JP2000339646A - Magnetic recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit reciprocating recording/reproducing and normal recording/ reproducing to a magnetic tape. SOLUTION: A first rotary magnetic head pair 15A, 15B which are attached along the outer peripheral surface of an upper drum (rotary drum) 180 deg. apart from each other and have prescribed positive and negative azimuth angles ±α deg.and a second rotary magnetic head pair 15E, 15F which are attached along the outer peripheral surface of the upper drum 180 deg. apart from each other and have larger positive and negative azimuth angles ±βdeg. than the azimuth angles of the first rotary magnetic head pair are crossed using a drum shaft 16 as the center and also the attaching heights of the second rotary magnetic head pair 15E, 15F are displaced by 2N track pitches (N is a positive number of one or more) relative to the first rotary magnetic head pair 15A, 15B attached.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device such as a helical scan type VTR which records and reproduces an information signal by a rotary magnetic head by reciprocating a magnetic tape.

[0002]

2. Description of the Related Art Current helical scan type VTRs have only one running direction of the magnetic tape during recording. Therefore, when reproducing the recorded signal, the magnetic tape must be rewound until the start of recording. Therefore, when recording is to be resumed when the magnetic tape has been recorded to the end, the recording must be rewound to the beginning of the magnetic tape, and when endless recording is to be performed, such as in a monitoring VTR, rewinding is required. There is a problem that a recording signal is lost for the operation time.

Therefore, in order to enable continuous recording for a long time in a VTR, an apparatus for recording and reproducing by reciprocating a magnetic tape has been proposed. There are mainly two methods for reciprocating the magnetic tape. As a first method, the recording area of the magnetic tape is divided into two steps in the width direction, and one area is used for recording in the forward direction (forward direction) and the other area is used for recording in the backward direction (reverse direction). Some are used.

However, as a method of dividing the recording area of the magnetic tape into upper and lower stages, it is necessary to move the position of the recording and reproducing head up and down between the forward path and the backward path.
The configuration of the TR mechanism must be significantly changed, which is not very practical.

On the other hand, a second method is disclosed in
As disclosed in Japanese Patent Application Laid-Open No. 0-85316, there is a method in which every other recording track is recorded on the outward path, and is recorded on an unrecorded track area formed between the recorded tracks on the return path.

FIGS. 12 (a) and 12 (b) are a top view and a side view of a main part of a rotating four-head type magnetic recording / reproducing apparatus to which a conventional reciprocating recording / reproducing method can be applied, and FIG. 4
FIG. 14 shows a recording track pattern recorded reciprocally by the head-type magnetic recording / reproducing apparatus. FIG. 14 shows a recording track pattern when normal recording is performed only in the forward direction by the rotating four-head magnetic recording / reproducing apparatus shown in FIG. FIG.

As shown in FIGS. 12 (a) and 12 (b), in a rotating four-head magnetic recording / reproducing apparatus 100 to which a conventional reciprocating recording / reproducing method can be applied, a magnetic tape T is guided by guide poles 101 and 102. And travels in both directions while spirally contacting the outer peripheral surface of the guide drum 103 for approximately 180 °. In addition, the rotating disk 104 is
3, four video heads 105A to 105D are disposed at positions divided by 90 ° on the outer peripheral edge of the rotating disk 104, and are rotatably held between the upper and lower drums 3 in the direction of the arrow.
180 degrees clockwise only by head motor (not shown)
It is rotated at a predetermined speed of 0 rpm.

At this time, the video heads 105A and 105B facing each other at a distance of 180 ° are inclined clockwise from the vertical direction by an angle α °, and the azimuth angle + α
° is set. On the other hand, video heads 105A, 1
The gaps of the video heads 105C and 105D, which are 90 ° apart from each other and 05B apart from each other and 180 ° apart from each other, are set at an azimuth angle −α ° with the gap inclined at an angle α ° counterclockwise from the vertical direction. I have. In addition, 10
Reference numeral 6 denotes an erasing head, and 107 denotes an audio control head.

As shown in FIG. 13, when the magnetic tape T is recorded while traveling in the forward direction (forward direction), the video heads 105A and 105B use the tracks A1 and B for recording.
Record every other track in the order of 1, A2, B2,
On the other hand, when recording while traveling in the backward direction (reverse direction), first, the track at the reversal position is detected, and then the capstan motor is stopped by a capstan servo circuit (not shown), so that the track when the magnetic tape travels in the backward direction is recorded. After correcting the scan tilt angle to match the tilt angle during forward recording, the video heads 105C and 105C fill the unrecorded track areas formed between the recorded tracks.
D is recorded on every other track in the order of tracks C1, D1, C2 and D2. In addition, at the lower end of the magnetic tape T,
At the time of outward recording on the magnetic tape T, a control pulse CP is recorded by the audio control head 107 in synchronization with the rotation of the rotating disk 104.

[0010]

By the way, in the rotating four-head magnetic recording / reproducing apparatus 100 to which the above-mentioned conventional reciprocating recording / reproducing system can be applied, the video heads 105A to 105A are used.
When recording back and forth on the magnetic tape in 5D, the angle of the gap of the video heads 105A to 105D (hereinafter, referred to as azimuth angle) is set so that adjacent tracks have opposite azimuth angles ± α °. Therefore, good recording and reproduction can be performed without causing crosstalk between adjacent tracks. However, as shown in FIG. 14, on the other hand, the magnetic tape T is run only in the forward direction, and the tracks are recorded and reproduced side by side on the magnetic tape T by the video heads 105A and 105B. In the case of (1), the adjacent tracks have the same azimuth angle + α °, and crosstalk occurs between the adjacent tracks, so that good recording and reproduction cannot be performed. Similarly, although illustration is omitted,
Also in the case of normal recording and reproduction only in the forward direction using the video heads 105C and 10D, adjacent tracks have the same azimuth angle -α, and good recording and reproduction cannot be performed.

Further, when erasing a recorded track, the entire surface of the magnetic tape T is erased by the erasing head 106, so that only the track on which the forward path has been recorded or the track on which the backward path has been recorded cannot be erased.

Therefore, a magnetic recording / reproducing apparatus which generates less crosstalk during reciprocal recording / reproducing on a magnetic tape than before and is capable of recording / reproducing only in the normal forward direction or recording / reproducing only in the backward direction is desired. In addition, a magnetic recording / reproducing apparatus capable of erasing only the track on which the forward path is recorded or only the track on which the return path is recorded is desired.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has been made in a state where a magnetic tape is spirally wound at a predetermined angle around a rotating drum to which a plurality of rotating magnetic head pairs are attached. A magnetic recording / reproducing apparatus that reciprocally records and reproduces information signals on the magnetic tape by the plurality of pairs of rotating magnetic heads while transporting the magnetic tape at a predetermined speed in a reciprocating direction; A first pair of rotating magnetic heads that are mounted 180 degrees apart along a plane and have predetermined azimuth angles in the opposite directions, and are mounted 180 degrees apart along the outer peripheral surface of the rotating drum; A second pair of rotating magnetic heads having azimuth angles opposite to each other greater than a predetermined azimuth angle of the first pair of rotating magnetic heads are attached so as to intersect about the drum axis. 2N mounting height of the second rotary magnetic head pair relative to the first rotary magnetic head pair
A rotating drum assembly for rotatably supporting the rotating drum mounted by displacing by a track pitch (where N is a positive number of 1 or more); and one of the first and second rotating magnetic head pairs The information signal is recorded every other track on the magnetic tape being transported in the outward direction by the pair of rotating magnetic heads, and after the outward recording, the magnetic tape is reversed in the backward direction to be recorded by the one rotating magnetic head pair. A recording means for recording an information signal every other track in the track area formed between the completed tracks by the other rotating magnetic head pair; The previously recorded track is erased earlier by the other pair of rotating magnetic heads, and at the time of backward recording by the other pair of rotating magnetic heads, Erasing means for previously erasing a track recorded by a pair of magnetic heads with one pair of rotating magnetic heads, a recording trajectory in the forward direction by the pair of rotating magnetic heads, and a returning direction by the other pair of rotating magnetic heads Means for matching the recording trajectory of the magnetic recording / reproducing apparatus.

In the magnetic recording / reproducing apparatus of the present invention, the recording means may move the magnetic tape in a forward or backward direction only in a forward or backward direction at a predetermined speed during reciprocation.
And information signals are recorded as track pairs on adjacent tracks on the magnetic tape by the first rotating magnetic head pair or the second rotating magnetic head pair, and the erasing means is provided. Is characterized in that it does not operate at the time of recording at the above 1/2 speed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the magnetic recording / reproducing apparatus according to the present invention will be described below in detail with reference to FIGS.

FIG. 1 is an overall configuration diagram for explaining a magnetic recording / reproducing apparatus according to the present invention.

As shown in FIG. 1, a magnetic recording / reproducing apparatus 1 according to the present invention employs a helical scan method using a rotating magnetic head, and a first and second rotating magnetic tapes are applied to a magnetic tape T which reciprocates. Head pair (15A, 15B),
(15E, 15F), the rotary magnetic head assembly 10 which performs reciprocal recording and reproduction of information signals and also performs recording and reproduction only in the normal forward direction or recording and reproduction only in the backward direction, and the magnetic tape T in the forward direction and the backward direction. And a rotary magnetic head for drawing out the magnetic tape T from a tape cassette (not shown) and wrapping the magnetic tape T around the rotary magnetic head assembly 10 spirally over a predetermined angle (about 180 °). A pair of tape loading members 4 and 4 movably provided on the left and right sides of the assembly 10 and a control pulse CP provided on the right side of the rotating magnetic head assembly 10 and provided at the lower end of the magnetic tape T (FIGS. 9 to 11).
Head 5, a system control circuit 6 for controlling the overall operation of the apparatus 1, a capstan servo circuit 7 for controlling the transfer of the magnetic tape T, and a drive and tilt angle of the rotary magnetic head assembly 10. It comprises a drum servo circuit & tilt angle corrector 8 for control, and a signal processing block 9 for processing signals for recording and reproduction.

The above-mentioned capstan servo circuit 7 controls the driving of the capstan 2 and the control head 5 based on a control signal from the system control circuit 6, and sends a control signal to the capstan 2 to 2
While holding the magnetic tape T between the magnetic tape T and the pinch roller 3, at the time of reciprocating recording / reproducing, the magnetic tape T is at twice the speed of recording / reproducing only in the normal forward direction or twice the speed of recording / reproducing only in the backward direction. Is controlled in a reciprocating direction. The normal recording / reproduction only in the forward direction means that the magnetic tape T is transported only in the forward direction (forward direction), and the information signal is made adjacent to the track on the magnetic tape T by a pair of rotating magnetic heads having different azimuth angles. On the other hand, the recording / reproduction only in the backward direction means that the magnetic tape T is transported only in the backward direction (reverse direction) and is performed in the same manner as described above.

During recording on the magnetic tape T in the forward direction, a control pulse is recorded at the lower end of the magnetic tape T by the control head 5 in synchronization with the rotation of the rotary magnetic head assembly 10, and the forward direction is recorded. The recording is performed by changing the duty of the control pulse only when the control pulse is reversed from the homeward direction or from the homeward direction to the forward direction. During recording on the magnetic tape T in the backward direction and during reciprocal reproduction on the magnetic tape T, the traveling of the magnetic tape T is performed via the capstan servo circuit 7 using the control pulse reproduced by the control head 5. The control is performed so as to be the same as in the direction recording, and the control pulse whose duty is changed is detected to perform the inversion operation.

The above-described drum servo circuit & angle correction unit 8
Is connected to a drum control motor or the like of the rotary magnetic head assembly 10 and controls the drum rotation at a predetermined rotation speed by a drum servo circuit 8A (FIG. 5), as described later. ), The inclination angle correction control of the rotary magnetic head assembly 10 is performed. By this tilt angle correction control, the first and second rotating magnetic head pairs (15
A, 15B) and (15E, 15F), the recording trajectory in the forward direction (forward direction) by the pair of rotating magnetic heads and the recording trajectory in the backward direction (reverse direction) by the other pair of rotating magnetic heads. Are matched.

The above-mentioned signal processing block 9 is connected to the first and second pairs of rotary magnetic heads (15A, 15B) and (15E, 15F) attached to the rotary magnetic head assembly 10, and performs signal processing for recording and reproduction. I do.

Next, the rotary magnetic head assembly 10 described above
Will be described with reference to FIGS.

FIG. 2 is a longitudinal sectional view showing a rotary magnetic head assembly which is a main part of the present invention, FIG. 3 is an exploded perspective view showing the rotary magnetic head assembly, and FIGS. FIG. 5 is a top view for explaining the first and second pairs of rotating magnetic heads attached to the rotating magnetic head assembly, and a mounting position diagram. FIG. 5 is a configuration diagram schematically showing the entire configuration of the rotating magnetic head assembly.
6A to 6C are schematic diagrams for explaining the operation of the rotary magnetic head assembly, and FIG. 7 shows the relationship between the entire drum correction, the primary correction, and the secondary correction in the rotary magnetic head assembly. FIG.

The rotary magnetic head assembly 10 described above is an essential part of the present invention. This rotary magnetic head assembly 10 can be used by the applicant for variable speed reproduction (high-speed search reproduction, slow reproduction, still reproduction). DD that allows the rotating magnetic head to follow the recording marks on the magnetic tape so that no band noise occurs on the screen even if the rotating magnetic head reproduces across the recording marks (signal tracks) recorded on the magnetic tape.
(Dynamic Drum) system, this DD system is applied to the reciprocating recording / reproducing operation on the magnetic tape T in the present embodiment, and the rotating magnetic head assembly 10
The first and second rotating magnetic head pairs (15A, 1
5B) and (15E, 15F).

As shown in FIGS. 2 and 3, 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 a rotating drum (hereinafter, referred to as an upper drum) 14 are assembled in order from below to above.

First, on the outer periphery of the upper drum 14, a tape sliding contact surface 14a for winding and guiding the magnetic tape T over a predetermined angle (approximately 180 °) is formed in a cylindrical shape. A pair of first and second rotating magnetic heads (15A, 15B) and (15E, 15F) are mounted close to the lower drum 13 along the surface 14a.

Here, as shown in an enlarged manner in FIGS. 4A and 4B, the first rotating magnetic head pair (15A, 15B)
Are mounted 180 degrees apart from each other along the outer peripheral surface of the upper drum 14 so as to face each other.
A and 15B are set to a predetermined azimuth angle and have azimuth angles that are opposite to each other. That is, one rotating magnetic head 15
A indicates that the gap is angle α ° clockwise from vertical.
At the azimuth angle + α °, and the other rotating magnetic head 15B has an azimuth angle −α ° with the gap inclined at an angle α ° counterclockwise from the vertical direction.
As an example of this, the rotating magnetic heads 15A,
The azimuth angle ± α ° of 15B is set to ± 6 °.

Further, the second rotating magnetic head pair (15E,
15F) is the first rotating magnetic head pair (15A, 15A).
B) and along the outer peripheral surface of the upper drum 14 by 180
The rotating magnetic heads 15E and 15F are attached to each other at a distance from each other, and the first rotating magnetic head pair (1
5A, 15B), the azimuth angle is set to be larger than the azimuth angle, and the azimuth angle is opposite. That is, the azimuth angle of one rotating magnetic head 15E is set to + β °, and the azimuth angle of the other rotating magnetic head 15F is set to −β °.
And, as an example of this, the rotating magnetic heads 15E, 1
The azimuth angle ± β ° of 5F is set to ± 20 °.

Further, the first and second rotating magnetic head pairs (1
5A, 15B) and (15E, 15F) are mounted on the upper drum by the first rotating magnetic head pair (15A, 15B).
And a second pair of rotating magnetic heads (15E, 15F) are mounted so as to intersect the drum shaft 16, which is the center of rotation of the upper drum. More specifically, a first pair of rotating magnetic heads 15A having an azimuth angle + α ° is attached ahead of the rotating direction of the upper drum, and subsequently, a reverse azimuth is applied to the rotating magnetic head 15A. A second pair of rotating magnetic heads 15E having an angle of -β ° is attached, followed by a first pair of rotating magnetic heads 15B having an azimuth angle of -α °.
A second pair of rotating magnetic heads 15F having a reverse azimuth angle + β ° with respect to 5B is attached. Reciprocal recording can be performed by the head switching operation in the order of the rotating magnetic head 15A, the rotating magnetic head 15F, the rotating magnetic head 15B, and the rotating magnetic head 15E.

Further, the second rotating magnetic head pair (15E,
The mounting height H of 15F) is displaced by 2N track pitch (where N is a positive number of 1 or more) with respect to the first rotating magnetic head pair (15A, 15B).
Here, the first and second rotating magnetic head pairs (15A, 15A)
B) and (15E, 15F) are attached at different heights because one of the first and second pairs of rotating magnetic heads (15A, 15B) and (15E, 15F) will be described later. During forward recording by the pair of rotating magnetic heads, the track already recorded by the one pair of rotating magnetic heads is erased beforehand by the other pair of rotating magnetic heads, and at the time of backward recording by the other pair of rotating magnetic heads, This is because the track already recorded by the other rotating magnetic head pair is erased first by the one rotating magnetic head pair. At this time, the first and second rotating magnetic head pairs (15A, 15B), (15E,
15F) is formed in such a size that the same track width can be obtained on the magnetic tape T, so that no trouble occurs in the erasing operation.

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 first and second rotating magnetic head pairs (15A, 15B) and (15E, 15F) are integrally mounted is a drum motor 18 (FIG. (Shown) can be rotated in the direction of the arrow. At this time, the drum motor 18
Is a stator 18a fixed to the upper end side of the drum shaft 16.
And a rotor 18b that rotates integrally with the upper drum 14. The signals of the first and second pairs of rotary magnetic heads (15A, 15B) and (15E, 15F) are transmitted between the rotary transformer 19 mounted on the upper drum 14 and the rotary transformer 20 mounted on the lower drum 13. Have been giving and receiving.

Further, a lead ring 12 having a spiral lead 12a for guiding a reference edge Te at the lower end of the magnetic tape T is provided separately from the lower drum 13 below the outer periphery of the lower drum 13. I have. The lead ring 12 is
As shown in FIG. 3 in an enlarged manner, the lead 12a having a lead angle γ is fitted at the upper end of the lead 12a with a predetermined angle at the upper end thereof in a state of being close to the outer peripheral surface of the spirally formed small diameter portion 13b. It is roughly composed of an annular portion 12b and a bottom portion 12c formed spirally over an angle. 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. Further, on the upper surface of the bottom surface portion 12 c of the lead ring 12, the first rotation fulcrums 12 f and 12 on the left side 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 drum servo circuit 8A of the drum servo circuit & tilt angle correction section 8 of the rotary magnetic head assembly 10 determines the running direction and running speed of the magnetic tape T according to a command from the system control circuit 6. While controlling, it outputs DD control information to the below-described tilt angle correction unit 8B corresponding to various operation modes.

On the other hand, the inclination angle correction section 8B is provided with a DD motor (inclination angle driving motor) 8B1 as a power source and a reduction gear comprising a plurality of gears which are connected to the DD motor 8B1 right and left. Mechanisms 8B2 and 8B3 and a rotary encoder 8B4 for detecting rotation of the DD motor 8B1
And a preset sensor 8B5 for detecting the position of the speed reduction mechanism 8B2.

At this time, the left reduction mechanism 8B2 is engaged with the first and second geared screws 21 and 23, and the right reduction mechanism 8B3 is engaged with the right first and second geared screws 22 and 2.
4 is engaged.

Further, a preset sensor 8B for position detection
As 5, for example, a configuration in which 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 may be used. The preset sensor 8B5 outputs a signal output from the preset sensor 8B5 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 three-dimensional object 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 8B5 is
By knowing from the measurement of the number of output pulses from B4, the direction and amount of deviation of the rotary magnetic head assembly 10 from the reference position of the drum shaft 16 and the direction and amount of deviation of the lead ring 12 from the reference position are determined. You can ask.

The above-described tilt angle correction unit 8B moves the drum shaft 16 of the rotary magnetic head assembly 10 including the upper drum 14, the lower drum 13, and the lead ring 12 in the direction of arrow R or the direction of arrow L in FIG. The first and second geared screws 21 and 23 are tilted by predetermined amounts, respectively.
And a control operation for moving the right and second geared screws 22 and 24 forward and backward.

The lead ring 12 is also tilted by a predetermined amount in a predetermined direction under the control of the tilt angle correction unit 8B.
Accordingly, regardless of whether the traveling direction of the magnetic tape T is the forward direction or the backward direction, the magnetic tape T is determined by the rotation locus of the first and second rotating magnetic head pairs (15A, 15B) and (15E, 15F). The recording trace (signal track) drawn on T has a predetermined track angle, that is, a state in which the inclination angle has been corrected, and the lead 12a of the lead ring 12 moves along the movement locus of the reference edge Te of the magnetic tape T. Are matched.

As described above, by the operation of the tilt angle correction section 8B, the rotation trajectories of the first and second rotating magnetic head pairs (15A, 15B) and (15E, 15F) rotating in a predetermined direction are obtained. The recording / reproducing operation can be performed such that the angle (track angle) between the magnetic tape T and the reference edge Te becomes a predetermined angle.

Next, the operation of the rotary 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. Note that the inclination angle correction unit 8B
Is used for variable speed reproduction during normal forward recording / reproducing. Here, the description will be made by applying the tilt angle correction unit 8B during reciprocating recording / reproducing.

First, as schematically shown in FIG.
When recording / reproducing the magnetic tape T in the forward direction, the drum shaft 16 is held in a neutral state, and the upper and lower drums 14 and 13 coaxially supported by the drum shaft 16 and the lead ring 12 are connected to the drum base. It is held substantially parallel to the drum base 11 without tilting with respect to the drum base 11. That is, the left and right first and second pivot points 1 on the drum base 11
1c, 11d and the left and right first and second rotation fulcrums 12f, 2g on the lead ring 12 correspond to the bottom portion 13 of the lower drum 13.
c is in contact with the back surface. 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, the lower drum 13
Due to the strong urging force of the compression spring 27 (FIG. 5) tightly mounted between the drum base 11 and the lower drum 13, the drum base 11
The compression spring 2 is biased toward the side and the lead ring 12 is tightly fitted between the drum base 11 and the lead ring 12.
Since the lower drum 13 is pressed toward the lower drum 13 by a weak urging force of 5, 26 (FIG. 5), the lower drum 13 is reliably supported on the above-mentioned four pivot points while maintaining its height. At the same time, the lead ring 12 is also securely supported while maintaining its height. 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, when reproducing the magnetic tape T recorded on the outward path, the magnetic tape T moves its reference edge Te to the read ring 12.
Traveling at a predetermined speed guided by the lead 12a of
First and second rotating magnetic head pairs (15A, 15B),
The rotation locus of (15E, 15F) coincides with the recording trace (signal track) recorded on the magnetic tape T.

Next, as schematically shown in FIG.
When performing the backward recording on the magnetic tape T on which the outward recording is performed, the drum shaft 16 is tilted in the direction of arrow R in order to make the rotational trajectory of the rotational magnetic head of the backward recording follow the rotational trajectory of the rotating magnetic head recorded on the outward path. If you want to record
The DD motor 8B1 (FIG. 5) is driven to rotate the left and first gear-equipped screws 21 and 23 in a direction to push them upward. At this time, the right first and second geared screws 22,
Numeral 24 rotates in the direction of retreating from the lower drum 13 to reverse the rotation direction of the first and second geared screws 21 and 23 on the left.

That is, when the left first gear-equipped screw 21 screwed to the drum base 11 is pushed upward, its upper end pushes up the left bottom surface portion 13 c of the lower drum 13. 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, 13 coaxially supported on the drum shaft 16 together with the lead ring 12 are rotated clockwise 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). The primary correction (track correction) is performed by rotating counterclockwise by the primary correction tilt angle (track correction tilt angle) θ1 shown in FIG.

This primary correction (track correction) is performed by using the recording trace formed on the magnetic tape T and the rotational trajectory surfaces of the first and second rotating magnetic head pairs (15A, 15B) and (15E, 15F). So that the lower drum 13
In the direction in which the lead ring 12 is pressed down,
By rotating the lead ring 12 in a direction opposite to the direction of the correction of the entire drum, the magnetic tape is displaced in opposite directions on the entrance side and the exit side of the winding.

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 secondary correction is 1
The magnetic tape T is pulled in the direction of the rotation by the rotation of the rotary magnetic head assembly 10 accompanying the next correction, so that the reference edge Te is connected to the lead 12a on the entrance side of the magnetic tape T with respect to the rotary magnetic head assembly 10. The lead edge 12 is rotated to adjust the lead 12a to the reference edge Te of the magnetic tape T because the reference edge Te tends to be pressed against the lead 12a on the exit side.

Here, even when the secondary correction is performed,
The lead 12a and the first and second rotating magnetic head pairs (15
A, 15B) and (15E, 15F) of course maintain the relative angle with respect to the rotation locus plane.

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 rotating magnetic head assembly 10 by the lead 12a by the secondary correction. When the magnetic tape T runs, the first and second rotating magnetic head pairs (15A, 15A) are guided stably over the entire winding range.
The rotation trajectories B) and (15E, 15F) coincide with recording marks (signal tracks) recorded on the magnetic tape T.

Next, as schematically shown in FIG.
When performing the backward path recording on the magnetic tape T on which the forward path recording is performed, the drum shaft 16 is tilted in the direction of the arrow L so that the rotational path of the rotational magnetic head of the backward path recording may follow the rotational path of the rotational magnetic head recorded on the forward path. If you want to record
The DD motor 8B1 (FIG. 5) is driven in a direction opposite to the case where the drum shaft 16 is tilted in the direction of the arrow R to rotate the right first and second geared screws 22 and 24 in a direction to push them upward. And the first and second geared screws 21 and 2 on the left side
3 is 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.

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.

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

That is, in FIG. 7, the entire 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,
In accordance with the correction angle between the lead 12a of the lead ring 12 and the rotation locus plane of the first and second rotating magnetic head pairs (15A, 15B) and (15E, 15F), that is, according to the running speed of the magnetic tape T. , Lead ring 1 for lower drum 13
This is an angle at which the second lead 12a should be inclined in a direction opposite to the inclination direction of the entire drum correction.

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. Looking at this tendency, for example, when the drum shaft 16 is inclined in the direction of arrow R, the upper and lower drums 14 and 13
Of the magnetic tape T with respect to the upper and lower drums 14 and 13 by the clockwise rotation with respect to the lead 12a, the magnetic tape T tends to be lifted upward and separated from the lead 12a. , 13
On the exit side of the magnetic tape T, the magnetic tape T tends to be pulled downward and pressed against the leads 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).

Next, the signal processing circuit 9 described above,
The second rotating magnetic head pair (15A, 15B), (15
C, 15D) will be described with reference to FIG.

FIG. 8 is a diagram showing a configuration for transmitting and receiving information signals between the signal processing circuit and the first and second pairs of rotating magnetic heads.

In FIG. 8, reference numeral 38 denotes an input terminal of a recording information signal to be recorded in the magnetic recording / reproducing apparatus 1 according to the present invention, and 39 denotes a magnetic recording / reproducing apparatus 1 according to the present invention. This is an output terminal for a reproduction information signal reproduced from the tape T.

Reference numeral 40 denotes a recording amplifier for recording the recording information signal (video signal) supplied to the input terminal 38 on the magnetic tape T, and operates according to a command from the system control circuit 6.

On the other hand, reference numeral 41 denotes a preamplifier for amplifying a reproduction signal when reproducing the magnetic tape T. The preamplifier 41 operates in accordance with a command from the system control circuit 6 and operates as a preamplifier.
Is output to the output terminal 39.

An erasing signal generator 42 generates an erasing signal in accordance with a command from the system control circuit 6 in order to erase a recorded track recorded on the magnetic tape T.

The switch SW1 outputs the erase signal from the erase signal generator 42 to the first and second rotating magnetic head pairs (15A, 1A).
5B) and (15E, 15F). The switch switches between ON and ON only during reciprocal recording on the magnetic tape T, as will be described later, during normal recording on the magnetic tape T and during magnetic recording. It switches to the OFF side during reciprocal reproduction from T and during normal reproduction from magnetic tape T.

SW2 and SW3 convert the recording information signal from the recording amplifier 40 and the erasing signal from the erasing signal generator 42 into the first and second rotating magnetic head pairs (15A, 15A).
B) and (15E, 15F), which are selectively supplied to the first rotary magnetic head pair (1) via the switch SW4 by the switch SW2 at the time of outward recording on the magnetic tape T as described later. 15A, 15B), the switch SW3 supplies an erasing signal to the second pair of rotating magnetic heads (15E, 15F) via the switch SW5.
When W3 supplies the recording information signal to the second pair of rotating magnetic heads (15E, 15F) via the switch SW5, the switch SW2 sends the erase signal to the first pair via the switch SW4.
To the pair of rotating magnetic heads (15A, 15B).

SW4 and SW5 are switches for switching between recording on the magnetic tape T and reproduction from the magnetic tape T, and the switch SW4 is connected to the first rotating magnetic head pair (15A, 15B). , On the other hand, switch SW
5 is connected to the second rotating magnetic head pair (15E, 15F).

At this time, the above-mentioned switches SW1 to SW5 are operated according to commands from the system control circuit 6.

Next, the recording / reproducing operation of the magnetic recording apparatus 1 according to the present invention having the above configuration will be described with reference to FIGS. 1, 5, 8 and 9 to 11.

FIG. 9 is a diagram showing a recording track pattern reciprocally recorded by the magnetic recording / reproducing apparatus according to the present invention, and FIG. 10 is a magnetic recording / reproducing apparatus according to the present invention using the first and second rotating magnetic head pairs. 11A and 11B are diagrams for explaining a reciprocating recording operation and an erasing operation at the time of the reciprocal recording, wherein FIG. 11A shows a forward pass recording, FIG. 11B shows a forward pass recording, FIG.
FIG. 3 is a diagram showing a recording track pattern when normal recording is performed only in the forward direction by the magnetic recording and reproducing apparatus according to the present invention.

First, the first and second rotating magnetic head pairs (1
5E, 15F) and (15E, 15F), the magnetic tape T is helically wound around an upper drum (rotating drum) 14 at a predetermined angle (approximately 180 °), and the magnetic tape T is reciprocated. The first and second rotating magnetic head pairs (1
5E, 15F) and (15E, 15F), when the information signal is reciprocally recorded with the same track width, as described above, the predetermined speed of the magnetic tape T is set only during normal forward recording / reproducing or backward recording / reproducing. The transfer is controlled at twice the speed of the time only. Assuming that the track pitch between adjacent tracks on the magnetic tape T is Tp (FIG. 9), as described above, the second rotating magnetic head pair (15E, 15F) on the upper drum 14 2N (where N is 1) for one rotating magnetic head pair (15A, 15B)
It is displaced by the above (positive number) × track pitch Tp, and the following FIGS. 10A and 10B illustrate a case where N = 1, but N may be a positive number equal to or more than 1. . At this time, the position separated by 2N tracks is defined by the pitch when the tape is stopped. When the magnetic tape T is running, the upper drum 14
Since the rotation direction of the magnetic tape T and the running direction of the magnetic tape T are different in the case of reciprocating recording, the track pitch is strictly shifted, but the tape transport speed is lower than the rotation of the upper drum 14 and is of an order that can be ignored.

Here, at the time of forward recording on the magnetic tape T, the switch SW1 connected to the erase signal generator 42 is switched to the ON side by each switching control signal from the system control circuit 6 shown in FIG. The recording amplifier 40 and the common terminal of the switch SW2 are connected to each other, and the common terminals of the switches SW1 and SW3 are connected to each other, and the switches SW4 and SW5 are switched to the recording side. The recording information signal from the recording amplifier 40 is supplied to one rotating magnetic head pair (15A, 15B), while the second rotating magnetic head pair (15A, 15B) having the azimuth angle ± β ° is provided.
The erasing signal from the erasing signal generator 42 is supplied to the pair of rotating magnetic heads (15E, 15F).

As shown in FIGS. 9 and 10A, at the time of outward recording on the magnetic tape T, the recording information signal input by the first rotating magnetic head pair (15A, 15B) is Tracks A1, B1, A2, B on T
.. Are recorded on every other track in the order of 2, A3,. At this time, a control pulse CP is recorded at the lower end of the magnetic tape T by the control head 5 in synchronization with the rotation of the upper drum 14, and is recorded by changing the duty of the control pulse CP near the end point of the outward recording. I have.

The first rotating magnetic head pair (15)
A, 15B), when the outward recording operation is started, first,
Since the rotary magnetic head 15A is on the track A1 in FIG. At this time, the rotating magnetic head 1
5A functions as an erasing head. Since the rotating magnetic head 15E is located at a position two tracks away from the track A1 in the tape running direction, the first rotating magnetic head pair (15A , 15B)
The recorded track B1 recorded in step (1) is erased in advance. Next, when the upper drum 14 is further rotated half a turn, the rotating magnetic head 15B is on the track of B1, so that the forward magnetic recording is performed. Therefore, the track A2 previously recorded by the first pair of rotating magnetic heads (15A, 15B) is erased in advance because the track A2 is located two tracks away in the tape running direction. In this way, the track F2, the tracks B1, A between the tracks A1, B1
A new recording operation can be performed while the track E2 between the two is left as it is.

That is, the first rotating magnetic head pair (15A,
15B), the second rotating magnetic head pair (1
5E, 15F) before the first rotating magnetic head pair (15
A, 15B) before erasing only the recorded track, and using the second rotating magnetic head pair (1
5E, 15F), the recorded track remains as it is.

Thereafter, when recording the magnetic tape T in the backward direction by reversing the magnetic tape T in the backward direction (reverse direction), first, the outward recording is stopped, the magnetic tape T is immediately reversed, and the magnetic tape T is reversed in the backward direction. The transfer is started, and the capstan 2 and the capstan servo circuit 7 start controlling the magnetic tape T in the backward direction. At this time, the control in the backward direction of the magnetic tape T is performed by reproducing the control pulse CP recorded on the outward path. The return track is positioned. At substantially the same time as the above, the inclination angle correction unit 8B is operated to record the recording trajectory in the forward direction (forward direction) by the first pair of rotating magnetic heads (15A, 15B) and the second pair of rotating magnetic heads (1).
5E, 15F), the inclination angle of the rotary drum assembly 10 is corrected so that the recording trajectory in the backward direction (reverse direction) coincides with the recording trajectory.

At the time of return recording on the magnetic tape T, the switch SW1 connected to the erasure signal generator 42 is switched to the ON side by each switching control signal from the system control circuit 6 shown in FIG. Here, the recording amplifier 4
0 and the common terminal of the switch SW3, and
By connecting the common terminals of the switches SW1 and SW2 to each other, the recording information signal from the recording amplifier 40 is supplied to the second pair of rotating magnetic heads (15E, 15F) having the azimuth angle ± β °, while Azimuth angle ± α °
The erase signal from the erase signal generator 42 is supplied to the first rotating magnetic head pair (15A, 15B) having

As shown in FIGS. 9 and 10 (B), at the time of the backward recording on the magnetic tape T, the first speed of the magnetic tape T is controlled while referring to the recorded control pulse CP. Rotating magnetic head pair (15A, 15A)
In the unrecorded track area formed between the recorded tracks recorded in B), the second rotating magnetic head pair (15E,
15F), the recording information signal input by the magnetic tape T
.. Are recorded every other track in the order of tracks E1, F1, E2, F2,. At this time, the unrecorded track area formed between the recorded tracks recorded by the first pair of rotating magnetic heads (15A, 15B) is formed only at the time of the first outward recording in the virgin state of the magnetic tape T. After that, the recording information signal has already been recorded.

The second rotating magnetic head pair (15)
E, 15F), when the return path recording operation is started, first,
Since the rotating magnetic head 15F is located on the track E1 in FIG. 10B, the homeward recording is performed. At this time, the rotating magnetic head 1
5F functions as an erasing head. Since the rotating magnetic head 15B is located at a position two tracks away from the track E1 in the tape running direction, the rotating magnetic head 15B has been previously moved to the second rotating magnetic head pair (15E). , 15F)
The previously recorded track F1 recorded in step (1) is erased first. Next, when the upper drum 14 is further rotated half a turn, the rotating magnetic head 15E is on the track of F1, so that the backward magnetic recording is performed. Since it corresponds to the rear position two tracks away, the recorded track E2 previously recorded by the second rotating magnetic head pair (15E, 15F)
Is deleted first. In this way, the tracks E1, F
A new recording operation can be performed while leaving track B2 between tracks 1 and track A2 between tracks F1 and E2 as they are.

That is, the second rotating magnetic head pair (15E,
15F), the first rotating magnetic head pair (1
5A, 15B) and the second rotating magnetic head pair (15
E, 15F), only the recorded track is erased in advance, and the first rotating magnetic head pair (1
5A, 15B) are left as they are.

Similarly, by repeating the magnetic tape T a plurality of times in the reciprocating direction, reciprocating recording and reproduction can be continuously performed.

The state shown in FIG. 9 is described using the first pair of rotating magnetic heads (15A, 15B) during forward recording, and using the second pair of rotating magnetic heads (15E, 15F) during backward recording. However, conversely, using the second pair of rotating magnetic heads (15E, 15F) during forward recording and using the first pair of rotating magnetic heads (15A, 15B) during backward recording does not cause any problem. .

Here, after reciprocal recording on the magnetic tape T, adjacent tracks have opposite azimuth angles, and the first rotating magnetic head pair (15A, 15B) has an azimuth angle of ± α °, Two rotating magnetic head pairs (1
5A, 15B), the azimuth angle ± β ° is set to ± 6 °, and the azimuth angle ± β ° is set to ± 20 °. A with respect to the traveling direction of the head pair (15A, 15B)
Track 1 is + 6 °, track F2 adjacent to A1 is + 20 °, track B1 adjacent to F2 is -6 °,
The track of E2 adjacent to B1 is -20 °, the track of A2 next is + 6 °, and the azimuth angle difference with the least difference between adjacent tracks is 14 °, so that an appropriate azimuth effect can be obtained. That is, since the reverse azimuth angle between the adjacent tracks on the magnetic tape T at the time of reciprocal recording / reproduction has a larger angle difference than before, good recording / reproduction can be performed with almost no crosstalk interference from the adjacent tracks. it can.
For reciprocal reproduction on the magnetic tape T, the switches SW4 and SW5 shown in FIG. 8 are switched to the reproduction side to operate the preamplifier 41 according to a command from the system control circuit 6, while the recording amplifier 40 and the erasing signal generation The device 42 may be made inoperative.

As described above, if the second rotating magnetic head pair (15E, 15F) has an azimuth angle approximately three times the azimuth angle of the first rotating magnetic head pair (15A, 15B), good recording can be achieved. The reproduction characteristics can be obtained.

Next, as shown in FIG.
During normal recording / reproduction only in the outward direction of the
Is set to a half of a predetermined speed during reciprocating travel, for example, the first rotating magnetic head pair (15A,
15B), the recording information signal is recorded on adjacent tracks on the magnetic tape T as a track pair. Here, since the first rotating magnetic head pair (15A, 15B) is set to have an azimuth angle ± α ° opposite to each other, good crosstalk is not obstructed by adjacent tracks on the magnetic tape T. Recording and playback are possible.

Also, during normal recording and reproduction only in the forward direction of the magnetic tape T, the switch SW1 shown in FIG.
The connection between the second rotating magnetic head pair (15E, 15F) and the second rotating magnetic head pair (15E, 15F) is disconnected.
E, 15F) are inactive. When erasing a recorded track previously recorded on the magnetic tape T by the first rotating magnetic head pair (15A, 15B), it is sufficient to erase the track by a full-width erasing head (not shown).

The second rotating magnetic head pair (15E,
15F), the above-mentioned pair of tracks can be recorded in the same manner. Further, only the return speed of the magnetic tape T is set to に 対 し て of the predetermined speed during reciprocation, and the first rotation is performed. The above-described track pair can also be recorded using the magnetic head pair (15A, 15B) or the second rotating magnetic head pair (15E, 15F).

The technical idea of the present invention can be implemented by an analog recording system such as the well-known VHS system as a recording signal system or a digital recording system.

[0092]

According to the magnetic recording / reproducing apparatus according to the present invention described in detail above, in particular, the magnetic recording / reproducing apparatus is attached at a distance of 180.degree. A first pair of rotating magnetic heads having an azimuth angle, and forward and reverse azimuth angles that are mounted 180 degrees apart along the outer peripheral surface of the rotating drum and that are larger than a predetermined azimuth angle of the first pair of rotating magnetic heads The second with
And the second rotating magnetic head pair is mounted at a height of 2N track pitch (where N is 1) with respect to the first rotating magnetic head pair. The rotating drum mounted so as to be displaced by the above positive number) is rotatably supported by the rotating drum assembly, and is used for forward recording by one of the first and second rotating magnetic head pairs. The track already recorded by the one pair of rotating magnetic heads is erased beforehand by the other pair of rotating magnetic heads, and the track already recorded by the other pair of rotating magnetic heads is recorded at the time of backward recording by the other pair of rotating magnetic heads. Track is previously erased by one rotating magnetic head pair, so that the reciprocal azimuth angle between adjacent tracks on the magnetic tape during reciprocal recording / reproduction is larger than before. Therefore, good recording / reproduction can be performed with almost no crosstalk interference between adjacent tracks, and when erasing a recorded track, only the track recorded on the forward path or the track recorded on the backward path Only can be erased.

According to a second aspect of the present invention, in the magnetic recording / reproducing apparatus according to the first aspect, the recording means controls the magnetic tape at a predetermined speed during reciprocating traveling only in the forward direction or only in the backward direction. When transported at 1/2 speed, the first rotating magnetic head pair or the second rotating magnetic head pair records information signals on adjacent tracks on the magnetic tape as track pairs, and the erasing means comprises: Since it is not operated when recording at the above-mentioned 1/2 speed, it is possible to perform recording and reproduction only in the normal forward direction or only in the normal backward direction.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram for explaining a magnetic recording / reproducing apparatus according to the present invention.

FIG. 2 is a longitudinal sectional view showing a rotary magnetic head assembly which is a main part of the present invention.

FIG. 3 is an exploded perspective view showing the rotating magnetic head assembly.

FIGS. 4A and 4B are a top view and a mounting position diagram for explaining first and second rotating magnetic head pairs mounted on the rotating magnetic head assembly.

FIG. 5 is a configuration diagram schematically showing the entire configuration of the rotating magnetic head assembly.

FIGS. 6A to 6C are schematic diagrams for explaining the operation of the rotary magnetic head assembly.

FIG. 7 is a diagram showing a relationship among the entire drum correction, the primary correction, and the secondary correction in the rotating magnetic head assembly.

FIG. 8 is a diagram showing a configuration for transmitting and receiving information signals between a signal processing circuit and first and second pairs of rotating magnetic heads;

FIG. 9 is a diagram showing a recording track pattern recorded reciprocally by the magnetic recording / reproducing apparatus according to the present invention.

FIG. 10 is a diagram for explaining a reciprocating recording operation by the first and second rotating magnetic head pairs and an erasing operation during the reciprocal recording in the magnetic recording and reproducing apparatus according to the present invention.

FIG. 11 is a diagram showing a recording track pattern when normal recording is performed only in a forward direction in the magnetic recording apparatus according to the present invention.

12A and 12B are a top view and a side view of a main part of a rotating four-head magnetic recording and reproducing apparatus to which a conventional reciprocating recording and reproducing method can be applied.

13 is a diagram showing a recording track pattern recorded reciprocally by the rotating four-head type magnetic recording / reproducing apparatus shown in FIG.

FIG. 14 is a diagram showing a recording track pattern when normal recording is performed only in the forward direction in the rotating four-head magnetic recording / reproducing apparatus shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic recording / reproducing apparatus, 2 ... Capstan, 3 ... Pinch roller, 5 ... Control head, 6 ... System control circuit, 7 ... Capstan servo circuit, 8 ... Drum servo circuit & inclination correction part, 8A ... Drum servo Circuit, 8B ...
Inclination angle correction unit, 9: signal processing block, 10: rotating magnetic head assembly, 11: drum base, 12: lead ring, 13: lower drum, 14: rotating drum (upper drum), 15A, 15B: first Rotating magnetic head pair, 15
E, 15F: second rotating magnetic head pair, ± α °: azimuth angle of first rotating magnetic heads 15A, 15B, ± β °
The azimuth angles of the second rotating magnetic heads 15E and 15F, 1
6: drum shaft, 40: recording amplifier, 41: preamplifier,
42: erase signal generator, T: magnetic tape, Tp: track pitch.

Claims (2)

[Claims] In a state where a magnetic tape is spirally wound around a rotating drum to which a plurality of rotating magnetic head pairs are attached over a predetermined angle, the magnetic tape is transported at a predetermined speed in a reciprocating direction while the magnetic tape is being transferred. A magnetic recording and reproducing apparatus for reciprocally recording and reproducing information signals on and from the magnetic tape by a plurality of pairs of rotating magnetic heads, wherein the magnetic recording and reproducing apparatus is attached at a distance of 180 ° along the outer peripheral surface of the rotating drum, A first pair of rotating magnetic heads having an azimuth angle, and a pair of first and second rotating magnetic heads mounted at a distance of 180 ° along the outer peripheral surface of the rotating drum and having a azimuth angle larger than a predetermined azimuth angle of the first pair of rotating magnetic heads; A second rotating magnetic head pair having an azimuth angle is mounted so as to intersect about the drum axis, and the mounting height of the second rotating magnetic head pair is changed to the first rotating magnetic head. A rotating drum assembly that rotatably supports the rotating drum attached with a displacement of 2N track pitch (where N is a positive number of 1 or more) with respect to the air head pair, the first and second rotating magnets; An information signal is recorded every other track on the magnetic tape being transported in the forward direction by one of the rotating magnetic head pairs of the head pair, and after the forward path recording, the magnetic tape is reversed in the backward direction and Recording means for recording an information signal every other track by the other rotating magnetic head pair in a track area formed between tracks already recorded by the rotating magnetic head pair, The track already recorded by the one pair of rotating magnetic heads is first erased by the other pair of rotating magnetic heads, and the track read by the other pair of rotating magnetic heads is erased. An erasing unit for erasing a track recorded by the other rotating magnetic head pair first by the one rotating magnetic head pair during recording; a recording locus in a forward direction by the one rotating magnetic head pair; Means for matching the recording trajectory of the rotating magnetic head pair in the backward direction. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the recording means sets the magnetic tape at a speed half that of a predetermined speed during reciprocating traveling only in a forward direction or only in a backward direction. When transported, the first rotary magnetic head pair or the second rotary magnetic head pair records an information signal on adjacent tracks on the magnetic tape as a track pair, and the erasing means includes the aforementioned 1 A magnetic recording / reproducing apparatus which is not operated when recording at a speed of / 2.