JP2593517B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an R-DAT (rotary head digital audio tap).
The present invention relates to a magnetic recording / reproducing apparatus that performs magnetic recording / reproduction by scanning a magnetic head on a tape, such as an e recorder.

[Conventional technology]

In an R-DAT, a home VTR (video tape recorder), or the like, as shown in FIG. 4, a rotating disk (not shown) mounted on a rotatable drum shaft (not shown) rotates along with the drum shaft. An upper guide drum 45a for guiding the tape 41 is provided, and two magnetic heads 44 are mounted on the lower surface of the upper guide drum 45a at an interval of 180 °. These magnetic heads 44, 44 form the same plane by rotating the rotating disk,
They are set at the same height. On the other hand, below the rotating disk, a lower guide drum (not shown) is provided which faces the upper guide drum 45a in a state where the drum shaft is idle. 45a
Thus, one guide drum 45 is configured. In the vicinity of the guide drum 45, tape guides 42 and 43 are provided on the tape entrance side and the tape exit side, respectively.

Tape 41 pulled out from VTR cassette (not shown)
Indicates an erasing head, guide roller, audio
Tape guide 42 via CTL head, pinch roller, etc.
It is in contact with the peripheral surface of the guide drum 45 from 43, and the upper guide drum 45a rotates to scan the tape 41 while the magnetic heads 44 and 44 are alternately switched to perform recording and reproduction. It is supposed to do.

[Problems to be solved by the invention]

However, in the above-described conventional magnetic recording / reproducing apparatus, air is taken in between the guide drum 45 and the tape 41 that is in contact with the circumference, and the tape 41 floats on the surface of the guide drum 45. Becomes difficult to contact the tape 41, and good magnetic recording and reproduction cannot be performed. In particular, when the tape 41 is likely to float at a circumferential contact start point 41a, which is a position where the tape 41 starts to be circumferentially contacted with the guide drum 45, and when the rotation speed of the upper guide drum 45a is variable, as shown in FIG. As the rotation speed increases from 1800 rpm shown by the dotted line to 3600 rpm shown by the dashed line, and to 5400 rpm shown by the solid line,
The result was that the amount of air taken in increased and the flying height S of the tape increased.

Therefore, a blower fan is provided on the drum shaft to send the upper air downward, and to apply a suction force to the tape in circumferential contact.
A VTR head drum (see Japanese Patent Application Laid-Open No. 62-154360) has been proposed.

However, in the above-described head drum, the suction force acting on the drum shaft is determined by the rotation speed of the drum shaft, and the tape floating amount cannot be arbitrarily adjusted, so that good magnetic recording and reproduction cannot be performed depending on the rotation speed. Have a problem.

[Means for solving the problem]

In order to solve the above-described problems, the magnetic recording / reproducing apparatus of the present invention has a rotation speed variable, a guide drum for guiding the tape in circumferential contact, and scanning on the tape in circumferential contact for magnetic recording / reproducing. A magnetic recording / reproducing apparatus having a magnetic head for performing the pressing operation, wherein a pressing force urging means for pressing the tape from the side to the peripheral surface of the guide drum is provided around a peripheral contact point of the tape with the guide drum; The pressing force urging means is characterized in that the pressing force is variable according to a change in the rotation speed of the guide drum.

(Operation)

According to the above configuration, the tape urging means can press the tape against the guide drum side from the side thereof at the circumferential contact start point where the tape starts to circumferentially contact the guide drum. Further, the pressing force urging means can change the pressing force in accordance with a change in the rotation speed of the guide drum.

Therefore, when the rotation speed of the guide drum changes, it is possible to adjust the tape floating amount by changing the pressing force according to the change. Thus, even if the rotation speed of the guide drum changes, good magnetic recording and reproduction can always be performed by the magnetic head that scans the tape that is in contact with the circumference.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

A case in which this embodiment is applied to a VTR magnetic recording / reproducing apparatus will be described. As shown in FIG. 1, the guide drum 15 in the magnetic recording / reproducing apparatus has a rotatable disk (not shown) mounted on a rotatable drum shaft (not shown). An upper guide drum 15a that rotates and guides the tape 31 is provided. On the lower surface of the upper guide drum 15a, two magnetic heads 14 and 14 are respectively mounted at 180 ° intervals, and these magnetic heads 14 and 14 form the same plane by rotation of the upper guide drum 15a. Are set at the same height.

On the other hand, below the rotating disk, there is provided a lower guide drum (not shown) facing the upper guide drum 15a in a state where the above-mentioned drum shaft is loosely inserted.The lower guide drum and the upper guide drum 15a Thus, one guide drum 15 is configured. In the vicinity of the guide drum 15, tape guides 12 and 13 are provided on the entrance and exit sides of the tape.

On the peripheral surface of the guide drum 15, a tape 31 is in circumferential contact with the tape guides 12 and 13 respectively back and forth, and around a circumferential contact start point 31a, which is a position where the tape 31 starts to make contact with the guide drum 15. A compressed air ejecting device 1 as a pressing force urging means for pressing the tape 31 against the guide drum 15 is disposed on the side.

As shown in FIG. 3 (a), the above-described compressed air injection device 1 is composed of a support member 2, a rotating member 3, a holding member 4, and an injection member 5, and FIG. As shown in b), the support member 2 has an air flow passage 2a from the lower surface to the upper portion.
The pivot member 3 is rotatably inserted substantially at the center of the support member 2. On the peripheral surface of the rotating member 3, a holding member 4 having a cylindrical air flow passage 4a is implanted on one side thereof in a longitudinally lateral direction, and the air flow passages 2a and 4a communicate with each other. ing. Holding member 4
Is attached to the lower peripheral surface of the injection member 5, and the holding member 4
Is rotatably held. In addition, the injection member 5 includes an injection pipe 5a provided with an injection port 5d on a part of the peripheral surface and having an air flow passage 5c communicated with the air flow passage 4a.
It comprises closing members 5b provided to close the upper and lower portions of the injection pipe 5a.

In a magnetic recording / reproducing apparatus in which recording / reproducing is not performed, as shown in FIG. 2 (a), a VTR cassette 30 (indicated by a two-dot chain line in the figure) is arranged below the guide drum 15. The ejection member 5 of the compressed air ejection device 1 and the ejection roller members 25 are rotated by the rotation of the ejection member 5 of the compressed air ejection device 1 inside the tape 31 in the cutout portion 30a for ejecting the tape 31. Each roller of the roller members 25 is arranged. Then, between the VTR cassette 30 and the tape guide 12, in the order of processes,
A full width erasing head 24, a guide roller 20, and the like are provided. On the other hand, between the tape guide 13 and the VTR cassette 30, the audio erasing head 23,
An audio CTL head 28, a guide roller 20, a pinch roller 21, a capstan 22 corresponding to the pinch roller 21, a guide roller 20, etc. are provided.

In the above-described configuration, when performing recording / reproduction, as shown in FIG. 2 (b), the tape 31 is pulled out by the pull-out roller members 25, ... Conveyed. At this time, the recording and reproduction are performed by scanning the tape 31 while the magnetic heads 14 are alternately switched by the rotation of the upper guide drum 15a.

Here, on the side of the circumferential contact start point 31a, the above-mentioned compressed air injection device 1 is rotated around the support member 2 so that the injection member 5 causes its injection port 5d to face the tape 31. The compressed air sent from a compressed air supply device (not shown) is provided through the air flow passages 2a, 4a, 5c, and the injection ports 5d are provided.
From the tape 31. The amount of the compressed air is adjusted according to the change in the rotation speed of the upper guide drum 15a, and is set so that the tape 31 always has an optimum tape floating amount with respect to the guide drum 15 described above.

Therefore, no matter what rotational speed the upper guide drum 15a rotates, the tape 31 and the magnetic heads 14
And the magnetic head 14
・ 14 can always perform good recording and reproduction.

〔The invention's effect〕

As described above, the magnetic recording / reproducing apparatus according to the present invention has a variable rotation speed, a guide drum that guides the tape in circumferential contact, and a magnetic head that performs magnetic recording / reproducing by scanning on the tape in contact with the tape. In a magnetic recording and reproducing apparatus having
Around the starting point of contact with the guide drum on the tape,
A pressure urging means for pressing the tape from the side to the peripheral surface side of the guide drum is provided, and the pressure urging means is capable of changing the pressing force according to a change in the rotation speed of the guide drum. It is.

Therefore, when the rotation speed of the guide drum changes, it is possible to adjust the tape floating amount by changing the pressing force according to the change. As a result, even if the rotation speed of the guide drum changes, there is an effect that good magnetic recording and reproduction can always be performed by the magnetic head that scans the tape that is in contact with the circumference.

[Brief description of the drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a plan view showing a configuration around a guide drum, and FIG.
FIG. 3A is a plan view showing the magnetic recording / reproducing apparatus in a standby state, FIG. 3B is a plan view showing the magnetic recording / reproducing apparatus during recording / reproducing, and FIG. 1A is a side view, and FIG. 1B is a longitudinal sectional view. 4 and 5 show a conventional example, and FIG.
FIG. 5 is a plan view showing the configuration near the guide drum, and FIG. 5 is a graph showing the tape floating amount for each tape circumferential contact angle with the guide drum when the rotation speed of the upper guide drum is 5,400 rpm, 3,600 rpm, 1800 rpm. 1 is a compressed air injection device (pressing force urging means), 2 is a column member, 2a, 4a, 5c are air flow passages, 3 is a rotating member, 4 is a holding member, 5 is an injection member, 5b is a closing member, 5d is a jet, 12 ・
13 is a tape guide, 14 is a magnetic head, 15 is a guide drum,
15a is the upper guide drum, 30 is the VTR cassette, 31 is the tape, 31
a is the starting point of the circumference.

Claims (1)

(57) [Claims] 1. A magnetic recording / reproducing apparatus comprising: a guide drum having a variable rotation speed and guiding a tape in a circumferential direction; and a magnetic head for scanning a tape in a circumferential direction to perform magnetic recording / reproducing. Around the starting point of contact with the guide drum on the tape,
Pressing force urging means for pressing the tape against the peripheral surface of the guide drum from the side thereof is provided, and the pressing force urging means is capable of changing the pressing force according to a change in the rotation speed of the guide drum. A magnetic recording / reproducing apparatus characterized by the above-mentioned.