JPS58153255A - Magnetic tape device - Google Patents

Abstract

PURPOSE:To prevent a magnetic tape end from being damaged by a tape guide, etc., by separating a pinch roller and a capstan temporarily from each other and changing running directions, and absorbing variation in the running height of a magnetic tape immediately. CONSTITUTION:On a shaft 24 implanted at one end of a pinch roll lever 22, the pinch roller 192 is supported rotatably, and the pinch roller lever 22, coupling arm 36, and press-contacting lever 32 constitute a toggle mechanism. At the other end of the press-contacting lever 32, a pin 46 is provided so that it extends toward the back surface of a device through a hole formed in a substrate 2 and abuts on a bent part 21 provided to a main rod 48. The press-contacting lever 32 rotates clockwise continuously to move down against the energizing force of a tension spring 44 under the guidance of a long-sized hole 28 and at the same time, the pinch roller 192 is pressed against the capstan 72 with specific press-contacting pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves pulling out a magnetic tape from a cassette incorporating a pair of reel hubs for winding a magnetic tape, and attaching the magnetic tape at a predetermined angle to a rotating magnetic head drum installed outside the cassette to generate a signal. More specifically, a magnetic tape device that records or plays back a magnetic tape operates in accordance with the direction of rotation of a capstan motor that works in conjunction with a pinch roller to rotate a capstan in the forward and reverse directions, allowing the pre-containing magnetic tape to travel at a constant speed. The magnetic tape device, such as a video tape recorder, is equipped with a transmission means for selectively transmitting the magnetic tape to a reel base on the winding side of a pair of reel bases that engage with the pair of reel hubs. This is intended to solve the problem that occurs when the magnetic tape is pulled out of the cassette and attached to the rotating magnetic head drum, and the running direction of the magnetic tape is switched while reproducing signals. In other words, the above-mentioned magnetic tape device has a simple structure for driving the rotation of the capstan and the rotation of the reel.
Moreover, since it can be realized with only one motor, it is an excellent method for reducing weight and cost. However, the magnetic tape is pulled out from the cassette, attached at a predetermined angle to a rotating magnetic head drum installed outside the cassette, and the running of the magnetic tape is switched while reproducing signals. For example, when transitioning from a replay mode to a high-speed reverse replay mode, separate motors are used to drive the rotation of the reel and the rotation of the capstan. In the so-called two-motor system, in response to a capstan reversal command, the reel drive motor is reversed to switch the reel stand that winds the magnetic tape, or the reel drive motor is reversed to ensure that the reel stand is capable of winding the magnetic tape. After the magnetic tape starts rotating in the direction in which it can be wound, the capstan is delayed and then reversed to start running the magnetic tape in the opposite direction. However, in the method described above, the reel base is driven by the rotation of the capstan motor, so the capstan is reversed and cooperates with the pinch roller to run the magnetic tape backwards. However, the reel stand is not switched and driven immediately in response to the reversal of the capstan, and a time delay inevitably occurs.
When the cab 1 stun is reversed, the magnetic tape becomes slack, and the magnetic tape and the rotating magnetic head drum are not sufficiently attached, resulting in significant disturbances in the reproduced image.
The present invention solves this problem and provides a magnetic tape device capable of reproducing images without disturbance when changing the running direction of the magnetic tape even in the above-mentioned system. It is.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

1 to 4 show top views in each state of this embodiment. In the figure, a take-up reel stand 10 and a supply reel stand 12, which are rotatably loosely fitted to shafts 4 and 6 implanted on the upper surface of the substrate 2, are connected to a cassette 2o when the cassette 2o is attached to a predetermined position on the main body of the apparatus. ) 20 respectively engages with the take-up reel hub 14 and the supply reel hub 16, and both the reel stands 10, 12
It can be rotated integrally by the claw 8 provided in the. FIG. 5 shows a sectional view of the reel stand drive system, and the take-up reel stand 10. The supply reel stands 12 each have a reel gear 30 , 40 , which is connected to a shaft 50 mounted on the substrate 2 .
．． The take-up reel idler gear unit 62 and the supply reel idler gear unit 62, which are loosely and rotatably fitted into the reel 60, are engaged with each other and driven to rotate. The take-up reel idler gear unit 62 and the supply reel idler gear unit 62, as shown in FIG. A take-up reel idler gear 54b meshing with the reel gear 30.40 via the clutch means used, and a supply reel idler gear e4b.
The structure is such that it is transmitted to

On the other hand, a capstan 72 that is rotatably supported by a bearing member 70 fixed to the substrate 2 and is directly rotationally driven by a capstan motor 71 has a rotating roller portion 74 in a part thereof, and a predetermined The rotation is transmitted to the main idler 76, which is crimped with a crimping force of . The main idler 76 has a belt 84 stretched between a pulley part 78 that is integrally constructed and a relay roller 82 that is rotatably loosely fitted to a shaft 8o that is set on the base plate 2. 82. The shaft 80 has a rotating arm 88 that supports a rotatable idler gear 86 at one end.
is fitted loosely, and the rotating arm 8 is rotated so that the magnet 90, which is magnetized with multiple poles on the outer periphery, is approximately the same as the shaft 80.
It is placed together with 8. Furthermore, the relay roller 82
A magnetic material 92 having a magnetic hysteresis characteristic is fixed to the inner periphery of the relay roller 82 so as to face the magnet 90 with a predetermined clearance, and generates a predetermined attractive force between the relay roller 82 and the magnet 90 . A rotational force in the same direction as the rotational direction is applied to the rotating arm 88. Furthermore, the idler gear 86 is a gear portion 94 provided on the continuous relay roller 82.
Depending on the operation mode of the device, the relay roller 82 rotates to mesh with either the take-up reel idler gear 54a or the supply reel idler gear 64a, and the capstan motor 71
That is, the rotation of the capstan 72 is selectively transmitted to the take-up reel stand 1o or the supply reel stand 12 depending on the direction of rotation.

A pinch roller lever 22 is rotatably fitted loosely into a shaft 18 implanted in the substrate 2, and a pinch roller 192 is rotatably supported on a shaft 24 implanted at one end of the pinch roller lever 22. ing. A crimp lever 32 with a special elongated hole 28 that is rotatable and slidable in the longitudinal direction is loosely fitted onto the shaft 26 implanted in the substrate 2, and a pin 34 implanted at one end of the lever 32 is rotatably slidable in the longitudinal direction. A connecting arm 36 is loosely fitted into the connecting arm 36, and the other end of the connecting arm 36 is connected to the pinch roller lever 2.
It is rotatably fitted loosely into a bottle 38 which is installed at the other end of 2. In addition, a spring hook 42 is provided at the other end of the crimp lever 32.
is formed, and a tension spring 44 is stretched between the shaft 26 and the spring hook 42, biasing the crimp lever 32 upward in FIG. are in contact with each other. That is, the pinch roller lever 22, the connecting arm 36, and the pressure lever 32 constitute a so-called toggle mechanism. Further, at the other end of the crimp lever 32, a pin 46 is provided that extends through a hole (not shown) provided in the substrate 2 and extends toward the rear surface of the device, and comes into contact with a bent portion 21 provided in a main rod 48, which will be described later. It is composed of Therefore, when the main rod 48, which will be described later in FIG. The pinch roller 192 rotates until it comes into contact with the capstan 72. Pinch roller lever 22
is not rotated after that, but as the crimp lever 32 continues to rotate clockwise, it resists the biasing force of the tension spring 44, and is guided into the elongated hole 28 and moves downward in FIG. At the same time, the pinch roller 192 is pressed against the capstan 72 with a predetermined pressing force.

In the reproduction mode, as shown in Figure 2, the supply reel hub 16
The magnetic tape 180 wound above is guided from the front side of the cassette 2o by a tape pull-out member 182° 183 having guide posts 23.25 and 27.29 implanted therein through guide grooves 31 and 33, respectively, to a fixing member 184.1. The tape guide 190 is attached to a rotating magnetic head drum 186, a fixed head 188 for recording/reproducing audio signals, and a tape guide 190 fixed to the substrate 2. Furthermore, since the capstan 72 is rotating clockwise in FIG. 2, the main idler 76 is rotating counterclockwise in FIG. 2, and the belt 84 and relay roller 82 are also rotating counterclockwise in FIG. . Therefore, the pivot arm 88 is
The idler gear 86, which is applied with a rotational force in the counterclockwise direction in FIG. 2 around o and rotates clockwise in FIG. The magnetic tape 180 is rotated clockwise via the clutch means, and the magnetic tape 180 fed at a constant speed is wound around the take-up reel hub 14 without slack by the cooperation of the pinch roller 192 and the capstan 72.

Further, a tension arm 46 having a boss 47 implanted at one end is loosely fitted to a shaft 43 implanted on the surface of the substrate 2, and the tension arm 46 is supported by a tension spring 49 as shown in FIG. It is biased to rotate counterclockwise. The other end is configured to be able to be fitted through a sub-cam 142 (described later) disposed on the back surface of the substrate 2 through a hole 66 provided in the substrate 2, and is adapted to the operation mode of the device according to the rotation of the sub-cam 142. It can be rotated to the desired position. Further, the tension arm 45 has a first band fastener 57a rotatably mounted, and a band 69 is connected between the tension arm 45 and the second band fastener svb fixed to the board 2.
are connected so as to wind around the supply reel stand 12. As is well known, in the reproduction mode shown in FIG. 2, the braking force applied to the supply reel stand 12 by the band 59 is varied depending on the balance between the tension spring 49 and the tension of the magnetic tape 180 attached to the pin 47. The tension of the magnetic tape 180 is controlled to be constant.

On the other hand, a drive gear 160 driven by a drive motor 67 (see FIG. 10) is disposed on the back surface of the substrate 2 shown in FIGS. A sub-cam 142 is rotatably loosely fitted to the provided shaft 156.
It meshes with the Further, the sub-cam 142 is rotatably loosely fitted onto a shaft 164 embedded in the base plate 2, and has a gear on its outer periphery having the same number of teeth as the outer peripheral gear of the sub-cam 142, so that it rotates in synchronization with the same angle as the sub-cam 142. The main cam 162 meshes with the main cam 162. Further, the main cam 162 is a positive cam having more than 3,600 grooves 16b as shown in FIG.
As shown in the figure, a cam follower 165, which will be described later, moves only in the section where the lift amount changes. Furthermore, the rotation shaft 4 of the take-up reel stand 1o and the rotation shaft 60 of the take-up reel idler gear unit 62 extend from the front surface to the back surface of the board 2.
A main rod 48 having a cam follower 166 that engages with a groove 166 of the main cam 162 is attached to a guide shaft 132 implanted on the back surface of the substrate 2 and a rotation shaft 164 of the main cam 162. 35
, 37, 39, and 41 so as to be freely movable back and forth. Further, the main rod 48 is provided with the bent portion 21 so as to come into contact with a pin 46 provided at the other end of the crimp lever 32.

Further, the sub cam 142 also has 36 mm as shown in FIG.
The cam is a positive cam having a groove 144 extending over 0.00 mm, and the cam follower 14 engages with the groove 144 only in the section where the amount of lift changes, as shown in FIG. 11.
6 and partially indicated by a dashed line
0 is designed to reciprocate like the main rod 48.

Now, FIG. 6 shows a reproduction state, and at this time, the main cam 162 has been rotated by a rotation angle of 205 degrees clockwise in FIG. 6 from the stopped state as shown by the lift curve in FIG. At this time, the main rod 48 has moved 6 mm to the right in FIG. 6 from the stopped state, and the pin 46 in contact with the bent portion 21 has also moved to the right in FIG. is pressed against the capstan 72 with a predetermined pressing force by a tension spring 44. From this state, the drive motor 67 rotates forward, rotates the drive gear 16o clockwise, and sub-cam 142. When the main cam 162 is rotated counterclockwise and clockwise, respectively, at a rotation angle of 300'-p according to the lift curve shown in FIG. 11, the in-rod 48 moves 3 taR to the left in FIG. become a state. At this time, the pin 46 that is in contact with the bent portion 21
The pinch roller 192 also moves to the left, so that the pinch roller 192 is separated from the capstan 72. Then, the tensigon arm 46 rotates clockwise in FIG. 2 due to the rotation of the sub cam 142 and comes to the position shown in FIG. 3, so that the band 6
The winding of the band 9 around the supply reel stand 12 has become loose, and the braking force applied to the supply reel stand 12 by the band 59 has been released. Therefore, when the supply reel stand 12 is rotated counterclockwise in FIG. 3 to wind the magnetic tape 180 around the supply reel knob 16, the band 69 is prevented from being a load on the supply reel stand 12.

From this state, the drive motor 67 reverses, and the drive gear 160
counterclockwise and rotate the sub cam 142° main cam 1.
62 clockwise and counterclockwise, respectively, and
When the lift curve shown in the figure is reversed to a rotation angle of 25oO,
The main rod 48 moves three times to the right in FIG. 7, and enters the state of high-speed reversal replay mode shown in FIG. 8. At this time, the pinch roller 192 driven by the main rod 48 is pressed against the capstan 72 with a pressing force sufficient to drive the magnetic tape 180, just as in the case of the reproduction mode shown in FIG. However, the Te/Shion arm 46 is connected to the sub cam 142. The main cam 162 holds exactly the same position as when the rotation angle was 3 ocP, and the supply reel stand 1 of the band 59
2 is loosened, and the braking force applied to the supply reel stand 12 by the band 59 remains released. Also, a sub cam 142 is provided on the back side of the board 2.
There is also a detection switch 69 (shown only in FIGS. 9 and 10) for detecting the rotation angle of the main cam 162, so that the sub cam 142 and the main cam 162 operate at rotation angles of 26oO and 3oo0.

Now, in FIG. 10, when the changeover switch 61 is pressed in the reproduction mode shown in FIG. 6, a signal from the changeover switch 61 is sent to the motor drive circuit 65.

Based on the signal, the motor drive circuit 66 drives the drive motor 67.
The sub cam 142 and the main cam 162 are rotated counterclockwise and clockwise in FIG. 6, respectively, as described above. Then, the state shown in FIG. 7 is reached and the detection switch 69 is set to the rotation angle 3 of the sub cam 142 and the main cam 162.
00° and sends a signal to the motor drive circuit 66 and the forward/reverse switching circuit 73, the motor drive circuit 66 switches the drive motor 6.
7 and immediately reverse the sub cam 142. main cam 16
2 in the clockwise and counterclockwise directions in FIG. 7, respectively. At the same time, the forward/reverse switching circuit 73 receiving a signal from the detection switch 69 reverses the capstan motor 71, so that the capstan 72 starts rotating counterclockwise in FIG. The drive motor 67 is connected to the sub cam 142.
When the main cam 162 reaches a rotation angle of 250°, the detection switch 69 operates and sends a signal to the motor drive circuit 65.
It is designed to continue rotating until a stop command is issued.

As shown in the timing chart of FIG.
7 continues to rotate normally, and the pinch roller 192 is moved to the capstan 7.
Capstan motor 7 for 71 seconds after separating from 2
1. That is, since the capstan 72 continues to rotate in the normal direction, the drive of the magnetic tape 180 by the cooperation between the capstan 72 and the pinch roller 192 is stopped, but the two-take-up reel stand 10 is rotated by the take-up reel idler gear unit. Since a predetermined winding force is still applied through the clutch means 62, the magnetic tape 180 does not slacken.

Next, after the detection switch 69 detects the rotation angle 30o0 of the sub cam 142 and the main cam 162, the drive motor 67
, the capstan motor 71 reverses, and the pinch roller 19
During this period, the idler gear 86 meshes with the supply reel idler gear 64a due to the reverse rotation of the capstan 72, and the third In the figure, the prescribed rotational force is applied in the counterclockwise direction, so
Magnetic tape 180 connects capstan 72 and pinch roller 1
In cooperation with 92, there is no slack before starting the reverse run, and no slack occurs even if the reverse run starts after τ2 seconds.

Next, the operation of this embodiment will be explained.0 In order to switch from the reproduction mode position shown in FIG. 2 to the high-speed reverse reproduction mode, the changeover switch 6
When 1 is pressed, the drive motor 67 rotates and sub cam 1 is pressed.
42. The main cam 162 is rotated clockwise and counterclockwise in FIG. 6, respectively. By the time the tension arm 46 rotates to a rotation angle of 2500, the tension arm 46 rotates clockwise in FIG. 2, and the winding of the band 59 around the supply reel base 12 becomes slack. However, the capstan 72 continues to rotate clockwise in FIG. 2, and cooperates with the pinch roller 192 to cause the magnetic tape 180 to run at a constant speed. Furthermore, sub cam 14
2 and the main cam 162 continue to rotate, and the main iron 48 moves 3 mm to the left in FIG. stop. However, as the capstan 72 continues to rotate clockwise in FIG. do not have.

When the sub cam 142 and the main cam 162 rotate to a rotation angle of 3ooO, the detection switch 69 operates and the drive motor 6
7 is reversed, and at the same time, the capstan motor 71 is reversed at high speed. This state is shown in FIGS. 3 and 7. As the capstan 72 rotates counterclockwise in FIG. gives a counterclockwise rotational force. Then, while the sub cam 142 and the main cam 162 rotate from a rotation angle of 300° to 260°, the main rond 48 moves 31III11 to the right in FIG.
Since the bin 46 that is in contact with the bent portion 21 is similarly moved to the right, the pinch roller 192 is again pressed against the capstan 72 with a predetermined pressing force as shown in FIG. 4, and the magnetic tape 180 is moved in the opposite direction. drive at high speed. As mentioned above, the counterclockwise rotational force has already been applied to the supply reel stand 12 in FIG. Wind it around. Then, the sub cam 142 and the main cam 162 have a rotation angle of 260°.
When the rotation reaches the maximum speed, the detection switch 69 is activated again to stop the drive motor 67, and the state shown in FIG. The transition will be completed.

As described above in detail based on the embodiments of the present invention, according to the present invention, even when the magnetic tape is pulled out of the cassette and attached to the rotating magnetic head drum 186, the running direction of the magnetic tape can be changed. .

There is no slack in the magnetic tape and the attachment to the rotating magnetic head drum becomes unstable, and therefore, there is no disturbance in the reproduced image. Not only can a stable image be obtained, but the pinch roller and capstan can be separated once. Since the running direction is switched, changes in the running height of the magnetic tape that occur before and after the pinch roller and capstan when the running direction of the magnetic tape is switched can be immediately absorbed, and tape guides etc. This increases the reliability of the equipment, making it possible to prevent accidents such as damage to equipment.
Moreover, a great effect can be obtained in that high quality can be realized with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a surface view of the main parts of an embodiment of the present invention in a stopped mode;
Figure 2 is a surface diagram of the main parts in the regeneration mode, Figure 3 is a surface diagram of the main parts in the middle of the transition from the regeneration mode to the high-speed reverse reproduction mode, and Figure 4 is a surface diagram of the main parts in the high-speed reverse reproduction mode. Figure 6 is a schematic sectional view of the reel drive system, Figure 6 is a rear view of the main parts in the reproducing mode, Figure 7 is a back view of the main parts in the middle of the transition from the reproducing mode to the high-speed reverse reproducing mode, and Fig. 8 Figures 9 (a), t (b), (C), (d),
(e) is a timing chart for explaining the operation of an embodiment of the present invention, FIG. 10 is a main part diagram of the embodiment of the present invention, and FIG. 11 is a cam lift curve diagram. 20...Cassette, 45...Tension arm, 48...Main lock), 59...
・・・・・・ノ(nd, 61......Selector switch, 6
6... Motor drive circuit, 67... Drive motor, 69... Detection switch, 71...-\
...Capstan motor, 73...Forward/reverse switching circuit, 142...Sub cam, 162...
・Main cam, 18101. ..., magnetic tape, 186
...Rotating magnetic hent drum. Name of agent: Patent attorney Toshio Nakatashi and 1 other person) Figure 9 Figure 10

Claims (1)

[Claims] The magnetic tape is pulled out of the cassette from a cassette containing a pair of reels for winding the magnetic tape, and attached at a predetermined angle to a rotating magnetic head drum installed outside the cassette to transmit signals. a pair of reel stands that are configured to perform recording or reproduction and that engage with and rotate integrally with the pair of reel hubs; a capstan that runs the magnetic tape at a constant speed; and a capstan that runs the magnetic tape at a constant speed. a motor for rotationally driving the motor; a forward/reverse switching means for rotating the motor in the forward and reverse directions; and a forward/reverse switching means for rotating the motor in the forward and reverse directions; a pinch roller that cooperates with the capstan to drive the magnetic tape to travel; and a pinch roller drive means that presses the pinch roller against and separates it from the capstan. and a changeover switch for changing the operating mode of the apparatus and changing the running direction of the magnetic tape pulled out of the cassette, and in connection with the operation of the changeover switch, the pinch roller is driven by the pinch roller driving means. Separated from the capstan. Thereafter, the forward/reverse switching means reverses the motor, and the rotation transmission means switches the reel stand that transmits the rotation of the motor, and the pinch roller driving means presses the pinch roller to the capstan. A magnetic tape device characterized in that the magnetic tape device is configured to switch the running direction of the magnetic tape.