JPH07320349A - Magnetic recording/reproducing apparatus - Google Patents

Abstract

PURPOSE:To avoid the production of noise bar by regulating the recording tracks of a magnetic tape and the rotation track surface of a rotary magnetic head so as to agree with each other and, further inclining the drum shaft and the center axis of a lower drum. CONSTITUTION:In a normal reproducing mode, if a magnetic tape T runs at a required speed while the reference edge Te of the tape T is being guided by the lead 16 of a lead ring LR, the rotation tracks of magnetic heads Ha and Hb agree approximately with track patterns recorded on the tape T. In order to change a reproduction mode from the normal mode to an FF mode, a motor is driven and geared screws 4 and 5 are made to protrude upward from the middle positions in accordance with the speed multiplying number for fast feed. If the screw 4 is made to protrude, the tip of the screw 4 is pressed against the bottom of a lower drum Dd and a drum shaft 3 is turned around a straight line L4. If the screw 5 is made to protrude, the lead ring LR is turned around a straight line L3. With this constitution, even in the case of the FF reproduction or FB reproduction at a high multiplied speed, an excellent reproduced picture can be obtained.

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, and more particularly to a surface of a rotating magnetic head and a magnetic tape in response to a change in running speed of a magnetic tape which runs while slidingly contacting a part of a peripheral surface of a drum. The present invention relates to a magnetic recording / reproducing apparatus in which a rotary magnetic head can favorably trace a recording trace on a magnetic tape by changing the relative spatial positional relationship of

[0002]

2. Description of the Related Art A magnetic tape wound around a part of a peripheral surface of a drum structure composed of an upper drum and a lower drum is run at a predetermined running speed to rotate a magnetic head (hereinafter, simply referred to as "magnetic head"). A video tape recorder (hereinafter referred to as "VTR") can be cited as a typical example of a magnetic recording / reproducing apparatus that performs a recording / reproducing operation by performing a helical scan using ". In this type of VTR, in addition to normal reproduction (hereinafter referred to as "normal reproduction") in which the recording information is reproduced at the same magnetic tape traveling speed as during recording, the traveling speed and traveling direction of the magnetic tape during recording Has widely adopted a so-called variable speed reproduction (hereinafter referred to as "trick play") function of reproducing a magnetic tape by moving the magnetic tape at different traveling speeds (including stop) and traveling directions. Further, like time lapse or so-called frame shooting, the magnetic tape is run intermittently to record an event for a long time, and the recorded magnetic tape can be reproduced at a standard speed, for example. The VTR is also provided.

FIG. 1 shows a general example of a running system of a magnetic tape near the drum structure of a VTR. In the figure, the magnetic tape T is supplied from a supply reel (not shown) and transferred along a known traveling system, and then, the supply side guide roller SGR, the supply side inclined pole 1, the take-up side inclined pole 2 and the take-up side. By the up-side guide roller TGR, the drum structure DA including the upper drum Du and the lower drum Dd is obliquely wound around a predetermined angle range for traveling, and thereafter, is wound on a take-up reel (not shown) via a known traveling system. Taken. At this time, a recording mark pattern (hereinafter referred to as "tape pattern" or "track pattern") as shown in FIG. 3 is formed on the magnetic tape T by the magnetic heads Ha and Hb.

In the figure, a straight line connecting the point labeled "starting point" on the lower edge of the magnetic tape T and the point labeled +1 on the upper edge of the magnetic tape T, and a large number of lines parallel to this straight line. The straight line indicates the center of each track pattern. When the magnetic tape T on which such a track pattern is formed is reproduced while being transported in the same direction and at the same speed as during recording, the magnetic heads Ha and Hb trace on each of these tracks, and normal reproduction is performed. Will be done. However, if the traveling speed or direction of the magnetic tape T during reproduction is different from that during recording, the relative linear velocity between the magnetic tape T and the magnetic heads Ha and Hb changes.
Track patterns drawn on the magnetic tape T by the magnetic heads Ha and Hb are, for example, FF, STILL, and
It will be different as indicated by FB.

The straight lines drawn when the positions of the points indicated by +2, +3 ... +7 in FIG. 3 and the starting point are connected are in the same direction as the running direction of the magnetic tape T during recording. (Indicated by a plus sign), the magnetic tape T is run at a running speed that is 2 times, 3 times, ... 7 times the running speed of the magnetic tape T at the time of recording (hereinafter, referred to as " FF
"Play". 8) shows the rotation loci of the magnetic heads Ha and Hb drawn on the magnetic tape T.

Similarly, the straight lines drawn when the positions of the points indicated by -2, -3 ...- 7 and the starting point are connected are opposite to the running direction of the magnetic tape T during recording. In the direction (indicated by a minus sign), the magnetic tape T has a running speed that is 2 times, 3 times, ... 7 times the running speed of the magnetic tape T during recording.
2 shows the rotation loci of the magnetic heads Ha and Hb drawn on the magnetic tape T when the recording head is run to perform the reproduction operation (hereinafter referred to as “FB reproduction”). A straight line connecting the starting point and a point indicated by 0 on the upper edge of the magnetic tape T is used when the reproducing operation is performed with the magnetic tape T stopped (hereinafter referred to as "still reproduction"). The locus of rotation of the magnetic heads Ha and Hb drawn on the magnetic tape T is shown in FIG.

As a concrete example of this track pattern, a VHS (registered trademark) system VTR, which is one of the typical VTR systems, will be described below.
That is, the most common VHS VTR is 18 per minute.
The magnetic tape T travels around the outer periphery of a rotary drum having a diameter of 62 mm which rotates at 00 rotations in a spiral shape over about 180 °. And in recording in the standard mode (hereinafter referred to as "SP mode"), the magnetic tape is 33.3 per second.
The recording trace drawn on the magnetic tape T by the magnetic head having a track width of 58 μm transported by 5 mm is the magnetic tape T.
A video track angle of 5 ° 58'9.9 "is formed with respect to the reference edge Te of the VHS type VTR. In addition to this SP mode, a magnetic tape is 11.12 mm / s. There is a triple mode (hereinafter referred to as "EP mode") in which a magnetic head having a track width of 19 μm is used for recording. In this EP mode, the running speed and track width of the magnetic tape T are set to one third of those in the SP mode, so that it is possible to record on the magnetic tape of the same length three times as long. However, as will be described later, since the track width recorded on the magnetic tape is narrow, in order to accurately trace the magnetic heads Ha and Hb on each track in trick play, it is better than in the SP mode. Is also difficult.

Further, when the magnetic tape T is stopped, the rotation locus of the magnetic head drawn on the magnetic tape T is 5 ° 56′7.s relative to the reference edge Te of the magnetic tape T.
4 ". For example, the straight line connecting the position of the upper edge of the magnetic tape T indicated by +7 in the SP mode in FIG. 3 and the starting point is the reference edge T of the magnetic tape T.
An angle of 6 ° 10′54 ″ with respect to e, and for example, a straight line connecting the position of the upper edge of the magnetic tape T and the starting point indicated by −7 in the SP mode in FIG. , 5 ° 42 'with respect to the reference edge Te of the magnetic head T
It shows an angle of 25.7 ".

As is clear from the track pattern illustrated in FIG. 3, the track pattern recorded on the magnetic tape T in the SP mode and the magnetic tape T by the magnetic heads Ha and Hb during trick play. It will be in a state intersecting with the rotation trajectory of the magnetic head drawn above. Therefore, as shown in FIG. 2B, the signal level of the FM signal reproduced at the time of trick play changes greatly every time the magnetic heads Ha and Hb cross the recording trace, and
Looking at the FM signal envelope in the vertical scanning period, a large undulation occurs during one vertical scanning period. For this reason, as a reproduced image during trick play, only a reproduced image of poor quality in which a noise bar is generated can be obtained.

Recently, three recording traces having a recording trace width of 19 μm are simultaneously recorded in parallel on the magnetic tape T to form a recording trace pattern as shown in FIG. 4A on the magnetic tape. A new form of VTR (hereinafter referred to as "W-VHS system VTR"), which enables the recording and reproduction of so-called high-definition image information by forming it in T, has been commercialized. This W-VHS VTR
In the above, in the three recording marks formed on the magnetic tape T in parallel at the same time, two adjacent recording marks are recorded and reproduced by the two magnetic heads having azimuth angles in opposite directions. The remaining one recording mark is used for recording and reproducing an acoustic signal by another one magnetic head.

When a recorded magnetic tape T recorded by such a W-VHS system VTR is run at a speed higher than that at the time of recording for FF reproduction or FB reproduction, the movement locus of the magnetic head is as shown in FIG. "Starting point" in (a)
Indicated by a straight line connecting the position of the upper edge of the magnetic tape T indicated by the numeral +7 or -7 described above the upper edge of the magnetic tape T in the figure. Will be used. Therefore, since the two magnetic heads for video images having different azimuth angles perform the reproducing operation across the three recording marks formed on the magnetic tape T, the reproduced image is It will be full of noise bars.

Furthermore, although detailed description is omitted, in many consumer digital VTRs that have been recently proposed, the data amount of a video signal is compressed and recorded by a high-efficiency encoding method, and therefore, during FF reproduction. When the rotary magnetic head performs a reproducing operation across the recording traces of the magnetic tape T, such as during FB reproduction, an image may not be reproduced at all depending on the arrangement state of blocks of data arranged in a mosaic pattern. Occur.

In order to solve such a problem, it suffices to make the rotational locus of the magnetic head and the recording trace of the magnetic tape T coincide with each other, and the following method has been conventionally proposed. A magnetic head is attached to an electro-mechanical conversion element as an actuator, and the electro-mechanical conversion element is controlled by an open loop control circuit or a closed loop control circuit to displace the magnetic head in the direction traversing the recording trace of the magnetic tape T. The magnetic head along the recording trace of the magnetic tape T. For example, as disclosed in Japanese Utility Model Publication No. 63-34126, Japanese Utility Model Publication No. 61-158633, etc., a rotary drum to which a magnetic head is attached and a lower drum are integrally tilted so that the rotary head has a magnetic tape. How to follow T's trace. For example, as disclosed in Japanese Examined Patent Publication No. 61-22376, in order to limit the height in the width direction of the magnetic tape provided on the entrance side of the magnetic tape with respect to the drum and the exit side of the magnetic tape from the drum. The method of changing the height of the guide to cause the rotary head to follow the recording trace of the magnetic tape T.

[0014]

However, as described above, the V-shape which controls the rotational locus of the magnetic head by using the electro-mechanical conversion element as the actuator is used.
In TR, since the electro-mechanical conversion element has to be provided in a narrow space inside the rotary drum, the electro-mechanical conversion element to be used needs to have a small shape and size, but the electro-mechanical conversion element has a small shape and size. It is difficult for the mechanical conversion element to give a large displacement to the magnetic head. Further, even when the magnetic head is largely displaced by the electro-mechanical conversion element, it is necessary to maintain a good head touch condition with respect to the magnetic tape, but a good head touch performance is achieved by using a small actuator having good operating characteristics. Is always difficult to maintain. Furthermore, in the actuator, due to the limitation of the amplitude frequency characteristic, for example, in the SP mode, the noiseless search up to about ± 3 times speed is at most feasible, and the high speed search of ± 5 times speed or ± 7 times speed or more is supported. There is a drawback that cannot be done.

Also, the above-mentioned Japanese Utility Model Publication No. 63-34126.
In the magnetic recording / reproducing apparatus disclosed in the publication, an arc-shaped guide portion for guiding the reference edge Te of the magnetic tape T comes into contact with the reference edge Te of the magnetic tape T in a state of so-called point contact. Therefore, the reference edge Te of the magnetic tape T which is not in contact with the arcuate guide portion is inevitably in an unstable state. When the magnetic tape T is recorded at a relatively low recording density, that is, when the recording trace width is relatively large, normal reproduction is barely possible.
In both cases of F reproduction and FB reproduction, there is a problem that the noise bar cannot be satisfactorily removed. The problem is that the magnetic tape T has the above-mentioned VH
This is even more serious when the recording is performed at a relatively high recording density as in the EP mode in the S type VTR, that is, when the recording trace width is relatively small.

[0016] The above-mentioned actual exploitation Sho 61-15863
In the magnetic recording / reproducing apparatus disclosed in Japanese Patent Laid-Open No. 3, a member (guide portion) for guiding the reference edge Te of the magnetic tape T over a predetermined length is separated from the lower drum and provided in the fixing portion of the apparatus. Therefore, it is necessary to prevent the fluctuation of the position of the reference edge Te of the magnetic tape T, which has occurred in the magnetic recording / reproducing apparatus disclosed in Japanese Utility Model Publication No. 63-34126, from occurring at least during the normal reproducing operation. It is possible. However, in order to perform the FF reproducing operation or the FB reproducing operation, when the rotating drum and the lower drum to which the magnetic heads are attached are integrally tilted, the tape is in sliding contact with the tape sliding contact surfaces of the upper and lower drums. The running magnetic tape T is
The reference edge Te is inclined with the upper and lower drums and tends to be displaced in a direction away from the guide portion. Therefore, during the FF reproduction operation or the FB reproduction operation,
As the upper and lower drums tilt, the reference edge Te of the magnetic tape T is likely to be separated from the guide portion, and the position of the reference edge Te of the magnetic tape T in that portion fluctuates to generate a noise bar. There is.

That is, this method is applied to the VHS of the above-mentioned VHS system.
When applied to TR, in SP mode, the track width of the recording trace of the magnetic tape T is relatively large at 58 μm,
Even if the rotary drum to which the magnetic head is attached and the lower drum are integrally tilted to perform the FF reproduction operation or the FB reproduction operation, noise bars are hardly generated in the reproduced image. This is because a part of the reference edge Te of the magnetic tape T is separated from the member (guide portion) for guiding the reference edge Te of the magnetic tape T by the integral inclination of the rotating drum and the lower drum, This is because even if the position of the reference edge Te of the magnetic tape T in the separated portion changes, the amount thereof has little influence on the track width of 58 μm. However, since the track width in EP mode is 19 μm, which is one-third of the track width in SP mode, this separation amount cannot be ignored, and it is clear that noise bars may occur in the reproduced image. Became.

Needless to say, the above-mentioned problem also occurs in the above-mentioned W-VHS system VTR in which the recording trace pattern as shown in FIG. 4A is formed on the magnetic tape T. Absent. The present invention has been made to solve these problems. When the magnetic tape is played back at a speed different from that during recording, or when the magnetic tape is run in the opposite direction to the recording. It is an object of the present invention to provide a magnetic recording / reproducing device in which a noise bar does not occur even in the case of doing so.

Further, an object of the present invention is, for example, that the lead angle of the lower drum is 5 ° 5 with respect to the reference edge Te of the magnetic tape T.
Recording is performed with the tilt angle set to 8'9.9 ", that is, so-called frame shooting recording is performed in units of the field of the television signal or the frame signal, and the pattern recorded by this frame shooting satisfies the VHS standard. It is an object of the present invention to provide a magnetic recording / reproducing apparatus that obtains a continuous moving image such as a CG image when continuously reproducing this continuously.

[0020]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the invention according to claim 1 is directed to "a part of a peripheral surface of a drum structure including an upper drum and a lower drum. In a magnetic recording / reproducing apparatus that performs a recording / reproducing operation on a wound magnetic tape by using a rotary magnetic head mounted on the upper drum, a drum shaft that rotatably supports the upper drum, An actuator provided on the upper drum for displacing and driving the rotary magnetic head in a direction parallel to the drum axis, and a state in which a recording trace formed on the magnetic tape and a rotation locus surface of the rotary magnetic head coincide with each other. And a first inclination for inclining the drum shaft with respect to the central axis of the lower drum, which includes a position regulating guide portion for regulating the position of the reference edge of the magnetic tape and a sliding contact surface of the magnetic tape. Drive means and below A second tilt drive means for tilting the central axis of the lower drum so that a guide portion for controlling the position of the magnetic tape on the ram coincides with the position of the reference edge of the magnetic tape. A magnetic recording / reproducing device that

According to a second aspect of the present invention, "a rotary magnetic head mounted on the upper drum is used for a magnetic tape wound around a part of a peripheral surface of a drum structure including an upper drum and a lower drum. In a magnetic recording / reproducing apparatus that performs a recording / reproducing operation by a recording / reproducing operation, a drum shaft that rotatably supports the upper drum and coaxially supports the upper drum and the lower drum, and a drum shaft provided on the upper drum. An actuator for displacing and driving the rotating magnetic head in a direction parallel to the drum axis,
A state in which a small-diameter portion formed under the sliding contact surface of the magnetic tape of the lower drum and having a smaller diameter than the sliding contact surface, a recording trace formed on the magnetic tape, and a rotation locus surface of the rotating magnetic head match each other. The first tilting drive means for tilting the drum shaft and the lower drum are configured separately, and are loosely fitted in a state of approaching the outer peripheral surface of the small diameter portion formed on the lower drum. A position regulating guide portion for regulating the position of the reference edge of the magnetic tape, and a second inclination portion for inclining the position regulating guide portion so that the position regulating guide portion coincides with the reference edge position of the magnetic tape. A magnetic recording / reproducing apparatus comprising a tilt drive means. Is provided.

[0022]

Embodiments of the magnetic recording / reproducing apparatus of the present invention will be described below with reference to the accompanying drawings. FIG. 5 is a perspective view showing a schematic configuration around the drum structure DA in the first embodiment of the present invention. The drum structure DA is composed of an upper drum Du and a lower drum Dd. The upper drum Du is equipped with magnetic heads Ha and Hb (hereinafter referred to as "magnetic heads Ha and Hb"), and a drum motor Md drives the drum shaft 3 to rotate.
Is driven to rotate around. On the other hand, the lower drum Dd is configured separately from the lead ring LR, and is supported by the drum shaft 3 coaxially with the upper drum Du. As will be described later in detail, the drum shaft 3 is configured to be tiltable in a predetermined direction with respect to the lead ring LR by pushing the bottom surface of the lower drum Dd by the geared screw 4. Further, the lead ring LR is configured to be tiltable in a predetermined direction with respect to the drum structure DA by being pushed by the geared screw 5.

The specific configuration of the first embodiment will be described below with reference to FIGS. 6 to 9. FIG. 6 is a plan view of the drum structure DA showing a state in which the magnetic tape T is wound around a part of the outer peripheral surface thereof. In the figure, the magnetic tape T is a drum structure DA with inclined poles 1 and 2.
It is wound in a range corresponding to an angle slightly larger than 180 degrees with respect to the outer peripheral surface of the drum. In the figure, O is the drum shaft 3 which should be the center of rotation of the upper drum Du.
The position indicated by 90 degrees is the center position of the winding range of the magnetic tape with respect to the peripheral surface of the drum. The straight line L1 is a straight line connecting the center position of the winding range of the magnetic tape with respect to the peripheral surface of the drum and the position O of the shaft center of the drum shaft 3, and the straight line L2 is the position of the shaft center of the drum shaft 3. It is a straight line that passes through O and is orthogonal to the straight line L1. FIG. 7A is a cross-sectional view of the structure around the drum structure, and shows a cross section taken along a straight line L2 in FIG. Similarly, FIG. 7B shows a cross section taken along a straight line L1 in FIG. Note that in FIG. 7A, the drum motor Md described in FIG. 5 is omitted for simplicity. Similarly, in FIG. 7B, the upper drum Du is omitted in addition to the drum motor Md. FIG. 8 is an exploded perspective view of the upper drum Du, the lower drum Dd, the lead ring LR, the drum base DB, and the like.

In these figures, the drum base DB is fixed to a chassis or the like (not shown) of the apparatus. Screws 4 and 5 with gears are screwed into the drum base DB in the direction of 0 degree, and the motor shown in FIG.
(A) It is configured to be driven up and down in the middle. Further, spring holding holes 6 and 7 are provided in the drum base DB in a direction of 180 degrees, and these spring holding holes 6 and 7 are provided.
Coil springs 8 and 9 are arranged at 7, respectively. On the other hand, as shown in FIG.
The fulcrum pins 10 and 11 with collars are planted in the 90-degree direction and the 270-degree direction, respectively, and their upper ends are loosely fitted into the holes 12 and 13 formed in the lead ring LR as described later. Then, the rotation fulcrum of the lead ring LR is formed. A lead ring LR is placed on the geared screw 5, the coil spring 8, and the collared fulcrum pins 10 and 11. Here,
Colored fulcrum pins 10, 11 collars 10a, 11a
Is to set a clearance required between the bottom surface of the lead ring LR and the drum base DB in order to allow tilt rotation of the lead ring LR around the straight line L3 connecting the fulcrum pins 10 and 11. In addition, the fulcrum pins 10 and 11 and the holes 12 formed in the lead ring LR,
The lead ring LR and the lead ring LR are loosely fitted to each other with a slight clearance. The clearance allows the lead ring LR to tilt and rotate, and positions the lead ring LR with respect to the drum base DB.

As shown in FIG. 8, the lead ring LR is generally composed of an annular portion 14 and a bottom portion 15, and the upper end surface of the annular portion 14 guides the reference edge Te of the magnetic tape T. 16 are formed. Also, the bottom portion 15
A hole 17 is formed in the center of the hole, and a knife edge portion 17a to be fitted to a lower small diameter portion 20 of the lower drum Dd described later is formed on the inner peripheral portion of the hole 17. Furthermore, a through hole 18 through which the above-mentioned geared screw 4 penetrates is provided in the 0 degree direction of the bottom surface portion 15, and a coil spring 9 penetrates and projects in the 180 degree direction. A through hole 19 should be provided.
The lower small diameter portion 20 of the lower drum Dd, which is supported coaxially with the upper drum Du via the drum shaft 3, has a lead ring L.
The bottom surface of the lower drum Dd is loosely fitted in the knife edge portion 17a formed on the inner peripheral portion of the R
Also, the coil spring 9 is placed in contact with the coil spring 9. It should be noted that the lower drum Dd has a bottom surface of 90 degrees and 27 degrees.
As shown in the cross-sectional shape in FIG. 7B, convex fulcrums 22 and 23 are formed in the direction of 0 degree, and the arm portion of the leaf spring 24 attached to the lower end surface of the lower small diameter portion 20. 24a and 24b are configured to bias the lower drum Dd downward in the drawing in the directions of 90 degrees and 270 degrees to press the convex fulcrums 22 and 23 against the lead ring LR. Therefore, this also urges the lead ring LR downward.

A drum shaft 3 is press-fitted into the lower drum Dd, and a rotary transformer 25a is fixed inside the lower drum Dd. The rotary transformer 25b is mounted on the upper drum which will be described later.
Send and receive signals to and from. Further, the outer peripheral surface of the lower drum Dd is a magnetic tape sliding contact surface 26 around which the magnetic tape T is wound and guided, and a small diameter portion smaller than the magnetic tape sliding contact surface 26 and loosely fitted in the inner diameter of the lead ring LR. 2 and 21. The drum shaft 3 has bearings 27,
The upper drum Du is rotatably supported via 28. A rotary transformer 25b is fixed to the upper drum Du, and voice coil motors 29 and 30 are mounted on the upper drum Du. Magnetic heads Ha and Hb are attached to the voice coil motors 29 and 30, respectively. Here, the voice coil motors 29, 30 are supplied with electric power from a power source (not shown) so that the magnetic heads Ha, Hb can be displaced in a direction parallel to the drum shaft 3. As described above, the rotor of the drum motor Md (not shown) is fixed to the upper drum Du, and the stator is fixed to the drum shaft 3 to rotate the upper drum Du around the drum shaft 3. Has become.

Next, the operation of the magnetic recording / reproducing apparatus of this embodiment will be described. In normal playback mode,
As shown in (a), the drum shaft 3 and the center axis of the lead ring LR substantially coincide with each other, and these axes are substantially perpendicular to the drum base DB. That is, in this state, the magnetic tape T recorded in the standard mode is guided at its reference edge Te by the lead 16 of the lead ring LR and has a predetermined speed corresponding to the normal reproduction mode (33.35 mm / s in the case of VHS system VTR). When driving in the magnetic head H
The rotational trajectories of a and Hb are in a state of substantially matching the track pattern recorded on the magnetic tape T. Therefore, if the voice coil motors 29 and 30 are controlled by a known method so that the magnetic heads Ha and Hb follow the track pattern, the envelope in a good state as illustrated in FIG. 2A. Is obtained. As a control method of the voice coil motors 29 and 30, for example, there is a method such as closed loop control so that the envelope of the reproduced FM signal is always in a constant state. In the normal reproduction mode, the coaxiality between the drum shaft 3 and the center axis of the lead ring LR, the perpendicularity of these axes with respect to the drum base DB, and the like may be mechanically uniquely fixed. When such a configuration is adopted, control of the voice coil motors 29 and 30 is not always necessary.

Next, in order to change the state of the normal reproduction mode to the state of the FF reproduction mode, a motor (not shown) is driven to move the geared screws 4 and 5 in accordance with the number of fast-forwarding speeds as shown in FIG. All you have to do is move upwards. That is, when the geared screw 4 is fed out, its tip presses the bottom surface of the lower drum Dd. As a result, the lower drum Dd, the upper drum Du, and the drum motor Md, which are integrally configured via the drum shaft 3, rotate clockwise around the straight line L4 against the biasing force of the coil spring 9. By this rotation operation, the angle of the rotation locus surface of the magnetic heads Ha, Hb with respect to the lead 16 of the lead ring LR is changed, and the lead 16 and the magnetic heads Ha, H that are substantially adapted to the desired rapid feed multiple speed.
The relative angle of the rotation trajectory plane of b is obtained. (Hereinafter, the correction for changing the relative angle between the lead 16 and the rotational locus surfaces of the magnetic heads Ha and Hb described above may be referred to as "track correction" for convenience.)

Further, since the geared screw 5 is also extended upward in the figure at the same time, its tip presses the bottom surface of the lead ring LR. As a result, the lead ring L
R rotates clockwise around the straight line L3 against the urging force of the coil spring 8 by a predetermined angle. This is because the magnetic tape T is pulled in the direction of the rotation by the rotation of the drum structure DA due to the track correction, so that the reference edge Te tends to separate from the lead 16 at the entrance side of the magnetic tape T with respect to the drum structure DA. And the reference edge Te tends to be pressed against the lead 16 on the outlet side, so that the lead ring LR is rotated to align the lead 16 with the reference edge Te of the magnetic tape T. (Less than,
Magnetic tape T accompanying track correction by rotating the lead 16
For the sake of convenience, the correction adjusted to the displacement of the reference edge Te may be referred to as “lead correction”. It is needless to say that the relative angle between the lead 16 and the rotational locus surface of the magnetic heads Ha and Hb adapted to the fast-forward multiple speed is maintained even when the lead correction is performed. .

Therefore, the magnetic tape T is corrected by the track correction.
Even if the reference edge Te of the magnetic tape T is separated from the lead 16, this lead correction allows the reference edge Te of the magnetic tape T to be stably guided by the lead 16 over the entire winding range around the drum structure DA, and therefore, is expected. When the magnetic tape T travels at the fast-forward multiple speed, the rotation loci of the magnetic heads Ha and Hb become substantially in agreement with the track pattern recorded on the magnetic tape T. Therefore, if the voice coil motors 29 and 30 are controlled by a known method so that the magnetic heads Ha and Hb follow the track pattern, the envelope in a good state as illustrated in FIG. 2A. Is obtained.

Next, for example, in order to change the state from the normal reproduction mode to the FB reproduction mode, the motor (not shown) may be rotationally driven, contrary to the case where the FF reproduction mode is set. This allows the geared screws 4, 5 to
In FIG. 7A, the coil springs 8 and 9 are retracted downward.
It is easily understood that the lower drum Dd and the lead ring LR are rotated counterclockwise around the straight lines L3 and L4 by the urging force of the track correction and the lead correction, respectively.

As described above, according to this embodiment, in the FF reproduction mode or the FB reproduction mode, the drum structure DA is inclined by a predetermined angle with respect to the lead 16 of the lead ring LR to perform the track correction, and the track is corrected. Lead ring L for displacement of magnetic tape T due to correction
R is inclined and lead correction is performed, and further, upper drum D
Since the magnetic heads Ha and Hb mounted on u are appropriately driven by the voice coil motors 29 and 30 to follow the track pattern, the accuracy of the inclination angle of the drum structure DA for track correction and lead correction The accuracy of the inclination angle of the lead ring LR can be relatively gentle. Further, since the track loci of the magnetic heads Ha and Hb and the track pattern of the magnetic tape are substantially matched by the track correction and the read correction, the magnetic head H by the voice coil motors 29 and 30.
Since the displacement amounts of a and Hb are small, the voice coil motors 29 and 30 themselves can be downsized and the amplitude frequency characteristics can be improved.

In the first embodiment, the voice coil motors 29 and 30 are used as the actuators for displacing the magnetic heads Ha and Hb. However, the actuators are not limited to this. For example, a configuration using a bimorph as shown in FIG. 9 is possible. 9A and 9B show a mode of the upper drum Du to which the magnetic heads Ha and Hb are attached by a bimorph. FIG. 9A is a side sectional view of the upper drum Du, and FIG. 9B is from the lower drum Dd side. FIG. In the figure, reference numerals 31 and 32 are bimorphs, and magnetic heads Ha and Hb are attached to the respective tips, and the bimorphs 31 and 32 are bent by applying a voltage to the bimorphs 31 and 32 from a power source (not shown). The magnetic heads Ha and Hb are displaced in a direction parallel to the drum shaft 3.

Next, a second embodiment of the present invention will be described with reference to FIG.
0, with reference to FIG. When the present embodiment is compared with the first embodiment described above, in the first embodiment, the lead ring LR having the lead 16 is configured separately from the lower drum Dd, and the track correction is performed by this lead ring. L
It is supported coaxially with respect to R via the drum shaft 3 and is performed by inclining the upper drum Du and the lower drum Dd integrally, and lead correction is performed on the lead ring LR and the drum structure DA integrally on the drum base DB. In the second embodiment, the lead 16 for guiding the reference edge Te of the magnetic tape T is formed integrally with the lower drum Dd, and the track correction is performed by the magnetic head Ha. , Hb
Is performed by inclining the upper drum Du on which is mounted with respect to the lower drum Dd, and the lead correction is different in that the lower drum Dd and the upper drum Du are integrally inclined with respect to the drum base DB. .

Hereinafter, the specific structure of the second embodiment will be described focusing on this difference, and the description of the structure common to the first embodiment will be omitted. FIG. 10 is a perspective view showing a schematic configuration around the drum structure DA in the second embodiment of the present invention. The drum structure DA is composed of an upper drum Du and a lower drum Dd. The upper drum Du is a magnetic head Ha, H
b is mounted and is driven to rotate around the drum shaft 3 by the drum motor Md. On the other hand, a lead 16 for guiding the reference edge Te of the magnetic tape T is integrally formed on the lower drum Dd. Then, the bottom surface of the intermediate member 33 (see FIG. 11) integrally supported with the upper drum Du via the drum shaft 3 is pushed by the geared screw 34, so that the upper drum Du moves downward together with the intermediate member 33 and the drum shaft 3. Drum D
Track correction is performed by inclining in a predetermined direction with respect to d. Further, the lower drum Dd is configured to be tilted in a predetermined direction with respect to the drum base DB by being pushed by the geared screw 35 to perform lead correction.

FIG. 11A is a sectional view of the structure around the drum structure, and shows a section taken along a straight line L2 in FIG. Similarly, FIG. 11B shows a cross section taken along the straight line L1 in FIG. In addition, FIG.
In (b), the drum motor Md and the upper drum Du described in FIG. 10 are omitted for simplicity of description. The drum base DB is fixed to a chassis or the like (not shown) of the device, and in the direction of 0 degree, the geared screw 34,
35 is screwed together, and a motor (not shown) causes
(A) It is configured to be driven up and down in the middle. Further, spring holding holes 6, 7 are provided in the drum base DB in the direction of 180 degrees, and spring holding holes 53, 54 are provided in the directions of 90 degrees and 270 degrees. These spring holding holes 6, 7, 53 are provided. , 54 are provided with coil springs 8, 9, 55, 56, respectively.

On the other hand, as shown in FIG. 11B, fulcrum pins 10 and 11 with collars are respectively planted in the 90 ° direction and the 270 ° direction of the drum base DB, as will be described later. The upper end of the lower drum Dd is loosely fitted into the holes 36 and 37 formed in the lower drum Dd to form a pivotal fulcrum of the lower drum Dd. And these screw 35 with gear,
Coil spring 9 and fulcrum pins 10 and 11 with collar
A lower drum Dd is placed on the top of the. Here,
Colored fulcrum pins 10, 11 collars 10a, 11a
Is to set a clearance required between the bottom surface of the lower drum Dd and the drum base DB in order to allow the tilt rotation of the lower drum Dd around the straight line L5 connecting the fulcrum pins 10 and 11. Also, each fulcrum pin 10,
11 and the holes 36 and 37 formed in the lower drum Dd are loosely fitted with a slight clearance, and this clearance gives a degree of freedom of tilting rotation of the lower drum Dd to the drum base DB of the lower drum Dd. It is configured to be positioned.

The lower drum Dd is provided with a magnetic tape sliding contact surface 26 for winding and guiding the magnetic tape T and a lead 16 for guiding the reference edge Te of the magnetic tape T on the outer peripheral surface thereof, and the bottom surface thereof will be described later. Through-holes 42-45 through which the rotary transformer mounting portions 38-41 of the intermediate member 33 are to be fitted loosely.
Is provided. Also, bosses 48, 4 that freely penetrate through through holes 46, 47 formed at corresponding positions of the intermediate member 33 in the directions of 90 degrees and 270 degrees on the bottom surface of the lower drum Dd.
9 is provided, and at the center of the bottom surface of the lower drum Dd, there is formed a through hole 50 having a knife-edge-shaped cross section that is loosely fitted to the drum shaft 3 that coaxially supports the intermediate member 33 and the upper drum Du. ing. The leaf springs 24 similar to those of the first embodiment described above are attached to the bosses 48 and 49. The leaf springs 24 move the lower drum Dd in the directions of 90 degrees and 270 degrees, as shown in FIG. (B) It is urged downward in the middle.

On the other hand, the drum shaft 3 is pressed into the upper drum D.
The intermediate member 33, which is supported coaxially with u, is provided with convex fulcrums 51 and 52 in the directions of 90 degrees and 270 degrees.
The action of 5, 56 presses and urges the bottom surface of the lower drum Dd to form a rotation fulcrum of the upper drum Du. That is, the upper drum Du coaxially supported via the intermediate member 33 and the drum shaft 3 has a contact surface with the lower drum Dd of the convex fulcrum 51 and a contact surface with the lower drum Dd of the convex fulcrum 52. Straight line L connecting
It is supported so that it can be tilted about 6 as the central axis.

Next, the operation of the magnetic recording / reproducing apparatus of this embodiment will be described. In the normal playback mode, FIG.
As shown in (a), the central axes of the drum shaft 3 and the lower drum Dd substantially coincide with each other, and these axes are substantially perpendicular to the drum base DB. That is, in this state, the magnetic tape T recorded in the standard mode is guided at its reference edge Te by the lead 16 of the lower drum Dd and has a predetermined speed corresponding to the normal reproduction mode (3 seconds per second in the case of the VHS system VTR).
When the magnetic heads Ha and Hb travel at a speed of 3.35 mm), the rotation loci of the magnetic heads Ha and Hb substantially match the track pattern recorded on the magnetic tape T. Therefore, the voice coil motors 29 and 30 are controlled by a known method to control each magnetic head H.
If a and Hb follow the track pattern,
As shown in FIG. 2A, a reproduction signal having a good envelope is obtained.

Next, in order to change the state of the normal reproduction mode to the state of the FF reproduction mode, a motor (not shown) is driven and the geared screws 34 and 35 are moved in accordance with the double speed number of the fast feed as shown in FIG. All you have to do is move upwards. That is, when the geared screw 34 is paid out, the tip of the screw 34 pushes the bottom surface of the intermediate member 33. As a result, the upper drum Du and the drum motor Md, which are integrally formed via the drum shaft 3, resist the urging force of the coil spring 8 and form a straight line L.
Rotate clockwise around 6 to make track correction.
Further, since the geared screw 35 is also extended upward in the figure at the same time, its tip presses the bottom surface of the lower drum Dd. As a result, the lower drum Dd rotates clockwise around the straight line L5 by a predetermined angle against the biasing force of the coil spring 9 to perform lead correction. It should be noted that the relative angle between the lead 16 and the rotational trajectory surface of the magnetic heads Ha and Hb adapted to the fast-forward multiple speed is maintained even when the lead correction is performed. This is similar to the case of the first embodiment.

Next, for example, in order to change the state from the normal reproduction mode to the FB reproduction mode, a motor (not shown) may be rotationally driven, contrary to the case where the FF reproduction mode is set. This allows the geared screws 34, 35
11A is retracted downward in FIG. 11A, and the biasing force of the coil springs 8 and 9 causes the intermediate member 33 and the lower drum Dd to rotate counterclockwise around straight lines L6 and L5, respectively, to correct the track. It is easily understood that the lead correction is performed.

As described above, according to the present embodiment, in the FF reproduction mode or the FB reproduction mode, the upper drum Du supported coaxially with the intermediate member 33 via the drum shaft 3 with respect to the lead 16 of the lower drum Dd. Track correction is performed by inclining by a predetermined angle, and the lower drum Dd is inclined to perform lead correction with respect to the displacement of the magnetic tape T due to this track correction, and further, the magnetic head mounted on the upper drum Du. Ha and Hb are voice coil motors 29 and 3
Since it is driven appropriately by 0 to follow the track pattern, the accuracy of the inclination angle of the upper drum Du for track correction and the accuracy of the inclination angle of the lower drum Dd for lead correction are relatively gentle. can do. Further, since the track loci of the magnetic heads Ha and Hb and the track pattern of the magnetic tape are made to substantially match by the track correction and the read correction, the displacement amounts of the magnetic heads Ha and Hb by the voice coil motors 29 and 30 are also changed. Since only a small size is required, the voice coil motors 29, 30 themselves can be downsized and the amplitude frequency characteristics can be improved. As with the first embodiment, not only the voice coil motors 29, 30 but also a bimorph can be used as the actuator for displacing the magnetic heads Ha, Hb.

[0044]

As described above in detail, according to the magnetic recording / reproducing apparatus of the present invention, the relative angle between the position regulating guide portion for guiding the reference edge of the magnetic tape and the rotational trajectory surface of the rotary magnetic head. A mechanism for track correction that changes the value and a mechanism for lead correction that rotates the position control guide to match the displacement of the reference edge of the magnetic tape that accompanies the track correction, and rotate the upper drum. Since the actuator for displacing the magnetic head in a direction parallel to the drum axis is provided, a good reproduced image can be obtained even when the magnetic tape recorded at a relatively high recording density is FF reproduced or FB reproduced at a high speed. Obtainable. Further, since the accuracy of the inclination angle of the drum structure or the upper drum for track correction and the accuracy of the inclination angle of the position control guide portion or the lower drum for lead correction can be made relatively gentle. The mechanism system for driving the tilting of the can also be constructed relatively inexpensively. Furthermore, since the track locus surface of the rotary magnetic head and the track pattern of the magnetic tape are made to substantially coincide with each other by the track correction and the read correction, the displacement amount of the rotary magnetic head by the actuator can be small, so that the actuator itself. Can be miniaturized, and the amplitude frequency characteristic can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a general example of a running system of a magnetic tape near a drum structure of a VTR.

FIG. 2 is a diagram showing an FM reproduced signal waveform.

FIG. 3 is a diagram showing a relationship between a recording trace pattern recorded on a magnetic tape and a rotation trajectory of a magnetic head during trick play.

FIG. 4 is a diagram showing a relationship between a recording trace pattern of a magnetic tape in a W-VHS system VTR and a rotation locus of a magnetic head during trick play.

FIG. 5 is a perspective view showing a schematic configuration around a drum structure DA according to the first embodiment of the present invention.

FIG. 6 is a plan view of the drum structure DA showing a state in which the magnetic tape T is wound.

FIG. 7 is a sectional view around the drum structure DA according to the first embodiment of the present invention.

FIG. 8 is an exploded perspective view showing an upper drum Du, a lower drum Dd, a lead ring LR, a drum base DB and the like according to the first embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of an upper drum Du when a bimorph is used as an actuator for displacing the magnetic heads Ha and Hb in a direction parallel to the drum shaft 3.

FIG. 10 is a perspective view showing a schematic configuration around a drum structure DA according to a second embodiment of the present invention.

FIG. 11 is a sectional view around a drum structure DA according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Inclined pole on the supply side 2 Inclined pole on the take up side 3 Drum shaft 4 Screw with gear 5 Screw with gear 6 Spring holding hole 7 Spring holding hole 8 Coil spring 9 Coil spring 10 Colored fulcrum pin 11 Colored fulcrum pin 12 Hole 13 hole 14 annular part 15 bottom part 16 lead 17 hole 18 through hole 19 through hole 20 lower small diameter part 21 small diameter part 22 convex fulcrum 23 convex fulcrum 24 leaf spring 25a rotating transformer 25b rotating transformer 26 magnetic tape sliding contact surface 27 bearing 28 Bearing 29 Voice coil motor 30 Voice coil motor 31 Bimorph 32 Bimorph 33 Intermediate member 34 Screw with gear 35 Screw with gear 36 Hole 37 Hole 38 Rotation transformer attachment portion 39 Rotation transformer attachment portion 4 Rotating transformer mounting portion 41 Rotating transformer mounting portion 42 Through hole 43 Through hole 44 Through hole 45 Through hole 46 Through hole 47 Through hole 48 Boss 49 Boss 50 Through hole 51 Convex fulcrum 52 Convex fulcrum 53 Spring holding hole 54 Spring holding hole 55 coil spring 56 coil spring DA drum structure Du upper drum Dd lower drum LR lead ring Md drum motor DB drum base Ha magnetic head Hb magnetic head

Claims (2)

[Claims] 1. A magnetic tape, which is wound around a part of a peripheral surface of a drum structure composed of an upper drum and a lower drum, for performing a recording / reproducing operation by using a rotary magnetic head mounted on the upper drum. In a recording / reproducing apparatus, a drum shaft that rotatably supports the upper drum, an actuator that is provided on the upper drum and drives the rotary magnetic head to be displaced in a direction parallel to the drum shaft, and the magnetic tape. The position regulating guide portion for regulating the position of the reference edge of the magnetic tape and the sliding contact surface of the magnetic tape are so arranged that the recording trace formed on the magnetic tape and the rotational locus surface of the rotary magnetic head are aligned with each other. First tilt drive means for tilting the drum shaft with respect to the center axis of the lower drum, and a position regulating guide portion for the magnetic tape on the lower drum are provided at a position of a reference edge of the magnetic tape. Match The magnetic recording / reproducing apparatus is provided with the second tilt drive means for tilting the central axis of the lower drum. 2. A magnetic tape, which is wound around a part of the peripheral surface of a drum structure composed of an upper drum and a lower drum, for performing a recording / reproducing operation by using a rotary magnetic head mounted on the upper drum. In a recording / reproducing apparatus, a drum shaft that rotatably supports the upper drum and coaxially supports the upper drum and the lower drum, and the rotary magnetic head provided on the upper drum and having the rotary magnetic head. An actuator that is displaced in a direction parallel to the magnetic tape, a small-diameter portion that is formed below the sliding surface of the magnetic tape of the lower drum, and has a smaller diameter than the sliding surface, a recording mark formed on the magnetic tape, and the rotation. First tilt drive means for tilting the drum shaft so that the rotation locus surface of the magnetic head coincides with the lower drum, and the small-diameter portion formed on the lower drum separately from the lower drum. Approaching the outer peripheral surface of And a position regulating guide part for loosely fitting the magnetic tape to regulate the position of the reference edge of the magnetic tape, and the position regulating guide part so that the position regulating guide part coincides with the reference edge position of the magnetic tape. And a second tilt drive means for tilting the magnetic recording / reproducing apparatus.