JPS6017073Y2 - Magnetic tape reversing device for magnetic recording and reproducing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape reversing device for a magnetic recording and reproducing apparatus that runs a magnetic tape in reverse and reproduces images in a backward state.

Normally, when reproducing images in a magnetic recording and reproducing apparatus, the magnetic tape 1 pulled out from the feed reel 2a equipped with a drive device in the winding direction in FIG. The film is wound around a cylinder 9 to which a cylinder 9 is attached, and is driven to rotate in the normal direction by a capstan 14 and a pin f-roller 15, and is wound onto a take-up reel 2b.

That is, the magnetic tape 1 pulled out from the feed reel 2a
is guided by the tape guide 3, tension pole 4, tape guide 5, erasing head 6, impedance roller 7, and entry side moving tape guide Bat and 8b, and is wound around the cylinder 9.

The magnetic tape 1 that has come out of the cylinder 9 is moved to the exit side moving tape guide lea, 10b, and the impedance roller 1.
1. The tape passes through the audio head 12, tape guide 13, capstan 14, and pinch roller 15, and then is wound onto the take-up reel 2b.

In addition, when the magnetic tape 1 is pulled out from the take-up reel 2b and run in reverse so as to be wound onto the feed-out reel 2a, and the image is reproduced in reverse, the magnetic tape 1 is guided and run in the completely reverse order of the normal rotation described above. let

That is, the magnetic tape 1 is fed out at a constant speed in the direction of the dotted arrow by the capstan 14 and the pinch roller 15, taken up by the feeding reel 2a, and run in reverse.

By the way, when using the cassette 2 for 120 minutes, the reel diameter of the magnetic tape 1 is 1 at the beginning and end of the winding.
The radius ratio changes to approximately =4.

Therefore, when running in reverse, the tape winding angle near the fixed guide 3, tension pole 4, and fixed guide 5 changes, and the required winding torque on the feed reel 2a changes depending on the tape winding diameter of the feed reel 2a. .

Figure 2 shows an example of actual measurements, where the horizontal, vertical, and vertical axes show the winding diameter of the feeding tape and the winding torque of the feeding reel (
gr - cm ) is taken.

In FIG. 2, the shaded area 22 indicates the optimal torque area, and
The upper part shows the range where the magnetic tape 1 is sagging due to insufficient pulling force on the magnetic tape 1.

Furthermore, the instep part is a region where the tension of the magnetic tape 1 is too strong and the edge of the magnetic tape 1 is scratched or only the edge portion is stretched and folds appear.

Therefore, the required torque of the feed reel 2a is reduced to the magnetic tape 1.
In order to maintain an appropriate range depending on the winding diameter, it is necessary to change the winding torque by some means.

To do this, for example, the torque of the motor of the drive device for the take-up reel 2a must be controlled.

Furthermore, during reverse running during reverse playback, the feed reel 2a
Since the magnetic tape 1 is pulled by using the magnetic tape 1 as a driving unit, the winding force is transmitted through the spirally laminated tape layers, which makes the winding force unstable.

In addition, tape guide mechanisms such as tape guides on the entry side, which are located between the feed reel and the cylinder, are necessary for stabilizing running when running in the forward direction, but when running in reverse, they are required due to their frictional resistance. This will only serve as an extra load resistance and will increase the instability of the winding force.

On the other hand, the tension pole 4 is elastically attached via a spring so that the magnetic tape 1 is pressed against the tape guides 3 and 5 during normal rotation of the magnetic tape so that the tension of the magnetic tape 1 is always constant.

Therefore, if the magnetic tape 1 runs in constant contact with the tension pole 4 even when running in reverse, the tension pole 4 will vibrate, leading to unstable running where the magnetic tape 1 will flutter when running. It has become.

The purpose of this invention is to reduce the change in the winding torque due to changes in the tape winding diameter of the feed reel when the magnetic tape runs in reverse, and to run smoothly and stably without controlling the drive motor of the feed reel. An object of the present invention is to provide a magnetic tape reversing device for a magnetic recording/reproducing device that can perform the following steps.

The present invention performs a reverse running operation in which the magnetic tape is wound and guided over a predetermined angular range around a cylinder equipped with a rotating magnetic head, and the magnetic tape is run in the opposite direction from normal forward running. At this time, the magnetic tape is removed from at least the tape guide located closest to the tension pole among the tape guides arranged in the tape running path between the payout reel and the cylinder to guide the tape during forward running operation. This is to separate the two.

The means for separating the magnetic tape from the tape guide includes, for example, means for moving the tension pole so as to separate it from the magnetic tape.

An embodiment of the magnetic tape reversing device of the magnetic recording and reproducing apparatus of the present invention will be described below with reference to FIG. 3, in which the same parts as in FIG.

Reference numeral 17 denotes a solenoid, and the solenoid 17 attracts the plunger 18 in response to a signal from an operation control section (not shown) when the magnetic tape 1 is pulled out from the take-up reel 2b and wound on the feed reel 2a. ing.

The plunger 18 is connected to one end of a frame 19 rotatably attached to a shaft 24, and at the other end of the frame 19 is an arm 2 whose one end is fixed to a rotatably provided shaft 25.
0 is rotatably connected.

The shaft 25 has an arm 20 and an arm 28 at a substantially L-shaped position.
is fixed, and one end of the arm 21 is rotatably connected to the free end side of the arm 28.

At the other end of the arm 21, one end is rotatably attached to a shaft 26, and at the other end, when the magnetic tape 1 is running in the normal direction, the magnetic tape 1 is pressed against the tape guides 3, 5 with a predetermined tension. An arm 16 with a tension pole 4 attached thereto to hold the tape 1 is rotatably attached.

Actuating member 2 by arms 19, 20, 27, 21, 16
8 is formed.

In the magnetic tape reversing device of this embodiment, when the magnetic tape 1 is wound in the forward direction from the feed reel 2a to the feed cylinder 9 and then wound to the take-up reel 2b, the tension pole 4 applies the tension of the spring (not shown). The magnetic tape 1 is attached so that it is always in contact with the magnetic tape 1 with a constant tension through the magnetic tape 1. Therefore, the magnetic tape 1 runs while contacting the erasing head 6 and the tape guides 3 and 5.

In the case of reverse running in which the image is played back in the backward state, the magnetic tape 1 is moved between the capstan 14 and the pinch roller 1.
5 from the take-up reel 2b, run in the direction of the dotted line arrow in Figure 3, and wind up on the pay-out reel 2a.

That is, the magnetic tape 1 includes a capstan 14, a pinch roller 15, a tape guide 13, an audio head 12, an impedance roller 11, an output side moving tape guide 10b,
10a, cylinder 9 person side moving tape guide 8b,
8a, it is guided by an impedance roller 7 and wound onto a feed reel 2a.

When the magnetic tape 1 runs in reverse, the plunger 18 of the solenoid 17 is attracted by a signal from the operating section, so the arm 19 is rotated counterclockwise and the arm 20
．． 27 is rotated clockwise, and the tension pole 4 is separated from the magnetic tape 1 via the arm 21.16.

Therefore, the tension pole 4
By moving so as to be pulled away from the magnetic tape 1, not only the tension pole 4 but also the tape guide 3,
The magnetic tape 1 also runs without coming into contact with the magnetic tape 5.

In this way, in the case of reverse running, the magnetic tape 1 is moved from the tape guide on the entrance side of the cylinder 9, particularly from the tape guide 3 which is disposed on the magnetic recording/reproducing device, is closest to the feed reel 2a, and has the highest tape tension. By separating the tape guide, the influence of frictional resistance with the tape guide is eliminated, and the required winding torque on the feed reel 2a falls within the range shown by the shaded area 23 in FIG.

The results shown in Fig. 4 are actual measurement examples during experiments, and the range of stable winding torque during reverse running has been expanded, making it possible to enter the range in which stable winding can be achieved even with a constant winding torque. can.

In Fig. 4, the horizontal and vertical axes are shown in the same way as in Fig. 2, and the X part is the range of insufficient torque that prevents the magnetic tape 1 from being wound, and the V part is the range of tape due to excessive torque. This is the range where damage occurs.

From FIG. 4, in the magnetic tape reversing device shown in FIG. 3, if the winding torque of the feed reel 2a is set to a constant value of approximately 200 gr-cm, the magnetic tape will remain stable even if the tape winding diameter changes. This shows that tape 1 can run in reverse.

Also, during reverse running, the tension pole 4 is pulled away from the magnetic tape 1 by the plunger 18 of the solenoid 17 and the actuating member 28, so the magnetic tape 1
Unstable driving, such as rattling, is also eliminated.

As described above, the magnetic tape reversing device of the magnetic recording and reproducing apparatus of the present invention reduces the change in the winding torque due to the change in the tape winding diameter of the feeding reel when the magnetic tape runs in reverse, and the torque of the driving motor of the feeding reel is reduced. This has the effect of eliminating the need for control and allowing stable running with the winding torque kept at a constant value.

[Brief explanation of drawings]

Fig. 1 is a plan view of a conventional magnetic recording/reproducing device when the magnetic tape is running, Fig. 2 is a diagram of the winding torque characteristics of the payout reel when the magnetic tape is reversed in the device of Fig. FIG. 4 is a plan view of an embodiment of a magnetic tape reversing device of a magnetic recording and reproducing apparatus when the magnetic tape is running in reverse, and FIG. 4 is a winding torque characteristic diagram of the feeding reel of the device shown in FIG. 1... Magnetic tape, 3, 5... Fixed guide, 4... Tension pole, 9...
・Cylinder, 14... Capstan, 15.
...Pinch roller, 16.19,20,21,2
8... Arm, 17... Solenoid,
18... Plunger, 28... Operating member.

Claims (1)

[Scope of utility model registration request] A cylinder equipped with a rotating magnetic head and a tape guide for winding and guiding a magnetic tape around the cylinder at a predetermined angle, the tape guide moving to a position close to the entrance and exit sides of the magnetic tape of the cylinder to guide the magnetic tape. a tape guide including a movable tape guide to be wound around the cylinder; and a tension pole disposed on the input side of the cylinder to maintain tape tension on the magnetic tape on the input side of the cylinder when the magnetic tape runs in a normal rotation path; In the magnetic recording and reproducing apparatus equipped with the above, during a reverse running operation in which the magnetic tape is wound and guided around the cylinder and runs in the opposite direction to reproduce recorded signals, the tension pole is moved and the tape guide is moved. A tape reversing device for a magnetic recording/reproducing device, characterized in that a means is provided for separating contact between at least one chive guide disposed close to the tension pole and the magnetic tape.