JP3170102B2 - Rotating head device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head device used for a tape player such as a VTR, and more particularly to a rotary head device which supports an upper drum via a rolling bearing with respect to a fixed shaft fixed to a lower drum. About.

[0002]

2. Description of the Related Art FIG. 15 shows a rotary head device used in a conventional tape player. The rotary head device 1 includes a chassis 2 attached to a tape player body (not shown), and a lower drum 3 is fixedly connected to the chassis 2 by screw connection or the like.
A fixed shaft 4 is fixed to a central portion of the lower drum 3 in a protruding state. The fixed shaft 4 is provided with a pair of rolling bearings 5 and 6 which are spaced apart in the axial direction.

[0003] An upper drum 7 is provided via these rolling bearings 5 and 6. A rotary magnetic head 8 is provided on the lower surface of the peripheral portion of the upper drum 7. A stator 10 of a driving motor 9 is provided at an upper end of the fixed shaft 4.
Are connected by screws or the like.

A rotor 11 of a driving motor 9 is connected to an upper end of the upper drum 7 corresponding to the stator 10. In the rotary head device 1 configured as described above, the upper drum 7 is driven to rotate by the driving of the driving motor 9.

[0006] As shown in FIG. 16, a pulley 12 is provided above the upper drum 7, and a belt 13 wound around the pulley 12 is attached to a motor 1 mounted on the chassis 2.
4 drives the upper drum 7 to rotate. In the rotary head device 1 as described above, a lead groove L for guiding the magnetic tape M is formed on the outer peripheral surface of the lower drum 3 as shown in FIG. Then, the magnetic head 8 reproduces the trajectory 8a of the circular motion with high accuracy with respect to the lead groove L, so that good recording and reproduction can be performed.

However, it is impossible to completely prevent the trajectory 8a of the magnetic head 8 from being eccentric with respect to the lead groove L. One cause of such eccentricity is
A gap B is generated between the fixed shaft 4 and the rolling bearings 5 and 6 as shown in FIG. Due to the generation of the gap B, the rolling bearings 5 and 6 are inclined with respect to the fixed shaft 4 by A degrees (actually, the angle is extremely small but is emphasized in the figure).

[0007] The occurrence of such a shake has the following effects on magnetic recording and reproduction. For example, when the magnetic head 8 is eccentric in the X direction shown in FIG.
Is wound in the state shown by D1, the locus drawn by the magnetic head 8 draws the locus 8a shown in the range of D1 in FIG. At this time, the displacement amount in the Z direction is d1, and a curve shown by a locus 8a is drawn with respect to the tracking area TA in FIG.

When the magnetic tape M is wound in the state indicated by D3 when the magnetic head 8 is eccentric in the X direction shown in FIG. 23, the locus drawn by the magnetic head 8 becomes as shown in FIG.
Trajectory 8a indicated by the range D3. The displacement amount at this time is d3, and a curve as shown by a locus 8a is drawn with respect to the tracking area TA in FIG. in this way,
The shift width d of the trajectory 8a of the magnetic head 8 depends on the direction of deflection of the magnetic head 8 with respect to the magnetic tape M (lead groove L).
1 and d3 were different.

For this reason, the reproducibility of the locus 8a of the magnetic head 8 is not reliable, and the locus 8a is likely to vary depending on the product. As shown in FIG. There was a possibility that the performance would be significantly reduced.

Further, at present, there is a high demand for a tape player with a low price, and it is necessary to increase the grade of the rolling bearings 5 and 6 and use the rolling bearings 5 and 6 with low accuracy. in the conventional structure performance under such conditions it was impossible. Further, as shown in FIG. 17, the pressing force P on the magnetic head 8 generated on the magnetic tape M wound around the drum D is minimized at the winding start point S of the magnetic tape M, and the recording and reproducing accuracy of the magnetic signal is reduced. The lowest. That is, the conventional rotary head device 1 uses the magnetic tape M
At the winding start point S, the recording and reproducing performance is most deteriorated.

[0011]

The eccentricity of the magnetic head with respect to the lead groove formed in the lower drum cannot be completely eliminated even by high-precision processing. However, by selecting the winding range of the magnetic tape, the deviation of the locus drawn by the magnetic head can be minimized. However, conventionally, there has been no rotary head device having such a technical idea and a configuration for realizing the same.

Further, the pressing force of the magnetic head which comes into contact with the magnetic tape wound around the drum is minimized at the starting point of winding of the magnetic tape, and the recording and reproducing accuracy of the magnetic signal is most reduced. That is, the conventional rotary head device has a drawback that the recording and reproducing performance is lowest at the winding start point of the magnetic tape.

Therefore, the present invention provides a rotary head device capable of minimizing the amount of deviation of the locus drawn by the magnetic head by selectively disposing the eccentric direction of the magnetic head with respect to the magnetic tape (lead groove). It is another object of the present invention to provide a rotary head device capable of improving a pressing force on a magnetic head at a winding start point of a magnetic tape and obtaining high performance even if component accuracy is low.

[0014]

According to the first aspect of the present invention, a fixed shaft is protruded from a fixed lower drum, a rolling bearing is mounted on the fixed shaft, and the upper drum is interposed via the rolling bearing. Are rotatably supported, and two rigid support portions are provided on the peripheral surface of the fixed shaft, which are in contact with the rolling bearing inner peripheral surface, at a predetermined angle, and the elastic support portion has an angle formed by the two rigid support portions of the fixed shaft. It is arranged at a position substantially 180 degrees from the position of 1/2 and is provided on the side opposite to the range where the magnetic tape is wound around the drum, and urges the inner peripheral surface of the rolling bearing outward in the radial direction. Rotary head device.

According to a second aspect of the present invention, a fixed shaft is protruded from a fixed lower drum, and a pair of rolling bearings is mounted on the fixed shaft at a predetermined distance from the fixed shaft. The upper drum is rotatably supported, and the two rigid support portions that contact the inner peripheral surface of the rolling bearing on the peripheral surface of the fixed shaft are substantially 120
The elastic support member is provided at an angle of approximately 120 degrees from the rigid support portion, and the elastic support member is provided at an angle of about one-half of the winding angle of the magnetic tape around the drum.
Installed at a position of 80 degrees, the inner peripheral surface of the rolling bearing
The rotary head device is configured so as to be biased toward .

According to a third aspect of the present invention, the elastic support member is provided with a guide member that abuts on the inner ring of the rolling bearing, and a press-fit member interposed between the fixed shaft and the guide member. Rotary head device.

According to a fourth aspect of the present invention, the elastic supporting member is provided with a guide member which comes into contact with the inner ring of the rolling bearing, and a press-fitting member interposed between the fixed shaft and the guide member. Rotary head device.

According to a fifth aspect of the present invention, a fixed shaft is projected from a fixed lower drum, and a rolling bearing is mounted on the fixed shaft.
An upper drum rotatably supported via a rolling bearing is provided, a rotary magnetic head is provided on the upper drum, and an inner peripheral surface of the rolling bearing is spaced at a predetermined angle on a peripheral surface of the fixed shaft corresponding to the rolling bearing. Are provided, and the inner peripheral surface of the rolling bearing is directed radially outward at a position substantially 180 degrees from a position at a half of the angle formed by the two rigid supports of the fixed shaft. The magnetic support is provided at a position approximately 180 degrees from a position where the angle of the magnetic tape is wrapped around the drum is about 180 degrees. There is provided a rotary head device in which a drive motor for driving the upper drum to rotate via a belt is arranged within an angular range between the position where the support portion is arranged.

[0019]

[0020]

According to the configuration of the first aspect of the present invention, the rolling bearing is provided by a total of three points of the two rigid support portions provided at a predetermined angle on the peripheral surface of the fixed shaft and the elastic support portions. The inner ring can be held. Further, the intermediate point between the two rigid support portions is configured to correspond to the intermediate point of the winding angle of the magnetic tape. Since the elastic support portion is located at a position opposite to the winding range of the magnetic tape and urges the inner ring of the rolling bearing radially outward, while sufficiently securing the support rigidity of the upper drum, the trajectory of the magnetic head is maintained. Reproduction accuracy can be improved.

According to the second aspect of the present invention,
The position of one-half (approximately 60 degrees) of the two rigid support portions provided on the peripheral surface of the fixed shaft at an angle of approximately 120 degrees is approximately one-half the winding angle of the magnetic tape wound around the drum. In addition, an elastic support portion is provided between the fixed shaft and the rolling bearing at a position approximately 180 degrees from a position at a half of the winding angle of the magnetic tape so that the inner race of the rolling bearing can be radially moved. Since the outer drum is biased outward, the reproducibility of the magnetic head trajectory can be improved while sufficiently securing the support rigidity of the upper drum.

According to the third aspect of the present invention,
When the rolling bearing is mounted on the fixed shaft, the elastic supporting portion includes a guide member that abuts on the inner ring of the rolling bearing, and a press-fit member interposed between the fixed shaft and the guide member. First, without using a guide member and a press-fitting member, a rolling bearing can be mounted on a fixed shaft, and then a guide member can be used as a guide to insert a press-fitting member, without giving an axial pressure input to the rolling bearing. , An elastic supporting portion can be formed.

According to the fourth aspect of the present invention,
When the rolling bearing is mounted on the fixed shaft, the elastic supporting portion includes a guide member that abuts on the inner ring of the rolling bearing, and a press-fit member interposed between the fixed shaft and the guide member. Can be inserted without inserting the guide member and the press-fitting member, and the press-fitting member can be inserted later by using the guide member as a guide, so that the elastic support portion can be formed without applying an axial pressure input to the rolling bearing.

According to the fifth aspect of the present invention,
Two rigid support portions are formed on the peripheral surface of the fixed shaft corresponding to the rolling bearing at a predetermined angle to contact the peripheral surface of the rolling bearing, and a position substantially half of the angle formed by the rigid support portions is formed. And an elastic support portion is provided at a position 180 degrees from the angle, and a position of approximately half of the angle formed by the two rigid support portions corresponds to a position of approximately a half of the winding angle of the magnetic tape wound around the drum, By providing a drive motor for driving the upper drum via a belt within an angle range between the winding start point of the magnetic tape and the position of the elastic support portion,
The stress applied to the fixed shaft due to the winding of the belt can be prevented from reaching the elastic support portion.

[0025]

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described. First, a schematic configuration of the rotary head device 1 is shown in FIG.
This will be described with reference to FIG. The rotary head device 1 includes a chassis 2 attached to a tape player main body (not shown).
It is fixedly connected. A lead groove L for guiding the magnetic tape M is formed on the outer peripheral surface of the lower drum 3. A fixed shaft 4 whose positional relationship with the lead groove L is precisely set is fixed to the center of the lower drum 3 in a protruding state. The fixed shaft 4 is axially separated from the fixed shaft 4. A pair of rolling bearings 5 and 6 are mounted.

An upper drum 7 is provided via these rolling bearings 5 and 6. A rotary magnetic head 8 is provided on the lower surface of the peripheral portion of the upper drum 7. A stator 10 of a driving motor 9 is provided at an upper end of the fixed shaft 4.
Are connected by screws or the like.

The rotor 11 of the driving motor 9 is connected to the upper end of the upper drum 7 corresponding to the stator 10. In the rotary head device 1 configured as described above, the upper drum 7 is driven to rotate by the rotation of the drive motor. The fixed shaft structure of the rotary head device 1 configured as described above will be described in detail.

The fixed shaft 4 shown in FIG. 1 is configured as shown in, for example, FIGS.
The fixed shaft 4 is formed in a shape in which the other peripheral surface portions are cut away except for four peripheral surface portions T1, T2, T3, and T4 of the peripheral surfaces of the rolling bearings 5, 6 facing the inner rings 5a, 6a. Have been. That is, the four peripheral surface portions T1 to T4 are formed in a peripheral shape having the same center and the same radius, and only when the inner diameters of the inner races 5a and 6a of the rolling bearings 5 and 6 coincide with these, All of the peripheral surface portions T1 to T4 are inner rings 5a,
6a.

Then, two of the peripheral surface portions T2, T
3 is used as a rigid support portion, and other peripheral surface portions T1, T4
Are the outer diameters of the fixed shaft 4 and the inner rings 5a, 6a of the rolling bearings 5, 6.
A supplementary preparation is made in case of a match. Except for the two rigid support portions T2, T3 and the other peripheral surface portions T1, T4, the other peripheral surface portions 4a, 4b, 4c, 4d which have been cut off.
For example, the surfaces adjacent to each other are formed in a plane shape at an angle of about 90 degrees, and the opposing surfaces are arranged substantially parallel to each other.

The two rigid support portions T2, T3
As shown in FIG. 1, the intermediate points Tc2 and Tc3 of the circumferential dimensions of the respective peripheral surfaces are formed at an angle of about 120 degrees with each other.

Further, the two rigid support portions T2, T3
The elastic support portion 21 is provided at a position 4a that is approximately 120 degrees apart from the intermediate points TC2 and TC3. The elastic support portion 21 includes, for example, a press-fit member 23 inserted into a concave groove portion 22 formed along the axial direction with respect to the peripheral surface portion 4 a of the fixed shaft 4 cut in a planar shape, and the press-fit member 23. And a guide member 24 that comes into contact with the inner rings 5a and 6a of the rolling bearings 5 and 6. The press-fitting member 23 is, for example, a spring member having a C-shaped elastic section in the major axis direction, and the guide member 24 is, for example, a rectangular metal plate having a central portion formed in a convex shape.

Here, the elastic support 21 with respect to the fixed shaft 4
Will be described with reference to FIGS. 9 and 10. FIG. First, the rolling bearings 5 and 6 are mounted on the fixed shaft 4. Thereafter, the guide member 24 is inserted between the peripheral surface portion 4a of the fixed shaft 4 and the inner rings 5a, 6a. Then, the press-fitting member 23 is press-fitted between the guide member 24 and the fixed shaft 4 along the concave groove portion 22 of the peripheral surface portion 4a. By inserting the press-fitting member 23 using the guide member 24 as a guide in this manner, the axial force is prevented from acting on the rolling bearings 5 and 6, and the rolling bearings 5 are smooth and without impairing the precision of the bearings. Assembly can be performed.

The fixed shaft 4 having the elastic support portion 21 constructed as described above is used for the inner races 5a, 6a of the rolling bearings 5, 6.
When the inner diameter and the outer diameter of the inner ring 5a coincide with each other, as shown in FIG.
6a. At this time, the elastic support portion 21 also elastically contacts the inner rings 5a and 6a separately from the peripheral surfaces T1 to T4.

When the inner diameters of the inner rings 5a and 6a are larger than the outer diameter of the fixed shaft 4, as shown in FIG. 24 comes into contact with the inner rings 5a and 6a. The inner peripheral surfaces of the inner rings 5a and 6a are supported by three points of rigid support portions T2 and T3 and a guide member 24 of the elastic support portion 21.

That is, even if there is a gap between the fixed shaft 4 and the inner rings 5a, 6a of the rolling bearings 5, 6, the gap is set to be shifted in a predetermined direction (on the side where the elastic support portion 21 is provided). By supporting at three points, this state can be fixedly maintained, and the eccentric direction of the trajectory 8a of the magnetic head 8 can be determined. In the conventional structure, if a gap is generated, only one point or two points can be supported, and the eccentric direction cannot be fixed. However, according to the above-described structure, three points can be supported. The eccentric direction of the trajectory 8a of the head 8 can be set, and the rotation of the upper drum 7 can be stabilized.

When the fixed shaft 4 constructed as described above is incorporated into the rotary head device 1, when the wrap angle of the magnetic tape M moving in the direction of arrow R is 180 degrees, the arrangement as shown in FIG. The highest accuracy can be obtained by making the relationship. That is, the intermediate point G between the rigid support portions T2 and T3 is arranged at a position which is 1/2 of the 180-degree winding angle of the magnetic tape M, and the elastic support portion is located at a position (180 degrees) opposite to the intermediate point G. 21 is arranged. Here, the inner rings 5a and 6a of the rolling bearings 5 and 6 are supported at three points indicated by arrows F1 to F3 shown in the drawing.

FIG. 11 and FIG. 12 show the effect of improving the recording and reproducing accuracy of the magnetic tape M by such a configuration.
This will be described with reference to FIG. At a wrap angle D1 of 180 degrees shown in FIG.
The movement of the magnetic head 8 in the direction indicated by Y in the figure has the greatest influence on the displacement d1 (Z direction) of the trajectory 8a. For this reason, it is necessary to minimize the movement of the magnetic head 8 in the Y direction. As described above, the eccentric direction of the magnetic head 8 is set in the X direction in FIG. By giving rigidity to the contact side of the magnetic tape M by T2 and T3, the displacement d1 of the trajectory 8a can be minimized. Thereby, the reproduction accuracy of the locus 8a of the magnetic head 8 with respect to the lead groove L can be improved, and the recording and reproducing performance of the magnetic tape M can be improved. In other words, the deviation amount d1 shown in FIG. 20 can be set, and the locus 8a can be easily drawn in the tracking area TA.

From the above, it is possible to provide the rotary head device 1 with high recording and reproduction accuracy even if the component accuracy is low. In the above-described embodiment, the position of the elastic support portion 21 is opposite to the position G which is a half of the winding angle 180 degrees of the magnetic tape M. However, the present invention is not limited to this. The same effect can be obtained if the position is not opposed. Hereinafter, a second embodiment of the present invention will be described. The rotary head device 1 shown in FIG.
The wrap angle of the magnetic tape M is 90 degrees, and also in this case, similarly to the first embodiment, the rigid support portions T2 and T
The intermediate position G of No. 3 is arranged so as to correspond to a half position of the winding angle 90 degrees of the magnetic tape M.

With this configuration, the magnetic tape M can be wound in the state indicated by D2 in FIGS. This makes it possible to minimize the amount d2 of displacement of the trajectory 8a of the magnetic head 8 in the axial direction Z within the range corresponding to the magnetic tape M. Hereinafter, fixed shaft 4
A modified example of the elastic support portion 21 provided for is described with reference to FIGS. The elastic support portion 21 shown in FIG. 5 is a curved plate in which the guide member 24 is formed of an elastic member such as a synthetic resin, and the press-fit member 23 is a rigid member such as a metal cylindrical rod. Even with such a configuration, when the press-fitting member 23 is press-fitted, the guide member 24 is elastically deformed to guide the press-fitting member 23, so that the rolling bearings 5 and 6 can be assembled without applying an axial force.

It is also possible to use an elastic metal plate or the like as shown in FIG. Further, the elastic support portion 21 made of such a one-piece member is used.
The material is not limited to metal, and the same effect can be obtained by using resin. A third embodiment of the present invention will be described. The rotary head device 1 shown in FIG. 3 has a magnetic tape M having a wrap angle of, for example, 180 degrees. However, the rotary head device 1 has a driving motor 14 provided outside, and the upper drum 7 is driven to rotate by the belt 13. ing.

The motor 14 is arranged at a position between the position where the elastic support portion 21 is provided and the point S where the magnetic tape M starts winding. With such a configuration, a sufficient distance from the audio head AH provided on the winding side of the magnetic tape M to the motor 14 can be ensured, and generation of magnetic noise can be prevented. Further, bending stresses F4 and F5 act on the fixed shaft 4 due to the winding of the belt 13. The upper drum 7 is pressed toward the winding start position S of the magnetic tape M by the bending stresses F4 and F5. This allows
The upper drum 7 is moved to the winding start position S side of the magnetic tape M, and the contact pressure of the magnetic head 8 on the magnetic tape M at the winding start position S can be improved, so that the recording and reproducing performance can be improved.

In any of the rotary head devices 1 shown in FIGS. 1 to 3, the pressing force of the magnetic head 8 on the magnetic tape M at the winding start position S of the magnetic tape M is not limited to any other position. This is the position where the recording and reproduction performance is the lowest. Therefore, the amount of eccentricity Pd shown in FIG. 13 (the eccentricity Pd in the parallel state of the fixed shaft 4 and the upper drum 7 which is generated even if the structure is manufactured with high accuracy).
Can be used as shown in FIG. Here, the eccentricity Pd in the parallel state is the locus 8 of the magnetic head 8.
a, and only contributes to the pressing force of the magnetic head 8 against the magnetic tape M.

As shown in the drawing, the maximum eccentric side surface LS of the upper drum 7 is made to correspond to the winding start point S of the magnetic tape M, so that the maximum radial position of the magnetic head in the radial direction is set to the winding start point of the magnetic tape M. S. Thus, while the contact pressure of the magnetic head against the magnetic tape M was the lowest at the winding start point S of the magnetic tape M in the conventional structure, the arrow F6 in FIGS.
The pressing force F6 can be generated as shown by. That is, high recording and reproducing performance can be obtained even at the winding start point S of the magnetic tape M.

[0045]

According to the first aspect of the present invention, the eccentric direction of the magnetic head can be set on the opposite side of the winding range of the magnetic tape, so that the rotational trajectory of the magnetic head is higher than the lead groove (magnetic tape). The magnetic head can be reproduced with accuracy and the amount of displacement of the magnetic head in the axial direction can be minimized. In addition, by selectively arranging the magnetic head in the eccentric direction, the eccentric direction of the trajectory of the magnetic head is left to the accidental arrangement in the conventional structure, and the reproducibility of the trajectory during mass production is low. In addition, reproducibility of the locus during mass production can be further ensured.

Further, by providing the fixed shaft with the elastic support portion, it is possible to provide a rotary head device having high recording / reproducing performance even if the fitting accuracy between the fixed shaft and the inner ring of the rolling bearing is deteriorated.

According to the second aspect of the present invention, a fixed shaft having an elastic supporting portion is provided at a position substantially 180 degrees from a position at a half of the winding angle of the magnetic tape to correspond to a range of the winding angle of the magnetic tape. With the fixed shaft provided with two rigid support portions at the positions, the locus of the magnetic head with respect to the lead groove (magnetic tape) can be reproduced with high accuracy, and the fixed shaft and the rolling bearing of the same accuracy are used. A rotary head device capable of obtaining extremely high recording and reproducing performance as compared with the conventional structure can be provided.

According to the third aspect of the present invention, in addition to the effect obtained in the first aspect, the elastic supporting portion is separated into the guide member and the press-fitting member. Since the guide member abuts against the inner ring of the rolling bearing to guide the press-fitting member, it is possible to prevent the axial force from acting on the rolling bearing, thereby facilitating high-precision assembly.

According to the fourth aspect of the present invention, in addition to the effect obtained in the second aspect, the guide member guides when the press-fitting member is inserted, so that the elastic supporting portion is provided between the fixed shaft and the rolling bearing. , The work of inserting into the device becomes easy. Further, it is possible to prevent the axial stress from being applied to the rolling bearing during the press-fitting of the press-fitting member.

According to the fifth aspect of the present invention, the drive motor provided outside is disposed between the winding start point of the magnetic tape and the position of the elastic support portion, so that the magnetic head for the audio head or the like is provided. The influence can be prevented, and the storage space in the VTR main body can be reduced.

[0051]

[Brief description of the drawings]

FIG. 1 is a plan view of a rotary head device according to an embodiment of the present invention, in which a wrap angle of a magnetic tape is 180 degrees.

FIG. 2 is a plan view of a rotary head device according to another embodiment of the present invention, in which a wrap angle of a magnetic tape is 90 degrees.

FIG. 3 is a plan view of a rotary head device according to another embodiment of the present invention, in which a driving motor is provided outside a cylinder.

FIG. 4 is a perspective view showing a fixed shaft and an elastic support portion in one embodiment of the present invention.

FIG. 5 is a perspective view showing a fixed shaft and an elastic support portion according to another embodiment of the present invention.

FIG. 6 is a perspective view showing a fixed shaft and an elastic supporting portion according to another embodiment of the present invention.

FIG. 7 is an embodiment of the present invention, and is a plan view showing a state in which the diameter of the fixed shaft matches the inner diameter of the inner ring of the rolling bearing.

FIG. 8 is a plan view showing one embodiment of the present invention, in which the diameter of the fixed shaft is smaller than the inner diameter of the inner ring of the rolling bearing.

FIG. 9 is a front sectional view showing a step of mounting an elastic supporting portion between a fixed shaft and a rolling bearing.

FIG. 10 is a front sectional view showing a state in which an elastic supporting portion is mounted between a fixed shaft and a rolling bearing.

FIG. 11 is an explanatory diagram for explaining a relationship between a deflection amount of a magnetic head in a Z direction and a winding range of a magnetic tape.

FIG. 12 is a plan view showing a winding angle of a magnetic tape around a rotary head device.

FIG. 13 is a half sectional view of the rotary head device showing a state where the axis of the fixed shaft and the center of the trajectory of the magnetic head are parallel and eccentric.

FIG. 14 is a plan view of the rotary head device showing a state where the fixed shaft and the upper drum (magnetic head) are parallel and eccentric.

FIG. 15 is a front sectional view showing the basic configuration of a general rotary head device.

FIG. 16 is a front sectional view showing a basic configuration of a general rotary head device.

FIG. 17 is a contact pressure diagram of a magnetic head showing a pressure at which a magnetic tape is wound around the magnetic head in a conventional rotary head device.

FIG. 18 is a front sectional view showing a state of a fixed shaft of a conventional rotary head device and a rolling bearing mounted with a gap to the fixed shaft.

FIG. 19 is a view showing a state in which a magnetic tape is wound around a conventional rotary head device, and X, Y, and Z for explaining an eccentric direction and the like.
The perspective view which shows a direction.

FIG. 20 is an explanatory diagram showing an example in which a displacement of the magnetic head locus in the Z direction corresponds to a tracking area when the locus of the magnetic head is eccentric, which is a conventional example.

FIG. 21 is an explanatory diagram showing another conventional example in which, when the trajectory of the magnetic head is eccentric, the displacement of the trajectory of the magnetic head in the Z direction corresponds to the tracking area.

FIG. 22 is an explanatory diagram showing a relationship between the displacement amounts d1, d3 of the magnetic head in the Z direction and the winding positions D1, D3 of the magnetic tape when the trajectory of the magnetic head is eccentric, which is a conventional example.

FIG. 23 is a conventional example, in which the winding state of the magnetic tape is changed to D1, D when the trajectory of the magnetic head is eccentric in the X direction.
The top view shown by 3.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary head device 3 Lower drum 4 Fixed shaft 5, 6 Rolling bearing 7 Upper drum 8 Magnetic head 14 Driving motor 21 Elastic support part 23 Press-fit member 24 Guide member T2, T3 Rigid support part L Lead groove

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-252512 (JP, A) JP-A-62-252513 (JP, A) JP-A-62-259218 (JP, A) JP-A 62-252218 257677 (JP, A) JP-A-62-262214 (JP, A) JP-A-62-236179 (JP, A) JP-A-4-219612 (JP, A) JP-A-4-175512 (JP, A) JP-A-60-52953 (JP, A) JP-B-62-11204 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 5/52 F16C 27/06

Claims (5)

(57) [Claims] 1. A fixed shaft protruding from a fixed lower drum, a rolling bearing mounted on the fixed shaft, an upper drum rotatably supported via the rolling bearing, and an upper drum. A magnetic head that is provided and rotates together with the upper drum, two rigid support portions provided at a predetermined angle on a peripheral surface of the fixed shaft corresponding to the rolling bearing and abutting on an inner peripheral surface of the rolling bearing; Is arranged at a position substantially 180 degrees from a position of 1/2 of the angle formed by the two rigid support portions, and urges the inner peripheral surface of the rolling bearing toward the radially outer side, and applies the magnetic tape to the drum. A rotating head device comprising: an elastic support portion provided to face a side opposite to the winding range. 2. A fixed shaft protruding from a fixed lower drum, a pair of rolling bearings arranged in the axial direction at a predetermined distance from the fixed shaft, and a pair of rolling bearings via the pair of rolling bearings. The upper drum rotatably supported with respect to the rotary magnetic head provided on the upper drum and the peripheral surface of the fixed shaft corresponding to each rolling bearing are provided at an angle of approximately 120 degrees, and the rolling is provided. The two rigid support portions abutting on the inner peripheral surface of the bearing and the two rigid support portions
It is arranged at an angle of 0 degree, provided so as to urge the inner peripheral surface of each rolling bearing outward in the radial direction, and is substantially 180 degrees from the position of 1/2 of the angle at which the magnetic tape is wound around the drum. An elastic support portion provided at the position of
A rotary head device comprising: 3. The rotary head according to claim 1, wherein the elastic support portion includes a guide member abutting on an inner ring of the rolling bearing, and a press-fit member interposed between the fixed shaft and the guide member. apparatus. 4. The rotary head according to claim 2, wherein the elastic support portion includes a guide member abutting on the inner ring of the rolling bearing, and a press-fit member interposed between the fixed shaft and the guide member. apparatus. 5. A fixed shaft protruding from a fixed lower drum, a rolling bearing mounted around the fixed shaft, an upper drum rotatably supported via the rolling bearing, and an upper drum. A rotary magnetic head provided, two rigid support portions provided at a predetermined angle on a peripheral surface of the fixed shaft corresponding to the rolling bearing, and abutting against an inner peripheral surface of the rolling bearing; Disposed at a position approximately 180 degrees from a half of the angle formed by the two rigid support portions, biases the inner peripheral surface of the rolling bearing radially outward, and winds the magnetic tape around the drum. And the upper drum is rotationally driven via a belt, which is disposed within an angular range between an elastic support portion provided at a position substantially opposite to the above and a position at which the magnetic tape is wound around the drum and a position at which the elastic support portion is disposed. A driving motor, Rolling head device.