JPH08180339A - Magnetic head device - Google Patents

Abstract

PURPOSE: To suppress entrained amount of air between a contact surface of an upper side magnetic head and a disk like recording medium and to improve a touch of a magnetic head to the recording medium by constituting so that the area of the contact surface of the upper side magnetic head is smaller than the area of the contact surface of a lower side magnetic head. CONSTITUTION: By making the relations among the lengths L1 and the widths W1 , W2 , the widths G1 , G2 and the depths D1 , D2 of grooves, of the contact surfaces of the upper side/lower side magnetic heads L1 <L2 , W1 <W2 , G1 <G2 , the area of the contact surface 1a of the upper side magnetic head is constituted so as to be smaller than the area of the contact surface 2a of the lower side magnetic head. Thus, even when the number of revolution of a floppy disk is increased, the function of the buoyancy of the head 1 for the contact surface 1a of the head 1 and the upper side recording surface of the floppy disk is suppressed, and the touch of the head 1 to the floppy disk is held excellently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head device most suitable for application to a floppy disk device for high speed rotation.

[0002]

2. Description of the Related Art Conventionally, as a disk-shaped recording medium,
5 and 6 as a magnetic head device of a floppy disk device using a 3.5 inch floppy disk.
There is something like that shown in

In this magnetic head device, upper and lower magnetic heads 1 and 2, which are a pair of vertically symmetrical magnetic heads having the same structure, are provided on the upper and lower head supporting members, a head carriage 3 and a head arm 4. 3a and 4a are vertically symmetrically attached to the upper and lower facing surfaces 3b and 4b so as to face each other from above and below. Then, the base end 4c of the head arm 4 is screwed onto the head arm mount 3c integrally formed on the upper end of the base end of the head carriage 3 with a plurality of screws 6 via the plate spring 5 and the like. The upper and lower magnetic heads 1 and 2 are elastically moved from above and below to the upper and lower recording surfaces 7a and 7b of a horizontal floppy disk 7 such as 3.5 inches by the contact surfaces 1a and 2a which are the upper and lower opposing surfaces by the spring force such as. It is in contact so that it is sandwiched between them.

In this magnetic head device, a horizontal lead screw 9 which is normally and reversely driven by a stepping motor 8 and a needle 10 fixed to one side surface of the head carriage 3 and engaged with the lead screw 9.
And a thrust bearing portion 13 that is formed integrally with the other side surface of the head carriage 3 and that slides along a guide shaft 12 that is parallel to the lead screw 9. Head moving mechanism 14
It has.

Then, while the floppy disk 7 is horizontally rotated by a spindle motor (not shown), the head carriage 3 is driven by a screw feeding action of a lead screw 9 and a needle 10 which are normally and reversely rotated by a stepping motor 8. Is intermittently moved along the guide shaft 12 in the radial direction of the floppy disk 7 in the directions of arrows a and b at a constant pitch, so that the head arm 4 is integrated with the head carriage 3 at a constant pitch in the directions of arrows a and b. And the upper and lower magnetic heads 1 and 2 are moved intermittently at constant pitches in the directions of arrows a and b with the upper and lower magnetic heads 1 and 2 in contact with the upper and lower recording surfaces of the floppy disk 7. The upper and lower recording surfaces 7a and 7b of 7 are configured to be recorded and reproduced.

The upper and lower magnetic heads 1 and 2 are attached to the head carriage 3 and the head arm 4 as shown in FIG.

That is, the head carriage 3 and the head arm 4 are made of synthetic resin or the like. The upper magnetic head 1 is adhered to the substantially central portion of the lower surface of a substantially rectangular gimbal plate 16 made of a stainless plate or the like which is a swingable supporting means, and the outer periphery of the gimbal plate 16 is the tip 4 a of the head arm 4. Are attached to the upper and lower facing surfaces 4b by welding or adhesion.

The lower magnetic head 2 is adhered to a substantially central portion of the upper surface of a base plate 17 made of a stainless steel plate or the like which is a fixed support plate, and the outer periphery of the base plate 17 is above and below the tip 3a of the head carriage 3. It is attached to the facing surface 3b by welding or adhesion.

A pair of upper and lower magnetic shield plates 18 and 19 for magnetically shielding the upper and lower magnetic heads 1 and 2 from above and below are adhered to the lower surface 3d and the upper surface 4d of the head carriage 3 and the head arm 4, respectively. Has been done.
Further, a pair of upper and lower flexible printed boards 20 for signal transmission to the upper and lower magnetic heads 1 and 2,
21 is wired along a pair of upper and lower grooves 3e, 4e formed along the central portions of the upper and lower facing surfaces 3b, 4b of the head carriage 3 and the head arm 4.

The gimbal plate 16 has a plurality of inner and outer cuts 16a formed along the outer periphery of the upper magnetic head 1 in directions substantially orthogonal to each other. The cuts 16a form the upper magnetic head 1 along the arrow a. , And b direction, and a gimbal function of swingably supporting in an arrow y direction perpendicular thereto.

The gimbal function of the gimbal plate 16 causes the upper magnetic head 1 to move to the floppy disk 7.
During the recording and reproducing of, while freely swinging in the directions of arrows x and y in conformity with the flexure of the floppy disk 7, the floppy disk 7 is elastically placed on the lower magnetic head 2 in an optimum state from beginning to end. It is pressing.

Then, as shown in FIG. 3, the upper and lower magnetic heads 1 and 2 having the same structure and having a vertically symmetrical shape.
In the head slider 23, a slider 22 made of ceramic is combined with a head core 23, and the outer circumference thereof is surrounded by a shield ring 24.

Then, in the substantially central portion of the contact surfaces 1a, 2a of the upper and lower magnetic heads 1, 2 shown by hatching in FIG.
Grooves 25 are formed along the direction. A chamfered curved surface 26 is formed on the outer periphery of the contact surfaces 1a, 2a. The head core 23 has a head gap 27 for recording and reproduction and a head gap 2 for erasing.
8 are formed.

[0014]

According to the conventional magnetic head device configured as described above, the upper magnetic head 1 has a gimbal function that allows the upper magnetic head 1 to freely swing in the directions of arrows x and y by the gimbal plate 16. Therefore, compared with the lower magnetic head 2 fixed to the head carriage 3, the contact (contact state) of the contact surface 1a of the upper magnetic head 1 with the floppy disk 7 is likely to be unstable.

When the contact surface 1a of the upper magnetic head 1 with respect to the floppy disk 7 is badly contacted, irregular gaps are formed between the upper and lower magnetic heads 1 and 2 and the floppy disk 7, and these upper surfaces are contacted with each other. Also, the outputs of the lower magnetic heads 1 and 2 are likely to be reduced, or the outputs are likely to be modulated.

2 is a graph in which the relative output levels of the upper magnetic head 1 and the lower magnetic head 2 with respect to the rotational speed of the floppy disk 7 are measured. In the conventional upper magnetic head 1, a solid line is shown in FIG. As shown in, the output starts to decrease when the rotation speed of the floppy disk 7 exceeds 300 rpm, and the rotation speed changes from 720 rpm to 1200 r.
By the time it reaches pm, the output becomes extremely low.

As a result, in the conventional magnetic head device, the rotation speed of the floppy disk 7 is 720 rpm to 1200 rpm.
It could not be applied to a high-speed rotation type floppy disk device of rpm.

The reason why the upper magnetic head 1 is less likely to hit the floppy disk 7 as the rotational speed of the floppy disk 7 is higher is that the relative speed between the floppy disk 7 and the upper magnetic head 1 increases. The amount of air entrained between the contact surface 1a of the magnetic head 1 and the upper recording surface 7a of the floppy disk 7 increases, and the air pressure causes the buoyancy F to push the upper magnetic head 1 upward (see FIG. 5). Is likely to become larger.

In FIG. 2, the output of the lower magnetic head 2 is 1
This is a measurement of how the output of the upper magnetic head 1 changes with an increase in the rotation speed of the floppy disk 7 when it is set to 00%. It is clear that the output of the magnetic head 1 has decreased.

In the 3.5 inch floppy disk 7, the innermost track radius is 2 on the lower recording surface 7b.
It is 4.6875 mm, and the radius is 23.3 mm on the upper recording surface 7a.
It is 1875 mm, and the contact surfaces 1a and 2a of the upper and lower magnetic heads 1 and 2 completely hit the upper and lower recording surfaces 7a and 7b of the floppy disk 7 (the contact state is an ideal state). ), The output difference between the upper and lower magnetic heads 1 and 2 is
It is 6% due to the difference in relative speed with respect to the floppy disk 7 of 2.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a magnetic head device capable of easily improving the contact of the upper magnetic head with the disk-shaped recording medium. .

[0022]

According to a first aspect of the present invention, there is provided a magnetic head device according to the present invention, wherein upper and lower magnetic heads are provided on upper and lower recording surfaces of a disk-shaped recording medium by their contact surfaces. In the magnetic head device for contact, the area of the contact surface of the upper magnetic head is smaller than the area of the contact surface of the lower magnetic head.

A second invention of the magnetic head device of the present invention is a magnetic head device in which the upper and lower magnetic heads are brought into contact with the upper and lower recording surfaces of a disk-shaped recording medium by their contact surfaces. The depth of the groove formed on the surface is deeper than the depth of the groove formed on the contact surface of the lower magnetic head.

A third invention of the magnetic head device of the present invention is a magnetic head device in which the upper and lower magnetic heads are brought into contact with the upper and lower recording surfaces of a disk-shaped recording medium by their contact surfaces. The width of the groove formed on the surface is larger than the width of the groove formed on the contact surface of the lower magnetic head.

[0025]

According to the first aspect of the magnetic head device of the present invention configured as described above, the contact surface area of the upper magnetic head is smaller than the contact surface area of the lower magnetic head.
Even if the rotational speed of the disk-shaped recording medium becomes high, the amount of air entrained between the contact surface of the upper magnetic head and the disk-shaped recording medium can be suppressed.

In the second aspect of the magnetic head device of the present invention, the depth of the groove formed on the contact surface of the upper magnetic head is deeper than the depth of the groove formed on the contact surface of the lower magnetic head. Even if the number of rotations of the disk-shaped recording medium is increased, the air trapped between the contact surface of the upper magnetic head and the disk-shaped recording medium can easily escape along the groove.

According to the third aspect of the magnetic head device of the present invention, the width of the groove formed on the contact surface of the upper magnetic head is larger than the width of the groove formed on the contact surface of the lower magnetic head. Even if the rotation speed of the disk-shaped recording medium becomes high,
Air trapped between the contact surface of the upper magnetic head and the disk-shaped recording medium can easily escape along the groove.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magnetic head device to which the present invention is applied will be described below with reference to FIG. It should be noted that the same structural parts as those in FIGS. 2 to 6 are denoted by the same reference numerals to omit redundant description.

FIG. 1A shows the upper magnetic head 1 of the present invention.
1B shows the lower magnetic head 2 of the present invention.

In the first aspect of the present invention, the area of the contact surface 1a of the upper magnetic head 1 shown by hatching in FIGS. 1A and 1B is changed to the area of the contact surface 2a of the lower magnetic head 2. It is configured to be smaller than.

At this time, the contact surface 1a has a length of L ₁ and a width of W.
₁ , the width of the groove 25 is G ₁ , the depth is D ₁ , and the contact surface 2
the length of a L _2, the width W _2, the width of the groove 25 G _2, the depth is taken as D _2, by the _{L 1 <L 2 W 1 <} W 2 G 1> G 2 The area of the contact surface 1a can be easily made smaller than the area of the contact surface 2a.

Thus, the contact surface 1 of the upper magnetic head 1
By configuring a to be smaller than the contact surface 2a of the lower magnetic head 2, in the magnetic head device shown in FIGS. 5 and 6, even if the rotational speed of the floppy disk 7 becomes higher than 720 rpm, The amount of air entrained between the contact surface 1a and the floppy disk 7 can be suppressed.

Therefore, the contact surface 1a of the upper magnetic head 1
And the upper recording surface 7a of the floppy disk 7 can suppress the action of the buoyancy F that pushes the upper magnetic head 1 upward by the air, so that the upper recording surface 7a of the floppy disk 7 can be prevented. The contact of the contact surface 1a of the upper magnetic head 1 can be improved.

The second aspect of the present invention is the same as shown in FIG.
In (B), the depth D ₁ of the groove 25 of the upper magnetic head ₁
The is obtained by deeper configuration than the depth D ₂ of the groove 25 of the lower magnetic head 2. D ₁ > D ₂

[0035] Thus, if deeper configuration than the depth D ₂ of the groove 25 the depth D ₁ of the lower magnetic head 2 in the grooves 25 of the upper magnetic head 1, the magnetic head device shown in FIGS. 5 and 6 , The rotation speed of the floppy disk 7 is 720 rpm
Even if it becomes higher than the above, the air trapped between the contact surface 1a of the upper magnetic head 1 and the floppy disk 7 can be removed by the groove 2
It is possible to easily escape along the line 5.

Therefore, the contact surface 1a of the upper magnetic head 1
And the upper recording surface 7a of the floppy disk 7 can suppress the action of the buoyancy F that pushes the upper magnetic head 1 upward by the air, so that the upper recording surface 7a of the floppy disk 7 can be prevented. The contact of the contact surface 1a of the upper magnetic head 1 can be improved.

The third aspect of the present invention is also shown in FIG.
As already described in (B), the groove 2 of the upper magnetic head 1
The width W ₁ of _No. 5 is larger than the width W ₂ of the groove 25 of the lower magnetic head 2. W ₁ > W ₂

Thus, if the width W ₁ of the groove 25 of the upper magnetic head 1 is made larger than the width W ₂ of the groove 25 of the lower magnetic head 2, the area of the contact surface 1a of the upper magnetic head 1 is reduced. The area of the contact surface 2a of the side magnetic head 2 can be made smaller, and the amount of air entrained between the contact surface 1a of the upper magnetic head 1 and the upper recording surface 7a of the floppy disk 7 can be suppressed, and at the same time, There is a synergistic effect that the trapped air can easily escape along the groove 25 having the increased width W ₁ .

As a result of the above, the first, second and third aspects of the present invention
According to the invention, as shown by the broken line in FIG. 2, the rotation speed of the floppy disk 7 exceeds 720 rpm, and 1200 r
Even when reaching pm, it was possible to suppress the extreme decrease in the output of the upper magnetic head 1 and improve the stable output of the upper magnetic head 1.

Therefore, according to the magnetic head device of the present invention, the rotation speed of the floppy disk 7 is 720 rpm to 1 rpm.
It can be sufficiently applied to a high-speed rotation type floppy disk device of 200 rpm.

The embodiment of the present invention has been described above.
The present invention is not limited to the above embodiments, and various modifications can be made based on the technical idea of the present invention.

[0042]

The magnetic head device of the present invention constructed as described above has the following effects.

According to the first aspect of the present invention, the area of the contact surface of the upper magnetic head is made smaller than the area of the contact surface of the lower magnetic head, so that the upper magnetic head can operate even if the rotational speed of the disk-shaped recording medium becomes high. Since it is possible to suppress the amount of air entrapped between the contact surface and the disk-shaped recording medium,
Even when the number of rotations of the disk-shaped recording medium is high, the contact of the upper magnetic head with the disk-shaped recording medium can be improved, and stable output can be obtained.

According to the first aspect of the invention, the length of the contact surface of the upper magnetic head is made smaller than the length of the contact surface of the lower magnetic head, or the width of the contact surface of the upper magnetic head is made smaller. It is possible to easily improve the contact of the upper magnetic head with respect to the disk-shaped recording medium with a very simple structure such as making the width smaller than the width, and it is very low cost.

According to the second aspect of the invention, the depth of the groove formed on the contact surface of the upper magnetic head is set deeper than the depth of the groove formed on the contact surface of the lower magnetic head, so that the number of rotations of the disk-shaped recording medium is increased. Even if the height increases, the air entrapped between the contact surface of the upper magnetic head and the disk-shaped recording medium can be easily escaped along the groove, so that the rotation speed of the disk-shaped recording medium increases. However, it is possible to improve the hit of the upper magnetic head with respect to the disk-shaped recording medium and obtain stable output.

In the third aspect of the invention, the width of the groove formed on the contact surface of the upper magnetic head is made larger than the width of the groove formed on the contact surface of the lower magnetic head, and the rotational speed of the disk-shaped recording medium is high. In this case, the air trapped between the contact surface of the upper magnetic head and the disk-shaped recording medium can be easily escaped along the groove. The contact of the upper magnetic head with the linear recording medium can be improved, and stable output can be obtained.

According to the second and third inventions, the depth of the groove formed on the contact surface of the upper magnetic head is made deeper than the depth of the groove formed on the contact surface of the lower magnetic head, or the depth of the groove of the upper magnetic head is increased. With a very simple structure such as making the width of the groove larger than the width of the lower magnetic head, it is possible to easily improve the contact of the upper magnetic head with the disk-shaped recording medium, resulting in a very low cost. Is.

According to the first, second and third inventions, since the lower magnetic head can be fixed to the lower head supporting member and the upper magnetic head can be swingably attached to the upper head supporting member, the high speed can be achieved. In the rotary type floppy disk device, stable output of the upper magnetic head can be obtained.

According to the first, second and third inventions, since the disk-shaped recording medium is composed of the floppy disk, it is possible to obtain a stable output of the upper magnetic head in the high-speed rotation type floppy disk device.

[Brief description of drawings]

1A and 1B are drawings for explaining an embodiment of a magnetic head device of the present invention, in which FIG. 1A shows a plane and side surfaces of an upper magnetic head, and FIG. 1B shows a lower magnetic head. The plane and the side surface of FIG.

FIG. 2 is a graph in which the relative output levels of the upper and lower magnetic heads are measured with respect to the rotation speed of the floppy disk in the floppy disk device.

FIG. 3 is a perspective view of a magnetic head.

FIG. 4 is a perspective view illustrating attachment of upper and lower magnetic heads of a floppy disk device to a head arm and a head carriage.

FIG. 5 is a side view illustrating a head moving mechanism of the floppy disk device.

FIG. 6 is a plan view of FIG.

[Explanation of symbols]

1 Upper Magnetic Head 1a Contact Surface of Upper Magnetic Head 2 Lower Magnetic Head 2a Contact Surface of Lower Magnetic Head 3 Head Carriage (Lower Head Support Member) 4 Head Arm (Upper Head Support Member) 5 Leaf Spring (Biasing Means) ) 7 Floppy disk (disk-shaped recording medium) 16 Gimbal plate (swingable supporting means) 25 Groove L ₁ Length of contact surface of upper magnetic head L ₂ Length of contact surface of lower magnetic head W ₁ Upper magnetic Width of head contact surface W ₂ Width of contact surface of lower magnetic head D ₁ Groove depth of upper magnetic head D ₂ Groove depth of lower magnetic head G ₁ Width of upper magnetic head groove G ₂ Lower Side magnetic head groove width

Claims (7)

[Claims] 1. A magnetic head device for contacting upper and lower magnetic heads with upper and lower recording surfaces of a disk-shaped recording medium by these contact surfaces, wherein the contact surface area of the upper magnetic head is equal to that of the lower magnetic head. A magnetic head device characterized by being configured to be smaller than the area. 2. The area of the contact surface of the upper magnetic head is made smaller than the contact surface of the lower magnetic head by making the length of the contact surface of the upper magnetic head smaller than the length of the contact surface of the lower magnetic head. The magnetic head device according to claim 1, wherein 3. The area of the contact surface of the upper magnetic head is made smaller than the area of the contact surface of the lower magnetic head by making the width of the contact surface of the upper magnetic head smaller than the width of the contact surface of the lower magnetic head. The magnetic head device according to claim 1, wherein 4. A magnetic head device for contacting upper and lower magnetic heads with upper and lower recording surfaces of a disk-shaped recording medium by these contact surfaces, wherein a depth of a groove formed in the contact surface of the upper magnetic head is lower magnetic field. A magnetic head device characterized in that it is formed deeper than the depth of the groove formed on the contact surface of the head. 5. A magnetic head device for contacting upper and lower magnetic heads with upper and lower recording surfaces of a disk-shaped recording medium by these contact surfaces, wherein a width of a groove formed in the contact surface of the upper magnetic head is lower magnetic head. A magnetic head device having a width larger than the width of a groove formed on the contact surface of the magnetic head device. 6. The lower magnetic head is fixed to a lower head supporting member, and the upper magnetic head is swingably attached to the upper head supporting member. Alternatively, the magnetic head device according to claim 4 or 5. 7. The magnetic head device according to claim 1, 2 or 3, 4 or 5 or 6, wherein the disk-shaped recording medium is a floppy disk.