JP2000215561A - Rotary magnetic head assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To put the reference edge of a magnetic tape to be positively along the lead of a lead ring corresponding to the running direction of the magnetic tape. SOLUTION: When a rotary magnetic head assembly 10A is constituted by adopting a DD system, especially when a magnetic tape T runs in one direction (positive (+) direction), while being in contact with the sliding contact surface 14a for magnetic tape on a rotating upper drum 14 and a sliding contact surface HL for magnetic tape on the standstill lower drum 13, the magnetic tape T tends to run along carved lines HL1 formed on the sliding contact surface 13a for magnetic tape on the lower drum 13, so that the magnetic tape T in the running state to one direction (positive direction) is inclined to go down to the side of a bottom surface part 12c (downward) of the lead ring 12, since an angle α1 of carved lines HL1 is being set to the angle larger than a lead angle α of the lead 12a of the lead ring 12, the force F1 is generated for pressing a reference edge (lower end part) Te of the magnetic tape T to the lead 12a of the lead ring 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus of a helical scan type, and more particularly to a rotary magnetic head assembly which enables a rotary magnetic head to trace a recording mark on a magnetic tape during variable speed reproduction. .

[0002]

2. Description of the Related Art FIG. 1 is a block diagram showing a general rotary magnetic head assembly, and FIG. 2 is a view for explaining a state when variable speed reproduction is performed using a general rotary magnetic head assembly. .

As shown in FIG. 1, a general rotary magnetic head assembly 100 applied to a helical scan type magnetic recording / reproducing apparatus (VTR) is fixedly installed on a chassis S and has a magnetic tape T Lower drum 1 on which a lead 101a for guiding a reference edge (lower end) Te spirally is formed.
01 and an upper drum 104 rotatably provided around the drum shaft 102 in the direction of the arrow with respect to the lower drum 101, and having rotating magnetic heads 103a and 103b integrally attached thereto. Then, the magnetic tape T is moved by a pinch roller and a capstan (not shown) while the magnetic tape T is moved by the lower drum 101 and the upper drum 10.
4 are helically wound over a predetermined angle, and helical scanning is performed by the rotating magnetic heads 103a and 103b to record and reproduce video signals, audio signals, digital signals, and the like on the magnetic tape T.

Incidentally, the magnetic tape T recorded by the general rotary magnetic head assembly 100 is run faster, slower, or stopped at a normal reproduction speed to perform high-speed search reproduction (FF reproduction, FB reproduction), slow reproduction, still reproduction, and other variable-speed reproduction, as shown in FIG.
Since a and (103b) cross the recording trace (signal track) tr recorded on the magnetic tape T, band noise N is generated on the screen of the monitor TV as shown in FIG. 2B.

[0005] On the other hand, the applicant of the present invention has proposed that during variable speed reproduction (high-speed search reproduction, slow reproduction, still reproduction), a rotating magnetic head reproduces data across a recording mark (signal track) recorded on a magnetic tape. We have developed a DD (Dynamic Drum) system that can follow a rotating magnetic head along a recording mark on a magnetic tape so that band noise does not occur on a screen, and provide a magnetic recording / reproducing apparatus equipped with this DD system. Has been well received by users.

A magnetic recording / reproducing apparatus equipped with the above-mentioned DD system is disclosed in Japanese Unexamined Patent Publication No. Hei 8-273255 and Nikkei Mechanical 1995.
15 no. Although described in detail in, for example, Japanese Patent No. 454, the configuration and operation principle of a rotary magnetic head assembly employing a DD system will be described with reference to FIGS.

FIG. 3 shows a DD (Dynamic Drum).
FIG. 4 is an exploded perspective view showing a rotating magnetic head assembly employing a DD (Dynamic Drum) system, and FIG. 5 is an exploded perspective view showing a rotating magnetic head assembly employing a DD (Dynamic Drum) system. FIGS. 6A to 6C schematically show the overall configuration of the employed rotating magnetic head assembly. FIGS. 6A to 6C show DD (Dynam).
FIG. 7 is a schematic diagram for explaining the operation of the rotary magnetic head assembly employing the ic Drum (ic Drum) system.
FIG. 4 is a diagram showing the relationship between the entire drum correction, the primary correction, and the secondary correction in a rotating magnetic head assembly that employs a dynamic drum system.

As shown in FIGS. 3 and 4, DD (Dyn)
The configuration of a rotary magnetic head assembly 10 employing an amic drum system includes a drum base 11 fixedly mounted on a chassis base (not shown).
1, a lead ring 12, a lower drum 13, and an upper drum 14.
Are assembled in order from the bottom to the top.

First, a tape sliding contact surface 14a for winding and guiding the magnetic tape T over a predetermined angle is formed on the outer periphery of the upper drum 14 in a cylindrical shape.
回 転 The rotating magnetic heads 15a and 15b
It is mounted close to.

Next, a drum shaft 16 is press-fitted into the center of the lower drum 13.
4 is coaxially supported via upper and lower bearings 17,17. A magnetic tape T is provided around the lower drum 13.
The tape sliding surface 13a for winding and guiding the
Is formed in a cylindrical shape with substantially the same diameter as the tape sliding contact surface 14a. In the lower drum 13, a small-diameter portion 13b having a smaller diameter than the tape sliding contact surface 13a is formed spirally below the tape sliding contact surface 13a, and has a smaller diameter than the small-diameter portion 13b below the center of the bottom surface portion 13c. A lower small diameter portion 13d is formed so as to protrude toward a drum base 11 described later.

Only the upper drum 14, to which the rotating magnetic heads 15a and 15b are integrally attached, is rotatable about the drum shaft 16 in the direction of the arrow by the driving force of a drum motor 18 (only shown in FIG. 3). . At this time, the drum motor 18 includes a stator 18 a fixed to the upper end of the drum shaft 16 and the rotor 1 that rotates integrally with the upper drum 14.
8b. Also, upper drum 1
4 between the rotary transformer 19 mounted on the lower drum 13 and the rotary transformer 20 mounted on the lower drum 13.
a and 15b are transmitted and received.

A spiral lead 1 for guiding a lower edge reference edge Te of the magnetic tape T is provided below the outer periphery of the lower drum 13.
The lead ring 12 formed with 2 a is provided separately from the lower drum 13. The lead ring 12 is loosely fitted in a state of being close to the outer peripheral surface of a spirally formed small diameter portion 13b below the lower drum 13, as shown in an enlarged view in FIG. The L-lead 12a is roughly composed of an annular portion 12b formed spirally over a predetermined angle and a bottom surface portion 12c. A central hole 12d is formed in the center of the bottom surface portion 12c of the lead ring 12 so as to penetrate therethrough. An inner peripheral portion of the central hole 12d is coaxially fitted with the lower small diameter portion 13d of the lower drum 13. A knife edge portion 12e to be formed is formed. Therefore, the upper and lower drums 14 and 13 coaxially supported by the drum shaft 16 are
The lead ring 12 can be coaxially fitted on the bottom surface 12c. In addition, on the upper surface of the bottom surface portion 12c of the lead ring 12, left-side first rotation fulcrums 12f and 12f are symmetrical about the drum shaft 16 as shown in FIG.
f and right second rotation fulcrums 12g, 12g protrude forward and backward in the depth direction, respectively, and these left first fulcrum 12f, 12f and right second fulcrum 12g, 1g.
2g is in contact with the back surface of the bottom portion 13c of the lower drum 13 so as to be able to come and go as described later. A drum base 1 described below is provided on the bottom surface 12 c of the lead ring 12.
1, a left first fulcrum 11c formed on the upper surface 11a,
Four through-holes 12h are drilled for the entry of 11c and the right-hand second pivot points 11d, 11d. Also,
On a bottom surface portion 12c of the lead ring 12, a first geared screw 21, which will be described later, is symmetrical about the drum shaft 16,
Evacuation holes 12i, 12i into which the second member 22 enters, and a second
Screw holes 12j, 12 into which screws 23, 24 with gears are screwed
j is formed.

Next, a drum base 11 serving as a base of the rotary magnetic head assembly 10 is fixedly installed below a lead ring 12. The drum base 11 is provided with a lower drum 13 at the center of the upper surface 11a, as shown in FIG.
A central escape hole 11b into which the lower small diameter portion 13d enters is formed, and the first rotation fulcrums 11c on the left and the second rotation fulcrums 11d on the right are symmetrically symmetrical about the drum shaft 16. 11d protrude forward and backward in the depth direction, respectively. These left first fulcrum 11c, 11
c and the right second rotation fulcrum 11d, 11d penetrate through four through holes 12h of the lead ring 12 and contact with the back surface of the bottom portion 13c of the lower drum 13 in a manner to be described later. In contact. Further, screw holes 11e, 11e into which first geared screws 21, 22 described later are screwed into the drum base 11 symmetrically about the drum shaft 16, and second geared screws 23, 24 described later enter. Through holes 11f are formed respectively.

As shown in FIG. 5, a compression spring 2 is provided between the drum base 11 and the lead ring 12 and between the drum base 11 and the lower drum 13, respectively.
5, 26 and 27 are mounted so that the above-mentioned parts are connected to each other in a predetermined state. The compression springs 25, 26, and 27 shown in the figure are functionally shown, and are provided at predetermined mounting portions.

The tilt angle correction unit 30 of the rotary magnetic head assembly 10 includes a DD motor (tilt drive motor) 31 serving as a power source, and a plurality of gears connected left and right to the DD motor 31. (Gear) reduction mechanism 32,3
3, a rotary encoder 34 for detecting the rotation of the DD motor 31, and a preset sensor 35 for detecting the position of the speed reduction mechanism 32.

At this time, the left reduction mechanism 32 is engaged with the left and first geared screws 21 and 23, and the right reduction mechanism 33 is engaged with the right first and second geared screws 22 and 24.
And are engaged.

Further, the preset sensor 35 for position detection has a configuration in which, for example, an arc-shaped light shielding plate is moved in an optical path in which a light emitting element and a light receiving element are arranged to face each other. Things may be used. Also, the preset sensor 35 outputs the signal output from the preset sensor 35 at the moment when the arc-shaped light shielding plate is removed from the optical path where the light emitting element and the light receiving element are arranged to face each other. It is used as information indicating the reference position of the drum shaft 16 of the head assembly 10 and the reference position of the lead ring 12.

The amount of rotation of the light shielding plate from the reference position in the preset sensor 35 is known by measuring the number of pulses output from the rotary encoder 34, so that the drum shaft 1 of the rotary magnetic head assembly 10 can be used.
6, the direction and amount of deviation from the reference position and the direction and amount of deviation of the lead ring 12 from the reference position can be obtained.

The DD control circuit 36 outputs DD control information in accordance with various operation modes such as the running direction and the running speed of the magnetic tape T from the system control circuit 37, and outputs the DD control information to the inclination angle correcting section 30. send.

The tilt angle correction unit 30 is provided with the upper drum 14
The drum shaft 16 of the rotary magnetic head assembly 10 including the lower drum 13 and the lead ring 12 is tilted by a predetermined amount in the direction of arrow L or the direction of arrow R in FIG. 1, screw with second gear 21, 23
Alternatively, a control operation is performed such that the right and second right and second geared screws 22 and 24 advance and retreat.

The lead ring 12 is also tilted by a predetermined amount in a predetermined direction under the control of the above-described tilt angle correction unit 30, so that the running direction of the magnetic tape T can be either forward or reverse. Even if the rotating magnetic head 15
The recording traces (signal tracks) drawn on the magnetic tape T by the rotation trajectories a and 15b are brought into a state where the track angle is determined, that is, the inclination is corrected, and the reference edge Te of the magnetic tape T is moved. The lead 12a of the lead ring 12 coincides with the track.

As described above, the inclination angle correction unit 30
By the above operation, the angle (track angle) between the rotation locus of the rotating magnetic heads 15a and 15b rotating at a specific number of rotations in a specific rotation direction and the reference edge Te of the magnetic tape T is set to a predetermined angle. The recording and reproducing operation can be performed in such a state.

Next, the operation of the rotating magnetic head assembly 10 having the above configuration will be described in more detail with reference to FIGS. 6 (a) to 6 (c) and FIG.

First, as schematically shown in FIG.
When recording or reproducing on the magnetic tape T running at a standard speed, for example, in the normal reproduction mode, the drum shaft 1
The upper and lower drums 14 and 13 coaxially supported by 6 and the lead ring 12 are held substantially parallel to the drum base 11 without being inclined with respect to the drum base 11. That is, the left and right first and second rotation fulcrums 11c and 11d on the drum base 11 and the left and right first and second rotation fulcrums 12f and 2g on the lead ring 12 correspond to the bottom surface 13c of the lower drum 13. It is in contact with the back. At this time, the left and right first gear-equipped screws 21 and 22 screwed to the drum base 11 are retracted downward without contacting the bottom surface 13 c of the lower drum 13, while the right and left first geared screws 21 and 22 screwed to the lead ring 12. The two-gear screws 23 and 24 are also retracted downward without contacting the bottom surface 13c of the lower drum 13. Also, lower drum 1
3 is urged toward the drum base 11 by a strong urging force of a compression spring 27 (FIG. 5) narrowly mounted between the drum base 11 and the lower drum 13, and the lead ring 12 is connected to the drum base 11 by a lead. Due to the weak urging force of the compression springs 25 and 26 (FIG. 5) tightly mounted between the lower drum 1 and the
3 side, the lower drum 13
The lead ring 12 is securely supported on the pivot point of the point while maintaining the height dimension, and the lead ring 12 is also reliably supported while maintaining the height dimension. Therefore, the drum shaft 16 and the virtual drum shaft of the lead ring 12 match with high accuracy, and these shafts are perpendicular to the drum base 11. In this state, the magnetic tape T recorded in the standard mode has its reference edge Te aligned with the lead 12a of the lead ring 12.
And travel at a predetermined speed corresponding to the normal reproduction mode, the rotation trajectories of the rotary magnetic heads 15a, 15b are recorded traces (signal tracks) recorded on the magnetic tape T.
Will be in the state that matches. Here, the case where the normal reproduction mode is designated by the mode designation means (not shown) has been described. However, when the so-called recording mode for recording on the magnetic tape T running at the standard speed is designated, the drum shaft 16 is also designated.
The same operation is performed for adjusting the inclination angle of the virtual drum axis of the lead ring 12.

Next, as schematically shown in FIG.
In the case where recording or reproduction is performed on the magnetic tape T traveling in one direction (+ direction) at a speed different from the standard speed, for example, to change from the normal reproduction mode to the FF reproduction mode, the DD motor 31 ( 5) to drive the first and second geared screws 21 and 2 on the left in accordance with the double speed of rapid traverse.
3 is rotated in a direction to push it upward. At this time, the first and second geared screws 22 and 24 on the right side are reversed in the direction of rotation of the first and second geared screws 21 and 23 on the left side, so that they rotate in a direction to retract from the lower drum 13. I have.

That is, when the left first geared screw 21 screwed to the drum base 11 is pushed upward, its upper end pushes up the left bottom surface portion 13c of the lower drum 13, so that Right second fulcrum 11
d, the right bottom surface portion 13c of the lower drum 13 abuts, while the left first fulcrum 11 on the drum base 11
c is separated from the left bottom surface portion 13c of the lower drum 13. As a result, the upper and lower drums 14, 13 coaxially supported on the drum shaft 16 together with the lead ring 12, resist the urging force of the compression spring 27 (FIG. 5), and the second pivot 11d on the drum base 11. Rotate clockwise around.

Accordingly, the upper and lower drums 14 and 13 coaxially supported on the drum shaft 16 together with the lead ring 12 are rotated clockwise with respect to the drum base 11 by the entire drum correction inclination angle θ shown in FIG. As a result, the entire drum is corrected, and the inlet side of the winding of the magnetic tape is displaced upward and the outlet side is inclined so as to be displaced downward.

Further, at the same time when the first geared screw 21 is pushed out, the left second geared screw 23 screwed to the lead ring 12 is also pushed upward in FIG. Abuts on the bottom surface 13c on the left side of the lower drum 13 due to this reaction force.
c is in contact with the first rotating fulcrum 12f on the left side of the lead ring 12 and the bottom surface 13 on the left side of the lower drum 13.
Separate from c. As a result, the bottom surface portion 13c on the left side of the lead ring 12 is centered on the right second rotation fulcrum 12g on the lead ring 12 against the lower drum 13 against the urging force of the compression spring 25 (FIG. 5). In the FF playback mode, the primary correction (track correction) is performed by rotating counterclockwise by the primary correction tilt angle (track correction tilt angle) θ1 shown in FIG.

The primary correction (track correction) in the FF reproduction mode is performed so that the recording trace formed on the magnetic tape T and the rotation locus surfaces of the magnetic heads 15a and 15b coincide with each other. 13 to the lead ring 12
By rotating the lead ring 12 in a direction to press down, that is, in a direction opposite to the direction of the overall drum correction, the magnetic tape winding is displaced in opposite directions on the entrance side and the exit side.

Then, the first screwed to the drum base 11
From the correction inclination angle θ of the entire drum by the geared screw 21, 1 is set by the second geared screw 23 screwed to the lead ring 12.
By subtracting the next correction tilt angle (track correction tilt angle) θ1, the lead ring 12
(Secondary correction inclination angle (lead correction inclination angle) θ2). This secondary correction (lead correction) is performed by the lead 12 a of the lead ring 12.
Of the magnetic tape T and the lead ring 12 with respect to the drum base 11 in the direction opposite to each other on the entrance side and the exit side of the winding of the magnetic tape. Incline by the minute. This FF playback 2
The next correction is that the magnetic tape T is pulled in the direction of the rotation by the rotation of the rotary magnetic head assembly 10 accompanying the primary correction, so that the reference position is determined on the entrance side of the magnetic tape T with respect to the rotary magnetic head assembly 10. The edge Te tends to separate from the lead 12a, and the reference edge Te tends to be pressed against the lead 12a on the exit side. Therefore, the lead ring 12 is rotated to adjust the lead 12a to the reference edge Te of the magnetic tape T. .

Here, even when the secondary correction is performed,
Lead 12a and magnetic head 15 adapted to the rapid traverse speed
It goes without saying that the relative angles of the rotation trace surfaces a and 15b are maintained.

Therefore, even if the reference edge Te of the magnetic tape T is separated from the lead 12a by the primary correction, the reference edge Te of the magnetic tape T is connected to the rotary magnetic head assembly 10 by the lead 12a by the secondary correction. When the magnetic tape T runs at the desired fast-forward double speed, the rotation trajectories of the magnetic heads 15a and 15b are aligned with the recording traces (signal tracks) recorded on the magnetic tape T because the guide is stably guided over the entire winding range. In this state, the reproduced signals exhibit the envelope in a good state without the band noise N (FIG. 2).

Next, as schematically shown in FIG.
In the case where recording or reproduction is performed on the magnetic tape T traveling in the other direction (−direction) at a speed different from the standard speed, for example, from the state of the normal reproduction mode to the state of the FB reproduction mode, the above-described FF reproduction is performed. The DD motor 31 (FIG. 5) is driven in a direction opposite to that of the mode, and the right and first right and second geared screws 22 and 24 are rotated in a direction of pushing out the right and second gears 22 and 24 in accordance with the double speed of the fast return. In addition, the first and second geared screws 21 and 23 on the left side are rotated in a direction to retract from the lower drum.

That is, when the right first geared screw 22 screwed to the drum base 11 is pushed upward, the upper end pushes up the right bottom surface portion 13 c of the lower drum 13. Left first pivot 11
c contacts the left bottom surface portion 13 c of the lower drum 13, while the right second rotation fulcrum 11 on the drum base 11.
d is separated from the right bottom surface portion 13c of the lower drum 13. As a result, the upper and lower drums 14, 13 coaxially supported on the drum shaft 16 together with the lead ring 12, the first rotation fulcrum 11c on the drum base 11 against the urging force of the compression spring 27 (FIG. 5). Rotate counterclockwise around
The whole drum correction is performed.

Further, at the same time when the first geared screw 22 is pushed out, the right second geared screw 24 screwed to the lead ring 12 is also pushed upward in FIG. Abuts on the right bottom surface portion 13c, the reaction force causes the left first rotation fulcrum 12f on the lead ring 12 to move from the lower drum 13 to the left bottom surface portion 13c.
c on the other hand, the right second rotation fulcrum 12 g on the lead ring 12 is connected to the right bottom portion 13 of the lower drum 13.
Separate from c. Thus, the right bottom surface portion 13c of the lead ring 12 pushes down on the lower drum 13 against the urging force of the compression spring 26 around the left first rotation fulcrum 12f on the lead ring 12 (see FIG. (Clockwise) to perform primary correction in the FB playback mode.

Then, the first screwed to the drum base 11
The secondary correction of the lead ring 12 with respect to the drum base 11 is performed by subtracting the primary correction by the second gear screw 24 screwed to the lead ring 12 from the entire drum correction by the gear screw 22.

The effect of the above-described operation in the FB reproduction mode is the same as the effect of the operation in the FF reproduction mode, and a reproduced signal showing a good envelope without band noise N (FIG. 2) is obtained.

Next, the relationship between the overall drum correction, the primary correction, and the secondary correction described above will be further described with reference to FIG.

That is, in FIG. 7, the whole drum correction inclination angle θ is the first geared screw 2 screwed to the drum base 11.
This is an angle at which the upper and lower drums 14, 13 integrated with the drum shaft 16 together with the lead ring 12 are to be inclined with respect to the drum base 11. The primary correction inclination angle θ1 is determined by the second geared screw 23 (or 24) screwed to the lead ring 12,
The lead 12a of the lead ring 12 and the magnetic head 15a,
The lead 12a of the lead ring 12 is inclined with respect to the lower drum 13 in the direction opposite to the inclination direction of the entire drum correction according to the correction angle between the rotation track surface 15b and the running speed of the magnetic tape T. It should be an angle.

On the other hand, as described above, with the primary correction, the reference edge Te of the magnetic tape T is
There is a tendency to move away from the lead 2a or to be pressed against the lead 12a. If this tendency is observed in, for example, the case of the FF reproduction mode, the upper and lower drums 14 and 13 rotate clockwise with respect to the lead 12a of the lead ring 12 integrally with the drum shaft 16 so that the upper and lower drums 1 and 2 rotate.
At the entrance side of the magnetic tape T with respect to the upper and lower drums 14 and 13, the magnetic tape T tends to be lifted upward and separated from the lead 12a. It tends to be pulled and pressed against the lead 12a.

The upper and lower drums coaxially supported on the drum shaft 16 together with the lead ring 12 with respect to the drum base 11 in order to correct such a tendency and make the reference edge Te of the magnetic tape T coincide with the lead 12a. The secondary correction inclination angle θ2 is the angle at which the primary correction angles 14, 14 are to be finally tilted in substantially the same direction as the primary correction inclination angle θ1. The secondary correction tilt angle θ2 is an angle obtained by subtracting the primary correction tilt angle θ1 from the entire drum correction tilt angle θ. In other words, the relationship is θ2 = θ−θ1 (θ = θ1 + θ2).

[0042]

In the rotating magnetic head assembly 10 employing the DD (Dynamic Drum) system as described above, the rotating magnetic head assembly is used for variable speed reproduction (high-speed search reproduction, slow reproduction, still reproduction). The rotating magnetic heads 15a, 15b are designed so that band noise does not occur on the screen even when the tracks 15a, 15b are reproduced across recording marks (signal tracks) recorded on the magnetic tape T.
b can follow the recording trace on the magnetic tape T.

At this time, as shown in FIG. 5 (b), the tape sliding contact surface 13a formed on the outer periphery of the lower drum 13 separate from the lead ring 12 has a lead angle α of the lead 12a of the lead ring 12 (see FIG. The saw HL having the same angle α as in 4) is finished in parallel with the lead 12a using a lead processing machine. Since the magnetic tape T runs along the direction of the cut HL formed on the tape sliding surface 13a of the lower drum 13, the force applied to the magnetic tape T by the frictional force is reduced. It is parallel to the running direction.

Here, the magnetic tape T is made up of the upper and lower drums 14,
When running while spirally winding over a predetermined angle along the tape sliding contact surfaces 13a of the lower drum 13, the angle α of the cut HL formed on the tape sliding contact surface 13a of the lower drum 13 is particularly: This affects the generation of a force F that presses the reference edge Te of the magnetic tape T against the lead 12a of the lead ring 12, and the angle α of the cut HL is changed to the lead ring 1
By setting the same angle as the lead angle α (FIG. 4) of the second lead 12a, either the case where the magnetic tape T runs in one direction (+ direction) or the case where the magnetic tape T runs in the other direction (− direction). In this case, a force F for pressing the reference edge Te of the magnetic tape T against the lead 12a of the lead ring 12 to substantially the same degree is generated.

However, whether the magnetic tape T runs in one direction (+ direction) or in the other direction (-direction), the above-described generation of the pressing force F is satisfied. That is, the lead 1 of the reference edge Te of the magnetic tape T in each running direction of the magnetic tape.
2a cannot be completely satisfied. In particular, the running direction of the magnetic tape T is one direction (+
Of the reference edge Te of the magnetic tape T with respect to the
In the case where importance is placed on the pressing performance on the lead a of the magnetic tape T with respect to the lead 12a in the other direction (−direction), the tape sliding surface 13a of the lower drum is used. Is an issue. Further, as the thickness of the magnetic tape T becomes thinner, the angle α of the cut HL formed on the tape sliding surface 13a of the lower drum tends to have a greater influence on the running direction of the magnetic tape T.

Therefore, the running direction of the magnetic tape T is one direction (+ direction) and the other direction (-direction).
There is a need for a rotary magnetic head assembly that exclusively supports the performance of pressing the reference edge Te of the magnetic tape T against the leads 12a.

[0047]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a first invention is to provide a rotatable upper drum mounted with a rotating magnetic head and a lower drum on a drum shaft. A substantially annular lead ring formed coaxially and formed with a lead for guiding the reference edge of the magnetic tape is smaller in diameter than the magnetic tape sliding contact surface formed below the magnetic tape sliding contact surface of the lower drum. While being loosely fitted close to the outer peripheral surface of the small diameter portion, the center hole of the lead ring is fitted coaxially with the lower portion of the lower drum, and the upper and lower shafts are coaxially supported by the lead ring and the drum shaft. A drum is supported on a drum base, and the magnetic tape wound around a part of the peripheral surface of the upper and lower drums is rotated at a predetermined angle with respect to a reference edge of the magnetic tape by using the rotating magnetic head. Forming a tilt record When performing the recording / reproducing operation, the recording ring formed on the magnetic tape and the rotational trajectory surface of the rotary magnetic head coincide with the drum axis with respect to the lead of the lead ring so as to be in a state of coincidence. A primary correction for tilting the upper and lower drums supported on the upper and lower drums in opposite directions at an entrance side and an exit side of winding the magnetic tape around the upper and lower drums in accordance with a running speed of the magnetic tape; The upper and lower drums coaxially supported by the lead ring and the drum shaft with respect to the drum base so that the upper and lower drums are aligned with the reference edge of the magnetic tape. In a rotary magnetic head assembly provided with a tilt angle correcting means for performing a secondary correction for tilting in opposite directions to each other, a grinding formed on a magnetic tape sliding contact surface of the lower drum. The angle of the eye, a rotary magnetic head assembly being characterized in that machined in the angle greater than the lead angle of lead of the lead ring.

According to a second aspect of the present invention, there is provided a lead for supporting a rotatable upper drum and a lower drum coaxially with a drum shaft and for guiding a reference edge of a magnetic tape. The formed substantially annular lead ring is loosely fitted close to the outer peripheral surface of a small-diameter portion smaller than the magnetic tape sliding contact surface formed below the magnetic tape sliding contact surface of the lower drum, and the lead ring The center hole of the lower drum is coaxially fitted with the lower drum, and the lead ring and the upper and lower drums coaxially supported on the drum shaft are supported on a drum base. When performing a recording / reproducing operation by forming an inclined recording mark at a predetermined angle with respect to a reference edge of the magnetic tape using the rotating magnetic head on the magnetic tape in a state wound around the magnetic tape, Is formed The upper and lower drums coaxially supported on the drum shaft with respect to the lead of the lead ring so that the recording track and the rotation locus surface of the rotary magnetic head coincide with each other, at the traveling speed of the magnetic tape. Accordingly, a primary correction is made to incline in opposite directions at the entrance side and the exit side of the magnetic tape winding around the upper and lower drums, so that the lead of the lead ring coincides with the reference edge of the magnetic tape. The lead ring with respect to the drum base,
A rotary magnet provided with tilt angle correction means for performing secondary correction for tilting the upper and lower drums coaxially supported by the drum shaft in directions opposite to each other at an entrance side and an exit side of the magnetic tape winding. In the head assembly, the angle of the cut formed on the magnetic tape sliding contact surface of the lower drum is cut at an angle opposite to and smaller than the lead angle of the lead of the lead ring. A rotating magnetic head assembly characterized by being processed.

Further, according to a third aspect of the present invention, there is provided a lead for supporting a rotatable upper drum and a lower drum coaxially on a drum shaft, and for guiding a reference edge of a magnetic tape. The formed substantially annular lead ring is loosely fitted close to the outer peripheral surface of a small-diameter portion smaller than the magnetic tape sliding contact surface formed below the magnetic tape sliding contact surface of the lower drum, and the lead ring The center hole of the lower drum is coaxially fitted with the lower drum, and the lead ring and the upper and lower drums coaxially supported on the drum shaft are supported on a drum base. When performing a recording / reproducing operation by forming an inclined recording mark at a predetermined angle with respect to a reference edge of the magnetic tape using the rotating magnetic head on the magnetic tape in a state wound around the magnetic tape, Is formed The upper and lower drums coaxially supported on the drum shaft with respect to the lead of the lead ring so that the recording track and the rotation locus surface of the rotary magnetic head coincide with each other, at the traveling speed of the magnetic tape. Accordingly, a primary correction is made to incline in opposite directions at the entrance side and the exit side of the magnetic tape winding around the upper and lower drums, so that the lead of the lead ring coincides with the reference edge of the magnetic tape. The lead ring with respect to the drum base,
A rotary magnet provided with tilt angle correction means for performing secondary correction for tilting the upper and lower drums coaxially supported by the drum shaft in directions opposite to each other at an entrance side and an exit side of the magnetic tape winding. The rotary magnetic head assembly according to claim 1, wherein the angle of the cut formed on the magnetic tape sliding contact surface of the lower drum is cut in parallel with the rotation locus of the rotary magnetic head. .

[0050]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a rotary magnetic head assembly according to the present invention will be described below with reference to FIGS.
Embodiments> to <Third Embodiment> will be described in detail in this order.

The rotary magnetic head assembly according to the present invention has a DD (Dynamic) described in detail with reference to FIGS.
(Drum) system, and has the technical concept of the rotating magnetic head assembly 10.
In the third embodiment, the angle of the cut HL formed on the tape sliding surface 13a of the lower drum 13 described above depends on whether the magnetic tape T runs in one direction (+ direction) or not. Separately from the case where the magnetic tape T travels in the other direction (− direction), the angle of the slit HL is set exclusively for the traveling direction of the magnetic tape T, so that the magnetic tape T moves in the traveling direction of the magnetic tape T. Lead 12a of T reference edge Te
In this embodiment, the pressing performances of the first and second embodiments are characterized in that they correspond to each other. For convenience of description, the same components as those shown in FIGS. In addition, different portions will be denoted by new reference numerals, and different points will be mainly described.

<First Embodiment> FIG. 8 is a view for explaining a rotary magnetic head assembly according to a first embodiment of the present invention.

As shown in FIG. 8A, the rotary magnetic head assembly 10A according to the first embodiment of the present invention has a DD (Dynamic Dru) described in detail with reference to FIGS.
m) Since it has the technical idea of the rotating magnetic head assembly 10 employing the system, as described in the prior art,
The rotating magnetic head assembly 10A according to the first embodiment includes a rotatable upper drum 1 on which rotating magnetic heads 15a and 15b are mounted.
4 and a lower drum 13 are coaxially supported on a drum shaft 16, and a substantially annular lead ring 12 formed with a lead 12 a for guiding a reference edge Te of the magnetic tape T is attached to a magnetic tape slide of the lower drum 13. The magnetic tape slide-fitting surface 13a formed at the lower portion of the contact surface 13a is loosely fitted close to the outer peripheral surface of the small-diameter portion 13b smaller than the sliding surface 13a. The lead ring 12 and the upper and lower drums 14 and 13 coaxially supported by the drum shaft 16 are fitted on the drum base 11 and are wound around a part of the peripheral surface of the upper and lower drums 14 and 13. The recording and reproducing operation is performed by forming rotating recording traces at a predetermined angle with respect to the reference edge Te of the magnetic tape T on the magnetic tape T using the rotating magnetic heads 15a and 15b.

At this time, the drum shaft 16 is moved with respect to the lead 12a of the lead ring 12 so that the recording trace formed on the magnetic tape T and the rotational trajectory surfaces of the rotary magnetic heads 15a and 15b coincide with each other. First correction in which the upper and lower drums 14, 13 coaxially supported are inclined in opposite directions at the entrance side and the exit side of the winding of the magnetic tape around the upper and lower drums 14, 13 according to the traveling speed of the magnetic tape T. The upper and lower drums 14, 13 coaxially supported by the lead ring 12 and the drum shaft 16 with respect to the drum base 11 so that the leads 12a of the lead ring 12 coincide with the reference edge Te of the magnetic tape T. Inclination angle correction having a plurality of pivot points 11c, 11d, 12f, 12g for performing a secondary correction for inclining in the opposite directions at the entrance and exit sides of the magnetic tape winding. Also point having a 30 is as described in the prior art.

Here, as shown in FIG. 8B, in the rotating magnetic head assembly 10A of the first embodiment according to the present invention, when the magnetic tape T is run in one direction (+ direction), Lead 12a of lead ring 12 of magnetic tape T
In this case, the angle .alpha.1 of the cut HL1 formed on the magnetic tape sliding contact surface 13a of the lower drum 13 is adjusted so that the pressing performance against the rotary magnetic head set described in the prior art is performed. This is different from the angle α of the cut HL formed on the magnetic tape sliding contact surface 13a of the lower drum 13 of the three-dimensional body 10.

That is, the magnetic tape sliding contact surface 1 of the lower drum 13
The angle α1 of the cut HL1 formed at 3a is cut by using a lead processing machine at an angle larger than the lead angle α (FIG. 4) of the lead 12a of the lead ring 12 formed separately therefrom.

Accordingly, the magnetic tape T travels in one direction (+ direction) while being in contact with the rotating magnetic tape sliding surface 14a of the upper drum 14 and the rotating magnetic tape sliding surface HL of the lower drum 13 in a stationary state. Then, the magnetic tape T is attached to the lower drum 13
Of the lead ring 12a of the lead ring 12 (see FIG. 4).
The magnetic tape T traveling in one direction (+ direction) is set to a larger angle than the lead ring 12.
About to go down (to the lower side) of the bottom surface portion 12c. As the magnetic tape T descends, the reference edge (lower end) T of the magnetic tape T
e to press the lead e against the lead 12a of the lead ring 12.
1 is generated, whereby the reference edge (lower end) Te of the magnetic tape T can be reliably pressed against the leads 12a of the lead ring 12, and the effect is particularly remarkable for a thin magnetic tape T.

In the first embodiment, when the magnetic tape T is run in the other direction (−direction), the pressing performance of the magnetic tape T against the lead 12a of the lead ring 12 is in one direction (+ direction). Although it is inferior to the case of running, it is needless to say that it is in a usable range including other operations.

<Second Embodiment> FIG. 9 is a view for explaining a rotary magnetic head assembly according to a second embodiment of the present invention.

As shown in FIG. 9, the rotary magnetic head assembly 10B according to the second embodiment of the present invention also has the same configuration as that shown in FIGS.
The technical concept of the rotating magnetic head assembly 10 employing the DD (Dynamic Drum) system described in detail with reference to FIG.

The rotary magnetic head assembly 1 of the second embodiment
0B, when the magnetic tape T runs in the other direction (−direction), the performance of pressing the magnetic tape T against the leads 12a of the lead ring 12 of the magnetic tape T has the best characteristics. In this case, The angle -α2 of the cut HL2 formed on the magnetic tape sliding contact surface 13a of the lower drum 13 is equal to the angle -α2 of the cut HL formed on the magnetic tape sliding contact surface 13a of the lower drum 13 of the rotary magnetic head assembly 10 described in the related art. Is different from the angle α.

That is, the magnetic tape sliding contact surface 1 of the lower drum 13
The angle -α2 of the cut HL2 formed at 3a is a tilt angle opposite to the lead angle α (FIG. 4) of the lead 12a of the lead ring 12 formed separately therefrom, and the lead angle α
Cutting is performed at a smaller angle using a lead processing machine.

Accordingly, the magnetic tape T travels in the other direction (-direction) while being in contact with the rotating magnetic tape sliding surface 14a of the upper drum 14 and the rotating magnetic tape sliding surface HL of the lower drum 13 in a stationary state. Then, the magnetic tape T is attached to the lower drum 13
Of the ground line HL2 formed on the sliding surface 13a of the magnetic tape 13a.
Is set at an angle opposite to the lead angle α of the lead 12a of the lead ring 12 (FIG. 4) and smaller than the lead angle α, so that the other direction (−direction)
The magnetic tape T running on the bottom surface 1 of the lead ring 12
It is going to descend to the 2c side (downward). When the magnetic tape T descends, a force F2 is generated which presses the reference edge (lower end) Te of the magnetic tape T against the lead 12a of the lead ring 12, thereby causing the reference edge (lower end) Te of the magnetic tape T to move to the lead ring. 12 can be reliably pressed against the leads 12a, and the effect is particularly remarkable for a thin magnetic tape T.

In the second embodiment, when the magnetic tape T runs in one direction (+ direction), the pressing performance of the magnetic tape T against the lead 12a of the lead ring 12 is in the other direction (-direction). Although it is inferior to the case of running, it is needless to say that it is in a usable range including other operations.

<Third Embodiment> FIG. 10 shows a third embodiment according to the present invention.
FIG. 4 is a diagram for explaining a rotary magnetic head assembly according to the embodiment.

As shown in FIG. 10, the rotary magnetic head assembly 10C according to the third embodiment of the present invention also has a DD (Dynamic Drum) described in detail with reference to FIGS.
The technical concept of the rotating magnetic head assembly 10 employing the system is provided.

The rotary magnetic head assembly 1 of the third embodiment
Even at 0C, similarly to the second embodiment, when the magnetic tape T is run in the other direction (-direction), the performance of pressing the magnetic tape T against the leads 12a of the lead ring 12 of the magnetic tape T is the best. In this case, a cut H formed on the magnetic tape sliding contact surface 13a of the lower drum 13 is formed.
The angle β of L3 is different from the angle α of the cut HL formed on the magnetic tape sliding contact surface 13a of the lower drum 13 of the rotary magnetic head assembly 10 described in the related art.

That is, the magnetic tape sliding contact surface 1 of the lower drum 13
The angle β of the saw HL3 formed in 3a is different from that of the second embodiment in that it is cut in parallel with the rotation trajectories of the rotary magnetic heads 15a and 15b using a normal lathe. Here, the grind HL3 is easily formed on the magnetic tape sliding contact surface 13a of the lower drum 13 by a normal lathe without using an expensive lead processing machine.

Accordingly, the magnetic tape T travels in the other direction (-direction) while being in contact with the rotating magnetic tape sliding surface 14a of the upper drum 14 and the rotating magnetic tape sliding surface HL of the lower drum 13 in a stationary state. Then, the magnetic tape T is attached to the lower drum 13
Is to travel along the cut HL3 formed on the sliding surface 13a of the magnetic tape, the angle β of the cut HL3 is set parallel to the rotation trajectories of the rotary magnetic heads 15a and 15b. The magnetic tape T running in the direction (-direction) attempts to descend to the bottom surface 12c side (downward) of the lead ring 12. When the magnetic tape T is lowered, the reference edge (lower end) Te of the magnetic tape T is connected to the lead ring 12.
A force F3 is generated to press the reference edge (lower end) Te of the magnetic tape T against the lead 12a of the lead ring 12, which is particularly effective for a thin magnetic tape T. Appears remarkably.

In the third embodiment, the magnetic tape T
Is moved in one direction (+ direction), the performance of pressing the magnetic tape T against the lead 12a of the lead ring 12 is inferior to that in the case of running the magnetic tape T in the other direction (-direction), but includes other operations. Needless to say, it is in a usable range.

[0071]

In the rotary magnetic head assembly according to the present invention described in detail above, according to the first aspect, DD (Dy
In particular, when a rotary magnetic head assembly is configured by adopting a magnetic drum system, the angle of the cut formed on the magnetic tape sliding contact surface of the lower drum is cut to an angle larger than the lead angle of the lead of the lead ring. Because it was processed
When running the magnetic tape in one direction (+ direction)
The magnetic tape sliding surface of the upper drum while the magnetic tape is rotating,
If the magnetic tape travels in one direction (+ direction) while being in contact with the magnetic tape sliding contact surface of the lower drum in a stationary state, the magnetic tape tends to travel along the cut formed on the magnetic tape sliding contact surface of the lower drum. Because of the relationship in which the angle of the grind is set as described above, the magnetic tape running in one direction (+ direction) tends to descend to the bottom side (downward) of the lead ring. As the magnetic tape descends, a force is generated that presses the reference edge (lower end) of the magnetic tape against the lead of the lead ring, thereby securely pressing the reference edge (lower end) of the magnetic tape against the lead of the lead ring. The effect is particularly remarkable for a thin magnetic tape.

According to the second aspect, DD (Dy
In particular, when a rotary magnetic head assembly is configured by employing a magnetic drum system, the angle of the notch formed on the sliding surface of the lower drum with the magnetic tape is inclined by an angle opposite to the lead angle of the lead of the lead ring. When the magnetic tape is run in the other direction (-direction), the magnetic tape runs along the notch formed on the sliding surface of the lower drum when the magnetic tape runs in the other direction (-direction). Therefore, the magnetic tape running in the other direction (−direction) tends to lower toward the bottom side (downward) of the lead ring because of the relationship in which the angle of the cut is set as described above. This lowering of the magnetic tape generates a force that presses the reference edge (lower end) of the magnetic tape against the lead of the lead ring, thereby securely pressing the reference edge (lower end) of the magnetic tape against the lead of the lead ring. Can,
In particular, the effect is remarkable for a thin magnetic tape T. Furthermore, according to claim 3, DD (Dynam
When the rotary magnetic head assembly is configured using the ic Drum) system, in particular, the angle of the cut formed on the magnetic tape sliding contact surface of the lower drum is cut in parallel with the rotation locus of the rotary magnetic head. Therefore, when the magnetic tape is caused to travel in the other direction (−direction), the magnetic tape tends to travel along the notch formed on the magnetic tape sliding contact surface of the lower drum. , The magnetic tape running in the other direction (−direction) tends to descend to the bottom side (downward) of the lead ring. This lowering of the magnetic tape generates a force that presses the reference edge (lower end) of the magnetic tape against the lead of the lead ring, thereby securely pressing the reference edge (lower end) of the magnetic tape against the lead of the lead ring. The effect is particularly remarkable for a thin magnetic tape. At this time, the cut formed on the sliding surface of the lower drum with the magnetic tape can be easily cut by a normal lathe without using an expensive lead processing machine.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a general rotating magnetic head assembly.

FIG. 2 is a diagram for explaining a state when variable speed reproduction is performed using a general rotating magnetic head assembly.

FIG. 3 is a longitudinal sectional view showing a rotating magnetic head assembly employing a DD (Dynamic Drum) system.

FIG. 4 is an exploded perspective view showing a rotating magnetic head assembly employing a DD (Dynamic Drum) system.

FIG. 5 is a configuration diagram schematically showing the entire configuration of a rotating magnetic head assembly employing a DD (Dynamic Drum) system.

FIGS. 6A to 6C show DD (Dynamic Dr.).
um) A schematic diagram for explaining the operation of the rotary magnetic head assembly employing the system.

FIG. 7 is a diagram showing the relationship between the entire drum correction, the primary correction, and the secondary correction in a rotating magnetic head assembly employing a DD (Dynamic Drum) system.

FIG. 8 is a diagram illustrating a rotary magnetic head assembly according to a first embodiment of the present invention.

FIG. 9 is a view for explaining a rotary magnetic head assembly according to a second embodiment of the present invention.

FIG. 10 is a view for explaining a rotary magnetic head assembly according to a third embodiment of the present invention.

[Explanation of symbols]

10A: Rotary magnetic head assembly of the first embodiment, 10B ...
Rotary magnetic head assembly of the second embodiment, 10C ... Rotary magnetic head assembly of the third embodiment, 11 ... Drum base, 12
... Lead ring, 12a ... Lead, 12c ... Bottom part, 1
2d: central hole, 13: lower drum, 13a: magnetic tape sliding contact surface, 13b: small diameter portion 13b 14: upper drum, 14a: magnetic tape sliding contact surface, 15a,
15b rotary magnetic head, 30 tilt angle correction unit, HL
Reference numeral 1 denotes a cut formed on the tape sliding surface of the lower drum (first embodiment), α1 denotes an angle of the cut formed on the tape sliding surface of the lower drum (first embodiment), and HL2 denotes a tape of the lower drum. Grinding formed on the sliding surface (second embodiment), α2... Angle formed on the tape sliding surface of the lower drum (second embodiment), HL3... Formed on the tape sliding surface of the lower drum Saw (third embodiment), β: angle of the saw formed on the tape sliding surface of the lower drum (third embodiment), T: magnetic tape, T
e: Reference edge.

Claims (3)

[Claims] 1. A substantially annular shape having a rotatable magnetic head mounted thereon and a rotatable upper drum and a lower drum coaxially supported on a drum shaft, and formed with a lead for guiding a reference edge of a magnetic tape. The lead ring is loosely fitted in a state where it is close to the outer peripheral surface of the small diameter portion smaller than the magnetic tape sliding contact surface formed below the magnetic tape sliding contact surface of the lower drum, and the center hole of the lead ring is moved to the lower hole. The lead ring and the upper and lower drums coaxially supported on the drum shaft are supported on a drum base by being coaxially fitted with a lower portion of the drum, and are wound around a part of the peripheral surface of the upper and lower drums. When performing a recording / reproducing operation by forming an inclined recording trace at a predetermined angle with respect to a reference edge of the magnetic tape using the rotating magnetic head on the magnetic tape in a state, a recording trace formed on the magnetic tape is formed. And the rotating magnetism The upper and lower drums coaxially supported on the drum shaft with respect to the leads of the lead ring so that the rotation locus surfaces of the heads coincide with each other. Primary correction for inclining in the opposite directions at the entrance side and the exit side of the magnetic tape winding, and relative to the drum base so that the lead of the lead ring coincides with the reference edge of the magnetic tape. Tilt angle correcting means for performing secondary correction for tilting the upper and lower drums coaxially supported by the lead ring and the drum shaft in directions opposite to each other at an entrance side and an exit side of the winding of the magnetic tape. In the rotary magnetic head assembly having: a cutting angle formed on the magnetic tape sliding contact surface of the lower drum to an angle larger than the lead angle of the lead of the lead ring. A rotating magnetic head assembly, characterized in that: 2. A substantially annular ring having a rotatable magnetic head mounted thereon and a rotatable upper drum and a lower drum coaxially supported on a drum shaft, and formed with a lead for guiding a reference edge of a magnetic tape. The lead ring is loosely fitted in a state where it is close to the outer peripheral surface of the small diameter portion smaller than the magnetic tape sliding contact surface formed below the magnetic tape sliding contact surface of the lower drum, and the center hole of the lead ring is moved to the lower hole. The lead ring and the upper and lower drums coaxially supported on the drum shaft are supported on a drum base by being coaxially fitted with a lower portion of the drum, and are wound around a part of the peripheral surface of the upper and lower drums. When performing a recording / reproducing operation by forming an inclined recording trace at a predetermined angle with respect to a reference edge of the magnetic tape using the rotating magnetic head on the magnetic tape in a state, a recording trace formed on the magnetic tape is formed. And the rotating magnetism The upper and lower drums coaxially supported on the drum shaft with respect to the leads of the lead ring so that the rotation locus surfaces of the heads coincide with each other. Primary correction for inclining in the opposite directions at the entrance side and the exit side of the magnetic tape winding, and relative to the drum base so that the lead of the lead ring coincides with the reference edge of the magnetic tape. Tilt angle correcting means for performing secondary correction for tilting the upper and lower drums coaxially supported by the lead ring and the drum shaft in directions opposite to each other at an entrance side and an exit side of the winding of the magnetic tape. In the rotary magnetic head assembly provided with: the angle of the notch formed on the magnetic tape sliding contact surface of the lower drum is set at an angle opposite to the lead angle of the lead of the lead ring; A rotary magnetic head assembly characterized by being cut to an angle smaller than the lead angle. 3. A substantially annular ring having a rotatable magnetic drum mounted thereon and a rotatable upper drum and a lower drum coaxially supported on a drum shaft, and formed with a lead for guiding a reference edge of a magnetic tape. The lead ring is loosely fitted in a state where it is close to the outer peripheral surface of the small diameter portion smaller than the magnetic tape sliding contact surface formed below the magnetic tape sliding contact surface of the lower drum, and the center hole of the lead ring is moved to the lower hole. The lead ring and the upper and lower drums coaxially supported on the drum shaft are supported on a drum base by being coaxially fitted with a lower portion of the drum, and are wound around a part of the peripheral surface of the upper and lower drums. When performing a recording / reproducing operation by forming an inclined recording trace at a predetermined angle with respect to a reference edge of the magnetic tape using the rotating magnetic head on the magnetic tape in a state, a recording trace formed on the magnetic tape is formed. And the rotating magnetism The upper and lower drums coaxially supported on the drum shaft with respect to the leads of the lead ring so that the rotation locus surfaces of the heads coincide with each other. Primary correction for inclining in the opposite directions at the entrance side and the exit side of the magnetic tape winding, and relative to the drum base so that the lead of the lead ring coincides with the reference edge of the magnetic tape. Tilt angle correcting means for performing secondary correction for tilting the upper and lower drums coaxially supported by the lead ring and the drum shaft in directions opposite to each other at an entrance side and an exit side of the winding of the magnetic tape. In the rotating magnetic head assembly comprising: the angle of the cut formed on the magnetic tape sliding contact surface of the lower drum is cut in parallel to the rotation locus of the rotating magnetic head. A rotating magnetic head assembly characterized by the following.