JPH0246573A - Head positioning mechanism for flexible disk device - Google Patents

Abstract

PURPOSE:To attain the high accurate positioning by integrally molding a carriage to support a magnetic head with a thermoplastic resin having a linear expansion coefficient close to the line1r expansion coefficient of a magnetic recording medium. CONSTITUTION:A carriage 3 is composed of integral moldings of a thermoplastic crystalline resin having a linear expansion coefficient close to the linear expansion coefficient of a magnetic recording medium 1. Consequently, the misregistration of a magnetic head 2 in the working temperature range can be eliminated. Namely, even at the time of a low temperature and at the time of a high temperature, an A=B relation is obtained, and even at the time of the temperature change, the magnetic head 2 can be moved to the same position. Thus, the misregistration of the magnetic head due to the temperature change at the time of the use can be eliminated with a very easy means.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a head positioning mechanism for a flexible disk device.

[Conventional technology]

Figure 1 shows the head positioning mechanism of a general flexible disk device. In Figure 9, (1) has a coefficient of linear expansion of 1.
A magnetic recording medium made of polyethylene terephthalate resin of 9×10 cwL/crIL/°C, (2) a magnetic head, and (3) a carriage on which this magnetic head is mounted.
Linear expansion coefficient is 30.6 x 10 ctn/crn/
℃ is a drive motor for moving the carriage (3), (5) is a lead screw rotated by this drive motor (4), and (6) is this lead screw (5).
) is a needle that moves by rotation of the carriage (
3) is planted. (7) is a pressure spring for applying a constant pressure to this needle (6) and lead screw +51, and (8) is a guide rod that slides and guides the carriage (3).

FIG. 2 is a cross-sectional view of FIG.
), (2) shows the above-mentioned magnetic head, and (3) shows the above-mentioned carriage. And A in the diagram
is the distance from the center of the spindle motor, which is the reference for the TKOO position (18) of the magnetic recording medium (1), to the TKOO position (1a).
), and 8 indicates the distance from the center of the spindle motor to the magnetic head (2).

Next, the operation will be explained. When moving the magnetic head (2) to a predetermined position on the magnetic recording medium (1), the drive motor (4) rotates by a displacement angle commensurate with the amount of movement of the magnetic head (2). As the drive motor rotates, the lead screw (5) rotates, and the needle (6), which is in contact with its guide groove (5th) with a predetermined contact pressure, moves in the axial direction of the lead screw (5). do. As the needle (6) moves, the carriage (3) moves along the guide rod (8), and as a result, the magnetic head (2) moves to a predetermined position on the magnetic recording medium Ill.

To explain the operation, 1. For example, when the temperature during use is low, the distance A from the center of the spindle motor to the TK00 position and the distance A from the center of the spindle motor to the magnetic head (2
), there is a relationship of A<8, and the magnetic head (2) is shifted in the outer circumferential direction of the magnetic recording medium 11) from the TKOO position of the magnetic recording medium)1), and on the other hand, when the temperature is high, A> 8, the magnetic head (2) is displaced in the inner circumferential direction with respect to the TKOO position of the magnetic recording medium fil.

[Problem to be solved by the invention]

When a flexible disk device having a head positioning mechanism with the above configuration is used in a temperature range of, for example, 5 to 50°C, the coefficient of linear expansion of the polycarbonate used for the carriage (3) is 30.6X10 cr as described above.
IL/cm/°C and linear expansion coefficient of magnetic recording medium 19X
10 crn 7cm 7°C, the above temperature change causes a shift in expansion and contraction between the magnetic recording medium (1) and the head positioning mechanism, and the magnetic head ( 2)
There was a problem in that even if an attempt was made to move the TKOO position, the TKOO position would be moved to a position deviated from the TKOO position.

It is an object of the present invention to solve the above-mentioned problems caused by the above-mentioned temperature changes and to enable highly accurate positioning.

[Means to solve the problem]

In the head positioning mechanism of a flexible disk device according to the present invention, a carriage (3) supporting a magnetic head is provided.
is integrally molded with a thermoplastic resin (liquid crystal polymer) having a coefficient of linear expansion closer to that of the magnetic recording medium.

[For production]

In the head positioning mechanism of the present invention, the carriage on which the magnetic head is mounted is made of an integrally molded thermoplastic crystalline resin having a specific coefficient of linear expansion, so that the difference between the coefficient of linear expansion and the coefficient of linear expansion of the magnetic recording medium is The off-track phenomenon caused by temperature changes during use can be eliminated.

〔Example〕

An embodiment of this invention will be described below. In other words, the head positioning mechanism of the flexible disk drive has exactly the same configuration as that shown in Fig. 1, but the carriage (3) on which the magnetic head (2) is mounted has a linear expansion coefficient of 15.6 x 10 ctrt. /cafc(D) It is characterized by being composed of an integrally molded product of thermoplastic crystalline resin (liquid crystal polymer).

That is, the carriage (3) in this invention.

19X10' which is the linear expansion coefficient of the magnetic recording medium 111
Close to cIIL/clIL/℃ 15.6X10
Since it is made of an integrally molded thermoplastic crystalline resin (liquid crystal polymer) with a coefficient of linear expansion of ctn/cIIL/°C, the position of the magnetic head (2) can be prevented within the operating temperature range of approximately 5 to 50°C. can be eliminated. In other words, in Fig. 2, the relationship is A*B even at low temperatures and high temperatures, and even with the above temperature changes, the magnetic head (2
) will move to the same position.

〔Effect of the invention〕

The head positioning mechanism of the flexible disk device of the present invention uses an integrally molded thermoplastic crystalline resin for the carriage on which the magnetic head is mounted as described above, and reduces the linear expansion coefficient of the carriage, which is used for magnetic recording. Since the coefficient of linear expansion is made to be as close as possible to the linear expansion coefficient of the medium, it is possible to eliminate positional deviation of the magnetic head due to temperature changes during use with an extremely simple means.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a head positioning mechanism of a conventional flexible disk device including that of the present invention, and FIG. 2 is a sectional view taken along the line um in FIG. In the figure, 11) is a magnetic recording medium, and (2) is a magnetic head. (3) is a carriage. In other figures, the same reference numerals indicate the same parts.

Claims (1)

[Claims] A head positioning mechanism for a flexible disk device, characterized in that a carriage on which a magnetic head is mounted is integrally molded from a thermoplastic crystalline resin having a coefficient of linear expansion closer to that of a magnetic recording medium.