JPH03150760A - Recording or reproducing device - Google Patents

Abstract

PURPOSE:To secure a sure and stable contact with a magnetic head as well as the quick separation from the head at stop by specifying the depths and the shapes of plural projecting parts and groove parts of a negative pressure pad, a recess part near the head, and the cut parts of the projecting parts respectively. CONSTITUTION:A magnetic head 25 is provided in a center recessed part 24 of a negative pressure pad 20. A 1st circular projecting part 23 is formed to surround the part 24 at the side opposite to a magnetic sheet 3 of the part 24. Then a circular recess part 22 is formed outside the part 23 to surround the part 23. Furthermore a 2nd circular projecting part 21 is formed outside the part 22 together with a projecting surface opposite to the sheet 3. At the same time, the rear fringe part of the part 23 serving as the downstream side to the revolution of the sheet 3 is partly cut. Thus a cut part 26 is obtained. The largest depth is set to the part 24 and the depth is sequentially reduced at a groove part 22 and then the part 26. Thus it is possible to secure a sure and stable contact with the head 25 and the quick separation from the head 25 at stop.

Description

[Detailed description of the invention] [Industrial application field]
Particularly, the present invention relates to a stabilizing member (pad) as an interface that stabilizes the contact state between the head and the recording medium.

[Prior Art] Recording or reproducing apparatuses for recording and reproducing information on and from sheet-like recording media such as flexible magnetic disks have been known.

In this type of device, in order to bring the running magnetic sheet into stable contact with the magnetic head, a stabilizing plate (pad) is used that generates hydrodynamic pressure that presses the magnetic disk against the head as the magnetic sheet runs. ing.

FIGS. 4(a) and 4(b) are a plan view and a side sectional view taken along the center line, showing an example of a negative pressure pad generally used in a recording or reproducing device.

As shown in the figure, a recess 3 is provided in the center of the negative pressure pad 30.
4 is formed, and a head mounting opening 3 in which the magnetic head 4 is mounted so as to protrude toward the upper surface of the pad.
5 is formed. On the outside of the recess 34, there is a ring (an annular first protrusion 33
An annular groove 32 is formed on the outside of the first protrusion 33 so as to surround the protrusion 33, and a protrusion surface that closely faces the magnetic sheet 3 is formed on the outside of the groove 32. An annular second protrusion 31 is formed.

In addition, a notch 36 is formed at the rear edge of the first protrusion 33 of the negative pressure pad on the downstream side with respect to the rotational direction of the magnetic sheet by cutting out a portion of the sliding surface adjacent to the magnetic sheet. Also, in the rear edge of the second protrusion 31 on the downstream side with respect to the rotational direction of the magnetic sheet, a notch 37 is formed by cutting out a portion of the sliding surface adjacent to the magnetic sheet.
is formed.

Further, the recess 34, the groove 32, and the notch 36, 37 are each formed to have the same depth.

Assuming that the direction of rotation of the magnetic sheet is the direction indicated by arrow B in the figure, a negative pressure is generated between the negative pressure pad 30 and the recording medium 3 due to the air flow generated by the running of the magnetic sheet 3.

In other words, the effect of this type of negative pressure pad is that when the magnetic sheet runs, the air in the space in the groove 32 facing the magnetic sheet is caused to flow between the protruding surfaces of the protrusions 31 and 33 and the magnetic sheet due to the viscosity of the air. It flows out from gaps and cutouts 36, 37 provided on the protruding surface. Furthermore, since almost no air flows into the space and the gap between the protruding surface and the magnetic sheet, negative pressure is generated between the space, the protruding surface, and the magnetic sheet, and the magnetic sheet It is attracted by pressure and brought into close contact with the magnetic head.

When such a negative pressure pad is used and the magnetic sheet is rotated, the pressure distribution of the negative pressure applied to the magnetic sheet is hydrodynamically analyzed as shown by a curve 22 in FIG. 5. Figure 5 shows positions P1 to P on the center line of the negative pressure pad on the horizontal axis.
10, and the vertical axis represents the magnitude of the pressure (negative pressure) between the magnetic sheet 3 and the magnetic sheet 3. Also, the change in pressure is measured by observing the magnetic sheet. I write it in cir wide 1-.

As can be seen from the figure, P1 to P2 corresponding to the protrusion 31
The pressure is greatly reduced (negative pressure) at the groove portion 32, and the depth relative to the magnetic sheet becomes deeper at the groove portion 32, so that the pressure gradient becomes gentler. Also, looking at the downstream side, due to the notches 36 and 37, the depth of the pad relative to the magnetic sheet is uniform at P6 to PIO, so the pressure changes from atmospheric pressure at a constant gradient, and eventually the pressure changes from atmospheric pressure to P5 to PIO around the magnetic head. At P6, the pressure distribution remains relatively unchanged and a nearly constant negative pressure can be obtained.

This brings the magnetic sheet into pressure contact with the head 4, which has the effect of keeping the head touch stable while the magnetic sheet is rotating.

[Problems to be Solved by the Invention] However, as can be seen from the curve β2 in FIG. 5, in the negative pressure pad shown in the conventional example, a constant negative pressure can be generated near the Fi1 air head, so the magnetic Although it is possible to keep the suction force against the sheet constant around the head, the drop in negative pressure is particularly large on the upstream side of the magnetic head (the Therefore, the contact state between the magnetic sheet and the magnetic head is unstable, which tends to cause floating of the magnetic sheet with respect to the head, vibration, and a decrease in pressure contact force, resulting in the problem that a good head touch cannot be obtained. be.

[Means for Solving the Problems] The present invention has been made with the aim of solving the above-mentioned problems, and is characterized by relatively moving the head and the sheet-like recording medium. A recording or reproducing apparatus for recording or reproducing, comprising a stabilizing member disposed around the head and generating pressure to press the recording medium against the head as the recording medium rotates, a first protrusion having a surface protruding toward a side facing the recording medium; and a groove formed on the outside of the first protrusion, the a second protrusion having a surface protruding on a side facing the recording medium, and the first protrusion has a notch formed on the downstream side of the head with respect to the running direction of the recording medium. In the recording or reproducing device, the cutout portion and the groove portion are formed to have different depths.

According to another feature of the present invention, there is provided a recording or reproducing apparatus that performs recording or reproducing by relatively moving a head and a sheet-like recording medium, the apparatus being arranged around the head, and arranged around the recording medium. A stable member is provided that generates pressure to press the recording medium against the head as the recording medium rotates, and has a surface protruding toward the side facing the recording medium. a first protrusion; and a second protrusion having a surface formed on the outside of the first protrusion through a groove formed on the outside of the first protrusion and protruding toward the side facing the recording medium. a protrusion, the first protrusion has a notch formed on the downstream side of the head with respect to the running direction of the recording medium, and the first protrusion has a depth greater than the recess and the groove. in a recording or reproducing device that is formed.

[Function] As a result, the negative pressure in the vicinity of the magnetic head, that is, the magnetic sheet attraction force, is held constant, and the negative pressure itself is prevented from decreasing, so that the head Stable and good head touch can be obtained in the vicinity.

[Embodiments] Hereinafter, embodiments of the recording or reproducing apparatus according to the present invention will be described in detail with reference to the respective figures.

FIG. 1 is a perspective view showing an embodiment of the recording or reproducing apparatus of the present invention.

In the figure, reference numeral 1 denotes a disk jacket, in which a recording magnetic sheet 3 is rotatably housed. At the center of the magnetic sheet 3, there is a center core 2 that is securely positioned and held with a spindle attached to a rotating shaft of a spindle motor 10, which will be described later.

Reference numeral 13 denotes a disk drive device that rotates the disk inside the loaded disk jacket. 4 is a magnetic head for recording and reproducing, and 5 is a negative pressure pad that is arranged around the magnetic head 4 and generates an attractive force (negative pressure) by the rotation of the disk, the details of which will be described later. Head 4 and negative pressure pad 5
is fixed to a helad carriage 6 for moving the head by adhesive.

The head carriage 6 has a convex portion 7 of an elastic member 7 such as a plate spring.
It is engaged with a head feeding mechanism, that is, a step motor 9 and a lead screw 8 via a. Also, the other end is
It is supported by a guide rod 12 so as to be slidable in the axial direction, and is moved in the radial direction of the magnetic sheet 3 as shown by the arrow A in units of a predetermined amount by driving the motor 9 .

10 is a spindle motor that rotates the magnetic sheet 3, and has a chucking section 11 that holds the center core 2 of the disk. The chucking portion 11 and the magnetic sheet are held in a removable manner by well-known means when the disk jacket is attached or removed. The rotation of the spindle motor IO rotates the magnetic sheet 3, and the sheet 3 is attracted to the pad 5 due to the hydrodynamic action between the sheet 3 and the negative pressure pad 5, thereby causing the magnetic head 4, and a good head touch can be obtained.

FIGS. 2(a) and 2(b) are plan views showing an embodiment of a negative pressure pad used in a recording or reproducing apparatus according to the present invention;
FIG. 3 is a side sectional view along the centerline.

As shown in the figure, a recess 2 is provided in the center of the negative pressure pad 20.
4 is formed, and a head mounting opening 2 in which the magnetic head 4 is mounted so as to protrude toward the upper surface of the pad.
5 is formed. On the outside of the recess 24, a ring (an annular first protrusion 23
An annular groove 22 is formed on the outside of the first protrusion 23 so as to surround the protrusion 23, and a protrusion surface that closely faces the magnetic sheet 3 is formed on the outside of the groove 32. An annular second protrusion 21 is formed.

Furthermore, a notch 26 is formed at the rear edge of the first protrusion 23 of the negative pressure pad on the downstream side with respect to the direction of rotation of the magnetic sheet by cutting out a portion of the sliding surface adjacent to the magnetic sheet. Also, in the rear edge of the second protrusion 21 on the downstream side with respect to the rotational direction of the magnetic sheet, a notch 27 is formed by cutting out a portion of the sliding surface adjacent to the magnetic sheet.
is formed.

In addition, a feature of the present invention lies in the relationship in which the depths of the recess 24, the groove 22, and the notch 26 and 27 are set. To give an example of concrete numerical data, the external shape of the negative pressure pad is 6.5 m/m, and the width of the protrusion 21 is 0.25 m/m. Although it is preferable that the width of 0.
It is set at 5m/m. Also, the depth is 5olLm
It is.

Further, the width of the protrusion 23 is 0.4 m/m, and the diameter of the recess 24 is 4.2 m/m.

The depth of the notch 27 is the same as the depth of the groove 22, which is 50 μm.
and the width is 2 m/m.

The depth of the notch 26 is as shallow as possible (preferably set, in this example, the depth is 3C) to the extent that it can eliminate the adhesion of the magnetic sheet to the negative pressure pad after the magnetic sheet is stopped, and the width is 0.6 m. /m.

The depth of the recessed portion 24 is deeper than the recessed groove portion 22, and is 110 μm.

Assuming that the magnetic sheet rotation direction is the direction indicated by arrow B in the figure, a negative pressure is generated between the negative pressure pad 20 and the recording medium 3 due to the air flow generated by the running of the magnetic sheet 3.

In other words, as mentioned above, the action of this type of negative pressure pad is as follows.
The groove portion 22 facing the magnetic sheet due to the viscosity of air
The air in the space inside the space flows through the gap between the protruding surface of the protrusion 2123 and the magnetic sheet, and the notch 26.2 provided on the protruding surface.
On the other hand, almost no air flows into the space and the gap between the protruding surface and the magnetic sheet, so a negative pressure is generated between the space, the protruding surface, and the magnetic sheet, and the magnetic sheet The magnetic head is attracted by the negative pressure and brought into close contact with the magnetic head.

The basic operation of such a negative pressure pad is the same as described above.

When the pressure distribution of the negative pressure applied to the magnetic sheet is analyzed hydrodynamically when the magnetic sheet is rotated, it becomes as shown by the curve ρ1 in FIG. 3. In FIG. 3 as well, the horizontal axis corresponds to positions P1 to P10 on the center line of the negative pressure pad, and the vertical axis represents the magnitude of the pressure (negative pressure) between the magnetic sheet 3 and the magnetic sheet 3.

The pressure on the upper surface of the negative pressure pad changes depending on the depth of the negative pressure pad relative to the magnetic sheet, that is, the distance of the portion opposing the magnetic sheet. Therefore, the depth relationship of the recess 24, groove 22, notch 26, etc. of the negative pressure pad 20 greatly influences the pressure distribution. The deeper the depth of each part, the more gradual the slope of the pressure, and the shallower the part, the steeper the slope.

As can be seen from the figure, Pl to P2 corresponding to the protrusion 21
Since the pressure is greatly reduced (negative pressure) and the depth relative to the magnetic sheet becomes deeper at the concave groove portion 22, the pressure gradient becomes gentler. Also, looking at the downstream side, due to the notches 26 and 27, the depth of the pad relative to the magnetic sheet is uniform from P6 to P1°, so the pressure changes from atmospheric pressure at a constant gradient, and eventually P5 in the peripheral area of the magnetic head. ~P6, the pressure distribution remains relatively unchanged and a nearly constant negative pressure can be obtained. This brings the magnetic sheet into pressure contact with the head 4, which has the effect of keeping the head touch stable while the magnetic sheet is rotating.

Analyzing the above action in more detail, the slope of the pressure in the portions P2 to P3 and P8 to PIO is
and the depth of the notch 27. In order to suppress the rise in pressure from P2 to P3, it is better to make the groove portion 22 deeper, but this also reduces the rise in pressure from P8 to PLO. The pressure must return to atmospheric pressure at PIO, so if the groove 22 is made as deep as or deeper than the recess 24, the negative pressure at P2 will be small (and a large negative pressure, or suction force, can be obtained around the head). (naru)

Moreover, the width of the protrusion 21 is thick (
Affect. In other words, the narrower the width of the protrusion 21, the steeper the slope of the pressure, so the negative pressure becomes thicker.

Therefore, the negative pressure pad 20 according to the embodiment of the present invention is designed to obtain a sufficiently large negative pressure at P2 by appropriately selecting the width of the protrusion 21 and the depth of the groove 22 and cutout 27. There is.

The pressure gradients at P4 to P5 and P6 to P7 are determined by the depth of the recess 24. Here, the recess 24 is located inside the protrusion 23, and it is desirable to have a flat and stable negative pressure in order to obtain a good head touch. So P4
~P5 and P6~P7, measures are taken to increase the depth of the recess 24 to suppress the increase in pressure as much as possible.

The slope of the pressure at P4-P5 and P6-P7 is P2
~ P3, P8 ~ It is gentler than the pressure gradient of PLO,
The depth of the concave portion 24 is set to be deeper than the concave groove portion 22 and the notch portion 27 (
It can be seen that the effects obtained by doing so are being obtained.

Between P5 and P6, there is a hole 25 for attaching the head.
is formed, and its depth can be considered to be infinitely deeper than the recess 24 and the groove 22. Therefore P
It can be seen that the pressure is almost flat from 5 to P6.

The pressure gradient between P7 and P8 is determined by the depth of the notch 26. If the notch 27 is deep, the gradient of the pressure at P7 to P8 becomes gentle, and the negative pressure around the head becomes small, as in the negative pressure pad shown in FIGS. 4 and S.

Conversely, if the depth of the notch 26 is set to O (zero), P7 to P8
Since the pressure gradient becomes steep, a large negative pressure is obtained around the head.

However, if the notch 26 is not provided, the magnetic sheet will remain attracted to the negative pressure pad even after the magnetic sheet is stopped, so it is necessary to provide the notch 26. By making the depth of the notch 26 as shallow as possible to prevent the magnetic head from adhering to the negative pressure pad after the magnetic sheet is stopped, a large pressure increase can be obtained at P7 to P8.
A large negative pressure can be obtained around the head.

As described above, the negative pressure pad of the present invention can obtain a flat, stable, and sufficiently large negative pressure around the magnetic head, making the contact state of the magnetic sheet with the head stable and reliable, and achieving better recording and reproduction. can perform actions.

[Effects of the Invention] As described above, according to the recording or reproducing apparatus of the present invention, the plurality of protrusions for generating negative pressure on the upper surface of the negative pressure pad, the grooves formed between the protrusions, and the vicinity of the head While the magnetic sheet is being rotated, the shape including the depth relationship of each of the recessed portions and notches formed in the protrusion is adjusted within a range that can prevent the magnetic sheet from sticking to the negative pressure pad after the magnetic sheet is stopped. Since the setting was made to obtain a large negative pressure, that is, a magnetic sheet adsorption force, when the magnetic sheet is rotating, the magnetic sheet is brought into contact with the magnetic head reliably and stably by the large negative pressure, and when the magnetic sheet is stopped, the magnetic sheet is quickly brought into contact with the magnetic head. It can be spaced apart from the negative pressure pad, and stable and safe recording and reproducing operations can be performed at all times.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a disk drive device to which the present invention is applied; FIGS. 2(a) and 2(b) are a plan view and a side view showing a first embodiment of a negative pressure pad in the present invention; Figure 3 is a pressure distribution characteristic diagram showing the pressure distribution of the negative pressure pad in Figure 2 in comparison with the pressure distribution of a general negative pressure pad. Figures 4 (a) and 4 (b) are A plan view and a side view showing an example of the negative pressure pad, and FIG. 5 is a pressure distribution characteristic diagram showing the pressure distribution characteristics of the negative pressure pad shown in FIG. 1...Jacket 3...Magnetic sheet 4...Magnetic head 13...Disk drive device 5.20.30...Negative pressure pad 21.31...Second protrusion 22.32. ... Concave groove portion 23.33... First protrusion 24゜25゜26゜27゜4... Concave portion 5... Opening for magnetic head device 6... Notch of first protrusion 7... Notch part of the second protrusion Sho3

Claims (3)

[Claims] (1) A recording or reproducing device that performs recording or reproducing by relatively moving a head and a sheet-like recording medium, which is arranged around the head and rotates the recording medium as the recording medium rotates. a stabilizing member that generates pressure to press against the head; the stabilizing member includes a first protrusion having a surface protruding toward a side facing the recording medium;
a second protrusion formed outside the first protrusion through a groove formed on the outside of the protrusion and having a surface protruding toward the side facing the recording medium; The protrusion No. 1 is characterized in that a cutout is formed on the downstream side of the head with respect to the running direction of the recording medium, and the cutout and the groove are formed to have different depths. Recording or playback equipment. (2) The recording or reproducing device according to claim (1), wherein the cutout portion is formed shallower than the groove portion. (3) A recording or reproducing device that performs recording or reproducing by relatively moving a head and a sheet-like recording medium, which is arranged around the head and rotates the recording medium as the recording medium rotates. a stabilizing member that generates pressure to press against the head, the stabilizing member having a recess around the head and a first protrusion having a surface protruding toward a side facing the recording medium; A second surface formed outside the first protrusion through a groove formed on the outside of the protrusion and having a surface protruding toward the side facing the recording medium.
The first protrusion has a notch formed on the downstream side of the head with respect to the running direction of the recording medium, and has a depth greater than the recess and the groove. A recording or reproducing device characterized by being formed in.