JPH1021608A - Drum of magnetic recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin drum of which thickness is roughly equal to the tape width and particularly realize reduction in size and thickness of a portable VTR. SOLUTION: The magnetic drum 1 is composed of a rotating body 17 attaching a magnetic head 18 to the external circumference area and upper and lower drums 2, 3 which are provided with a certain inclination angle keeping an interval at the upper and lower portions of the rotating body 17. Here, when a helical scanning magnetic recording apparatus is structured by providing a lead 20 for running a magnetic tape 4 horizontally, the upper and lower drums 2, 3 are fixed to the apparatus side, the upper drum 2 is cut almost parallel to the magnetic tape 4 just above the upper end of the magnetic tape 4 and the magnetic tape 4 is cut almost horizontally just below the lead 20 of the lower drum 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum for a helical scan magnetic recording apparatus for recording a magnetic tape by obliquely scanning a head.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view of a drum of a conventional helical scan magnetic recording apparatus. A drum 100 comprises an upper rotating drum 101 and a lower fixed drum 102, which are entirely inclined. It was done. A magnetic tape 103 is wound horizontally across the upper rotating drum 101 and the lower fixed drum 102. The magnetic tape 103
The tape guide 104 is supplied from a supply reel (not shown).
Is wound around the drum 100 by about 180 °, travels in the direction of the arrow, is guided by the tape guide 105, and is wound on a winding reel (not shown).

[0003] A magnetic head 106 is fixed to the peripheral edge of the upper rotating drum 101, and the contact surface of the magnetic tape 103 with the drum 100 (the magnetic tape 1 shown in FIG.
03 is scanned, and magnetic signals such as video signals are recorded on tracks 107 formed diagonally on the magnetic tape 103. Also, the magnetic tape 1 is attached to the lower fixed drum 102.
A lead 108 is formed for horizontally moving 03.

[0004]

FIG. 6 is a side view of the drum of the conventional helical scan magnetic recording apparatus shown in FIG. 5, and in the above-mentioned conventional example, the drum 100 is used to move the magnetic tape 103 horizontally. Since it is inclined, the upper rotating drum 101 with respect to the width m of the magnetic tape 103,
Both the lower fixed drum 102 must be provided with idle spaces 109 and 110 which do not participate in the running of the magnetic tape. As a result, the height n of the drum 100 becomes large, which prevents the magnetic recording apparatus from being downsized. Was.

FIG. 7 is a perspective view of a drum of another conventional helical scan magnetic recording apparatus, which has been proposed to solve the above-mentioned problem and to make the drum 150 thinner. The drum 150 is composed of upper and lower fixed drums 151 and 152 which are provided vertically.
A magnetic head 153 is disposed along an elliptical gap between the upper and lower fixed drums 151 and 152, and the magnetic head 153 is rotated by approximately 180 °.
Is to scan and record the magnetic tape 154 wound around.

FIG. 8 is a plan view showing a track pattern on a magnetic tape of a drum of another conventional helical scan magnetic recording apparatus shown in FIG. 7, and the magnetic head 153 draws an elliptical locus. The track pattern 155 obtained by viewing the trajectory 153 from the side of the magnetic tape 154 is
Since there are the substantially horizontal portions 155a and 155b, when the substantially horizontal portions 155a and 155b are scanned, they overlap with the adjacent tracks T1, T2, and T3, and cause noise in recording. This is a magnetic tape 154
Can be avoided when the magnetic tape is wound around the drum 150 at a shallow winding angle, but cannot be avoided when the magnetic tape is wound at approximately 180 °, and only limited use is possible.

Accordingly, an object of the present invention is to reduce the thickness of a drum so as not to hinder tape running and recording, and particularly to reduce the size and thickness of a portable VTR (video tape recorder) and the like.

[0008]

In order to solve the above-mentioned problems, a magnetic head is mounted on an outer peripheral edge portion of a disk, and the magnetic head is provided at an interval above and below the rotating body so as to be inclined. In a helical scan magnetic recording device comprising a lower drum and a lead for horizontally moving a magnetic tape on a lower drum, both the upper and lower drums are fixed to the device side, and the upper drum is a magnetic tape. Was cut almost parallel to the magnetic tape just above the upper end of the tape, and the lower drum was cut almost parallel to the magnetic tape just below the lead.

Since the upper and lower drums are fixed, it is possible to cut the upper and lower drums of the upper and lower drums to make the drum a thin drum close to the tape width.
R (video tape recorder) and the like can be reduced in size and thickness.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a perspective view of a drum of a magnetic recording apparatus according to the present invention. A cylindrical drum 1 used in a helical scan magnetic recording apparatus such as a portable VTR (video tape recorder) is provided with a vertical interval. It comprises a hollow upper drum 2 and a lower drum 3. The upper and lower drums 2 and 3 are both fixed to the apparatus side and provided at an angle, and a magnetic tape 4 such as a video tape is horizontally wound around the upper drum 2 and the lower drum 3 by about 180 °.

The magnetic tape 4 is supplied from a supply reel (not shown), is guided by a tape guide 5 on the left side of the drum 1 in the figure, and travels in the direction of the arrow. The tape guide 5
It comprises a post 6 for regulating the height of the magnetic tape 4 and an inclined post 7 for regulating the vertical movement of the magnetic tape 4. Then, guided by the tape guide 8 on the right side of the drum 1 in the figure,
It travels in the direction of the arrow and is taken up on a take-up reel (not shown). Similarly, the tape guide 8 includes an inclined post 9 for regulating the vertical movement of the magnetic tape 4 and a post 10 for regulating the height of the magnetic tape 4.

A predetermined twist is applied to the magnetic tape 4 by the left tape guide 5 and wound around the drum 1.
The twist of the magnetic tape 4 is returned by the right tape guide 8. The left and right tape guides 5 and 8 are mounted on a loading arm (not shown), and move from the near side to the far side during recording and reproduction to wind the magnetic tape 4 around the drum 1 as shown in the figure.

Reference numeral 11 denotes a full-width erasing head, which is a member for erasing contents recorded on the magnetic tape 4 by applying a high-frequency current at the time of recording. Reference numeral 12 denotes an audio erasing head, which is a member for erasing only the audio signal that has already been recorded. Reference numeral 13 is an audio recording head, and 14 is a control head.

Reference numeral 15 denotes a capstan, 16 denotes a pinch roller, and the pinch roller 16 is a member that can freely contact and separate from the capstan 15.
6, the capstan 1 which presses the magnetic tape 4 and rotates.
The pulling torque of 5 causes the magnetic tape 4 to run during recording and playback. In addition, capstan 1
Driving 5 is performed by using a DC motor and rotating it with a belt, or by using a motor shaft of a DD (direct drive) motor directly as a capstan 15 to provide a flywheel effect inside the motor.

FIG. 2 is a cross-sectional view of the drum of the magnetic recording apparatus according to the present invention. The lower drum 3 is fixed to a shaft 22 which is inclined from the apparatus side, and a disk is mounted on the shaft 22 via bearings 23, 23. 17, magnetic heads 18, 18 are mounted on the outer edge of the disk 17, and a magnet 25 is mounted on the upper surface of the disk 17 via a magnet yoke 24.
Next, the upper drum 2 having the coil 27 is fitted and fixed to the shaft 22 from above, so that the coil 27 faces the magnet 25.

A trans rotor 28 is provided on the lower surface of the disk 17 and a trans stator 29 is provided on the lower drum 3 side.
And the number of rotations is monitored. Magnet 25
And the coil 27 constitute a motor 30.
, The magnet 25, that is, only the disk 17 rotates around the shaft 22.

FIG. 3 is a side view of the drum of the magnetic recording apparatus according to the present invention.
Between the upper and lower drums 2, 3, a disk 17 having substantially the same diameter
Is provided. Two magnetic heads 18 are mounted on the outer peripheral edge of the disk 17 at an interval of 180 °, and are caused to abut on the inner peripheral surface of the magnetic tape 4 running while rotating to scan obliquely. By providing two magnetic heads 18 and running the magnetic tape 4 at a low speed (for example, about 30 revolutions / second) while the magnetic tape 4 is wound around the drum 1 by approximately 180 °,
The two magnetic heads 18 run on the magnetic tape 4 alternately and diagonally, and the diagonal video tracks 19
(... indicates a plurality of lines, the same applies hereinafter), and a large number are formed in parallel to record video signals.

By synchronizing the rotation speed of the magnetic head 18 with the frame frequency (fv) of the video signal, the magnetic head 1
Each time 8 rotates a half turn, a video signal of one field is recorded on one video track 19. At the time of reproduction, the video tracks 19 are alternately scanned by the two magnetic heads 18, and the output signal is switched by an electric circuit to be taken out as a continuous signal. During playback, the same speed as during recording,
The inner peripheral surface of the magnetic tape 4 is scanned at the same angle.

In order to make the magnetic tape 4 wound around the drum 1 run horizontally, leads 20 are provided on the lower drum 3. The drum 1 has a shape that is cut substantially parallel to the magnetic tape 4 immediately below the lead 20 of the lower drum 3 and cut substantially parallel to the magnetic tape 4 immediately above the upper end of the magnetic tape 4 of the upper drum 2. . The upper and lower drums 2 and 3,
By making the lower portion cut just above and below the magnetic tape 4, the height b of the drum 1 is reduced to a thickness close to the width c of the magnetic tape 4 with respect to the height a of the inclined conventional drum. can do.

FIG. 4 is a side view showing the relationship between the drum and the video cassette of the magnetic recording apparatus of the present invention. The upper and lower parts of the upper and lower drums 2 and 3 are cut just above and below the magnetic tape 4. With this configuration, it is possible to form a thin drum close to the width of the tape 4, and the thickness can be substantially the same as that of the video cassette 21, so that the size and thickness of a portable VTR can be reduced. it can.

Next, the operation of the drum of the magnetic recording apparatus of the present invention will be described. In FIG. 2, the upper and lower drums 2 and 3 are fixed to the apparatus side by the shaft 22, and a motor 30 that rotates around the shaft 22 is provided. The motor 30 drives the disk 17. The upper and lower drums 2 and 3 can be fixed to the apparatus side without interfering with the rotation of the motor 30, and there is no need to take out a stay or the like from outside the drum 1 and fix it to the apparatus side. 1 can be made compact.

In FIG. 3, the magnetic tape 4 wound around the upper and lower drums 2 and 3 inclined at an angle of about 180 ° at a low speed (for example, about 30 revolutions / second).
And the two magnetic heads 18 rotating in synchronism with the frame frequency (fv) of the video signal scan obliquely on the inner peripheral surface of the magnetic tape 4 alternately and obliquely on the magnetic tape 4 surface. Are formed in parallel and a video signal is recorded.

Since the upper and lower drums 2 and 3 are fixed, there is no need to provide an idle space in the upper and lower drums 2 and 3 which does not allow the magnetic tape 4 to travel. Therefore, the drum 1 has a shape cut substantially parallel to the magnetic tape 4 just below the lead 20 of the lower drum 3 and cut almost parallel to the magnetic tape 4 just above the upper end of the magnetic tape 4 of the upper drum 2. Therefore, the drum 1 can be a thin drum close to the width of the magnetic tape 4, and in particular, the size and thickness of a portable VTR or the like can be reduced.

[0024]

According to the present invention, the following effects are exhibited by the above configuration. According to a first aspect of the present invention, there is provided a disk having a magnetic head attached to an outer peripheral edge thereof, and upper and lower drums provided at an interval above and below the disk with an interval therebetween, and the magnetic tape is caused to travel horizontally on the lower drum. In the helical scan magnetic recording device provided with leads for the upper and lower drums, both are fixed to the device side, the upper drum is cut just above the upper end of the magnetic tape almost in parallel with the magnetic tape, and the lower drum is cut. Immediately below the lead, the shape was cut substantially parallel to the magnetic tape.

Since the upper and lower drums are fixed, it is possible to cut the upper and lower drums of the upper and lower drums to make the drum into a thin drum close to the tape width.
R (video tape recorder) and the like can be reduced in size and thickness.

[Brief description of the drawings]

FIG. 1 is a perspective view of a drum of a magnetic recording apparatus according to the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a side view of the same.

FIG. 4 is a side view showing a relationship between a drum and a video cassette of the magnetic recording apparatus of the present invention.

FIG. 5 is a perspective view of a drum of a conventional helical scan magnetic recording device.

FIG. 6 is a side view of the same.

FIG. 7 is a perspective view of a drum of another conventional helical scan magnetic recording device.

8 is a plan view showing a track pattern on a magnetic tape of a drum of another conventional helical scan magnetic recording apparatus shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... drum, 2 ... upper drum, 3 ... lower drum, 4 ... magnetic tape, 5, 8 ... tape guide, 17 ... disk, 1
8 magnetic head, 19 video track, 20 lead, 21 video cassette, 22 axis, 30 motor.

Claims (1)

[Claims] 1. A disk having a magnetic head mounted on an outer peripheral edge thereof, and upper and lower drums provided at an interval above and below the disk with an interval provided therebetween, and a magnetic tape is caused to travel horizontally on a lower drum. Helical scan magnetic recording apparatus provided with a lead for fixing the upper and lower drums together to the apparatus side, and cutting the upper drum substantially parallel to the magnetic tape just above the upper end of the magnetic tape; A drum for a magnetic recording apparatus, wherein the drum has a shape cut substantially parallel to a magnetic tape immediately below the lead.