JPS63166007A - Head for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent spacing loss due to the increase of relative velocity from being increased, by setting the position of a read/write gap in a specific range on the outflow end of a sliding part assuming the length of the sliding part in the inflow/outflow direction of gas as one. CONSTITUTION:When a disk 1 is rotated and is moved in a direction of arrow head G for a head, the head 10 floats by a dynamic pressure effect due to air compression generated between the head 10 and the disk. At this time, a gap quantity between the head and the disk is distributed in a state where the quantity on the inflow side of the head is larger than that on the outflow side. And relation (h1<h) always exists between the gap quantities (h) and (h1), and relation p1<=1/4 is set, therefore, it goes to h1<=1/2h. In such way, the value of the (h1) goes to the value less than the surface coarseness of a medium and almost negligible, and the spacing loss due to the (h1) can be almost neglected.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to magnetic recording for recording (storing) information on a 70-tube disc and reproducing (reading) information from the 70-tube disc. This invention relates to a head for a playback device.

[Conventional technology]

As a conventional 70-tube disk head.

For example, there is one used in a floppy disk drive (hereinafter abbreviated as FDD) device shown in the perspective view of the main part in FIG. In the figure, (1) is a carriage equipped with a head for writing and reading information on a floppy disk (hereinafter simply referred to as FD) (i2) and FDII). (3) is a pair of guides that support the carriage (2), guide the movement of the carriage (2) in the X axis (radial direction of the FD), and are fixed in movement in the Y axis (circumferential direction of the FD). It's a bar.

In this type of device, the head (2a) (2b) mounted on the carriage (2a) (2b) is shown in the cross-sectional view of the head portion of the PDD device in which the cross-section of the head is omitted in Figure 10. There is a pair of 4a) and (4b) with FD (1) in between. The core portions (6a) (6b) of this head with gaps are such that the valley heads (4a) (4b) are FD (
1) Two flat end surfaces on the side that slide into contact with (sliding part X7aX7b
) and (7c) (7a), one side (7a) and (7a) respectively.
7C) reeds.

The opposing head has a slightly different radial position on the disk. (This amount is determined by the standard.

Usually there is a shift of 8 tracks. ) (5a) (5b) are covered by gimbal plates.

FIG. 11(a) is a side view showing the conventional head in FIG. 10, and FIG. 11(b) is a plan view seen from the sliding part side with the FD (1). In this type of head (4), the read/write gap (hereinafter referred to as R/WG) (8) is located at 5
g11 As shown in Figure (a), the position (C) is 10-half the head length; 9 The position shown by the dashed line (C) is the length p from the inlet end (4) in Figure 9; (It was formed on the N side. This length p was determined in consideration of the azimuth loss being almost 0. The length p is usually set to several hundred μm or less and is located at a position of approximately 1A of the shaft 1. In the above, azimuth loss is the loss that occurs due to the angle θ of the playback head gap with respect to the recording track, and azimuth loss is the loss caused by the angle θ, where the wavelength is λ, and the azimuth loss is the loss that occurs when the FD moves as the FD rotates. Particularly 1) means the position where the air flow formed by the dynamic pressure effect between vD and the head (4) enters the head (4), and the outflow end (B) means the position from which the air flow exits; (Hereinafter, the inflow end is included) and the outflow end (B) is used in the above meaning). (9) is the erase gap (hereinafter abbreviated as EG), which is formed at the outflow end (BJ side) by a length q from the position (C) that is half of the head length l.
The direction of movement of D is shown.

In such a conventional head device, for example,
45105. 59-48867 and 59-9427
As disclosed in Publication No. 4, it was thought that the head and the FD were always in contact with each other, and that the spacing between the head and the FD was almost zero. Head (4)
The clearance between the head (4) and the FD (11) is
Since the pressure generated by the air flow between them is small, it is always considered to be constant and approximately zero at any position on the head (4).

Under such conditions, the head gap position can be located anywhere on the head from the standpoint of spacing loss. In other words, spacing loss L, S
F2 record ttl length λ, head FDiJ] spacing (at head gap position) according to d Generally Lll = x
7 (aaX is a constant here).

Until now, this d was approximately 0 and did not change, so the reduction in output was considered to be approximately 0 regardless of the position of the gap on the head.

Furthermore, 41! According to JP-A No. 50-34213, in order to reduce signal loss, it is necessary to equip the device with an extra device such as a blower or air pipe to blow air to the FD, which increases the cost of the device. was there.

[Problem that the invention seeks to solve]

As described above, in conventional head devices, the spacing amount is considered to be approximately constant and zero regardless of the position of the head. Also, extra equipment was required to achieve zero spacing. However, it is highly fake (measurement degree ±103μr)
IL) When the clearance measurement device was used to perform actual subtraction, F
When D is rotating, as shown in the explanatory diagram of Fig. 13, the head (4) is
It was found that the spacing distribution between 1F D (11) was large on the inlet side of the head (4), and small on the R and outlet sides.In the figure, (A') (B') (
C') (B) is the inflow end, outflow end (B), and shape center position (C) of the head (4), respectively, 1%/W G +
This is the position of FD+1) opposite to 8). (h) is n/
This is the amount of clearance at wots+. Although it was predicted that the condition for this gap to occur would normally require a large relative speed between the head (4) F D (0),
It was found that approximately 11 μm was generated even at a very low speed of 1.2 m/S (head pressing load 1519 f).
conditions). This amount is approximately 0.0 when calculated by head gap position substitution.
Equivalent to 5 μm.

In the case of a linear recording density of 30 KFRPI, this corresponds to a spacing loss of about 3 dB, resulting in a large decrease in output. Since this amount of output reduction is proportional to the linear recording density, the output deterioration increases even more when recording at a higher density.

It becomes a big problem. Note that the difference in the amount of clearance between the inflow end and the outflow end becomes proportional to this as the relative speed increases, as shown in the characteristic diagram in Figure 14, which shows an actual measurement example of the relationship between the rotational speed of the FD and the clearance. and increase. Therefore, it is clear that the spacing loss increases as the relative speed increases.

In the figure, the vertical axis represents the clearance (h) (μrIL), the horizontal axis represents the position in the head, the characteristic curve) → is the relative speed & v = 1.3 rn/8, O-O is v = 1 .0 m/8.

Δ-I is v=0.6m/S, E→ is v = OyX
/8 is shown. Note that this is an actual measurement example where the pressure Ogf, that is, the air pressure that supports only the head's own weight, is generated between the head and disk.

This invention was made to solve the above-mentioned problems, even when the linear recording density increases.

Another object of the present invention is to obtain a head for a magnetic recording/reproducing device that exhibits less spacing loss even when the rotational speed of a floppy disk increases and the relative speed increases.

[Means for solving problems]

In the head for a magnetic recording/reproducing device of the present invention, gas flows in and out between the floppy disk and the opposing sliding portion as the disk rotates, and a read/write gap is provided in the sliding portion. In the disk for recording and reproducing information, when the length of the sliding portion in the gas inflow and outflow direction is 1, the position of the read/write gap is within the range T1 on the outflow end side of the sliding portion. It was established in

[Effect]

The head in this invention has the R/WG position in the range of 1/4 liter of the outflow end of the sliding part, that is, in a position close to the head outflow end, so it is suitable for high linear density recording and increase in relative speed. This makes it difficult to be affected by the accompanying spacing loss.

〔Example〕

The invention will now be explained with reference to the drawings.

FIG. 1 (aJ is a side view showing a head for a magnetic recording/reproducing device according to an embodiment of the present invention, and FIG. 1(b) is a plan view seen from the side of the sliding part with the FD. In the figure, utt is In the head of the embodiment, aJ is R/W G, and the shape center line of the head aO is the center line (C) in the air inflow direction (disk rotation direction) on the sliding surface of the head (V).
It is placed on the B) side so that the amount of clearance at the gap position is about the same as the disc surface roughness.

When the maximum value of relative velocity is about 1.2m78, it is set to p1'-1[71. Further, (1) is an erase gap that determines the track width, and the value of tql is several hundred microhorses, and it is located further toward the outflow end (B) side than the R/WG.

FIG. 2 is an explanatory diagram showing the rotating state of the FD (1) of the head 11 (I) of this embodiment, where point A1 on the FD (11) corresponds to the inflow end (4) into which the air above the head 0 flows. Point B7 corresponds to the outflow end (B). Point 07 corresponds to the center line (C) of the shape of the head. Point V corresponds to the R/WGQI) position in this example. Decha 9 figures in the middle.

The hl shown at this point is the head σ・and FD(1
) There is a gap between. Note that B1 point is the conventional R7'wa
Corresponding to the position, h is the gap.

Next, the operation will be explained.

As shown in Fig. 2, when the disk (1) rotates and moves in the direction of arrow Q with respect to the head, the head +
11 rises to the surface. At this time, the amount of clearance between the head and the disk is larger on the inflow side of the head than on the outflow side.

The distribution is quite large. Therefore, there is always a relationship of hl<h between the clearance measurement and hl. Moreover, p
The relationship is 1≦earth F) ht≦+h.

Therefore, the value of hl is an almost negligible value that is less than the medium surface roughness, and the spacing loss due to phl can be almost ignored.

Incidentally, in an actual system, deterioration of the reproduction output is caused not only by the spacing loss, but also by eliminating the azimuth loss, which is the angular error of the trajectory of the reproduction head with respect to the recording track.

Next, we will discuss some ideas regarding this.

FIG. 3 shows the corresponding position of the gap line Q3 of the conventional head on the recording track α4. Disk rotation center (i
It is an explanatory diagram shown in comparison with s, etc., and the extension line of the gear line value passes through the disk rotation center a$, and the installation angle error and position offset error of the wrinkle head (in the form of parallel movement of the gap line 0) There is no azimuth loss unless there is an error due to the deviation of At this time, the gap line of the head (4) is located approximately at the center of the shape of the head, and the head is also disposed at the same position with respect to the line of symmetry of the carriage (2). Note that the arrow (R) indicates the rotation direction of the disk.

On the other hand, as shown in the explanatory diagram of FIG. 4, in the head αl of this embodiment, the gap line 0 is located on the outflow end side of the head shape center line, so when the head is mounted on the carriage, If the shape center line of the head is aligned with the shape center line of the carriage (i.e., the center of the sliding surface in the air inflow direction and the disk rotation direction), an angular error of θ shown in Figure 9 will occur, resulting in azimuth loss. occurs.

Therefore, when the head of this embodiment is disposed on a carriage, as shown in the explanatory diagram of FIG.

Head gap +! iα is the center of rotation of the disk a5
If it is arranged so that it passes through, azimuth loss will be eliminated.

That is, the head member is disposed on the carriage (2) with its shape center line (C) shifted by m toward the inflow end. It is easy to arrange the head on the carriage in this way.

More specifically, it is as shown in the explanatory diagram of FIG. This figure is a plan view of the carriage section including the head, viewed from the sliding surface side.

(5) is a gimbal plate that supports head αG;
is the head, (13 is the gap line of this head.

In addition, in the above example, the relative speed is 1.2F7! /S or less (this value is for a 15-inch disc at 30° rpm)
We have shown an example of a head in which the gap position is shifted under the condition (corresponding to the speed at the outer circumference when rotating at Since the amount of pacing changes, it is of course necessary to shift the gear position It from the center position of the head shape to a position where the spacing loss can be ignored in accordance with the amount of spacing. Naturally, the larger the spacing, the more children will be shifted.

Furthermore, in the above embodiment, the flat end surface (sliding part) on the side where the head slides on the FD is shown as a head that is approximately rectangular.
The side view of FIG. 7(a) is not limited to this.

Plan view from the sliding part side in (b), FD in Figure 51g8
A similar effect can be achieved even with a head having a shape as shown in the explanatory diagram of the rotating state. In Fig. 7(b), the dotted part is the flat end surface (sliding part) on the side where the head ση slides on the disk (1), and this is the flat end surface (sliding part) on the side where the head ση slides on the disk (1).
It has a rounded shape.

It is shaped like half an ellipse, so to speak.

A device having such a shape also has the same effect as above. In addition, in the case of head α of this shape, R/WGαυ and B,
Of course, the distance 1lliq1 of Gd2 is arranged such that B and G are within the flat end surface.

In the above, the surface of the FD facing the head is as follows.

In reality, it has a surface roughness of, for example, about 0.03 μm to 0.1 μmRmax, but it is not shown in FIG. on the other hand.

The surface roughness of the head is, for example, a mirror surface of 0.01 μm or less Rmax, and at least the surface roughness of the disk is good.

〔Effect of the invention〕

As described above, according to the present invention, gas flows in and out between the floppy disk and the opposing sliding portion as the disk rotates, and a read/write gap is provided in the sliding portion. Record information on the above disk,
In the regenerating device, when the length of the sliding portion in the direction of inflow and outflow of gas is 1, the position of the read/write gap is provided within the range of the outflow end side 11 of the sliding portion, As the linear recording density increases, the spacing loss can be almost ignored even when the disk rotational speed increases and the relative speed increases, so it can contribute to the miniaturization of devices that can perform higher density recording. This has the effect of providing a head for a magnetic recording/reproducing device.

[Brief explanation of the drawing]

FIG. 1(a) is a side view showing a head according to an embodiment of the present invention, FIG. 1(b) is a plan view seen from the sliding part side, and FIG.
FIG. 3 is an explanatory diagram showing the operating state of the head shown in the figure. W, Figure 3 is an explanatory diagram showing the head gap arrangement when there is no azimuth loss, Figure 4 is an explanatory diagram when there is azimuth loss, and Figure 5 is an explanatory diagram showing the head attachment state to the carriage according to an embodiment of the present invention. figure. 60 is a detailed explanatory diagram of FIG. 5, FIG. 7 is a side view showing a head according to another embodiment of the present invention, FIG. 60 is a plan view seen from the sliding part side, and FIG. Fig. 7 is an explanatory diagram showing the operating state of the head, Fig. 9 is a perspective view of the main parts of the FDD device related to the conventional example, Fig. 10 is a sectional view of the vicinity of the head of the FDD related to the conventional example, and Fig. 11 (=) is a side view of the head of the conventional example, (b) is a plan view seen from the sliding part side, FIG. 12 is an explanatory diagram showing the conventionally assumed operating state of the head, and FIG. 13 is the head of the conventional example. An explanatory diagram showing the operating state of F
It is an actually measured characteristic diagram showing the relationship between the rotational speed of D and the clearance. In the figure, (1) is a floppy disk, αQ, αη
is the head, αυ is the read/write gap, αJ is the read/write gap line, (1!19 is the center of disk rotation, (
A) is the inflow end, and (B) is the outflow end. Note that in the two figures, the same reference numerals indicate the same or equivalent parts.

Claims (2)

[Claims] (1) Gas flows in and out between the floppy disk and the opposing sliding portion as the disk rotates, and a read/write gap is provided in the sliding portion to record information on the disk; In the regenerating device, the read/write gap is located within a range of 1/4 l on the outflow end side of the sliding portion, where l is the length of the sliding portion in the gas inflow and outflow direction. A head for a magnetic recording/reproducing device. (2) Claim 1, characterized in that the extension line of the read/write gap passes through the center of rotation of the disk.
A head for a magnetic recording/reproducing device as described in 1.