JPH0546027B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application 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. 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 cylinder.

Conventional structure and its problems In general, the method of pulling out a magnetic tape from a cassette and attaching it to a rotating magnetic head cylinder is
It is roughly divided into two types: loading method and M loading method. Although the tape loading mechanism is complicated in the former case, the tape twist correction distance is long and the wrapping angle of the tape 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 rewound (hereinafter referred to as FF/REW). 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. It takes a lot of energy to do that.

Next, a conventional magnetic tape device will be explained with reference to FIGS. 1 and 2. A magnetic tape 2 is stretched between a supply reel and a take-up reel in a cassette 1. A pair of reel stands 4 and 5 are rotatably disposed on the shear yarn 3. The reel stands 4 and 5 engage with the supply reel and the take-up reel, respectively, and rotate together. A pulley 6 is disposed at approximately the same distance from both reel stands 4 and 5 and is driven to rotate in forward and reverse directions by a reel motor (not shown). Therefore, when the idler 7 is pressed against the pulley 6, the idler 7 contacts the supply reel stand 4 side or the take-up reel stand 5 side depending on the rotation direction of the pulley 6, and the rotation of the pulley 6 is transmitted to either reel stand. It is designed to do so. As the pulley 6 rotates clockwise as shown in FIG. , the rotation is transmitted to the take-up reel stand 5, so the take-up reel stand 5 rotates clockwise,
Wind 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, the tape pull-out pins 9, 10, 11, and 12 can be moved from the position in the cassette 1 shown by the broken line to the position shown by the solid line. It is arranged like this. When the tape is transferred at a constant speed, such as in playback or recording mode, the magnetic tape 2 is transferred to the capster 1.
3 and a pinch roller 14. 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 be wound around the tape pull-out pins 9 to 12 and the rotating magnetic head cylinder 8, so there will be no winding tension loss at each part. Therefore, the torque for winding up the magnetic tape 2 on the take-up reel stand 5 becomes very large. In particular, since it is wound around the rotating magnetic head cylinder 8 by about 190 degrees, the winding tension loss is large, and especially when the humidity is high, the loss becomes large and it becomes impossible to wind it. Therefore, as shown in FIG. 2, the magnetic tape 2 includes a rotary cylinder 8a having a magnetic head 15 and a motor (not shown) for driving the rotary cylinder 8a and for guiding the movement of the magnetic tape 2. FF/
During REW, the magnetic tape 2 is
An attempt was made to reduce the winding tension loss by forming a thin air film between the rotary magnetic head cylinder 8 and the rotating magnetic head cylinder 8, but this was not sufficient.
For this reason, in the conventional M loading type magnetic tape device, FF/REW is performed with the magnetic tape 2 stored in the cassette 1. However, there is a problem in that the tape must be loaded and unloaded each time, making the operation extremely complicated.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and an object of the present invention is to provide a magnetic tape device that can perform FF/REW with a magnetic tape attached to a rotating magnetic head cylinder.

SUMMARY OF THE INVENTION In order to achieve the above object, the magnetic tape device of the present invention has a magnetic tape device that pulls out a magnetic tape from a cassette containing a pair of reel hubs around which magnetic tape is wound and runs it along a rotating magnetic head cylinder. The tape device includes a rotating cylinder having a rotating magnetic head, a fixed cylinder coaxial with the rotating cylinder and guiding the running of the magnetic tape, a motor rotating the rotating cylinder in one direction, and the rotating cylinder. a control circuit for controlling the rotational speed of the motor; first and second operation switches for setting a constant speed mode and a fast winding mode; and a dual operation switch. is connected, and generates first and second reference signals corresponding to the constant speed mode and the fast winding mode so that the rotating cylinder rotates faster in the fast winding mode than in the constant speed mode. a generator, a detection signal from the rotational speed detection means and the reference for sending a signal to the control circuit to rotate the rotary cylinder at a rotational speed based on the signal from the reference signal generator; This configuration includes a comparator that compares the signal with a reference signal from the signal generator.

According to this configuration, the thickness of the air film between the magnetic tape and the rotating magnetic head cylinder becomes greater during fast winding than when the tape is transported at a constant speed.
At this time, when the second operation switch for setting the fast winding mode is operated, a corresponding second reference signal is generated from the reference signal generator, and this second reference signal and the rotation speed detection means The detected signal is compared with the comparator. A signal is then sent to the control circuit to rotate the rotating cylinder at a rotational speed based on the signal from the reference signal generator. In this way, in the fast winding mode, the rotating cylinder is reliably rotated at high speed in order to increase the thickness of the air film.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a circuit block diagram of a magnetic tape device in one embodiment of the present invention. In Figure 3,
The rotation speed of the rotary cylinder 8a is detected by a detection head 16, and converted by a rotation speed detection circuit 17 into a rotation signal such as a voltage proportional to the rotation speed. This rotation signal is compared with a reference signal from a reference signal generator 19 by a comparator 18, and according to the difference, a control circuit 20 controls a drive circuit 21 of a motor 22 that drives the rotation cylinder 8a. When the operation switch 23 is pressed, the device enters the so-called playback/recording mode in which the tape is transferred at a constant speed, and at the same time,
A reference signal generator 19 generates a first reference signal. When the operation switch 24 is pressed, the device enters the so-called FF/REW mode in which the tape is wound quickly, and at the same time, the reference signal generator 19 sets a second standard in which the rotating cylinder 8a rotates faster than in the constant speed mode. Generate a signal.

In the above configuration, when the operating switch 24 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 larger, and the fourth
As shown in the figure, the relative coefficient of friction between the magnetic tape and the rotating magnetic head cylinder decreases.

In this way, according to this embodiment, by increasing the rotational speed of the FF/REW rotating cylinder 8a,
Tension loss when winding the magnetic tape around the rotating magnetic head cylinder can be reduced.

Effects of the Invention As explained above, according to the present invention, in the fast winding mode, the rotating cylinder is driven at a higher rotational speed than in the constant speed mode, so that in the fast winding mode, there is a gap between the magnetic tape and the rotating magnetic head cylinder. Because the thickness of the air film is increased and the winding tension loss is reduced, even if FF/REW is performed while the magnetic tape is still wound around the rotating magnetic head cylinder, the tape can be wound with less energy than before. When the fast winding mode is set with the operating switch, a reference signal corresponding to this is generated from the reference signal generator, and this reference signal is compared with the detection signal from the rotational speed detection means in the comparator. Since the rotation speed of the rotating cylinder is controlled by the control circuit that receives the comparison result, the rotating cylinder can be reliably rotated at high speed in the fast winding mode.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the main parts of a magnetic tape device, FIG. 2 is a side view of a rotating magnetic head cylinder, FIG. 3 is a circuit block diagram of the main parts of a magnetic tape device according to an embodiment of the present invention, and FIG. 4 FIG. 2 is an explanatory diagram of the relationship between the relative coefficient of friction between the magnetic tape and the rotating magnetic head cylinder and the rotational speed of the rotating cylinder. 2... Magnetic tape, 8... Rotating magnetic head cylinder, 8a... Rotating cylinder, 8b... Fixed cylinder, 17... Rotation speed detection circuit, 19... Reference signal generator, 20... Control circuit, 21... ... Drive circuit, 22 ... Motor, 23, 24 ... Operation switch.

Claims (1)

[Claims] 1. A magnetic tape device that pulls out a magnetic tape from a cassette containing a pair of reel hubs on which magnetic tape is wound and runs it along a rotating magnetic head cylinder, which comprises: a rotating cylinder having a rotating magnetic head; a fixed cylinder that is coaxial with the rotating cylinder and guides the running of the magnetic tape; a motor that rotationally drives the rotating cylinder in one direction; a rotational speed detection means that detects the rotational speed of the rotating cylinder; and rotation of the motor. A control circuit for controlling the speed, first and second operation switches for setting constant speed mode and fast winding mode, and both operation switches are connected, and in the fast winding mode, the rotation speed is higher than in the constant speed mode. a reference signal generator that generates first and second reference signals corresponding to the constant speed mode and the fast winding mode so as to speed up the rotation of the cylinder; a comparator for comparing a detection signal from the rotational speed detection means with a reference signal from the reference signal generator so as to send a signal to the control circuit in order to rotate the magnetic tape at a rotational speed based on the rotational speed. Device.