourth cam groove 89 of the second cam gear 47 controls the first control it5.38. move it forward. Therefore, the contact between the projecting piece 39 of the first control plate 38 and the downwardly directed portion 40 of the link 44 is released, and the link 44 is rotated clockwise by the spring 43. The rear end of the protruding piece 39 is located at a downwardly facing portion 40.
opposite the front end of. This state is maintained during tape running.

The drive motor 5 is reversed in response to a cassette ejection signal from the system control, and the first and second cam gears 12.
47 in the opposite direction to that shown in FIG. See FIG. 9. The first control plate 38 is connected to the cam groove 89 of the second cam gear 47.
Move backwards. Therefore, the rear end of the protruding piece 39 engages with the downward portion 40 of the link 44, and then the link 44
move backwards. The reverse movement of link 44 is the piece 3
6 pushes the downward projecting piece 31 of the first slide plate 30 backward, and rotates the first slide plate 30 counterclockwise around the support shaft 37 against the biasing force of the spring 33 to move it backward. Slide it to. At this time, the pin 32 of the first slide plate 30 pushes the groove slope 48 and forcibly rotates the worm wheel 7 in the counterclockwise direction, so that the first teeth of the worm 6 and the worm wheel 7 mesh with each other. Worm wheel 7
is rotated by the worm 6. The rotation of the worm wheel 7 is controlled by the pin 32 by the groove slope 46.
is pushed out through the groove 45 and aligned along the cam surface 28. As the worm wheel 7 rotates counterclockwise, the protrusion 41 of the cam surface 28 comes into contact with the right side of the upwardly facing part 42 of the link 44, and moves the link 44 counterclockwise against the biasing force of the spring 43. Rotate. At this time, the projecting piece 39 of the first control plate 38
The engagement between the rear end and the front end of the downwardly facing portion 40 of the link 44 is released, and the link 44 moves forward due to the biasing force of the spring 43. As a result, as shown in FIG. 11, the protrusion 41 of the cam surface 28 is enabled to pass through the rear notch 42a of the upwardly facing portion 42 of the link 44, causing the worm wheel 7 to rotate counterclockwise.

Then, the rack 9 is moved forward to eject the cassette, and when the state shown in FIG. 4 is reached, the leaf switch 13 is activated to detect a signal and the drive motor 5 is stopped.

As is clear from the above, the cassette is loaded and ejected while the worm and worm wheel are engaged,
The tape loading operation is performed when the toothless part of the worm wheel and the worm are opposed to each other and torque transmission from the worm to the worm wheel is cut off. Therefore, −
Two drive motors can perform two tasks. In addition, for example, even if a cassette gets stuck during cassette loading, the worm stops rotating and no rotational torque is transmitted to the tape loading mechanism, so the movement of the tape loading mechanism precedes the movement of the cassette loading mechanism. , without becoming out of sync with the movement of the cassette loading mechanism. Note that during cassette loading, each follower on the 1st to 4th camshafts, which will be described later, moves along the same diameter portion.

The tape loading operation will be described with reference to FIG. The rotational torque from the drive motor 5 is transmitted to the first cam gear 12 via the pulley 11 and the reduction gear train 49. A second cam groove 50 is provided on the back surface of the cam gear 12, and a follower 14 having a pin 51 inserted into the cam groove 50 is held in the chassis so as to be swingable about a fulcrum 52. A rack 15 is attached to the tip of the follower 14.
, supported through the length and pin. The rack 15 has elongated holes 53, 53 on both sides thereof, through which pins fixed to the chassis are passed. As a result, the position of the pin 51 in the cam groove 5o changes in accordance with the rotation of the first cam gear 12, causing the follower 14 to rotate around the pin 52, thereby causing the rack 15 to rotate.
The illustrated example shows a state in which the first cam gear 12 is rotated in the direction of the arrow and the rack 15 is similarly moved in the direction of the arrow.

This rack 15 is made of an elongated plate 54 with an elongated hole drilled below its center, teeth 55 cut on one edge, and the other edge 56 stepped against the teeth 55. The shaft 57 of the small gear that meshes with the teeth 55 is placed along the edge 56. Therefore, during the reciprocating movement of the rack 15, the rack I5 is guided at three points: the elongated holes 53 and 53 that receive the pins fixed to the chassis, and the sliding contact between the shaft 57 and the edge 56. To make the locus of the rack 15 constant and to prevent the rack 15 from warping.

Movement of rack 15 rotates gear 16.16. One of a pair of links 17.17 is fixed to these gears 16.16, and the intermediate sinker is pivotally supported on the fixed link, and the tape drawer 18 is pivotally supported on the intermediate link. The movement of the tape drawer 18 is regulated by guide holes 19, 19 drilled in the chassis. In the illustrated example, the rack 15 is moving backward in the direction of the arrow, but in this case, the gear 16.
16 opens the link 17.17, moves the tape drawer body 18.18 backward along the guide hole 19.19, draws out the tape (not shown) from the cassette, and brings it into contact with the surface of the cylinder 20. . The tape drawer body 18 eventually comes into contact with the stopper at the end of the guide hole 19. To bring a body 18 into reliable and strong contact with a stopper. When returning the tape to the cassette, the tape drawer 18 may be moved forward by operating the cam gear 12 and rack 15 in the direction opposite to the arrow in FIG. Such movement is predetermined by the cam groove 50.

Next, press the pinch roller to the capstan 22 in the first step.
This will be explained with reference to FIG. A first cam groove 58 is provided on the surface of the first cam gear 12, and a follower 60 having a pin 59 inserted into the cam groove 58 is arranged on the chassis so as to be rotatable around the pin 61. An end of a slide plate 62 is pivotally supported at one end of a bell crank-shaped follower 60 via an elongated pin. Pins on the chassis are inserted into elongated holes 63, 63 drilled on both sides of the slide plate 62, and guided by the pins, the slide plate 62 is allowed to move linearly. A pinch roller arm 66 having a pinch roller 64 at one end and rotatable around a pin 65 is connected to the slide plate 62 via a spring 67. The spring 67 attempts to rotate the pinch roller arm 66 counterclockwise around the pin 65 along with the movement of the slide plate 62. pin 68
One end of the tape guide arm 69, which is rotatable around the circumference, is locked to the pinch roller arm 66, and the other end is locked to the spring 70. The motor 5 drives the first cam gear 1
2 in the direction of the arrow, the follower 60 moves into the cam groove 5.
8 to move the slide plate 62 in the direction of the arrow (FIG. 13 shows the rotated state). As a result, the spring 67 rotates the pinch roller arm 66 counterclockwise around the pin 65, presses the pinch roller 64 against the capstan 22, and rotates the tape guide arm 69 clockwise. When the motor 5 is rotated in the reverse direction, the first gum gear 12 and the slide plate 62 operate in the direction opposite to the arrow, rotating the pinch roller 64 clockwise away from the capstan 22. Slide plate 62
The cut and raised portion A pushes the edge B of the pinch roller arm 66, causing the arm 66 to rotate clockwise.

The features of the chassis 71 used in an example of the present invention will be described with reference to FIGS. 14-15. A surface 77 that includes the S reel stand 25 and the T reel stand 26, shafts 72, 73 for these reel stands, intermediate gears 74, 75 that mesh with both reel stands 25, 26, and a shaft 76, 76 for a brake to be described later. is a recessed portion lower than the other main surface 78. As a result, the bottom surface of the cassette 79 is connected to the main surface 7 of the chassis 71.
8, making it possible to make the VTR thinner. The recess 77 is formed by making a plurality of notches 80 in the chassis 71 and pressing or drawing the portion 77 downward. If the recess 77 is not provided, the cassette 79
The bottom surface of is raised by the difference in level between the recess 77 and the main surface 78. Therefore, the capstan 22 needs to be made higher by this height difference, and the VTR becomes thicker accordingly. However, in one example of the present invention, the reel stand is moved to the bottom side of the chassis 71, so the VTR can be made thinner. enable.

Furthermore, as is clearer from FIG. 15, the cassette 7
A band brake 107 is disposed between the lower surface of the chassis 78 and the main surface of the chassis 78, and the intermediate gear 7 is disposed within the recess 77.
By having the main brakes 119 and 120 act on the 4.75 cylindrical portion, it is possible to make the VTR thinner despite the use of the band brake 107 and the main brakes 119 and 120.

Next, from the capstan motor 23 to the reel stand 25.26
The means for transmitting torque to will be explained with reference to FIG. The output shaft of the capstan motor 23 is transmitted to the main gear 81 via a belt 88.

This main gear 81 is meshed with a deceleration bypass gear 82 equipped with a slip mechanism. The output gear of the bypass gear 82 is always meshed with the input gear 84 of a slave gear 83 with a clutch mechanism. However, since the main gear 81, input gear 84, and slave gear 83 are supported on the same shaft, the input gear 8
4 in the direction of the main gear 81, disengages the output gear of the bypass gear 82 with a slip mechanism from the input gear 84, and engages the input gear 84 with the main gear 81. The rotation will be directly transmitted to the slave gear 83. A pair of idle gears 86 and 87 are pivotally supported on a carrier 85 rotatably supported on the chassis 71, and one gear 86 is meshed with the slave gear 83 to form the idler 24. The other gear 87 is the intermediate gear 74 or 7.
5 can be engaged.

FIG. 15 shows a state in which the tape is being fed for reproduction of magnetic recording. The rotational torque from the capstan motor 23 rotates the main gear 81 and the bypass gear 82,
The intermediate gear 75 and the T-reel stand 26 are rotated via the input gear 84, the slave gear 83, and the side gears 86 and 87.

The slip mechanism of the bypass gear 82 is connected to each reel stand 25.
The upper limit of rotational torque to 26 is regulated to limit the application of high torque. When rotating the T-reel stand 26 at high speed, the input gear 84 is slid onto the shaft.
4 and the bypass gear 82, and input gear 84 is removed.
is engaged with the main gear 81. As a result, the rotation of main gear 81 is directly transmitted to slave gear 85.

When the S reel stand 25 needs to be rotated, such as when rewinding the tape, the capstan motor 23 is rotated in the opposite direction. This reverse rotation torque is generated between the slave gear 83 and the idle gear 8.
6, but this torque acts in a direction that separates the other eye gear 87 from the intermediate gear 75, so the eye gear 86 rotates around the center of the eye gear 86, and the other eye gear 87 rotates as the S reel. It meshes with the intermediate gear 75 on the stand 25 side. Due to the slip mechanism in the idler mechanism, the reverse rotation torque presses the idle gear 87 against the intermediate gear 74, causing the intermediate gear 74 and the S reel stand 25 to rotate.

In addition, when rotating the S reel stand 25 quickly, the input gear 84 is engaged with the main gear 81 by operating the clutch, and the rotational torque from the capstan motor 23 is transferred to the secondary gear without passing through the bypass gear 82 for deceleration. The signal is transmitted directly to the gear 83.

By the way, in the tape drive method in which the tape is wrapped around at least a portion of the outer circumferential surface of the cylinder 20, the load caused by the tape being wound around the cylinder 20 at a constant speed is transferred to the pinch roller 64, the capstan 22, and the T side during forward rotation. -Le stand 26
However, since it is received only by the S reel stand 25 during reverse rotation, the winding torque of the reel stands 25 and 26 is set to be larger during reverse rotation than during normal rotation. In this example, in order to obtain different limit torque values for the reel stand on the forward rotation side and the reverse rotation side, the capstan motor 23 is connected to each reel stand 25.
．． The reduction ratio up to 26 is made different. That is, T reel stand 2
6 is made smaller than the gear diameter of the S reel stand 25, and the unwinding torque on the S reel stand 25 side is made larger. in this case,
When the tape runs at high speed for rewinding and fast forwarding, such as in the case of direct connection without using the bypass gear 82 with a slip, the T side reel stand 26 has a higher speed than the S side reel stand 25 for a constant rotation speed of the first gear 86. Since the rotation speed is high, the rewind time and fast forward time for a given amount of tape are related, so when the tape is running at high speed, the rewind RE
Only in step W), the driving force of the capstan motor 23 is increased to make the rewind time equal to the fast forward (FF) time. When the bypass gear 82 is used, such as when the tape is running at a constant speed or during playback, the revue torque is greater than the playback torque, and the initial purpose can be achieved. The rotation speed of the capstan motor 23 can be easily increased using system control, so the winding torque (
(during constant speed driving) can be increased.

By the way, the second cam gear 47 meshes with the first cam gear 12, and the function of this second cam gear 47 is different from that of the first cam gear 12.
This will be explained with reference to Figure 6.17. A protrusion 92 of a driven plate 91 having a fourth cam groove 89 on the back surface of the second cam gear 47 and a pin 90 serving as a follower inserted into this cam groove 89 is connected to the first control plate 38. do. The driven plate 91 is long enough to receive a support shaft of the second gear cam 47 fixed to the chassis and a pair of pins spaced apart from the support shaft, and the reciprocating movement of the driven plate 91 is regulated by these elongated holes. First control board 38
is coupled to a second control plate 93 via a connecting plate 92. The connection plate 92 is connected to the T-side soft brake 94.
It controls the contact of the T-side soft brake 94, which is in contact with one end and receives the biasing force of the spring 95, with the T-reel stand 26. An S-side soft brake 98, which has a pin 96 inserted into a cam hole 95 at the left end of the second control plate 93 and is rotatable about a fulcrum 97, receives the biasing force of the spring 59 to
Trying to contact the reel stand 25. Pin 96 is in cam hole 9
5, the S side soft brake 98 rotates clockwise and separates from the S reel stand 25, releasing the braking force.

The tape tension lever 21 attempts to rotate counterclockwise around the fulcrum 100 by the spring 101;
One end of the lever 103, which is swingable around the pin 102, restricts this rotation. The other end of the lever 103 is connected to a bell crank 104, and a pin 105 fixed to one end of the bell crank 104 is connected to the cam surface 10 on the side edge of the second control plate 93.
6 as the contact point. One end of the band 107 wound around half the circumference of the S reel stand 25 is rotatably attached to the tension lever 21. When the second control plate 93 moves leftward from the position shown in FIG. 16 and reaches a position where the pin 105 faces the cam surface 106, the bell crank 104 and the lever 10
Rotation due to the urging force of the spring 101 of No. 3 is allowed,
The bell crank 104 rotates counterclockwise, the lever 103 rotates clockwise about the pin 102, and the pin 105 falls along the cam surface. As a result, the tape tension lever 21 is moved from the fulcrum 10 by the biasing force of the spring 101.
The lever 21 can be rotated counterclockwise around 0.
Press the tip pole of the band 107 against the tape and
The tape is wound around the reel stand 25 and back tension is applied to the tape.

A third cam groove 108 is provided on the surface of the second cam gear 47. A pin 110 is supported in the cam groove 10 so that it can freely reciprocate in the vertical direction on a slide plate 109 whose reciprocating locus is regulated by a combination of a pair of long, spaced apart pins and a pin on the chassis side.
Insert into 8. A part of the slide plate 109, which can be reciprocated from side to side in the figure by the cam groove 108, comes into contact with a link 112 which is rotatable about a fulcrum 111, and a part of this link 112 can be reciprocated relative to the chassis. The third control plate 113 is brought into contact with the rear end of the third control plate 113 supported by the third control plate 113 . Third control board 113
The front end of the fourth control plate 11 is connected horizontally through a long hole and a pin.
Connect to 4. The fourth control plate 114 is made reciprocatable with respect to the chassis by using a length and a pin.

The capstan brake 115 constantly rotates counterclockwise about the fulcrum 117 under the biasing force of the spring 116 and attempts to come into contact with the outer peripheral surface of the capstan motor 23 . Therefore, the protrusion 118 of the fourth control plate 114 is moved to the left, and the capstan brake 115 is moved to the fulcrum 117.
When rotated clockwise around the center, the braking force on the capstan motor 23 is released, and the fourth control plate 11
4 moves to the right, the protruding piece 118 separates from the capstan brake 115, and the biasing force of the spring 116 brings the capstan brake 115 into contact with the capstan motor 23, thereby applying the brake.

An S-side main brake 119 and a T-side main brake 12 apply braking force to an intermediate gear 74 that rotates the S reel stand 25 and an intermediate gear 75 that rotates the T reel stand 26.
Set 0. S side main brake 119, pin 122
It is rotatable around , and has a portion that can come into contact with the intermediate gear 74 and a pointed end 121 on the front side thereof. The T-side main brake 120 is rotatable around a pin 123, and has a portion that can contact the intermediate gear 75, a circular arc portion 124 on the front side to receive the tip portion 121, and a left end of the fourth control plate 114. It has an accessible portion 125. Both main brakes 11
9.120 are connected by a spring 126 so that both main brakes 119.120 can contact the rain intermediate gear 74.75 and apply a braking force. Fourth control board 1
14 is connected by the cam groove 108 to the link 111 and the third
When it is moved to the left via the control plate 113, its left end pushes the portion 125 of the T-side main brake 120,
The T-side main brake 120 is rotated clockwise to release the braking force on the intermediate gear 75, and one end of the arcuate portion 124 pushes up the pointed end 121 of the S-side main brake 119, causing the S-side main brake to rotate. 119 is rotated counterclockwise against the biasing force of spring 126 to release the braking force on intermediate gear 74. When the fourth control plate 114 is released from its contact with the left end portion 125, the spring 126 moves both main brakes 119, 120 to the intermediate gear 74.
75. As shown in FIG. 17, the piece 127 of the second control plate 93 pushes a part of the S-side main brake 119 to the right and pushes its pointed end 121 with the arcuate part 124 of the T-side main brake 120. If it is allowed to float, only the S-side brake 119 can be brought into a brake-released state. 128
is a clutch actuator, which is actuated as described below.

As mentioned above, the third cam groove 10 is used for the action of each brake.
8 plays a big role. The third cam groove 10B is the 18th cam groove 10B.
As shown in the figure, it consists of a raised part with a hand point and a part that slopes downward from a to b. The portion not marked with a hammer point becomes a groove surface with which the pin 110 slides. Furthermore, the movement of the pin 110 along the groove surface of the cam groove 10B reciprocates the slide plate 109, which is always urged leftward in FIG. 19 by the spring 133, and this movement causes the link 1
Although it has already been explained that the recontrol plates 113 and 114 are actuated through the slide plate 12, the slide plate 109 made of a metal plate is also rotatably arranged around a pin 129 provided on the slide plate 109. The ratchet 130 is made of a synthetic resin material. This ratchet 130 can be lifted by a pin 110 in contact with the third cam groove 108. A part of another ratchet 131 rotatably supported on the slide plate 109 side is able to come into contact with the tip of the ratchet 130, and connects both ratchets 130 and 131 with a spring 132. This spring 130 causes another ratchet 131 to rotate counterclockwise. Therefore, the other ratchet 131 is always the ratchet 130.
The spring 133 urges the slide plate 109 that does not come into contact with the slide plate 109 to the left.

The ratchet 130 has a braking plate 134 facing downward and having a tapered surface.
09 moves to the right by the third cam groove 108 and pin 110, the tapered surface of the brake plate 134 moves toward the pulley 1.
1, the rotating shaft 135 is overcome, and the state shown in FIG. 23 is reached, and when the rotating shaft 135 is rotating clockwise, a braking force is applied to the rotating shaft 135. On the other hand, when the rotating shaft 135 is rotated counterclockwise, this brake plate 13
4 is flipped upward to release the braking relationship between the braking plate 134 and the rotating shaft 135.

Finally, the operation of clutch actuator 128 will be described.

As already mentioned, the clutch is configured such that the rotation of the capstan motor 23 is directly connected to the reel stand side, or a pin 145 provided at 144 on the chassis is used to freely rotate the inner IC. The main lever 144 has a long piece 128 with elastic force of the actuator 128.
One end of a is slidably received. Separately, a sub lever 146 is rotatably supported on a pin 147 on the main lever side. The sub lever 146 is connected to the main bar 144 via a spring 148, and a piece 149 abuts against a side wall of the main lever 144. Further, the sub-lever 146 has a fork portion, and one leg 150 is connected to the protruding piece 1 of the fourth control plate 114.
18 and the other leg 151 contacts the protruding piece 118 facing the protruding piece 152 of the second control plate 93 against one leg 150, and the pin 14↓ is rotated counterclockwise around the pin 145. Rotate it. For this reason, the main lever 144 is
The third lever 154 is rotated clockwise around the pin 153 while elastically deforming the piece 128a.
directly connects the input gear 84 to the main gear 81 (see FIG. 30). In this state B (fast forward/@reverse), the actuator 128
The piece 128a tends to return the main lever 144 clockwise along with the spring 148 by its elastic force. Therefore, when the fourth control plate 114 moves to the right, the piece 128
a When the steel is in use, the fourth control plate 114 is moved to the left in order to apply the capstan brake 115. At this time, the piece 118 pushes the one leg 150, creating a direct connection between the gears. need to be avoided. On the other hand, when steel is used, the second control plate 93 is moved to the left in order to activate the back tension lever 21, so this movement is used to bring the protruding piece 152 into contact with the other leg 151. This abutment is achieved by rotating the secondary lever 146 clockwise around the pin 147 and moving one leg 150 to the protruding piece 11.
8 (see Figure 31).

Therefore, even if the fourth control plate 114 is moved to the left in order to apply the capstan brake 115, the protrusion 11
There is no contact between the leg 8 and the leg 150. In this way, the gears are not directly connected when steel is used.

Having described the configuration of the VTR 1 as an example of the present invention, the function of the above-described configuration in each mode will be explained with reference to FIG.

During cassette loading to attach the cassette to a predetermined position on the mechanism body, the pin 110 is inserted into the third cam groove 19.
At this time, the piece 38a of the first control plate 38 is positioned to the right of the ratchet 131 of the slide plate 109 due to the fourth cam groove. ,
While the slide plate 109 is moving to the right, the ratchet 131 comes into contact with the piece 38a, and when it moves further to the right, the ratchet 131 rotates clockwise around the pin 131a, and the arm 131b of the ratchet 131 rotates clockwise about the pin 131a. According to
Since one ratchet 130 is lifted counterclockwise around the pin 129, the slide Fi
109 moves to the left (in FIG. 28, it moves from point G to point E, and rapidly moves from the point where the floating portion marked with the hammer point is missing to point F). Then move on to the next tape load day.

(Stop - Fast forward 7 rewind) When stopped, the pin 110 is at position A of the third cam groove 108 shown in FIG. 28, but is moved to B by the counterclockwise rotation of the second cam gear 47. and slide plate 109
to the right, move the third control plate 113 forward and the fourth control plate 114 to the left via the link 112, and set the S side and T side main brakes 119 and 120 to the rain intermediate gear. 74.75, the capstan brake 125 is separated from the capstan motor 23, and the clutch 128 directly connects the main gear 81 to the slave gear 85. In addition, during the movement of the pin 110 from A to B, the fourth cam groove 89 causes the second control plate 93 to
The side soft brake 94 is released from the T reel stand 26, and the S side main brake 119 and the control plate 93 are set in a free state.

Thus, the states shown in FIGS. 19 to 23 are obtained.

In this state, the tape is directly wound up by the rotation of the capstan motor 23. Fast forward 7 times backward (FF/REW) at position B.

During this fast forwarding and rewinding, as shown in FIG. 30, the protruding piece 118 of the fourth control plate 114 pushes the leg 150, and the actuator 128 brings the clutch into the direct connection state with the main gear.

Referring to Figures 19-23, slide this time. In this state, the slide plate 109 and the ratchet 130 are
It is located as shown in Figure 9. When receiving the fast forward 7 rewind signal,
The drive motor 5 rotates clockwise (see Fig. 20),
The rotating shaft 135 rotated by the pulley 11 also rotates clockwise.

On the other hand, since the second cam gear 47 rotates counterclockwise (see Fig. 28), the pin 110 moves in the direction of barb B', and the slide plate 109 moves to the right (see Fig. 20). . At this time, the control plate 134 of the ratchet 130 comes into contact with the rotating shaft 135, and the ratchet 130 moves to the right while rotating counterclockwise around the pin 129 along the rotating shaft 135, and eventually the center of the rotating shaft. When it passes through, it is rotated clockwise by the force of the spring 132, and the state shown in FIG. 22 is reached. The state shown in FIG. 22 shows that the pin 110 has come to position B' in FIG. 28. In this example, the drive motor 5 is further operated to move the pin 110 to position B. Since the pin 110 at position B is released from the cam wall surface, the pin 110 attempts to move in the direction C together with the ratchet 130 and slide plate 109 due to the biasing force of the spring 133. However, the surface of the braking plate 134 opposite to the slope comes into contact with the rotating shaft 135 and restricts the leftward movement of the ratchet 130, resulting in the state shown in FIG. will be carried out.

(Fast forward 7 rewind one stop) At the time of fast forward 7 rewind FF/REW), the pin 110 is at position B of the third cam groove 10B, but upon receiving the stop signal, the FC brake is applied to the capstan motor 23. ,
That is, when electrical braking is applied by applying a reverse bias and the drive motor 5 reverses in the counterclockwise direction as seen in FIG. As a result, the slide plate 109 is instantly moved leftward by the spring 133 (see FIG. 25), and the pin 110 moves from B to C in the cam groove. Clockwise rotation of the second cam gear 47 lifts the pin 110 (as shown in Figure 26).
) It moves from position D to position A through the tapered surface, changing from the state shown in FIG. 23 to the state shown in FIG. 19. B to C
The instantaneous movement of the pin 110 to immediately moves the third control plate 113 backwards and the fourth control plate 114 to the right, causing the S-side and T-side main brakes 119.120 to shift to the intermediate gear 74.75. The capstan motor 115 brakes the capstan motor 23. Furthermore, clutch 1
2B is released, and the rotation of the main gear 81 is transmitted to the slave gear 83 (see FIG. 15) via the bypass gear 82 with a slip. While the pin 110 is moving from C to A via D, the pin 110 is lifted by a tapered groove surface formed at an angle so as to rise from C to A only between C and A. Braking plate 134 of ratchet 130 and rotating shaft 1
The engagement with 35 is released. Note that during this transition from C to A, the cam groove 89 of the second cam gear 47 causes the first and second
The second control plate 38.93 is activated, and this movement causes the portion 127 of the second control plate 93 to come into contact with the S-side main brake 119, thereby reversing only the S-side main brake 119.

Rotate in the needle direction to release the braking force on the intermediate gear 74. This immediately releases the tape tension that occurs when the tape is stopped, loosening the tape tension against the cylinder head and preventing tape damage.

This prevents damage (the state shown in Figure 17). Further, the connecting plate 92 releases the braking force of the T-side soft brake 94 on the T-reel stand 26.

By the way, in this embodiment, as described above (when transitioning from the fast forward or rewind state to the stop state), mega braking force is instantaneously applied to both reel stands by the main brakes 119 and 120, and instantaneously The system enters a stopped state and prevents unnecessary tape feeding, but on the other hand, this instantaneous braking action may cause the tape tension to increase rapidly and cause damage to the tape. Simultaneously with the mode transition to , the FG brake is activated on the capstan motor 23, that is, reverse bias is applied to apply electrical braking, and the delay time (
After ΔT), when the rotational speed of the capstan motor 23 has decreased to a certain extent, the drive motor 5 is activated to activate the instantaneous brake by the main brakes 119 and 120, thereby increasing the tape tension while minimizing excessive tape feeding. This makes it possible to prevent a rapid increase.

However, in this case, when the end of the tape (rider tape or trailer tape) is detected by the tape end sensor mechanism consisting of an LED and a light receiving element, the FC brake is applied to the capstan motor 23 and the main brakes 119 and 120 are instantaneously applied. It is necessary to operate the tape to stop the tape and prevent the tape from swinging off at the end of the tape.

(Stop-Regeneration) When receiving the regeneration signal, the first cam groove 58 of the first cam gear 12 and the pinch arm 66 press the pinch roller 64 against the capstan 22 before the steel mode.

On the other hand, the clutch 128 engages the main gear 81 with the bypass gear 82 in the stop mode, but when passing through the fast forward 7 rewind mode, the main gear 81 is engaged with the bypass gear 82 by the movement of the fourth control plate 114 instructed by the third cam groove 108. The gear 81 is directly connected to the slave gear 83, and when the regeneration mode is entered, the main gear 81 is connected by the movement of the second control plate 93 instructed by the fourth cam groove 89.
meshes with the bypass gear 82 with a slip. on the other hand,
The fourth cam groove 89 moves the second control plate 93 to the left,
By rotating the bell crank 104 counterclockwise and the lever 103 clockwise, the tension lever 21 causes the band brake 107 to act on the S reel stand 25 and applies pack tension to the tape. At this time, the connection plate 92 separates the T-side soft brake 94 from the T-side wheel, and the fourth control plate 114 separates the capstan brake 115 from the capstan motor. Further, both main brakes 119 and 120 are separated from the intermediate gears 74 and 75 due to the leftward movement of the second control plate 93, and the S-side soft brake 98 is also separated from the S-side reel.

It should be noted that the pin 110 in contact with the third cam groove 108 moves through AB to position E in FIG. 28 during playback. During this movement, the control plate 134 contacts the rotating shaft 135 and restricts the leftward movement of the slide plate 109.

(Playback → Steal (including slow)) In the playback mode, the state is shown in FIG. 22, and the drive motor 5 is stopped. When the steel signal is input, motor 5
rotates in the opposite direction, and by counterclockwise rotation of the rotary shaft 135, the rotary shaft 135 is moved by the brake plate 134 using the friction of the brake plate 134.
is instantly flipped up from the rotating shaft 135 (see FIG. 24), and the slide plate 109 moves to the left to instantly move the pin 110 from E to F (see FIG. 25). Second
When the cam gear 47 rotates in the clockwise direction, the pin 110 has a tapered groove surface (between F and G as well as between C and A).
(which is inclined to rise to
(See FIG. 26), the ratchet 130 rotates counterclockwise about the pin 129 to release the engagement between the brake plate 134 and the rotating shaft 135.

The pin 110 is displaced from position F to position G during steeling.

At position G, the pin 110 is lowered again, resulting in the state shown in FIG.

As described above, when the slide plate 109 instantaneously moves to the left due to the springing of the brake plate 134 from the rotating shaft 135, the spring 137 immediately moves the third control plate 113 backward, and the protrusion 118 immediately moves to the right. (see FIG. 17), and the capstan brake 115 is instantly applied to the capstan motor 23.

In this state, the portion 138 of the second control plate 93 comes into contact with a portion of the T-side main brake 120, and both main brakes 119 and 120 are released.

Furthermore, since the clutch actuator 128 is in the state shown in FIG. 31 at the time of steel, a power transmission path using a bypass gear 82 with a slit is adopted.

(Still→Regeneration) The pin 110 moves from G to E as seen in FIG. 28, and the ratchet 130 makes a false movement as shown in FIGS. 19-22 as described above. To move the slide plate 109 to the right, use the link 11.
2, against the biasing force of the spring 137, the third
control plate 113 is advanced. This movement of control plate 113 moves fourth control plate 114 to the left, releasing capsun brake 115. There is no change in the clutch 128 or both main brakes 119 and 120.

(Reproduction-Review) In this mode change, it is necessary to separate the back tension lever 21 from the tape and bring the T-side soft brake 98 into contact with the T-side rail stand.

When the fourth cam groove 89 moves the second control plate 93 further to the left, the cam surface 106 rotates the bell crank 104 clockwise, causing the lever 103 to rotate counterclockwise. Therefore, the tension lever 21 rotates clockwise,
The winding of the band 107 around the S reel stand 25 is loosened to release the back tension on the tape. The forward movement of the first control plate 38 causes the connection plate 92 to prevent the T-side soft brake 94 from contacting the T-reel stand 26 with the spring 95.
made possible by

(Review You Play) In Rev You mode, pin 110 moves from E to I. When a signal is sent from Rev You to return to play, motor 5
is reversed counterclockwise and pin 110 is H for pose.
Pass through position and return to position E. At this time, the fourth cam groove 89 releases the back tension on the tape and releases the T-side soft brake 94. Despite the counterclockwise rotation of the pin 110 relative to the cam groove 10B, the wall surface 1
39 restricts the return of the slide plate 109 to the left by the spring 133. Therefore, the rotating shaft 135 and the brake plate 134 are in the state shown in FIG. 22, and the engagement between them is not released even though the motor 5 is reversed counterclockwise.

(Playback-Cassette Ejection) In this mode change, the motor 5 reverses and the pin 110 moves from E→F-G-C→A-F (along wall 140)→G
-4 Passes the trajectory of C→D. When the pin 110 moves from E to F, the fourth contact plate 114 instantly moves to the right.

As is clear from the above description, in this example, the tape loading and pinch roller operating mechanisms are connected to the first cam gear 12 side, and the brake, clutch, and tension mode operating mechanisms are connected to the second cam gear 47 side. connect,
A mechanism operation section and a mode control section are differentiated for each cam gear. In this way, a small gear is arranged coaxially with the second cam gear 47, which plays an especially important role in mode control, and this small gear is connected to the gear 144 (
(see Figure 2). Therefore, the second cam gear 47
The rotation angle from the reference point is detected by a rotary encoder via the gear 144, and the system control confirms each of the above-mentioned modes based on this detection signal and controls the movement of each device.

As mentioned above, the second and fourth control plates 93.114 are
Since the chassis 71 reciprocates from side to side as seen in FIGS. 16 and 17, it is necessary to ensure that the locus of this movement is always constant. Generally, the chassis 71
A pin is planted in the control plate 93.114, and the pin is passed through the long hole drilled in the control plate 93.114.
．． 114, but in this example, the 14th
As shown in the figure, cut-out portions 144 and 145 are formed in a part of the chassis 71 in place of the pins.

These cut-out portions 144 and 145 form the chassis 71.

It is perpendicular to the ground and has a wide mountain-like part. For this reason,
As shown in FIG.
One end of the elongated hole in the receiving control plate 93, 114 is made large in dimension in a direction perpendicular to the long longitudinal direction to enable insertion into the elongated hole in the cut-and-raised portion 144, 145. In addition, these cut-out portions 144 and 145 not only serve as guides for the control plates 93 and 114, but also serve as members whose tops support the cassette 79 in parallel with the chassis 71, allowing one member to perform two functions. Make it. Also, the cut-out portion 144.14
5 can be done at the same time as machining the chassis 71, thereby eliminating the need for attaching the pins and the cassette supporter.

〔effect〕

In the present invention, a cam groove is formed on the surface of a cam gear rotated by a drive gear, a ratchet and a slide plate are combined with a pin that moves by the cam groove, and when the braking plate of the ratchet is engaged with the rotating shaft, Even when the pin is separated from the cam wall, it remains in place and when this engagement is released, the constant stroke pin moves instantaneously. In this way, since the existing cam gear is applied to enable quick movement of the pin, instantaneous braking can be applied to various members during mode transition without complicating the device.

It is also cheaper than using a plunger solenoid.

Furthermore, since a cam gear is used, the motor etc. can be placed in one corner of the chassis, allowing other parts to be placed in the center of the chassis.

[Brief explanation of the drawing]

Fig. 1 is a front view of a VTR according to an example of the present invention with the case removed, Fig. 2 is a bottom view thereof, Fig. 3 is an exploded perspective view of the worm wheel with missing teeth, and Figs. 4-11 are the worm and the worm wheel. FIG. 12 is a plan view showing the tape loading mechanism, FIG. 13 is a plan view showing the mechanism for pressing the pinch roller onto the capstan, and FIG. 14 is a plan view showing the tape loading mechanism. Partial perspective view, Figure 15 is a side view showing the tape feeding mechanism, Figures 16-17 are the first
Fig. 18 is a plan view showing the movement of each part operated by the cam gear, Fig. 18 is a plan view of the third cam groove, Fig. 19-2
Figure 6 is a front view showing the relative relationship between the slide plate, ratchet, and rotating shaft, Figure 27 is a chart showing the movement of each part in each mode, and a plane view showing the movement of the clutch actuator in reverse and steel modes. 32 is a side view of the cassette loading mechanism as seen from the arrow direction XXXn-xxxn in FIG. 1, and FIG. 33 is a plan view of the cassette loading mechanism. In the figure = 2... cassette loading mechanism, 3... tape loading mechanism, 4... tape running mechanism, 5...
... Drive motor, 6... Worm, 7... Worm wheel, 10... Missing tooth part, 12.47... Worm gear, 15... Hook, 20... Cylinder, 21
... Tape tension lever, 22 ... Capstan, 23 ... Capstan motor, 24 ... Idler mechanism, 25.26 ... Reel stand, 32 ... Pin, 38.93.113. 114...control board, 94.9
8... Soft lever, 115... Capstan brake, 119.120... Main brake.

Claims (5)

[Claims] (1) A rotating shaft rotated by a drive motor, a cam gear rotated by the output from the rotating shaft, a pin whose one end is inserted into a cam groove formed on the surface of the cam gear, a slide plate that supports the pin, It has a control plate that operates in conjunction with the slide plate and operates the main brake, a ratchet that is pivotally supported on the slide plate that receives the urging force of a spring, and a brake plate provided on the ratchet, and a brake plate that connects the brake plate and the rotating shaft. A magnetic recording/reproducing device characterized in that the engagement is released by rotation of a rotating shaft in one direction, and the ratchet instantly returns to its original position by the force of a spring. (2) Claim 1, wherein the disengagement between the brake plate and the rotating shaft is performed at least when converting from fast forward/rewind mode to stop mode and from playback mode to steel mode. magnetic recording and reproducing device. (3) In the fast forward/rewind mode and in the playback mode, the pin is located in the center of the cam groove and is maintained in that position by engagement between the brake plate and the rotating shaft. magnetic recording and reproducing device. (4) The cam groove consists of an outer circumferential wall, an inner semicircular wall, and a partial wall extending toward the center of the pair, so that when the rotating shaft and the brake plate are disengaged, the pin is 4. The magnetic recording/reproducing device according to claim 3, wherein the magnetic recording/reproducing device moves toward a circumferential wall. (5) During the transition from fast forward/rewind mode to stop mode, after the rotation speed has decreased due to the FG brake applied to the capstan motor, an instantaneous brake is applied to the reel stand, and when the tape end is detected, the capstan motor is A magnetic recording/reproducing device characterized in that an FG brake is applied and an instantaneous brake is applied to a reel stand at the same time.