JPH0563876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording/reproducing device with an improved chassis.

[Conventional technology]

A magnetic recording/reproducing device basically has a cassette loading mechanism, a tape loading mechanism, and a tape running mechanism. The tape running mechanism applies rotational torque to a supply reel stand and a rewind reel stand that engage with the reels in the cassette, a gear train including a brake that meshes with both reel stands and constitutes a speed reduction device, and a gear train. It has a capstan motor, and these parts are arranged on the front and back surfaces of the chassis.

Conventionally, a reel stand is engaged with a reel in a cassette and placed on a chassis to create a tape running standard surface for the chassis. Once this tape running reference plane is determined, the positions of the capstan, the pulley fixed to the capstan motor, the gear train, etc. relative to the chassis are inevitably determined.

[Problems to be solved by the present invention]

Adoption of the conventional method results in a large dimension between the tape running reference surface and the chassis surface, which increases the thickness of the magnetic recording/reproducing device accordingly, which goes against the desire for thinning. In fact, it has been a long-held desire to make this type of device thinner, and it is hoped that it will be realized as soon as possible.

Therefore, it is an object of the present invention to solve the above-mentioned problems of the prior art by reconsidering the method of taking the conventional tape running reference surface.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention has developed a means for bringing the tape running reference surface closer to the chassis. and provides a configuration in which the bottom surface of the cassette is brought close to the main surface.

A large number of holes are made between the recess and the other main surface of the chassis, and a press or drawing process is performed to create a step between the recess and the other main surface. An intermediate gear that meshes with the reel stand is arranged within the recess.

[Effect]

As before, the seed gear that receives rotational torque from the capstan motor, the bypass gear with a slip, and the slave gear with a clutch are arranged on the main surface of the chassis, and a part of the idler gear, an intermediate gear, and a reel stand are placed in the recess. , so there is no problem with tape running.

〔Example〕

As an example of the present invention, a magnetic recording/reproducing device for home use (hereinafter referred to as "video"), commonly known as a video
VTR) is shown in the attached diagram. Figure 1 shows the top of the VTR mechanism with the case removed, and Figure 2 shows the bottom. The VTR 1 includes a tape cassette device, a cassette loading mechanism 2 for ejecting the tape, a tape loading mechanism 3 for winding or returning the tape to a cylinder, and a tape running mechanism 4 for feeding the tape.

The cassette loading mechanism 2 is driven by a drive motor 5
It has a worm wheel 7 that is provided on the axis of the motor and meshes with a rotatable worm 6 that is directly connected to the motor.
This worm wheel 7 is connected to a rack 9 via a pinion 8. The rack 9 is connected to a mechanism described later (see Figures 32 and 33), and when the rack 9 moves upwards as seen in Figure 1, a cassette can be mounted on the chassis, and when the rack 9 moves downwards, the cassette can be ejected. Let it be. Worm wheel 7 has missing teeth 1
0, and when the toothless portion 10 faces the worm 6, that is, when the worm wheel 9 is moved from the worm 6
Tape loading mechanism 3 when there is no power transmission to
to apply the rotational torque of the drive motor 5 to the pulley 1.
1 and a reduction gear train 49, the signal is transmitted only to the tape loading mechanism 3.

The cassette loading mechanism is shown in Figures 32 and 33.
Use what is shown in the diagram. Inverted L-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 and outwardly from the cassette holder 158 are inserted into the groove 15.
6,157. Cassette holder 158
will move according to the locus determined by the grooves 156 and 157. A rack holder 161 is arranged apart from one side plate 155, and pins 162, 163 fixed to the rack holder 161 are inserted into elongated holes 164, 165 of the rack 9 to smooth the movement of the rack 9 in the longitudinal direction. Rack 9 tooth 1
66 meshes with a first gear 167 rotatably supported on the holder 161. A second gear 166 is disposed coaxially with the first gear 167 via a one-way clutch (not shown). A pin 169 is set up on the first gear 167 and inserted into the arc-shaped groove 170 of the holder 161. When the cassette is installed, the pin 169 is inserted into the central part of the end of the groove 170 to create a locked state. the second gear 168 and the third gear 171
It is connected to the fourth gear 172 via.

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

Due to the biasing force of the spring 178, the fan-shaped gear 17
4 is biased counterclockwise, and the end 2 of the through hole 200
02 and the protruding piece 201 come into contact with each other to prevent rotation of the sector gear 174, and as a result, the gear 172 and the sector gear 174 can rotate together. This fan-shaped gear 174 is connected to an output gear 180 via an intermediate gear 179.
The rotation of the output gear 180 is transmitted to the gear on the other side plate, and the gears on both side plates rotate at the same speed. 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 protrusion 201, and the rotation of the sector arm 174 rotates the arm 174a, which moves the pin 160 along the groove 157 via the lever 175. move it. Pin 159, 160
The movement of the groove 156 of the cassette holder 158,
Make a movement along 157. When cassette loading is completed, the biasing force of spring 178 allows the cassette to be pressed to a predetermined position on the chassis.

When the cassette is inserted, the drive motor 5 advances the rack 9 and the gears 167, 168, 171,
Rotate 172. The clockwise rotation of gear 172 is transmitted to sector gear 174 via pin 177, which rotates arm 174a clockwise to move cassette holder 158 rearward.
Eventually, as the holder 158 descends, the pin 169 enters the end of the groove 170 in the radial direction, creating a locked condition. Motor 5 is stopped at the same time.
At this point, the cassette is pressed against the chassis. At this time, the pin 177 moves away from one end of the groove 173. Note that the reverse driving force from the fourth gear 172 is not transmitted to the rack 9 due to the clutch between the gears 167 and 168.

In order to eject the cassette, the rack 9 is advanced, the gear 172 is rotated counterclockwise, and the cassette holder 158 is ejected by the biasing force of the spring 178.
return to its original position.

The rotational torque of the drive motor 5 is transmitted to the motor side pulley and worm 1 via the moder pulley and belt.
A pulley 11 including the pulley on the 41 side, a worm 141 that receives rotational torque from the pulley 11 using a belt, and a worm wheel 1 meshing with the worm.
42, the first cam gear 12 (having a cam groove that meshes with the small gear 143) via a reduction gear train 49 consisting of a small gear 143 (see Fig. 4-13) that rotates coaxially and integrally with the worm wheel 142; (see FIG. 2) and follows the cam groove 13.
By swinging the rack 15, the rack 15 is reciprocated. The movement of the rack 15 rotates the gear 16, opens the pair of links 17, moves the tape drawer 18 along the guide hole 19 bored in the chassis,
Wrap the tape around the cylinder 20 and return the tape to the cassette by reversing the motion. 21 indicates a tape tension lever.

The tape running mechanism 4 includes a capstan 22, a capstan motor 23, an idler mechanism 24, a supply reel stand 25 (referred to as an S reel stand), and a take-up reel stand 26 (referred to as a T reel stand). Rotation of the S-reel table 25 advances the tape to enable, for example, reproduction of magnetic recording, and rotation of the S-reel base 25 advances the tape, for example, to enable fast reversal of the tape.

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

Components between the drive motor 5 and the rack 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). The spur gear 27 integrated with the worm wheel 7 is the pinion 8.
is connected to the rack 9 through the worm wheel 7.
The rack 9 is reciprocated depending on the direction of rotation. 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. While the pin 32 is in sliding contact with the cam surface 28,
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 35
has a pair of elongated holes 35a, 35b, and the pins 34a, 34b planted in the base 34 fit into these elongated holes 35.
a and 35b, and guides the movement of the second slide plate 35. This second slide plate 35 has a downwardly facing portion 40 facing the protrusion 39 of the first control plate 38.
and an upwardly facing portion 4 facing the protrusion 41 of the cam surface 28.
2 and receives the biasing force of a spring 43, the link 44 is rotatably supported.

FIG. 4 shows the relative relationship of the above-mentioned parts when the cassette is 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 eventually comes to be immediately in front of the groove 45, and the portion immediately before the toothless portion 10 of the worm wheel 7 is engaged with the worm 6. From the state shown in FIG. 6 to the state shown in FIG. 7, the pin 32 is inserted into the groove 4.
5, the pin 32 of the first slide plate 30 presses the groove slope 46 with the force of the spring 33.
The first slide plate 30 rotates clockwise around the pin 37. As a result, this first slide plate 30
Following the movement, the worm wheel 7 is forcibly rotated clockwise, and the toothless portion 10 faces the worm 6 to eliminate the meshing therebetween, thereby transmitting torque between the worm 6 and the worm wheel 7. Eliminate. The protruding piece 31 of the first sliding plate 30 faces the piece 36 of the second sliding plate 35. In this state, the cassette is placed in a predetermined position. Once this cassette loading is completed, the tape loading operation begins.

FIG. 8 shows a state where 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.
The fourth cam groove 89 of No. 7 moves the first control plate 38 forward. For this reason, the projecting piece 39 of the first control plate 38
The contact between the downward 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 are rotated in the opposite direction to that shown in FIG. See FIG. 9. The first control board 38
is moved rearward by the cam groove 89 of the cam gear 47. Therefore, the rear end of the projecting piece 39 engages with the downwardly facing portion 40 of the link 44, and then the link 44 is moved rearward. 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 about the support shaft 37 against the biasing force of the spring 33. Slide it backwards. At this time, the pin 32 of the first slide plate 30
8 and forcibly rotate the worm wheel 7 in the counterclockwise direction, so that the first tooth of the worm 6 and the worm wheel 7 mesh with each other, and the worm wheel 7
is rotated by the worm 6.
This rotation of the worm wheel 7 causes the groove slope 46 to push out the pin 32 through the groove 45, and the cam surface 28
to follow. As the worm wheel 7 rotates counterclockwise, the protrusion 41 of the cam surface 28 is rotated against the link 4.
4, and rotates the link 44 counterclockwise against the biasing force of the spring 43. At this time, the engagement between the rear end of the protruding piece 39 of the first control plate 38 and the front end of the downwardly directed portion 40 of the link 44 is released, and the link 44 is moved forward by the biasing force of the spring 43. As a result, as shown in FIG. 11, the protrusion 41 of the cam surface 28
The worm wheel 7 is rotated counterclockwise by allowing passage through the rear notch 42a of the upwardly facing portion 42 of the worm wheel 7. 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, a signal is detected, and the drive motor 5 is stopped.

As is clear from the above, when the worm and worm wheel are engaged, the cassette is installed and
The tape loading operation is performed when the worm is discharged, the toothless portion of the worm wheel and the worm are opposed to each other, and the torque transmission from the worm to the worm wheel is cut off. Therefore, one drive motor can perform two tasks. In addition, for example,
Even if the cassette gets stuck during cassette loading, the worm stops rotating and no rotational torque is transmitted to the tape loading mechanism.The movement of the tape loading mechanism precedes the movement of the cassette loading mechanism. The movement of the cassette loading mechanism will not become out of sync. Incidentally, during cassette loading, each follower of 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 on the chassis so as to be swingable about a fulcrum 52. Rack 15 at the tip of follower 14
is supported through an elongated hole and a pin. Rack 15
has elongated holes 53, 53 on both sides thereof, and a pin fixed to the chassis is passed through these elongated holes. As a result, the position of the pin 51 in the cam groove 50 changes in accordance with the rotation of the first cam gear 12, and the position of the pin 51 in the cam groove 50 changes, causing the follower 14 to
2 to reciprocate the rack 15. 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 a long and narrow plate 54 with a long and narrow hole drilled below its center, teeth 55 cut on one edge, and a step on the other edge 56 relative to the teeth 55. The shaft 57 of the small gear that meshes with this tooth 55
along the edge 56. Therefore, during the reciprocation of the rack 15, the rack 15 is guided at three points: the elongated holes 53, 53 that receive the pins fixed to the chassis, and the sliding contact point between the shaft 57 and the edge 57. To make the locus of the rack 15 constant and to prevent the rack 15 from warping.

Movement of rack 15 rotates gears 16,16. These gears 16, 16 have a pair of links 1
7 and 17 are fixed, an intermediate link is pivotally supported on the fixed link, and a tape drawer body 18 is pivotally supported on the intermediate link. The movement of the tape drawer 18 is regulated by guide holes 19, 19 bored in the chassis. In the illustrated example, the rack 15 is moving backward in the direction of the arrow; in this case, the gear 1
6 and 16 open the links 17 and 17, and move the tape drawer bodies 18 and 18 backward through the guide hole 1.
9, 19 and tape (not shown)
is pulled out from the cassette and brought into contact with the surface of the cylinder 20. The tape drawer 18 eventually opens into the guide hole 1.
It comes into contact with the stoppers at the ends of 9 and 19, but at this time,
The pin 51 inserted into the second cam groove 50 is guided so as to be drawn inward from the outer circumferential direction of the cam groove 50, so that the tape can be wound around the cylinder 20 at a predetermined angle even though the load on the motor 5 is small. ,
Ensure that the tape drawer 18 is at the stopper, and
Make strong contact. When returning the tape to the cassette, operate the cam gear 12 and rack 15 in the opposite direction to the arrow in FIG.
8 should be moved forward. Such movement is predetermined by the cam groove 50.

Next, pressing the pinch roller onto the capstan 22 will be described with reference to FIG. 13. A follower 60 with a first cam groove 58 formed on the surface of the first cam gear 12 and a pin 59 inserted into the cam groove 58
is placed on the chassis so that it can rotate freely 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 hole and a pin. Elongated holes 6 drilled on both sides of the slide plate 62
A pin on the chassis is inserted into 3 and 63, and guided by the pin, the slide plate 62 is allowed to move linearly. It has a pinch roller 64 at one end and a pin 6
A pinch roller arm 66 rotatable about 5 is connected to the slide plate 62 via a spring 67. The spring 67 is connected to the pinch roller arm 66
is to be rotated counterclockwise around the pin 65 along with the movement of the slide plate 62. One end of the tape guide arm 69, which is rotatable around the pin 68, is locked to the pinch roller arm 66, and the other end is locked to the spring 70. When the first cam gear 12 is rotated in the direction of the arrow by the motor 5,
The follower 60 is rotated counterclockwise by the cam groove 58 (FIG. 13 shows the rotated state) and moves the slide plate 62 in the direction of the arrow. As a result, the spring 67 pushes the pinch roller arm 66 into the pin 65.
The pinch roller 64 is pressed against the capstan 22, and the tape guide arm 69 is rotated clockwise. When the motor 5 is rotated in the opposite 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. The cut and raised portion A of the slide plate 62 pushes the edge B of the pinch roller arm 66 and the arm 6
Rotate 6 clockwise.

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

Furthermore, as is clearer from FIG. 15, a band brake 107 is disposed between the lower surface of the cassette 79 and the main surface of the chassis 78, and
By applying the main brakes 119, 120 to the cylindrical parts of the intermediate gears 74, 75 disposed inside, the band brake 107 and the main brakes 119, 1
Despite the use of 20 mm, it is possible to make the VTR thinner.

Next, from the capstan motor 23 to the reel stand 2
The means for transmitting torque to 5 and 26 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 normally engaged with the input gear 84 of the slave gear 83 equipped with a clutch mechanism. However, main gear 81
Since the input gear 84 and the slave gear 83 are supported on the same shaft, the input gear 84 is connected to the main gear 81.
When the output gear of the bypass gear 82 with a slip mechanism and the input gear 84 are disengaged and the input gear 84 is engaged with the main gear 81, the rotation of the main gear 81 is caused by the rotation of the slave gear. 83. A pair of idle gears 8 are connected to a carrier 85 that is rotatably supported on the chassis 72.
6 and 87, and one gear 86 is connected to the slave gear 8.
3 to form an idler 24. The other idle gear 87 can mesh with the intermediate gear 74 or 75.

FIG. 15 shows a state in which a tape is being fed for reproduction of magnetic recording. The rotational torque from the capstan motor 23 rotates the main gear 81, bypass gear 82, input gear 84, and slave gear 8.
3. Rotate the intermediate gear 75 and the T-reel stand 26 via the idle gears 86 and 87. The slip mechanism of the bypass gear 82 is connected to each reel stand 25, 26.
The upper limit of rotational torque 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, the input gear 84 and the bypass gear 82 are disengaged, and the input gear 84 is engaged with the main gear 81. As a result, the rotation of the main gear 81 is directly caused by the rotation of the slave gear 8.
5.

When it is necessary to rotate the S reel stand 25, such as when rewinding the tape, the capstan motor 2
Rotate 3 in the opposite direction. This reverse rotation torque attempts to reversely rotate the slave gear 83 and the idle gear 86, but this torque acts in a direction to separate the other idle gear 87 from the intermediate gear 75, so that the idle gear 87 is supported. The carrier 85 rotates around the center of one idle gear 86, and meshes the other idle gear 87 with the intermediate gear 75 on the S reel 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 7
4 and the S reel stand 25 are rotated. When the S reel stand 25 is to be rotated 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 transmitted without passing through the bypass gear 82 for deceleration. Follow gear 83
transmitted directly to.

By the way, in the tape drive method in which a tape is wound around at least a portion of the outer peripheral surface of the cylinder 20,
During normal rotation, the pinch roller 64, capstan 22, and T-side reel stand 26 receive the load caused by the constant-speed tape wrapping around the cylinder 20, but during reverse rotation, the load is received only by the S reel stand 25, so the reel stand The winding torques 25 and 26 are set to be larger during reverse rotation than during forward rotation. In this example,
In order to obtain different values of the limit torque of the reel stand on the forward rotation side and the reverse rotation side, the reduction ratio from the capstan motor 23 to each reel 25, 26 is made different. That is, the gear diameter of the T reel stand 26 is made smaller than the gear diameter of the S reel stand 25, and the rewinding torque on the S reel stand 25 side is made larger. In this case, the T-side reel stand 26 is faster than the S-side reel stand 25 for a constant rotational speed of the idle gear 86 when the tape runs at high speed during rewinding and fast-forwarding, such as in the case of direct connection without using the bypass gear 82 with a slip. Since the number of revolutions is higher, the relationship is that rewinding time < fast forwarding time for a given amount of tape. Therefore, when the tape is running at high speed, the drive speed of the capstan motor 23 is increased only for rewinding (REW). Return time = 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 objective can be achieved. Capstan motor 23
Since increasing the rotation speed can be easily done through system control, the winding torque during reverse rotation (when running at constant speed) can be increased without increasing the number of parts.

By the way, the second cam gear 47 meshes with the first cam gear 12.
7 will be explained with reference to FIGS. 16 and 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 has a pair of elongated holes for receiving the support shaft of the second gear cam 47 fixed to the chassis and a pin spaced apart from the support shaft.
The reciprocating motion of 1 will now be regulated by the elongated hole. The first control plate 38 is coupled to the second control plate 93 via a connection plate 92. Connection plate 92
is in contact with one end of the T-side soft brake 94 and controls the contact of the T-side soft brake 94, which receives the biasing force of the spring 95, with the T-reel stand 26. Second
It has a pin 96 inserted into the cam hole 95 at the left end of the control plate 93 and is rotatable about a fulcrum 97.
The side soft brake 98 is about to contact the S reel stand 25 under the biasing force of the spring 59.
When the pin 96 enters the cam hole 95, 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 about the fulcrum 100 by the spring 101, but one end of the lever 103, which is swingable about the pin 102, restricts this rotation. The other end of the lever 103 is connected to a bell crank 104, and a pin 10 is fixed to one end of the bell crank 104.
5 is allowed to freely come into contact with the cam surface 106 on the side edge of the second control plate 93. One end of a band 107 that wraps 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, rotation of the bell crank 104 and the lever 103 by the biasing force of the spring 101 is permitted. and bell crank 10
4 rotates counterclockwise, the lever 103 rotates clockwise around the pin 102, and the pin 105 falls along the cam surface. As a result, the tape tension lever 21 is moved by the biasing force of the spring 101.
The lever 21 can be rotated counterclockwise about the fulcrum 100, and the tip pole of the lever 21 is brought into pressure contact with the tape, and the band 107 is wound around the S reel stand 25, giving back tension to the tape.

A third cam groove 10 is formed on the surface of the second cam gear 47.
8 will be provided. A pin 110 supported in a vertically reciprocating manner by a slide plate 109 whose reciprocating locus is regulated by a combination of a pair of spaced elongated holes and a pin on the chassis side is inserted into the cam groove 108. 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 rear end of the third control plate 113 supported by the third control plate 113 is brought into contact with the third control plate 113 . The front end of the third control plate 113 is connected to a horizontally oriented fourth control plate 114 via an elongated hole and a pin. The fourth control plate 114 is made reciprocatable relative to the chassis using elongated holes and pins.

The capstan brake 115 has a spring 1
16, it constantly rotates counterclockwise about the fulcrum 117 and attempts to contact the outer circumferential surface of the capstan motor 23. Therefore, when the protrusion 118 of the fourth control plate 114 is moved to the left and the capstan brake 115 is rotated clockwise about the fulcrum 117, the braking force on the capstan motor 23 is released. , and the fourth control board 11
4 moves to the right, the protruding piece 118 separates from the capstan brake 115, and the spring 116
The urging force causes the capstan brake 115 to come into contact with the capstan motor 23, and the brake is applied.

The S-side main brake 119 and T
A side main brake 120 is provided. The S-side main brake 119 is rotatable around a pin 122 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.
Spring 1 for both main brakes 119 and 120
26, both main brakes 119, 120
contacts both intermediate gears 74, 75 and can apply a braking force. Fourth control board 114
is moved to the left by the cam groove 108 via the link 111 and the third control plate 113, its left end pushes the portion 125 of the T-side main brake 120, causing the T-side main brake 120 to move clockwise. The brake force on the intermediate gear 75 is released, and one end of the arc portion 124 pushes up the pointed end 121 of the S-side main brake 119, causing the S-side main brake 119 to move counterclockwise toward the spring 1.
26 to release the braking force on the intermediate gear 74. When the fourth control plate 114 is released from contact with the left end portion 125, the spring 126 causes both the main brakes 119, 12
0 is brought into contact with intermediate gears 74 and 75. Furthermore, the first
As shown in FIG. 7, the piece 127 of the second control plate 93
, pushes a part of the S-side main brake 119 to the right and pushes the tip 121 of the S-side main brake 119 to the T-side main brake 1.
20, it is possible to bring only the S-side brake 119 into the brake-released state. 1
28 is a clutch actuator, which is actuated as described below.

As mentioned above, the third cam groove 108 plays a large role in the action of each brake. Third cam groove 1
08, as shown in FIG. 18, consists of a raised part with a hand point and a part inclined downward from a to b. For parts without hand points, pin 11
0 is the groove surface that comes into sliding contact. Moreover, the movement of this pin 110 along the groove surface of the cam groove 108 causes the spring 1
As already explained, the slide plate 109, which is always biased to the left in FIG. , the slide plate 109 made of this metal plate is also the slide plate 1
It has a ratchet 130 which is rotatably arranged around a pin 129 provided at 09 and is made of a synthetic resin material. This ratchet 130 is connected to the third cam groove 10.
It can be lifted by a pin 110 in contact with 8. A part of another ratchet 131 rotatably supported on the side of the slide plate 109 can come into contact with the tip of the ratchet 130, and connects both the ratchets 130, 131 with a spring 132.
This spring 130 causes another ratchet 131 to rotate counterclockwise. Therefore, another ratchet 131 does not always come into contact with the ratchet 130. The slide plate 109 is urged leftward by a spring 133.

The ratchet 130 has a brake plate 134 facing downward and having a tapered surface. When the slide plate 109 moves rightward from the state shown in FIG. 19 by the third cam groove 108 and the pin 110, the brake plate 1
The tapered surface of 34 overcomes the rotating shaft 135 rotated by the pulley 11, resulting in the state shown in FIG. 23, and applies a braking force to the rotating shaft 135 when the rotating shaft 135 is rotating clockwise. On the other hand, when the rotary shaft 135 is rotated counterclockwise, the brake plate 134 is flipped upward and the braking relationship between the brake plate 134 and the rotary shaft 135 is released.

Finally, the operation of the clutch actuator 128 will be described. As already mentioned, the clutch can connect the rotation of the capstan motor 23 directly to the reel stand side, or
Alternatively, a selection is made as to whether to input the signal to the bypass gear 82 side. See Figures 29A and B-31. The main lever 144 is rotatable around a pin 145 provided on the chassis. The main lever 144 slidably receives one end of the elastic long piece 128a of the actuator 128. Apart from this, the secondary lever 14
6 is rotatably supported on a pin 147 on the main lever side. The sub-lever 146 is connected to the main lever 144 via a spring 148, and a piece 149 abuts against a side wall of the main lever 144. Further, the secondary lever 146 has a fork portion, one leg 150 faces the protrusion 118 of the fourth control plate 114, and the other leg 151 faces the protrusion 152 of the second control plate 93. .

The fourth control plate 114 moves to the left in FIG. 29A, brings the protrusion 118 into contact with one leg 150, and rotates the pin 147 counterclockwise about the pin 145. Therefore, the main lever 144 is
45 and rotate clockwise around the pin 153 while elastically deforming the piece 128a.
The third lever 154 connects the input gear 84 directly to the main gear 81 (see FIG. 30). The state (fast forward/
During rewinding), the piece 128a of the actuator 128 attempts 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
The elastic force of a and the spring 148 automatically bring both levers 144, 146 into the state shown in FIG. 29A.

During still operation, the fourth control plate 114 is moved to the left in order to operate the capstan brake 115.
Press 50 to create a direct gear connection, so you need to avoid this. On the other hand, during still operation, the second control plate 93 is moved to the left in order to activate the back tension lever 21, and this movement is used to bring the protrusion 152 into contact with the other leg 151. This contact causes the secondary lever 146 to rotate clockwise around the pin 147, thereby positioning one leg 150 below the protruding piece 118 (see FIG. 31).
Therefore, even if the fourth control plate 114 is moved to the left in order to apply the capstan brake 115, the protruding piece 118 and the leg 150 do not come into contact with each other. In this way, there is no need to connect gears directly during still shooting,
The rightward movement of the second control plate 93 causes the spring 148 to bring the secondary lever 146 into the state shown in FIG. 29A.

Having explained 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. 27.

During cassette loading to attach the cassette to a predetermined position on the mechanism body, the pin 110 passes through point G of the third cam groove 108 and moves toward point E, but at this time, the pin 110 passes through point G of the third cam groove 108 and moves to point E. Since the piece 38a of the first control plate 38 is located to the right of the ratchet 131 of the slide plate 109, the piece 38a of the first control plate 38 is located on the right side of the ratchet 131 of the slide plate 109.
1 comes into contact with the piece 38a and moves further to the right, the ratchet 131 rotates clockwise around the pin 131a, and the arm 1 of the ratchet 131 rotates clockwise around the pin 131a.
31b, one ratchet 130 is connected to pin 1.
Since it can be lifted counterclockwise around 29,
Spring 1 without engaging rotating shaft 135
33, the slide plate 109 moves to the left (in FIG. 28, it moves from point G to point E, and rapidly moves from the place where the floating part marked with a hand point is missing to point F). . Then prepare for the next tape loading operation. During tape loading, the pin 110 is moved from point F to point A through the wall 140.
Move to a point.

(Stop→Fast forward/Rewind) When stopped, the pin 110 moves to the third position shown in FIG.
The cam groove 108 is at position A, but is moved to position B by the counterclockwise rotation of the second cam gear 47, and the slide plate 109 is moved to the right, and via the link 112, the third control Move the plate 113 forward and the fourth control plate 114 to the left, move the S side and T side main brakes 119, 120 away from both intermediate gears 74, 75, and capstan brake 125. The clutch 128 also 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 actuate the T-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. Perform fast forward/rewind (FF/REW) at position B.

During this fast forwarding/rewinding, as shown in Figure 30, the fourth
The protruding piece 118 of the control plate 114 presses the leg 150,
The actuator 128 engages the clutch and brings the gears into direct connection.

The relationship between the slide plate 109 and the pin 110 will be described once again with reference to FIGS. 19-23. When stopped, the pin 110 is located at point A in FIG. In this state, slide plate 109 and ratchet 1
30 is located as shown in FIG. When receiving the fast forward/rewind signal, the drive motor 5 rotates clockwise (see FIG. 20), and 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 bar B', and the slide plate 109 moves to the right (the 20th
(see figure). At this time, Ratchet 130
The control plate 134 contacts the rotating shaft 138, and the ratchet 130 moves to the right while rotating counterclockwise around the pin 129 along the rotating shaft 135.
After passing through the center of the rotating shaft, spring 1
It rotates clockwise with a force of 32, and eventually reaches the state shown in FIG. The 22nd state is shown in Figure 28.
This shows that the pin 110 has come to position B'. In this example, the drive motor 5 is further operated, and the pin 11
Move 0 to position B. Since the pin 110 at position B is released from the cam wall surface, it 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 on the opposite side to the slope comes into contact with the rotating shaft 135, and the ratchet 130
23 is obtained, and fast forwarding/rewinding is performed in this state.

(Fast forward/rewind → stop) When fast forwarding/rewinding (FF/REW), pin 1
10 is at position B of the third cam groove 108,
FG to capstan motor 23 upon receiving stop signal
Applying the brake, that is, applying reverse bias to apply electrical braking, and the drive motor 5
When reversed in the counterclockwise direction as shown in the figure, the brake plate 134
The ratchet 130 instantly flips up due to friction with the rotating shaft 135 (see FIG. 24). As a result, the slide plate 109 is instantly moved to the left by the spring 133 (see FIG. 25), and the pin 1
10 moves from B to C in the cam groove. The clockwise rotation of the second cam gear 47 passes through the tapered surface that lifts the pin 110 (the state shown in FIG. 26).
It moves from position A to position A, changing from the state shown in FIG. 23 to the state shown in FIG. 19. Pin 1 from B to C
10 instantly moves the third control plate 113 backward and the fourth control plate 114 to the right, and the S-side and T-side main brakes 119, 120
brakes the intermediate gears 74 and 76, and the capstan brake 115 brakes the capstan motor 23. Furthermore, the clutch 128 is released and the main gear 8
1 is transmitted to a slave gear 83 (see FIG. 15) via a bypass gear 82 with a slip. C
During the movement of pin 110 from D to A,
The pin 110 is lifted only between C and A by a tapered groove surface formed so as to rise from C to A, and is lifted by the brake plate 13 of the ratchet 130.
4 and the rotating shaft 135 are disengaged. During the transition from C to A, the first and second control plates 38 and 93 are actuated by the cam groove 89 of the second cam gear 47, and this movement causes the portion 127 of the second control plate 93 to move to S. The S-side main brake 119 comes into contact with the S-side main brake 119, and only the S-side main brake 119 is rotated counterclockwise, thereby releasing the braking force applied to the intermediate gear 74. As a result, the tension on the tape generated when the tape is stopped is immediately released, the tape tension against the cylinder head is loosened, and damage to the tape is prevented (the state shown in FIG. 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, the main brake 11 is instantly applied to both reel stands.
9 and 120 apply a mechanical braking force to the tape to instantly bring it to a halt and prevent excessive tape feeding, but on the other hand, this instantaneous braking action causes a sudden increase in tape tension, leading to damage to the tape. There can also be concerns. Therefore, at the same time as the mode transitions from the fast forward or rewind state to the stop state, the FG brake is activated on the capstan motor 23, that is, a reverse bias is applied to electrically brake the capstan motor 23, and the delay time (ΔT ) When the rotational speed of the capstan motor 23 decreases to a certain extent, the drive motor 5 is activated and the main brakes 119,1 are activated.
20 can be activated to prevent a sudden increase in tape tension while minimizing excessive tape feeding.

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

(Stop → Regeneration) When the regeneration signal is received, 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 is
In the stop mode, the main gear 81 is engaged with the bypass gear 82, but when passing through the fast forward/rewind mode, the third
the fourth control plate 1 directed by the cam groove 108 of
14 directly connects the main gear 81 to the slave gear 83, and furthermore, when the regeneration mode is entered, the fourth cam groove 8
9, the main gear 81 is shifted to the bypass gear 82 with slip.
mesh with. On the other hand, the fourth cam groove 89 moves the second control plate 93 to the left, rotates the bell crank 104 counterclockwise and the lever 103 clockwise, and uses the tension lever 21 to rotate the band brake 107. act on the S reel stand 25 and give back tension to the tape. At this time, the connection plate 92 separates the T-side soft brake 94 from the T-side reel, and the fourth control plate 114 separates the capstan brake 115 from the capstan motor. Also, both main brakes 119,1
20 becomes 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 also becomes separated from the S-side reel.

Note that the pin 110 in contact with the third cam groove 108
is moving through A-B 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→Still (including slow)) In the playback mode, the state is as shown in FIG. 22, and the drive motor 5 is stopped. When the steel signal is input, the motor 5 rotates in the opposite direction, and the rotation shaft 135 is rotated counterclockwise to move the rotation shaft 135 to the brake plate 134.
Using the friction of
The slide plate 109 moves to the left so that 0 is instantly moved from E to F (see FIG. 25). Second
The clockwise rotation of the cam gear 47 is caused by the pin 110
passes through the tapered groove surface (the section between F and G is sloped upward from F to G in the same way as between C and A), so it is lifted (see Fig. 26), and the ratchet 130 touches the pin 129. The control plate 134 is rotated counterclockwise around the center to release the engagement between the control plate 134 and the rotating shaft 135. During stilling, the pin 110 is displaced from position F to position G. At position G, the pin 110 descends again,
The state shown in FIG. 19 is reached.

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 part 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 during still operation, a power transmission path using a bypass gear 82 with a slit is adopted.

(Still → Playback) The pin 110 moves from G to E as seen in FIG. 28, and the ratchet 130 moves to the 19th -
Perform the movements shown in Figure 22. The slide plate 109 is moved to the right by the spring 1 via the link 112.
The third control plate 113 is moved forward against the urging force of 37. This movement of control plate 113 moves fourth control plate 114 to the left, releasing capstan brake 115. There is no change in the clutch 128 or both main brakes 119, 120.

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

When the fourth cam groove 89 moves the second control plate 93 further to the left, the cam surface 106
04 clockwise and the lever 103 counterclockwise. Therefore, the tension lever 21 rotates clockwise to loosen the band 107 around the S reel stand 25 and release the back tension on the tape. First control board 38
The forward movement of the connecting plate 92 allows the T-side soft brake 94 to come into contact with the T-reel stand 26 by means of a spring 95.

(Review You → Play) In the Rev You mode, pin 110 is moving from E to I. When a signal is sent from REV-U to return to playback, motor 5 reverses counterclockwise and pin 11
0 returns to E position through H position for pause. At this time, the fourth cam groove 89 releases the back tension to the tape and releases the T-side soft brake 94. Despite this counterclockwise rotation of pin 110 relative to cam groove 108, wall surface 1
39 is a slide plate 109 by a spring 133
regulated the return to the left. For this reason, the rotating shaft 1
35 and the brake plate 134 are in the state shown in FIG. 22, and their engagement 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 (wall surface 140
)→G→C→D path. 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,
A tape loading and pinch roller operating mechanism is connected to the first cam gear 12 side, and a brake, clutch, and tension mode operating mechanism is connected to the second cam gear 47 side, so that each cam gear has a mechanism operating part and a mode. It is distinguished from the control section. In this way, the second
A small gear is arranged coaxially with the cam gear 47, and this small gear is connected to the gear 1 on the rotary encoder (not shown) side.
44 (see Figure 2). Therefore, the rotation angle of the second cam gear 47 from the reference point is the same as the gear 144.
This detection signal is used by the system control to confirm each of the above-mentioned modes and control the movement of each device.

As mentioned above, the second and fourth control plates 93,1
14 reciprocates from side to side with respect to the chassis 71 as seen in FIGS. 16 and 17, so it is necessary to ensure that the locus of this movement is always constant. Generally, a pin is planted on the chassis 71,
This pin is passed through the elongated hole drilled in the control plates 93, 114, and the combination of the pin and the elongated hole
In this example, the 14th reciprocating motion is guided.
As shown in the figure, cut and raised portions 144 and 145 are formed in a part of the chassis 71 instead of the pins. The cut-out portions 144 and 145 are substantially perpendicular to the chassis 71 and have wide mountain-like portions.
Therefore, as shown in FIG. 17, one end of the elongated hole in the control plates 93, 114 that receives the cut-out portions 144, 145 is made larger in the direction perpendicular to the longitudinal direction of the elongated hole, and cut. This allows the raised portions 144 and 145 to be inserted into the elongated holes. Furthermore, the 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. do. Further, since the cut-out portions 144 and 145 can be made at the same time as processing the chassis 71, the work of attaching the pins and the cassette supporter is unnecessary.

〔effect〕

By providing a recess in the chassis for arranging the reel stand and bringing the tape running reference surface close to the other main surface of the chassis, the inner box for the cassette and the top plate can be moved approximately the height difference between the recess and the main surface of the chassis. This makes it possible to make the VTR even thinner.

[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 a worm wheel with missing teeth, and Fig. 4-
Fig. 11 is a plan view showing the relative relationship between 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. FIG. 15 is a side view showing the tape feeding mechanism; FIGS. 16-17 are plan views showing the movement of each component operated by the first cam gear; FIG. 19-26 is a plan view of the third cam groove; FIGS. 19-26 are front views showing the relative relationships among the slide plate, ratchet, and rotating shaft;
The figure is a chart diagram showing the movement of each part in each mode, Figure 28 is a plan view showing the movement of the pin along the third cam groove, Figures 29A and B-31 are stop, fast forward/reverse, A plan view showing the movement of the clutch actuator in steel mode, Fig. 32 is the arrow direction XXX in Fig. 1 showing the cassette loading mechanism.
-XXX side view and FIG. 33 are plan views of the cassette loading mechanism. In the diagram: 2...cassette loading mechanism, 3...
...Tape loading mechanism, 4... Tape traveling 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, 1
14... Control board, 94, 98... Soft lever,
115... Capstan brake, 119, 12
0...Main brake.

Claims (1)

[Claims] 1. A supply reel stand and a take-up reel stand that interlock with the reel in the cassette, a tape drive capstan,
and a magnetic recording/reproducing device having a single chassis having at least a tape running mechanism, wherein the surface of the chassis including both the reel stands is recessed relative to the other main surface, and the bottom surface of the cassette is brought close to the main surface. A magnetic recording/reproducing device characterized by: