JPS5992464A - Magnetic tape device - Google Patents

Abstract

PURPOSE:To take up a magnetic tape with a smaller amount of energy than the conventional even though an FF/REW is executed with the tape wound round a rotary magnetic head cylinder, by driving a rotary cylinder at a higher revolving speed than a constant speed mode in a fast winding mode. CONSTITUTION:The revolving speed of a rotary cylinder 8a is detected by a detection head 16 and then converted into a rotary signal of voltage, etc. which is proportional to the revolving speed of the cylinder 8a by a revolving speed detecting circuit 17. This rotary signal is compared with a reference signal sent from a reference signal generator 19 by a comparator 18. In accordance with the difference obtained from said comparison, a control circuit 20 controls a driving circuit 21 for motor 22 which drives the cylinder 8a. With push of an operation switch 23, a magnetic tape device shifts the tape at a constant speed. The generator 19 generates the 1st reference signal as soon as a so-called reproduction/video record mode is set. When an operation switch 24 is pushed, the tape device is set in an FF/REW mode to wind the tape quickly. At the same time, the generator 19 generates the 2nd reference signal to accelerate the revolving speed of the cylinder 8a than that of the constant speed mode.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic tape device that records/reproduces signals by pulling out a magnetic tape from a cassette and running it along a rotating magnetic head cylinder. In particular, the present invention relates to a magnetic tape device capable of fast forwarding or rewinding a magnetic tape while the magnetic tape is attached to a rotating magnetic head and cylinder.

Conventional Structures and Problems There are generally two types of methods for pulling out a magnetic tape from a cassette and attaching it to a rotating magnetic head cylinder: the U loading method and the M loading method. Although the tape loading mechanism is complicated in the former case, the tape twist correction distance N1 is long and the tape wrapping angle around the post is small, so even if the magnetic tape is attached to the rotating magnetic head cylinder, relatively little energy is required. It has the advantage of being able to be quickly wound or undone (hereinafter referred to as ``F'' or ``W''). On the other hand, with the M loading method, although the tape loading mechanism is simple, the tape twist correction distance is short and the wrapping angle of the tape around the post is large. This requires a huge amount of energy.

Next, a conventional magnetic tape device will be explained with reference to FIG. 1 and the second factor. A magnetic tape (2) is placed between the supply reel and take-up reel in the cassette (1).

The shearn (3) has a pair of reel stands (4) that engage with the supply reel and the take-up reel and rotate integrally with each other.
(5) is rotatably arranged.

A pulley (6) which is driven to rotate in forward and reverse directions by a reel motor C (not shown) is disposed at approximately the same distance from both reel stands (4) and (5). Therefore idler (7)
When the is pressed against the pulley (6), the idler (7) is moved to the supply reel stand (4) side or to the supply reel stand (4) side depending on the rotation direction of the pulley (6). 'i Rolling contact with the width reel stand (5) side, pulley (6)
The rotation of the reel is transmitted to one of the reel stands.

As shown in Figure 1, when the pulley (6) φ is rotated clockwise, the idler (7) pressed by the pulley (6) rolls to the right and connects the take-up reel stand (5) and the pulley. (6) and the take-up reel stand (5) to control the rotation of the retracting pulley (6).
As a result, the take-up reel stand (5) rotates clockwise and winds up the magnetic tape (2). In order to attach the magnetic tape (2) to the rotating magnetic head cylinder (8) having a rotating magnetic head inside, a tape pull-out corner pin (9) is used.
) αOfill O'4 is movable from the position in the cassette (1) shown by the broken line to the position shown by the solid line. During tape constant speed transport, such as in playback or recording mode, the magnetic tape (2) is driven by the capsulator and the pinch roller I. However, if you try to fast-forward the magnetic tape (2) while it is still wound around the rotating magnetic head cylinder (8), the magnetic tape (2) will slide out of the tape pull-out pin (
9) ~ (The magnetic tape (2) is wound on the take-up reel stand (5) to prevent winding tension loss at each part since it is wound around the magnetic tape and the rotating magnetic head cylinder (8). The torque is very large.The rotating magnetic head cylinder (
8), the tension loss is large during winding, and especially when the humidity is high, the loss becomes large and it becomes impossible to unwind. Therefore, as shown in FIG. 2, the magnetic tape (2) has a rotary cylinder (8a) having nine magnetic heads, a motor (not shown) for driving this rotary cylinder (8a), and a magnetic tape (2). In a state where it is attached to a fixed cylinder (8b) having a stepped portion for guiding the running of the tape (2), ? ``During F/REV, the rotating cylinder (8a)
By rotating the magnetic tape, a thin air film was formed between the magnetic tape (2) and the rotating magnetic head cylinder (8) to reduce tension loss during winding, but this was not sufficient. For this reason, in conventional M-loading type magnetic tape devices, "/REV" is performed with the magnetic tape (2) stored in the cassette (1). However, the tape must be loaded and unloaded each time. However, there was a problem in that the operation was extremely complicated.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional art, and aims to provide a rotary magnetic head cylinder with a magnetic tape attached thereto. 'F/
The purpose of the present invention is to provide a magnetic tape device that can perform REW.

Structure of the Invention In order to achieve the above-mentioned object, the magnetic tape device of the present invention pulls out a magnetic tape from a cassette containing a pair of reel nozzles wound with the magnetic tape and runs it attached to a rotating magnetic head cylinder. A magnetic tape device A,
a rotating cylinder having a rotating magnetic head, a fixed cylinder coaxial with the rotating cylinder and guiding the running of the magnetic tape, and a motor driving one of the seven rotating cylinders;
a rotational speed setting means for detecting the rotational speed of the rotating cylinder; and a control circuit that controls the rotation of the motor so that the rotating cylinder is driven at a higher rotational speed in the fast winding mode than in the constant speed mode. It is a configuration with.

With this configuration, the thickness of the air film between the magnetic tape and the rotating magnetic head cylinder is smaller than that when the tape is transferred at a constant speed.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below based on the IA aspect.

FIG. 3 is a circuit block diagram of a magnetic tape device according to an embodiment of the present invention. In Fig. 3, there is a rotary cylinder (2).
The rotation speed of 8a) is detected by the detection head CJ mallet, and converted into a rotation signal such as a voltage proportional to the rotation speed by the rotation speed detection circuit lIη.

This rotation signal is compared with the reference signal from the reference signal generator 091 by a comparator, and the control circuit changes the rotation signal according to the difference. 2
0) controls the drive circuit 121) of the motor t22 that drives the rotating cylinder (8a). When the operation switch is pressed, the device transfers the tape at a constant speed, enters the so-called playback/recording mode, and at the same time turns on the reference signal generator (19).
generates a first base fishing signal. When you press one flash of the operation switch, the device winds the tape by hand, so-called FF/RB.
At the same time as the W mode is entered, the reference signal generator α9) generates a second reference signal that causes the rotary cylinder (8a) to rotate faster than in the constant speed mode.

In the above configuration, when the % operation switch C24) is pressed, the rotating cylinder (8a) rotates faster than in the constant speed mode, so the air film between the magnetic tape and the rotating magnetic head cylinder becomes thicker, as shown in FIG. As shown in the figure, the relative coefficient of friction between the magnetic tape and the rotating magnetic head cylinder decreases.

As described above, according to this embodiment, by increasing the rotational speed of the rotary cylinder (8a) during 'FP/RI8W, it is possible to reduce the tension loss when the magnetic tape is wound around the rotary magnetic head 7 cylinder.

As described in detail, according to the present invention, the rotating cylinder is driven at a higher rotational speed in the fast winding mode than in the constant speed mode, so that the rotation between the magnetic tape and the rotating magnetic head cylinder in the fast winding mode is faster. The thickness of the air film between the holes is increased, reducing tension loss during winding, making it possible to wind the tape with less energy than before even when performing Axw while the magnetic tape is still attached to the rotating magnetic head cylinder. obtain.

[Brief explanation of drawings]

FIG. 1 is a plan view of the main part of the magnetic tape device, the second factor is a side view of the rotating magnetic head cylinder, and FIG. 3 is a circuit block diagram of the main part of the magnetic tape Aft in an embodiment of the present invention.
Figure 4 is an explanatory diagram of the relationship between the relative coefficient of friction between the magnetic tape and the rotating magnetic head 7 cylinder and the rotational speed of the rotating cylinder (2)...Magnetic tape, (8)...Rotating magnetism・Sodoshi 1) cylinder, (8a)...rotating cylinder, (8b)
... Fixed cylinder, 07) ... Rotation speed detection circuit,
(19)... Reference signal generator, (20)... Control circuit, (21)... Drive circuit 1, Secretion... Motor,! 5
1 [241... Operation switch representative Yoshihiro Morimoto Figure 2 ylp Figure 3 Figure 4 Rotating cylinder arrester

Claims (1)

[Claims] L A magnetic tape device t that pulls out a magnetic tape from a cassette containing a pair of reel hubs around which a magnetic tape is wound and runs it along a rotating magnetic head cylinder, the magnetic tape device having a rotating magnetic head. a cylinder, a fixed cylinder that is coaxial with the rotating cylinder and guides the running of the magnetic tape, a motor that drives the rotating cylinder, a rotational speed detection means that detects the rotational speed (r) of the rotating cylinder, and a manual winding mode. and a control circuit that controls the rotation of the motor so as to drive the rotary cylinder at a rotation speed higher than that in the constant speed mode.