JPH04283469A - Magnetic head assembly - Google Patents

Abstract

PURPOSE:To improve the reliability of a floppy disk device and to reduce its thickness. CONSTITUTION:A medium 12 is held by a magnetic head 1a stuck and fixed to a carriage 5 and a magnetic head 1b elastically supported by a gimbal spring 4 stuck and fixed to a holder 6. The medium 12 is displaced upward by H and the thickness H1 of the magnetic head 1b is made smaller than the thickness H0 of the magnetic head 1a in correspondence to this displacement quantity.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head assembly, and more particularly to a magnetic head assembly that is used in a floppy disk drive and has two magnetic heads facing each other.

0002

2. Description of the Related Art Generally, in a floppy disk device, a head is brought into contact with a medium to perform recording and reproduction. The head contact and its support mechanism are described in detail in Japanese Patent Publication No. 15866/1983. This mechanism will be explained with reference to the drawings.

FIG. 3 shows a side view of this type of magnetic head assembly. The recording medium 12 is sandwiched between two magnetic heads 11a and 11b on both sides. The lower magnetic head 11a is fixed to a carriage 15. The upper magnetic head 11b is fixed via a gimbal spring 14 to a holder 16 whose one end is rotatably supported by a carriage 15. This holder 16 is subjected to a rotational force counterclockwise in the drawing by a spring 20, whereby the magnetic head 116 is pressed against the recording medium 12.
Furthermore, the recording medium 12 is pressed against the magnetic head 11a. The magnetic heads 11a and 11b are surrounded by magnetic shields 18 and 19 that shield magnetic fields from the outside. The magnetic heads 11a and 11b receive and receive electrical signals via the flexible cable 17 (FIGS. 4(a) and 4(b)).
reference).

The upper magnetic head 11b is provided with a certain degree of freedom so that it can follow the surface of the recording medium. That is, as is clear from FIG. 5, the side portions of the gimbal spring 14 are fixed to the holder 16, and the magnetic head 11b is elastically supported by the gimbal spring 14. A gimbal spring 14 directly behind the magnetic head 11b is supported at a point by a pivot 21. This allows the magnetic head 11b to swing around the point where the pivot 21 contacts.

What should be noted here is that the two magnetic heads 1
1a and 11b have the same thickness (H0 = H1). Although this is not specifically mentioned in the above-mentioned Japanese Patent Publication No. 58-15866, considering the productivity of the magnetic head,
This is because it is customary to use two heads of similar size.

[0006]

In the magnetic head assembly of the conventional floppy disk device described above, the two magnetic heads 11a and 11b have the same thickness. The determination of this thickness will be explained with reference to FIG. 8.

Because of the flexibility of the floppy disk, when the medium is set in the device and sandwiched between the magnetic heads, the medium 12 is lifted by the magnetic head 11a and bends slightly (ΔH). In consideration of this deflection and the thickness of the medium case 22, the magnetic head 11a is designed to be as thin as possible in order to ensure a clearance between the case 22 and the carriage 15, and also to reduce the size (thinness) of the device. Determine the thickness. This determines the optimal thickness of the magnetic head 11a.
b will also be realized.

The thickness of the magnetic head 11b causes the following problems.

First, it hinders miniaturization (thinness) of the device. In recent years, there has been an increasing demand for miniaturization of information processing devices, so even differences of this magnitude are becoming important.

Second, it is desirable that the magnetic head 11b be made thinner in terms of its physical characteristics during recording and reproduction. This is because, as described above, the magnetic head 11b causes tilting (shaking of the magnetic head) as shown in FIG. 7, but this occurs more gently when the magnetic head 11b is thinner. If the magnetic head 11b is thick, the tilting will be severe, and the spacing between the head and the medium will vary widely, making the recording and reproducing characteristics of the head unstable, and the vibration of the head caused by resonance with the gimbal spring. In some cases, the phenomenon of "head noise" or scratches on the media may occur.

[0011]

[Means for Solving the Problems] In view of the above-mentioned problems, in the magnetic head assembly of the present invention, the thickness of the fixed magnetic head and the thickness of the magnetic head elastically supported by a gimbal spring and a pivot are changed. We are trying to optimize each.

0012

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, the lower magnetic head 1a is fixed to a carriage 5 driven by a drive means (not shown), and electrically connected to it by a flexible cable 7. The holder 6 has a top magnetic head 1b at one end via a gimbal spring 4, is supported by the carriage 5 at a holder fulcrum 6a, and receives a force centered on the fulcrum 6a counterclockwise in the drawing by a load spring 20. There is.

The magnetic head 1b also has a flexible cable 7.
An electrical connection is made by the magnetic head 1a.
, 1b are provided with a lower magnetic shield 8 and an upper magnetic shield 9, respectively, to prevent external magnetism.

When loading a recording medium, the holder tip 6b is moved in the X direction about the holder fulcrum 6a. After mounting, the recording medium 2 is held between the two magnetic heads 1a and 1b by the load of the load spring 20.

As shown in FIG. 5, in the upper magnetic head 1b, the gimbal spring 4 has its side portions fixed to the holder 6, and its center portion is held down by a pivot 21 at a point.

The basic configuration of this embodiment is the same as that described as the prior art. Also in this embodiment, when the recording medium 2 is loaded into the apparatus, it is pressed toward the lower magnetic head 1a. Here, the features of this embodiment will be described. In this embodiment, the thickness of the magnetic head is particularly studied, and the following two conditions are taken into consideration in determining the thickness.

The first condition concerns the top magnetic head 1b. As mentioned above, the thinner the magnetic head 1b, the more stable the characteristics, but if it is made too thin, the medium case and gimbal spring 4 will come into contact, so the minimum value is 1.9.
mm is set. In addition to this, considering the margin for tilting, 2.1 mm or more is appropriate.

The second condition concerns the lower magnetic head 1a. This magnetic head also needs to be thick enough so that the medium case and carriage 5 do not come into contact with each other. However, in consideration of making the device thinner, it also needs to be thinner.

In order to satisfy these two conditions as well as the thinness of the lower magnetic head 1a, what must be considered is the displacement of the medium within the case as previously explained with reference to FIG.

[0021] This displacement (ΔH) is from 0.1 mm to 0.2
Approximately mm occurs. Therefore, the difference in thickness between the upper surface magnetic head 1b and the lower surface magnetic head 1a is simply 0.2 mm to 0.2 mm.
4 mm (or more) is suitable.

Therefore, at the limit of the allowable value, the upper magnetic head 1
A magnetic head assembly is obtained in which the thickness H1 of b is 1.9 mm and the thickness H0 of the lower magnetic head 1a is 2.3 mm. Furthermore, considering the tilting margin, H1 = 2.1mm,
A magnetic head assembly with H0 = 2.5 mm is obtained. In addition, in the products that we have conventionally implemented at our company, H0 =
H1 = 2.7 mm. In this product, if the lower magnetic head 1a is left as is and the upper magnetic head 1b is made thinner, a magnetic head assembly with H1 = 2.3 mm and H0 = 2.7 mm can be obtained. Due to this value, it is meaningless to increase the thickness of the magnetic head because it increases the thickness of the device.

[0023] Therefore, H1 = 1.9 to 2.3 mm, H0
-H1≧0.4mm is a value that can achieve the object of the present invention. The state of this magnetic head will become clearer with reference to FIG.

[0024]

As explained above, the present invention realizes a thinner magnetic head supported by a gimbal spring in a magnetic head assembly of a floppy disk device without being constrained by the paired magnetic head. As a result, the negative effects caused by tilting the magnetic head are reduced, and furthermore,
By making this pair of fixed magnetic heads thinner in relation to the magnetic head supported by the gimbal spring, the device itself can be made thinner.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a magnetic head assembly according to an embodiment of the present invention.

2 is a two-sided view of the magnetic heads 1a and 1b in FIG. 1. FIG.

FIG. 3 is a side view showing a conventional magnetic head assembly.

4 is a two-sided view of the magnetic heads 11a and 11b shown in FIG. 3. FIG.

5 is a perspective view showing a joint between a gimbal spring and a holder, which is common to FIGS. 1 and 3; FIG.

FIG. 6 is a side view showing the relationship between a magnetic head and a medium according to an embodiment of the present invention.

FIG. 7 is a schematic diagram showing tilting of a magnetic head.

FIG. 8 is a side view showing the relationship between a conventional magnetic head and a medium.

[Explanation of symbols]

1a Bottom magnetic head 1b Top magnetic head 2 Recording medium H0 Thickness of bottom magnetic head H1 Thickness of top magnetic head

Claims (2)

[Claims] Claim 1: A first and a second magnetic head are connected to a floppy disk containing a flexible recording medium housed in a case through access windows provided at the same position on both sides of the case. In the magnetic head assembly that presses and holds the recording medium, the first magnetic head is fixedly fixed to the first support part and obtains a pressing force by pushing and displacing the recording medium, and the second support part has an elastic member. a second magnetic head that is fixed and pressed by the pressing force of the second support in the direction of the recording medium, and the second magnetic head has a width in a direction perpendicular to the surface of the recording medium. A magnetic head assembly characterized in that it is thinner than the first magnetic head. 2. A difference in width between the first magnetic head and the second magnetic head in a direction perpendicular to the recording medium surface is 0.
．． 2. The magnetic head assembly according to claim 1, wherein the diameter is 2 to 0.4 mm.