JPH0359816A - Rotating head type recording and reproducing device - Google Patents

Abstract

PURPOSE:To stably perform high-density recording and reproducing while holding a tape-like recording medium between two rotating heads by making the peripheral surface of a rotating drum into a conical surface, opposing the rotating heads in a state where the recording medium is held between the rotating heads and allowing the recording medium to protrude from the peripheral surface of the rotating drum at a position where the recording medium is started to be held between the rotating heads. CONSTITUTION:A projection part 8 whose radius is made larger than any other part is formed near a part where the rotating heads 4 and 6 of a fixed drum 2 are opposed to the recording medium 7. The recording medium 7 is wound to the rotating drum 1 and the fixed drum 2 so that it may contact with the rotating head 4 on an inner side near the projection part 8. When the recording medium 7 is made to travel in a state where it is wound to the peripheral surface of the rotating drum 1, it is smoothly inserted in a narrow gap between the two opposed rotating heads 4 and 6 without causing the side surface of the medium 7 to collide with the rotating heads 4 and 6, so that scanning is stably performed by the rotating heads 4 and 6. Thus, the high- density recording and reproducing is stably performed while holding the tape-like recording medium 7 between at least two rotating heads 4 and 6.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to a rotary head type recording and reproducing device used for recording and reproducing video signals and audio signals, and particularly relates to a rotary head type recording and reproducing device used for recording and reproducing video signals and audio signals. The present invention relates to a recording/reproducing device in which at least two rotating heads are installed facing each other.

(Prior Art) When performing high-density recording in a magnetic recording/reproducing device, a magnetic head needs to scan a narrow track on a recording medium at high speed. In recording and reproducing apparatuses using magnetic tape as a recording medium, a helical scan method is known as a method for stably scanning the magnetic tape at high speed.

This is a system invented by Mr. Sawazaki and described in Japanese Patent Publication No. 34-171, and is mainly composed of a cylindrical rotating drum 11 and a rotating head 14 attached to it, as shown in FIG. be done. The magnetic tape 17 is the rotating drum 1
1 and a stationary drum 12 provided coaxially therewith, the rotary head 14 travels in the longitudinal direction while being wound diagonally around the circumferential surface of the fixed drum 12 provided coaxially therewith.

As a result, the magnetic tape 17 is diagonally scanned at high speed by the rotary head 14.

At this time, as shown in FIG. 10, which shows the circumferential surface of the rotating drum 11 developed, the scanning locus on the magnetic tape 17 that is created during one rotation of one rotating head 14 is directed toward one side end of the magnetic tape 17. It originates from point A and ends at point B on the other side. Therefore, a part of the scanning trajectory from point A to point B is used for recording and reproduction.

As is well known, this helical scan method is now widely used in business and home VTRs (video tape recorders) as well as rotating head-type DATs (digital audio tape recorders).

By the way, the magnetic recording method currently in practical use is
As shown in Fig. 1, this is a longitudinal magnetic recording method in which a magnetic recording medium 17 is horizontally magnetized by a ring-shaped magnetic head 18, and this method is also used in rotary head-type recording and reproducing devices such as the helical scan method mentioned above. is used. In the in-plane magnetic recording method, adjacent magnetized areas cancel each other out, a so-called self-demagnetizing effect. This self-demagnetization becomes larger as the magnetized area becomes shorter and the linear recording density becomes higher, so it is a major factor that limits the recording density.

On the other hand, the perpendicular magnetic recording method proposed by Tsutsumi et al. in 1977 uses a perpendicular magnetic recording head as shown in Figure 12 to magnetize the recording medium in the perpendicular direction. This is a method that achieves a much higher linear recording density than other recording methods (s, 1wasakl
, et, al, 2 IEEE Transactio
n on MagneLics, M^G-13,5,p
, I272 (1977)). The perpendicular magnetic recording head shown in FIG. 12 is composed of two magnetic poles called a main magnetic pole 19 and an auxiliary magnetic pole 20, and performs scanning while sandwiching a magnetic recording medium 17 between the two magnetic poles 19 and 20. If such a perpendicular magnetic recording head is used, the magnetic recording medium 17
Since magnetization is formed in a direction perpendicular to the surface of the magnet, adjacent magnetized areas strengthen each other, so self-demagnetization does not occur, and on the contrary, higher density recording is more advantageous. This type of perpendicular magnetic recording head is called an auxiliary magnetic pole excitation type single magnetic pole head, and is one of the most effective magnetic heads for perpendicular magnetic recording.

Among recording and reproducing apparatuses that are always required to record at high density, there is a particularly strong demand for high-density recording in VTRs that handle video signals, which essentially have a large amount of information. Therefore, it is strongly desired to apply the perpendicular magnetic recording method to VTRs. However, the auxiliary magnetic pole excitation type 1 shown in FIG.
A perpendicular magnetic recording head such as a 1j magnetic pole head is used in a VTR.
When using magnetic tape 1 between two magnetic poles 19.
This is extremely difficult to achieve with the conventional helical scan method, as it requires high-speed scanning while sandwiching the 7.

Now, if a perpendicular magnetic recording head as shown in FIG. 11 is applied to the helical scan method, as shown in FIGS. is held by the head holding member 15, and these two rotary heads 14.16 are assumed to be two magnetic poles 19.20. Then, when the two rotating heads 14, 16 are rotated at high speed between the rotating drum 11 and the magnetic tape 14, 16, the magnetic tape is placed between them.
It is considered that the magnetic tape 17 is scanned with the magnetic tape 7 sandwiched therebetween. This situation is shown in FIG. 15, in which the rotating drum 11 is expanded. The two opposing rotary heads 1'4 and 16 scan the magnetic tape 17 from point A on the upper end side to point B on the lower end side. However, during one rotation of the rotating head 14° 16, there always exists a point P where the connecting portion of the head holding member 15 to the rotating drum 11 comes into contact with the upper end of the magnetic tape 17. Therefore, if the rotary drum 11 continues to rotate, the magnetic tape 17 will come into contact with the head holding member 15 at point P, making it difficult to run. This is an essential problem that cannot be avoided no matter how large the length D of the head holding member 15 is relative to the width a of the magnetic tape 4 or no matter how the tape 17 is wound. Therefore, it is extremely difficult to perform perpendicular magnetic recording by attaching the perpendicular magnetic recording head shown in FIG. 12 to the helical scan method.

On the other hand, along with the perpendicular magnetic recording method, the magneto-optical recording method is another recording method that can be expected to achieve ultra-high density recording. This method is already at the stage of practical use in an example using a disk-shaped recording medium. FIG. 16 shows a typical example of a magneto-optical recording/reproducing apparatus using a disk-shaped recording medium. In the figure, a magneto-optical disk 22 is rotated at high speed by a spindle motor 21. An optical head 23 and a magnetic head 24 are arranged to face each other with the magneto-optical disk 22 in between. The magnetic head 24 is for generating a magnetic field, and magnetizes the top of the magneto-optical disk 22. The optical head 23 includes a laser light source, an optical system, a photodetector, etc.
Heat is applied to the recorded portion from the back side of the disk 22 to selectively cause magnetization reversal, and during reproduction, the polarization angle (Kerr rotation angle) of the laser beam reflected by the disk 22 is detected and a reproduced signal is extracted.

When using a disk-shaped recording medium, magneto-optical recording can be performed with this configuration, but when applying magneto-optical recording to a helical scan method using a tape-shaped recording medium, the recording medium must be A structure sandwiched between an optical head and a magnetic head is required, and problems similar to those in perpendicular magnetic recording occur.

(Problem to be Solved by the Invention) As described above, the helical scan method used in the conventional rotary head type recording/reproducing device scans a flexible tape-shaped recording medium relatively stably and with high density. However, when applied to perpendicular magnetic recording or magneto-optical recording, in which recording and reproduction are performed by sandwiching a recording medium between two heads, the head holding member that holds one rotating head is This problem is extremely difficult because it interferes with the

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary head type recording and reproducing apparatus that can stably perform high-density recording and reproducing while sandwiching a tape-shaped recording medium between at least two rotary heads.

[Structure of the Invention (Means for Solving the Problems)] The present invention involves winding a tape-shaped recording medium around the circumferential surface of a rotating drum to which at least two rotating heads are attached, and rotating the rotating drum while simultaneously rolling the tape-shaped recording medium. In a device that performs recording and reproducing by running in the longitudinal direction, the circumferential surface of a rotating drum is made into a conical surface, and at least two rotating heads are opposed to each other with a recording medium in between, and two further rotating heads are arranged to move the recording medium. Means for causing the recording medium to protrude from the circumferential surface of the rotating drum is provided at the position where the recording medium begins to be sandwiched.

This means for making the recording medium protrude from the circumferential surface of the rotating drum is achieved, for example, by providing a convex portion near the opposing portion of the fixed drum between the rotary head and the recording medium. The height from the inside is S1 The protrusion distance of the rotating head on the side of the rotating drum is d1 The distance between at least two opposing rotating heads is g1 The thickness of the tape-shaped recording medium is t, then d<s<(d+g -t).

Furthermore, as another example of means for causing the recording medium to protrude from the circumferential surface of the fixed drum at the position where the two rotating heads begin to sandwich the recording medium, there is a method in which air is directed toward the recording medium from the circumferential surface of the rotating drum at this position. A means for spraying may be provided.

(Function) When the tape-shaped recording medium is wound around the conical surface of the rotating drum and run, the scanning locus of the rotating head during one rotation of the rotating drum is directed toward one side edge of the recording medium. originates from and ends on the same side.

In other words, since the circumferential surface of the rotating drum is a conical surface, the tape-shaped recording medium enters and wraps around the circumferential surface of the rotating drum from the bottom side toward the top side, and then turns around and wraps around the circumferential surface of the rotating drum again toward the bottom side. It travels towards the target and eventually separates from the circumferential surface of the rotating drum.

In this process, the recording medium passes between two opposing rotary heads, forming a scanning locus as described above. Therefore,
When the recording medium runs on the circumferential surface of the rotating drum, it is not interfered with by the head holding member that holds one of the rotating heads.

Alternatively, a concave portion may be provided in the fixed drum near the opposing portion of the rotating head and the recording medium to satisfy the above conditions;
Alternatively, if air is blown toward the recording medium from the circumferential surface of the fixed drum at the position where the two rotating heads begin to sandwich the recording medium, the tape-shaped recording medium will fit into the narrow gap between the two opposing rotating heads. The side surface of the medium is inserted smoothly without colliding with the rotating head, and is stably scanned by the rotating head.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

Fig. m1 is a perspective view showing a rotary head assembly which is a main part of a rotary head type recording/reproducing device according to an embodiment of the present invention, Fig. 2 is a side view thereof, and Fig. 3 is an exploded view of a rotating drum and a fixed drum. FIG. The conical rotating drum 1 has a circumferential surface formed by a conical surface. This rotating drum 1 has a shape in which the top of a cone is cut in a plane parallel to the axis of the cone.

A conical stationary drum 2 is provided below the rotating drum 1. The circumferential surface of the fixed drum 2 is formed by a conical surface that is an extension of the circumferential surface of the conical rotary drum 1. A drum motor 3 is arranged below the fixed drum 2. This drum motor 3 is for rotationally driving the rotating drum 1, and its rotating shaft passes through the inside of the fixed drum 2 and is connected to the rotating drum 1.

A first rotating head 4 is attached to the bottom of the rotating drum 1. Also, an L is provided on the end surface of the top side of the rotating drum 1.
The proximal end of the head holding member 5 is supported, and a second rotating head 6 is attached to the distal end of the head holding member 5 at a position facing the first rotating head 4 .

Here, for example, in the case of a perpendicular magnetic recording system in which the rotary heads 4 and 6 use a perpendicular magnetic recording head (auxiliary magnetic pole excitation type single magnetic pole head) as shown in FIG.
One rotary head 4 is the main magnetic pole 19, the other rotary head 5
is the auxiliary magnetic pole 20. Further, taking as an example the case of the magneto-optical recording method shown in FIG. 15, one of the rotary heads 4°6 is an optical head 23, and the other is a magnetic head 24 for generating a magnetic field.
It is.

A tape-shaped recording medium 7, for example, a magnetic tape, is wound around the circumferential surfaces of the rotating drum 1 and the stationary drum 2, and is driven to run in a longitudinal direction by a tape drive mechanism (not shown). At this time, the recording medium 7 is scanned at high speed by the rotating head 4.6 rotating together with the rotating drum 1, and information signals such as video signals and audio signals are recorded on the recording medium 7, or information signals such as video signals and audio signals are recorded on the recording medium 7. The information signal recorded on the is reproduced.

A convex portion 8 shown in FIG. 3 is formed in the vicinity of the opposing portion of the fixed drum 2 between the rotary heads 4 and 6 and the tape-shaped recording medium 7, the radius of which is selectively larger than that of other portions. The recording medium 7 is wound around the rotating drum 1 and the fixed drum 2 so as to contact the inner rotating head 4 near the convex portion 8 .

In the above configuration, since the circumferential surface of the rotating drum 1 is a conical surface, the tape-shaped recording medium 7 is formed on the circumferential surfaces of the rotating drum 1 and the fixed drum 2 from the bottom side to the top side when focusing on one point in the longitudinal direction. It enters toward the side, wraps around, then reverses and travels toward the bottom side, and finally separates from the circumferential surfaces of the rotating drum 1 and the fixed drum 2. Therefore, the scanning locus of the rotary head 4.6 on the recording medium 7 is as shown in diagram T54, for example.

FIG. 4 shows a developed view of the circumferential surface of the conical rotating drum 1, including rotating heads 4, 6, a head holding member 5, and a tape-shaped recording medium 7.
8, the peripheral surface of the rotating drum 1 is represented in a fan shape, and the rotary heads 4 and 6 are located on the outer periphery of the fan shape.

The rotation of the rotary drum 1 and the rotary heads 4, 6 corresponds in FIG. 4 to the movement of the rotary head 4.6 along the sector-shaped outer circumference. The rotating head 4.degree.6 scans the recording medium 7 along a trajectory in contact with the recording medium 7.

That is, if the traveling speed in the longitudinal direction of the recording medium 7 is much smaller than the normal scanning speed due to the rotation of the rotary head 4.6 (for example, although the former is several meters per second or more, On the other hand, the latter is several 0 per second or less), and the scanning trajectory of the rotating head 4.6 is
6 starts at a point A where the outer periphery of the fan shape intersects with one side edge of the tape-shaped recording medium 7, and ends at a point B on the same side edge. Information signals are recorded and reproduced using part or all of this scanning trajectory between AB.

According to the above configuration, there is no need to wind the tape-shaped recording medium diagonally around the rotating drum as in the conventional helical scan method, and the stress applied to the recording medium is reduced. It becomes possible to implement the method of scanning a recording medium by sandwiching the recording medium between two heads with a rotary head type diary recorder using a tape-shaped recording medium.

That is, regarding the latter point, it is necessary to use one of the heads as the second rotating head 6 and to hold it with the head holding member 5, so it is necessary to consider interference between the head holding member 5 and the tape-shaped recording medium 7. . However, according to the configuration of this embodiment, when the recording medium 7 is wrapped around the conical rotating drum 1 and the fixed drum 2, it first enters the circumferential surface of the fixed drum 2 from the bottom side toward the top side, Then, it enters onto the circumferential surface of the rotating drum 1 from the bottom side toward the top side. and,
After that, the tape-shaped recording medium 7 passes between the rotary heads 4.6, and then is reversed toward the bottom side of the rotary drum 1.
Furthermore, the fixed drum 2 passes over the bottom side of the fixed drum 2.
detaches from the surrounding surface.

Therefore, as shown in FIG. 4, the length D of the head holding member 5 is defined as
Distance X from the apex O of the cone 2 to the upper edge of the recording medium 7
If the difference is set to be larger than the difference, that is, (1>r' −x), the recording medium 7 will not come into contact with the head holding member 5 during the process of winding around the rotating drum 1 and the fixed drum 2. That is, The problems explained using FIGS. 13 to 15 when applying the technique of recording by sandwiching a tape-shaped recording medium between two opposing heads to the helical scan method are solved, and the recording medium 7 becomes stable. Can run.

Next, the effect of forming the convex portion 8 on a part of the circumferential surface of the fixed drum 2 will be explained. First 1. The operation without this convex portion 8 will be described with reference to FIG. Figure 8 shows the rotating head 4.
, 6, and (A) shows a state in which the recording medium 7 is not wound. g is the rotating head 4,
6, and several lOμ to obtain high playback output.
m is selected. d is the protrusion distance of the inner rotary head 4 from the rotary drum 1, and is selected to be approximately 30 μm in order to bring the rotary head 4 into close contact with the magnetic surface of the recording medium 7.

FIGS. 8(B), (C), and (D) show the state in which a magnetic tape with a thickness t of approximately 20 μm is wound as the recording medium 7, and the state immediately before the rotating head 4 on the inside comes into contact with the recording medium 7 is shown. By the rotation of the rotary drum 1, the recording medium 7 is
is moving upward in the direction of the arrow to be inserted between the rotating heads 5 and 6.

8(B), (C), and (D), the amount of winding of the recording medium 7 around the fixed drum 2 is large, and the fixed drum 2 is already wrapped just before the recording medium 7 is inserted between the rotating heads 4 and 6. In the state shown in FIG. 8(B) in which the recording medium 7 is in contact with the circumferential surface, the side surface of the recording medium 7 collides with the rotating head 4 on the inside.
It cannot be smoothly inserted between the rotating heads 4°6. Therefore, when the winding of the recording medium 7 is made small and the recording medium 7 is placed between the rotating heads 4 and 6, the recording medium 7 is placed between the rotating heads 4 and 6 as shown in FIG. 8(C) or (D). It must be in a state where it is floating from the circumferential surface of the fixed drum 2 by a distance 111is that is larger than the protrusion distance d of 4. However, in the state shown in FIG. 8(C), this distance S is greater than the distance d0g−t obtained by subtracting the thickness t of the recording medium 7 from the distance between the circumferential surface of the fixed drum 2 and the outer rotary head 6. In this case, the side surface of the recording medium 7 collides with the outer rotary head 6, and the recording medium 7 cannot be smoothly inserted between the rotary heads 4 and 6. Therefore, distance i! The conditions that iiS must meet are:
s<(d+g-t), and when this condition is satisfied, the recording medium 7 is smoothly inserted between the rotary heads 4 and 6 as shown in FIG. 7(D).

Here, for example, if the thickness t of the recording medium 7 is 20 μm, and the protrusion distance d of the rotary head 4 inside 1 is 30 μm, and the distance g between the rotary heads 4 and 6 is 60 μm, the distance S is 50±20 μm. Must-have. However, when considering vibrations transmitted to the recording medium 7 due to the rotation of the rotary drum 1 and fluctuations in the amount of wrapping due to subtle changes in the tension of the recording medium 7, it is possible to It is extremely difficult to suppress positional fluctuations to an accuracy of ±20 μm or less.

On the other hand, if the above-mentioned convex portion 8 is provided on the circumferential surface of the fixed drum 2 as in this embodiment, the above-mentioned problem is solved.

The reason for this will be explained below with reference to FIG. FIG. 6 shows that the rotating heads 4 and 6 are rotated by the rotation of the rotating drum 1 as shown in FIG.
-D shows the positional relationships among the recording medium 7, rotary drum 1, fixed drum 2, and rotary head 4.5 when moved to the angular position of D. (A) (B) (C) (D) They correspond to A to D in Figure 3, respectively.

At position A, as shown in FIG. 6(A), the rotary head 4 has not yet reached the contact position with the recording medium 7, but is already approaching the center 8 formed on the circumferential surface of the fixed drum 2. Position B is when the rotary head 4 has just come into contact with the recording medium 7, as shown in FIG. 6(B). Here, the height S of the convex portion 8 from the fixed drum 2 is the height of the rotating head 4.
The distance d is larger than the protrusion distance #td, and is set to a distance d0g−t, which is the distance between the circumferential surface of the fixed drum 2 and the outer rotary head 6 minus the thickness t of the recording medium 7. That is, the condition dos<(d+g−t) is satisfied. Therefore, the recording medium 7 is wound around the fixed drum 2 in a stable state, and the rotating head 4.
The sides are facing each other between 6 and 6.

Next, when the rotation of the rotary head 4.6 further advances and reaches position C, the height of the convex portion 8 gradually decreases as shown in FIG. 6(C), so that the recording medium 7 is Contact 4 smoothly. Then, from the state shown in FIG. 6(D) where the convex portion 8 has completely disappeared, the rotating heads 4, 6
can rotate and scan the recording medium 7.

In this way, the convex part 8 is formed near the opposing part of the rotary heads 4 and 6 of the fixed drum 2 and the recording medium 7, and the height s1 from the circumferential surface of the rotary drum 2 and the protrusion distance of the rotary head 4 d1 rotation By making the relationship between the distance g between the heads 4 and 5 and the thickness t of the tape-shaped recording medium 7 satisfy dos<(d+g-t), the recording medium 7 has a side surface that is similar to the rotating head 4,
The head 4.6 is inserted smoothly between the two heads without colliding with the head 4.6.

Moreover, since the recording medium 7 is wrapped around the circumferential surface of the fixed drum 2 sufficiently before the insertion position between the rotary heads 4.6 and is held by the convex portion 8, it is not in a floating state.
Rotational scanning can be performed stably without being affected by vibrations or fluctuations in the amount of winding caused by the rotation of the rotary drum 1.

In this embodiment, a part of the circumferential surface of the fixed drum 2 has a number of 1
Although it is necessary to form the protrusion 8 with a height of about 0 μm, such a protrusion 8 can be formed, for example, by the following processing method.

FIG. 5 is a diagram for explaining the method of machining the convex portion 8, in which a shallow groove is machined on the circumferential surface of the fixed drum 2 along a direction perpendicular to the longitudinal direction of the tape-shaped recording medium 7. A non-magnetic wire 9 made of stainless steel or the like having an appropriate diameter of several lOμm is stretched over this groove, and the gap between the wire and the groove is filled with an adhesive 10 such as epoxy adhesive.

With such a processing method, by appropriately selecting the diameter of the non-magnetic wire 9, the height S of the convex portion 8 can be adjusted and easily set to a desired value. As the material of the non-magnetic wire 9, in addition to stainless steel, other metal materials such as aluminum alloy, or various non-magnetic materials having appropriate hardness and smoothness such as plastic or fluororesin can be used.

FIG. 7 shows another embodiment of the present invention, in which the rotating heads 4 and 6 are moved to the angular positions A-D in FIG. 3 by the rotation of the rotating drum 1, similar to FIG. 6. Recording medium 7
and rotating drum 1, fixed drum 2 and rotating heads 4, 5
It shows the positional relationship of

In this embodiment, as shown in FIG. 7(B), instead of providing the convex portion 8 as shown in FIG. The recording medium 7 is made to protrude from the circumferential surface of the rotating drum 1 by blowing air toward the recording medium 7 from the circumferential surface of the fixed drum 2 through the flow path 32 on the west side of the drum 2. It is clear that this embodiment also provides the same effects as the previous embodiment.

The present invention is not limited to the embodiments described above, and can be implemented with various modifications. For example, in the embodiment described above, the opposing first and second rotating heads 4.6
Although the case is shown in which there is one set of rotating heads, the present invention can also be applied to a case where a plurality of sets of rotating heads are provided.

In addition, technical measures similar to those of conventional rotary head recording and reproducing devices have been added as appropriate, such as forming leads on the drum circumferential surface to guide the tape-shaped recording medium and forming grooves to control air flow. You can also.

[Effects of the Invention] According to the present invention, stable high-density recording and reproduction can be performed while holding a tape-shaped recording medium between at least two rotating heads. In particular, in the present invention, the recording medium is smoothly inserted between the two rotary heads without colliding with the rotary heads. At this time, the recording medium is wrapped around the fixed drum circumferential surface well in advance of the point where it comes into contact with the rotating head, and is held stably without floating. It is possible to stably rotate and scan the recording medium without being affected by fluctuations in the amount of winding.

Therefore, the helical scan method is applicable to perpendicular magnetic recording using an auxiliary magnetic pole excitation type 71 magnetic pole head, which was Tanashi's application.
It has become possible to use ultra-high density recording technology such as magneto-optical recording in rotary head type recording and reproducing devices, which is extremely effective for recording and reproducing devices such as video signals.

[Brief explanation of drawings]

1 and 2 are perspective views and side views showing one embodiment of the present invention, FIG. 3 is an exploded perspective view of a rotating drum and a fixed drum in the same embodiment, and FIG. 4 is a conical type of the same embodiment. The rotating drum is unfolded, and the rotating head, head holding member, and tape-shaped recording medium are shown in the figure. 6 shows changes in the positional relationship between the rotary head and the recording medium in the 161st embodiment, and FIG. 7 shows changes in the positional relationship between the rotary head and the recording medium in another embodiment of the present invention. 8 is a diagram showing changes in the positional relationship between the rotating head and the recording medium when there is no convex portion on the circumferential surface of the rotating drum, and FIG. 9 is a perspective view showing a conventional helical scan type tape scanning mechanism. , FIG. 10 is an exploded view of the rotating drum in FIG. 9 together with a rotating head, FIG. 11 is a diagram for explaining the conventional local magnetic recording system, and FIG. 12 is a diagram for explaining the conventional perpendicular magnetic recording system. Diagrams for explanation, Figures 13 and 14
The figure is a perspective view and a cross-sectional view showing an example in which the perpendicular magnetic recording method is applied to a conventional helical scan tape scanning mechanism.
FIG. 15 is an exploded view of the rotating drum of FIGS. 13 and 14 together with a rotating head, a head holding member, and a tape-shaped recording medium, and FIG. 16 is a diagram for explaining the conventional magneto-optical recording system. be. DESCRIPTION OF SYMBOLS 1... Conical rotating drum, 2... Conical fixed drum, 3... Drum motor, 4... First rotating head,
5... Head holding member, 6... Second rotating head,
7... Tape-shaped recording medium, 8... Convex portion, 9... Non-magnetic wire, 10... Adhesive, 19... Main RA pole,
20... Auxiliary magnetic pole, 23... Optical head, 24...
- Magnetic head, 31... tube, 32... channel.

Claims (3)

[Claims] (1) A tape-shaped recording medium is wound around the circumferential surface of a rotating drum on which a rotating head is mounted and a fixed drum provided coaxially with the rotating drum, and as the rotating drum is rotated, the tape-shaped recording medium is longitudinally In an apparatus for recording and reproducing by moving the drum in a direction, the circumferential surfaces of the rotating drum and the fixed drum are formed by conical surfaces, and at least two rotating heads facing each other with the recording medium in between are attached to the rotating drum. . A rotary head type recording/reproducing device comprising means for causing the recording medium to protrude from the circumferential surface at a position where the two rotary heads of the fixed drum begin to sandwich the recording medium. (2) A tape-shaped recording medium is wound around the circumferential surface of a rotating drum on which a rotating head is mounted and a fixed drum provided coaxially with the rotating drum, and while the rotating drum is rotated, the tape-shaped recording medium is longitudinally In an apparatus for recording and reproducing by moving the drum in a direction, the circumferential surfaces of the rotating drum and the fixed drum are formed by conical surfaces, and at least two rotating heads facing each other with the recording medium in between are attached to the rotating drum. , the height from the circumferential surface of the fixed drum of a convex portion near the opposing portion of the at least two rotating heads and the recording medium of the fixed drum is s, and of the at least two rotating heads, the side of the rotating drum is The following formula d<s<(d+g-t) is satisfied, where d is the protrusion distance of the rotary head at , g is the interval between the at least two rotary heads, and t is the thickness of the tape-shaped recording medium. A rotating head type recording and reproducing device. (3) Wrap a tape-shaped recording medium around the circumferential surface of a rotating drum on which a rotating head is mounted and a fixed drum provided coaxially with the rotating drum, rotate the rotating drum, and roll the tape-shaped recording medium longitudinally. In an apparatus for recording and reproducing by moving the drum in a direction, the circumferential surfaces of the rotating drum and the fixed drum are formed by conical surfaces, and at least two rotating heads facing each other with the recording medium in between are attached to the rotating drum. , a rotating head type recording device comprising means for blowing air from the circumferential surface of the fixed drum toward the recording medium at a position where the at least two rotating heads of the fixed drum begin to sandwich the recording medium. playback device.