JPS62239418A - Magnetic head device of cylindrical magnetic recording medium - Google Patents

Abstract

PURPOSE:To perform the good magnetic recording and reproducing operation even if a slight surface shake occurs in a cylindrical magnetic recording medium, by setting the turning fulcrum of a magnetic head supporting member to a specific part on the outside of the outer peripheral part of the cylindrical magnetic recording medium. CONSTITUTION:The turning fulcrum of a magnetic head supporting body S is set to a specific part. That is, the fulcrum is set in the area between the outside peripheral part of a cylindrical magnetic recording medium D and a line which connects a contact point Ha between the magnetic gap of a magnetic head H, which is placed on the normal of a slide face of the magnetic head H in the state where said normal passes the center of curvature of the curved surface of the cylindrical magnetic recording medium D, and the curved surface of the cylindrical magnetic recording medium D and a turning center O' of the magnetic head supporting member S provided in the other end part of the magnetic head supporting member S, whose one end part the magnetic head H is stuck to, and a part of which forms a chord on the circular section of the cylindrical magnetic recording medium D, and said fulcrum is set on the outside of the outside peripheral part of the cylindrical magnetic recording medium D in this area. Thus, the good magnetic recording and reproducing operation is performed even if eccentricity occurs somewhat.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides a cylindrical magnetic recording device that can be well applied to a miniaturized high-density magnetic recording and reproducing device that can be used for an image file system or a rewritable information recording and reproducing system. The present invention relates to a magnetic head device for a magnetic recording medium.

(Prior Art) Many information signal recording and reproducing devices have been known that use recording media with various configurations and are implemented according to various recording and reproducing methods. In a recording/reproducing device using a medium, if a grooveless type is used as the rotating recording medium, random access is easy when reproducing information from the rotating recording medium. When the target information signal is a non-visual video signal, there are various advantages such as ease of trick plays using special playback modes such as still image playback, slow-motion image playback, and 1x speed playback. Therefore, information signals have been recorded and reproduced using various recording and reproducing methods using rotating recording media (for example, magnetic recording and reproducing methods, optical recording and reproducing methods, reproducing methods that detect changes in capacitance values, and others). It is well known that devices are widely put into practical use, and the applicant's company also uses cylindrical magnetic recording media as a recording/reproducing device using a rotating recording medium having the above-mentioned characteristics. Many proposals have been made regarding ultra-compact magnetic recording and reproducing devices.

(Problems to be Solved by the Invention) Now, a magnetic head used for recording information signals on a cylindrical magnetic recording medium and reproducing information signals from a cylindrical magnetic recording medium has a magnetic gap of minute dimensions. However, the magnetic head has a much larger size than the minute magnetic gap mentioned above, and the sliding contact surface (the surface of the magnetic recording medium) in the magnetic head is The vertical and horizontal dimensions of the contacting surfaces) are also in the magnetic gap.

It is much larger than the track width.

By the way, when performing magnetic recording and reproducing using a cylindrical magnetic recording medium that is made of hard constituent materials and has a finite radius of curvature, the magnetic head has a center of curvature on the surface of the cylindrical magnetic recording medium. The sliding surface of the magnetic head is in contact with the surface of the cylindrical magnetic recording medium such that a magnetic gap exists on the opposite line, that is, the magnetic gap of the magnetic head and the surface of the magnetic recording medium are in good condition. It is well known that magnetic recording and reproducing operations cannot be performed satisfactorily unless the magnetic head is in a state of proper contact. The support member is fixed to one end and can be rotated using the other end as a fulcrum.5 If the cylindrical magnetic recording medium has surface runout, the magnetic head and the cylindrical The state of sliding contact with the surface of the magnetic recording medium changes depending on the surface runout of the cylindrical magnetic recording medium.

In order to make the surface runout of the cylindrical magnetic recording medium zero during magnetic recording and reproducing operations using the cylindrical magnetic recording medium, it is necessary to manufacture the cylindrical magnetic recording medium with extremely high precision, and to It is required that the cylindrical magnetic recording medium and the rotary drive section be coupled with high precision so that eccentricity does not occur when the cylindrical magnetic recording medium is rotationally driven by the rotation drive section. It is extremely difficult to satisfy the above conditions in a magnetic recording/reproducing device configured to perform cylindrical magnetic recording media. It is no exaggeration to say that even if an attempt is made to provide a magnetic recording/reproducing device in which the oscillation, h, of a cylindrical magnetic recording medium during magnetic recording/reproducing operation is zero, such a device would not be possible. isn't it.

Therefore, there has been a strong desire for a magnetic head device that can perform magnetic recording and reproducing operations in good condition even if the cylindrical magnetic recording medium has some surface runout during recording and reproducing operations.

(Means for Solving the Problems) The present invention provides a magnetic head that is arranged on the normal line of the sliding contact surface of the magnetic head in a state where the normal line of the sliding contact surface of the magnetic head passes through the center of curvature of the curved surface of the cylindrical magnetic recording medium. A contact point between the magnetic gap of the magnetic head located thereon and the curved surface of the cylindrical magnetic recording medium, and a magnetic head provided at the other end of the magnetic head support member to which the above-mentioned magnetic head is fixed at one end. The vicinity of the tangent to the circular cross section of the cylindrical magnetic recording medium, which is a straight line passing through the center of rotation of the support member, and the normal to the sliding surface of the magnetic head are cylindrical magnetically, and the curved surface of the support medium. a point of contact between the magnetic gap of the magnetic head and the curved surface of the cylindrical magnetic recording medium, which is located on the normal line of the sliding surface of the magnetic head when passing through the center of curvature;
The circular shape of the cylindrical magnetic recording medium described above is defined by a portion of a straight line connecting the rotation center of the magnetic head support member provided at the other end with the magnetic head fixed to one end of the magnetic head support member. A cylindrical structure in which the rotational fulcrum of the magnetic head support member is set in a region between the straight line such that a chord is formed in the cross section and outside the outer periphery of the cylindrical magnetic recording medium. The present invention provides a magnetic head device for a magnetic recording medium.

(Example) Hereinafter, specific contents of the magnetic head device for a cylindrical magnetic recording medium of the present invention will be described in detail with reference to the attached drawings. FIG. 1 is a perspective view of an embodiment of a magnetic head device for a cylindrical magnetic recording medium according to the present invention, and in FIG. 1, D is a cylindrical magnetic recording medium; is driven and rotated at a predetermined rotational speed in the direction of arrow R in the figure by a rotary drive device (not shown). Reference numeral S denotes a magnetic head support member to which a magnetic head H is fixed at one end, and the other end of the magnetic head support member S is rotatably supported by a rotation fulcrum. Therefore, when there is surface runout in the cylindrical magnetic recording medium, the magnetic head support member S rotates about the rotational fulcrum mentioned above, and the magnetic head I-1 rotates on the cylindrical magnetic recording medium. The displacement operation follows the surface runout of the

In the magnetic head device for the cylindrical magnetic recording medium shown in the embodiment shown in the first figure, the magnetic head support S is formed by punching and bending a thin metal plate into a triangular planar shape by press working. The rotation fulcrum of the magnetic head support S is 2 which is protruded from the holder HD.
pivots 1.2 and the two pivots 1, 2 mentioned above.
A pivot receiver, which is bored in the magnetic head support S so as to correspond to the above, is constructed by engaging with the holes 3 and 4.

Further, the coupling between the magnetic head support S and the holder HD is achieved by the magnetic attraction force between the permanent magnet 5 fixed to the magnetic head support S and the permanent magnet 6 fixed to the holder HD. It is being done.

The holder HD is attached to an actuator of a tracking control system that is fixed to the transfer mechanism.

In the magnetic head device for a cylindrical magnetic recording medium of the present invention, the rotation fulcrum of the magnetic head support S is the normal line of the sliding surface of the magnetic head H, which is the center of curvature of the curved surface of the cylindrical magnetic recording medium. A contact point Ha between the magnetic gap of the magnetic head H and the curved surface of the cylindrical magnetic recording medium, which is located on the normal line of the sliding surface of the magnetic head H in the passing state.
(See Figure 2) and the magnetic head H shown above in the -g3 section.
In the vicinity of the tangent to the circular cross section of the cylindrical magnetic recording medium described above, which is a straight line passing through the rotation center 0' of the magnetic head support member S provided at the other end of the magnetic head support member S to which the magnetic head support member S is fixed. (The above-mentioned magnetic head) When the normal line of the sliding surface passes through the center of curvature of the curved surface of the cylindrical magnetic recording medium, the magnetic air gap of the magnetic head H located on the normal line of the sliding surface of the magnetic l\\rad described above The contact point Ha with the curved surface of the magnetic recording medium and the rotation center of the magnetic head support member S provided at the other end of the magnetic head support member S to which the magnetic head (2) is fixed to one end. 0', within the area between the straight line such that a chord is formed in the circular cross section of the cylindrical magnetic recording medium, and from the outer periphery of the cylindrical magnetic recording medium. However, in the magnetic head device for a cylindrical magnetic recording medium of the present invention shown in FIG. An example is illustrated in which a magnetic head device for a cylindrical magnetic recording medium that satisfies the above-mentioned conditions is constructed using a magnetic head support S having such a configuration.

FIG. 2 is a diagram used to study the conditions for improving the surface runout tracking characteristics of a magnetic head device using a 5-cylindrical magnetic recording medium, and in this FIG. It is the outer peripheral surface of a shaped magnetic recording medium, and
Ha indicates the point of contact between the magnetic gap of the magnetic head H and the outer peripheral surface of the cylindrical magnetic recording medium, 0 indicates the center of rotation of the cylindrical magnetic recording medium, and O' indicates the rotation of the magnetic head support S. The center, OIt, is the center of the cylindrical magnetic recording medium.

Furthermore, the vector Δr is a rotational vector indicating the surface runout of the cylindrical magnetic recording medium D, the vector r is a vector indicating the radius of curvature of the cylindrical magnetic recording medium at the contact point Ha, and the vector a is a vector indicating the curvature radius of the cylindrical magnetic recording medium at the contact point Ha. A vector indicating the distance between the rotation center 0 of the magnetic head support S and the rotation center 0' of the magnetic head support S, and the vector Q indicates the distance between the rotation center 0' of the magnetic head support S and the magnetic gap between the magnetic head 11 and the cylindrical magnetic recording This is a vector indicating the distance from the contact point Ha that is in contact with the outer peripheral surface of the media.

Here, based on FIG. 2, when the magnetic gap of the magnetic head FT is in contact with the outer peripheral surface of the cylindrical magnetic recording medium at point Ha, the magnetic gap of the magnetic head H and the cylindrical magnetic recording medium are Conditions under which the manner of contact with the outer peripheral surface of the magnetic recording medium is not affected are as follows.

It is known in geometry that the angle θl in the quadrilateral 0'·Ha −0″·0 shown in FIG. 2 is expressed by the following equation (1).

al=cog"[((r"+Q'-a")/(2rQ)
) (Δr/r Q ) ・((Δr/2) + <
a cos 02))] ・・・・・・(1) In the above formula (1), the angle 01 when the runout Δr=o
When θ0 is set to 00, θ0 is expressed by the following equation (2).

0o=cos” ((r”10Q” −a”)/2 r
Q ) −(2) Substituting equation (2) into equation (1) yields (3
) formula is obtained.

01=coIJ' [cosθ0−(Δr/rQ)
((Δr/2)+a cos 021]...
(3) Therefore, the angular error Δθ between the angle O1 and the angle θ0 is expressed as the following equation (4) from equations (2) and (3) above.

Δ0=01−O0=cod” [cosθo−(Δr/rQ)((Δr
/2) + a cos θ2)] -00・・・・・・(
4) To improve the surface runout tracking characteristics of a magnetic head device,
The absolute value Δθwax of the angular error Δθ described above may be reduced, but from equation (4) above, the absolute value Δθ of the angular error Δ0 can be reduced.
It can be seen that Owax is expressed as the following equation (5).

ΔD max= l coiL[cosθo−(Δr/
rQ)((Δr/2)±a)] −(lol...
(5) Generally, the surface runout Δr is determined between the rotation center 0 of the cylindrical magnetic recording medium and the magnetic head support S.
is much smaller than the distance aa from the center of rotation 0', and if we insert the condition of Δr(a into equation (5) above, we get
The above equation (5) is expressed by the following equation (5a).

ΔOmax= l cos' (cosθ0±(aΔr
/r 1! ') Δr) -0o 1... (5a) Looking at this equation (5a), it can be seen that in a state where the rotation vector Δr indicating the surface runout of one cylindrical magnetic recording medium is given, the magnetic head In order to improve the surface runout tracking characteristics of the device, the absolute value ΔθIna of the angle error Δ0 described above is
In order to reduce What is necessary is to increase the distance Q from the contact point Ha that is in contact with the cylindrical magnetic recording medium and to decrease the distance gia between the rotation center 0 of the cylindrical magnetic recording medium and the rotation center 0' of the magnetic head support S. However, since the radius of curvature r of the cylindrical magnetic recording medium at the contact point Ha is determined by the cylindrical magnetic recording medium, magnetic recording is performed using a cylindrical magnetic recording medium with a certain radius of curvature r. In order to improve the surface runout tracking characteristics of the magnetic head device in a state where the rotational vector Δr indicating the surface runout of the cylindrical magnetic recording medium is given when performing coin reproducing, the above-mentioned angle is set. In order to reduce the absolute value Δθwax of the error, it is necessary to reduce the contact point Ha where the rotation center O' of the support S and the magnetic gap of the magnetic head H contact the outer peripheral surface of the cylindrical magnetic recording medium. It is clear that the distance Zjt (1) should be increased or the distance 9g1a between the rotation center O of the cylindrical magnetic recording medium and the rotation center 0' of the magnetic head support S should be decreased.

FIG. 3 shows a state in which a cylindrical magnetic recording medium with a radius r of 15.5u+I11 is driven and rotated with a surface runout with a peak-to-peak value of 80 μm, and the magnetic head support S
The distance r between the center of rotation ○'' and the contact point Ha where the magnetic gap of the magnetic head H contacts the outer peripheral surface of the cylindrical magnetic recording medium.
For each case where ¥Q is 10mm, 15mm, 20mm, :30mm, the absolute value Δθwax of the angle error Δθ with respect to the change in θ0 indicating the angle θ1 when the one-plane runout Δr=o
This is a chart showing how the changes are based on the results of the study with reference to the above-mentioned Figure 2.
Figure 4 shows the angle θ1 when the surface runout Δr=o when a cylindrical magnetic recording medium with a radius r of 15.5 mm is driven and rotated with a surface runout with a peak value of 80 μm. While maintaining the rotation center 0' of the magnetic head support S at 90 degrees, the contact point H where the magnetic gap of the magnetic head H contacts the outer peripheral surface of the cylindrical magnetic recording medium.
2 is a chart showing changes in the absolute value Δθrmax of the angular error Δθ when the distance 2 from a is changed, based on the results of the study with reference to FIG. 2 described above.

Looking at the above-mentioned FIG. 3, when the normal line of the sliding contact surface of the magnetic head H passes through the center of curvature of the curved surface of the cylindrical magnetic recording medium, the magnetic head H is located on the normal line of the sliding contact surface of the magnetic head H described above. The contact point I-I a between the magnetic gap of the magnetic head El and the curved surface of the cylindrical magnetic recording medium (see Figure 2), and the magnetic head support to which the magnetic head H is fixed to one end. The vicinity of the tangent to the circular cross section of the cylindrical magnetic recording medium described above by a straight line passing through the center of rotation ○' of the magnetic head support member S provided at the other end of the member S, and the magnetic head I indicated by 1γl. - The normal to the sliding surface in the magnetic head H when the normal to the sliding surface in I passes through the center of curvature of the curved surface of the cylindrical magnetic recording medium ~
A contact point Ha between the magnetic gap of the magnetic head H located at H and the curved surface of the cylindrical magnetic recording medium, and the other end of the magnetic head support member S to which the magnetic head H is fixed to one end. In the area between the straight line that forms a chord in the circular cross section of the cylindrical magnetic recording medium, a part of the straight line connecting the center of rotation O' of the magnetic head support member S provided in the , and if the rotational fulcrum ○' of the magnetic head support member S is set outside the outer periphery of the cylindrical magnetic recording medium described above, the absolute value Δθwax of the angular error Δθ is It is clear that the angle θ0 (angle when surface runout Δr = O +71) corresponds to the range showing an extremely small value, and looking at FIG. 4, the magnetic head support S If the distance Q between the rotation center 0' of the magnetic head H and the contact point Ha where the magnetic gap of the magnetic head H contacts the outer peripheral surface of the cylindrical magnetic recording medium is greater than or equal to the radius r of the cylindrical magnetic recording medium, then Absolute value Δ of angular error Δθ
It can be seen that θmas becomes extremely small.

FIG. 5 shows the above-mentioned magnetic field in a state in which the normal line of the sliding surface of the magnetic head H passes through the center of curvature of the curved surface of the cylindrical magnetic recording medium when implementing the magnetic head device for the cylindrical magnetic recording medium of the present invention. The contact point Ha between the magnetic gap of the magnetic head H and the curved surface of the cylindrical magnetic recording medium, which is located on the normal line of the sliding surface of the head H, and the magnetic field that fixes the magnetic head H to one end. A part of the straight line connecting the rotation center 0' of the magnetic head support member S provided at the other end of the head support member forms a chord with respect to the circular cross section of the cylindrical magnetic recording medium described above. A shape of a magnetic head support member S that can be suitably used when the rotation fulcrum 0' of the magnetic head support body S is set at a position, and a mounting posture of the magnetic head H to the magnetic head support member S. 5(a),
(e) is a configuration example in which the magnetic head support member S is bent, and (b) in FIG. 5 is a configuration example in which an inclined spacer is interposed between the magnetic head support member S and the magnetic head H. (c
) is an example of a configuration in which the mounting surface of the magnetic head H fixed to the magnetic head support member S is inclined, and (d) of FIG. 5 is an example of a configuration in which the magnetic head H is fixed to the magnetic head support member S in an inclined manner. In addition, FIG. 6 illustrates various attachment modes when the magnetic head support member S is rotatably attached to the holder HD, and (a) in FIG.
As already described in FIG.
D is a configuration example in which the holding body T and the magnetic head supporting member S are coupled by magnetic attraction between permanent magnets 5 and 6 fixed to the magnetic head supporting member S, respectively;
Figure 6(b) shows the gol and damper' provided on the holder IID.
l, 8 to magnetism? FIG. 6(c) shows an example of a configuration in which the magnetic head support member S is fixed to a rectangular parallelepiped rubber damper 9 provided on the holder HD. It shows. .

FIG. 7 shows a magnetic head positioned on the normal line of the sliding surface of the magnetic head described above in a state where the normal line of the sliding surface of the magnetic head H passes through the center of curvature of the curved surface of the cylindrical magnetic recording medium. ra magnetic air gap of H and the contact point with the curved surface of the cylindrical magnetic recording medium, and the magnetic head H described above at one end.
The tangent to the circular cross section of the cylindrical recording medium described above is a straight line passing through O' and the center of rotation of the magnetic head supporting member S provided at the other end of the magnetic head supporting member S to which the magnetic head supporting member S is fixed. This figure shows an example configuration in which the magnetic head device for a cylindrical magnetic recording medium of the present invention is implemented in such a manner that the rotation fulcrum 0' of the magnetic head support S is set at a position near 1. ．． The embodiment shown in FIG. 2 uses a linear magnetic head support member S as the magnetic head support member S,
Furthermore, using a magnetic head H that is vertically attached to the -@ portion of the linear magnetic head support member S,
The linear magnetic head supporting member S is arranged so that the direction in which it extends is such that the normal to the sliding surface of the magnetic head H passes through the center of curvature of the curved surface of the cylindrical magnetic recording medium. The linear magnetic head support is parallel to the tangent at the contact point between the magnetic gap of the magnetic head II and the curved surface of the cylindrical magnetic recording medium, which is located on the normal line of the sliding surface in the magnetic head II. FIG. 2 is a side view of a magnetic head device for a cylindrical magnetic recording medium of the present invention, showing an example configuration in which a rotation fulcrum of a member S is set; Even if the magnetic head device for a cylindrical magnetic recording medium is implemented in a state where the angle 01 described above is larger than 90 degrees, the cylindrical magnetic recording medium will have a cylindrical shape in a range where the amount of surface runout is small. When the magnetic head support member S rotates about its rotational fulcrum O' when the magnetic head D runs out, the angle O1 described above is approximately symmetrical about the angle θ0. As a result, the magnetic gap of the magnetic head and the surface of the cylindrical magnetic recording medium are in good contact, and stable recording and reproducing operations are performed.

(Effects) As is clear from the details described above, the present invention is effective for the magnetic head described above when the normal line of the sliding surface of the magnetic head passes through the center of curvature of the curved surface of the cylindrical magnetic recording medium. The point of contact between the magnetic gap of the magnetic head and the curved surface of the cylindrical magnetic recording medium, which is located on the normal line of the sliding surface in The vicinity of the tangent to the circular cross section of the cylindrical magnetic recording medium, which is a straight line that passes through the center of rotation of the magnetic head support member provided at the other end, and the normal to the sliding surface of the magnetic head are cylindrical. A point of contact between the magnetic gap of the magnetic head and the curved surface of the cylindrical magnetic recording medium, which is located on the normal line of the sliding surface of the magnetic head, passing through the center of curvature of the curved surface of the cylindrical magnetic recording medium, and one end. The circular cross section of the cylindrical magnetic recording medium described above is formed by a part of the straight line connecting the center of rotation of the magnetic head support member provided at the other end of the magnetic head support member to which the magnetic head is fixed. This is because the rotational fulcrum of the magnetic head support member is set within the area between the straight line where the string is formed and outside the outer periphery of the cylindrical magnetic recording medium. In the magnetic head device for a cylindrical magnetic recording medium of the present invention, the magnetic head and the magnetic head can be easily damaged by surface runout that inevitably occurs in a cylindrical magnetic recording medium during magnetic recording and reproducing operations using the cylindrical magnetic recording medium. Since the state of contact with the surface of the cylindrical magnetic recording medium can be maintained in a good state, it is possible that the cylindrical magnetic recording medium is not made with extremely high precision, or that the cylindrical magnetic recording medium and the drive rotation mechanism are Even if some eccentricity occurs depending on the manner of coupling, a good magnetic recording and reproducing operation can be performed, and the present invention can satisfactorily solve the above-mentioned conventional problems.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of a magnetic head device for a cylindrical magnetic recording medium according to the present invention, and FIG. 2 is a perspective view of a magnetic head device for a cylindrical magnetic recording medium that improves surface runout tracking characteristics. Figure 3 used to examine the conditions for
The figure shows the center of rotation 0' of the magnetic head support S and the magnetic head H when a cylindrical magnetic recording medium with a radius r of 15.5n+a+ is driven and rotated with a surface runout with a peak value of 80μI11. Distance from the contact point Ha where the magnetic gap contacts the outer peripheral surface of the cylindrical magnetic recording medium: II
Q is 10g+m. A chart showing how the absolute value Δθmax of the angular error Δ0 changes with respect to a change in θ0 indicating an angle 71ot when the runout Δr=0 for each case of 15 mm, 20 mm, :l0IIl+o, Figure 4 is 1.5.5
(2) In a state where a cylindrical magnetic recording medium with a radius r is driven and rotated with a surface runout with a peak value of 80 μm, the angle 01 when the surface runout Δr = O is [1
While maintaining o at 90 degrees, the distance Q between the rotation center ○' of the magnetic head support S and the contact point Ha where the magnetic gap of the magnetic head H contacts the outer peripheral surface of the cylindrical magnetic recording medium.
The angle when changing ? of the tool difference ΔO? 4!1 pair Δ
A chart showing changes in θwax, FIG. 5 is a side view of a configuration example of a magnetic/rad support member S that can be used in implementing the magnetic head device of the present invention, and FIG. 6 is a diagram showing the magnetic head support member S as a holder HD. FIG. 57 is a perspective view illustrating various attachment modes when the magnetic head is freely attached. FIG. H...Magnetic head, S...Magnetic head support member, D...
...Cylindrical magnetic recording medium, ■ID...Holding member.

Claims (1)

[Claims] The magnetic gap of the magnetic head and cylindrical magnetic recording located on the normal line of the sliding contact surface of the magnetic head described above in a state where the normal line of the sliding contact surface of the magnetic head passes through the center of curvature of the curved surface of the cylindrical magnetic recording medium. The aforementioned cylinder formed by a straight line passing through the point of contact with the curved surface of the medium and the center of rotation of the magnetic head supporting member provided at the other end of the magnetic head supporting member to which the aforementioned magnetic head is fixed at one end. Near the tangent to the circular cross section of the cylindrical magnetic recording medium, and on the normal to the sliding surface of the magnetic head when the normal to the sliding surface of the magnetic head passes through the center of curvature of the curved surface of the cylindrical magnetic recording medium. The contact point between the magnetic gap of the magnetic head located at the curved surface of the cylindrical magnetic recording medium, and the magnetic head provided at the other end of the magnetic head supporting member to which the magnetic head is fixed to one end. The above-mentioned cylindrical magnetic recording medium is located within a region between a part of the straight line connecting the center of rotation of the head support member and a straight line such that a chord is formed in the circular cross section of the above-mentioned cylindrical magnetic recording medium. A magnetic head device for a cylindrical magnetic recording medium, in which a rotational fulcrum of a magnetic head support member is set outside the outer periphery of the cylindrical magnetic recording medium.