JPS61117774A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To stabilize the accuracy of the positioning of head against thermal/ humidity variation by forming the virtual line from the point of fixation of the carriage and the driving belt to the recording/reproducing point of the magnetic head and the virtual line from the center of the driving pulley to the center of the disc parallel and by forming the driving pulley with invar. CONSTITUTION:The distance from the center point H of the magnetic disc 15 to the position of track E of the disc, and that from the center of driving I of the driving pulley 18 to the fixation point F where the carriage 13 and the driving belt 16 are fixed together, are made an equal length J. And distance from the disc center H to the center I of the driving pulley 18 is made of a length K. In effect by the above formation, the aberration of the length K due to thermal extension/shrinkage little causes an off tracking. Also, invar of which thermal expansion is extremely small is used as the material of the driving pulley 18, and further the linear expansion coefficient of the magnetic disc 15 and that of the driving belt 16 are made to approximately coincide. Therefore, the off tracking of the magnetic head against the magnetic disc caused by the environmental temperature variation is approximately annihilated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording/reproducing device, and in particular to a device that stabilizes the track positioning accuracy of a magnetic head against temperature changes and improves the track density of a magnetic disk. The present invention relates to a magnetic recording/reproducing device having a structure.

Conventional configurations and their problems In recent years, in magnetic recording and reproducing devices using magnetic disks such as floppy disk devices, as the storage capacity has increased, the track density on the magnetic disk has become higher. K
It is well known that the dimensional accuracy of mechanisms is increasing.
Device? Since the main mechanical parts and the magnetic disk are made of resin, the components expand and contract significantly due to changes in ambient temperature and humidity, resulting in off-track when positioning the magnetic head relative to the magnetic disk. This causes problems in increasing the track density in magnetic recording and reproducing devices using magnetic disks such as floppy disk devices.

The schematic structure of a conventional floppy disk device is shown in FIGS. 1 and 2. FIG. 1 shows a plan view, and FIG. 2 shows a side sectional view.

In the figure, two guide bars 2 are fixed on a substrate 1, and a carriage 3 slides using these guide bars as a guide. A magnetic head 4 is provided at the tip of the carriage 3, and the magnetic head 4 slides on the recording surface of the floppy disk 6 to perform recording and reproduction.

The carriage is moved by intermittent movement of the capstan roller 8, which engages with the shaft of the stepping motor 9, at rainbow track intervals. On the other hand, the floppy disk 6 is housed in a protective case 6, and inserted into the device from the direction of the arrow.A part of the protective case 6 is provided with an opening 5', and when inserted, the magnetic disk 4 is inserted into the case opening 5'. ' The floppy disk 6 is brought into contact with the surface of the floppy disk 60, and the floppy disk 6 is rotated (9) at a predetermined number of revolutions by the rotating shaft T and the drive motor 10iC to perform all recording and reproduction, and normally the floppy disk 6 is precisely placed on the recorded track. In order to fully position the magnetic head, K must be made of a material that expands and contracts less due to changes in temperature and humidity under the environmental conditions in which the floppy disk device is used. However, there are limits to the selection of materials alone, and the mechanical configuration of the floppy disk device must also be considered.

However, the conventional structure is as described above, and the substrate 1 is usually made of die-cast aluminum, the carriage 3 is made of synthetic resin, and the floppy disk 6 is made of a resin sheet commonly called Mylar coated with a magnetic material. It is something.

In FIG. 1, if the center of the floppy disk 6 is 2x, the position of the magnetic head 4 at a predetermined track position of the floppy disk is iY, and the drive position of the carriage 3 is 1z, then XY=B, YZ=C, XZ-D Then, D=, B- in any case with respect to temperature and humidity changes.
1-G K+, otherwise the magnetic head will not be positioned correctly.

Therefore, in the floppy disk device configured as described above, not only are the materials different and the coefficients of linear expansion with respect to changes in temperature and humidity are also different, but the dimensions of B or C are in a positional relationship in which they are enlarged with respect to changes in temperature and humidity. Not only is there each track ll? :The dimensions of both B and C changed, making the structure extremely vulnerable to changes in environmental conditions.

Purpose of the Invention In view of the above drawbacks, the present invention improves the track positioning accuracy of a magnetic head with respect to a magnetic disk such as a floppy disk.
It is an object of the present invention to provide a magnetic recording and reproducing device that is stable despite any temperature and humidity changes and can perform accurate high-density recording and reproducing.

Structure of the Invention The present invention provides a drive motor, a magnetic disk rotationally driven by the drive motor, a magnetic head provided on the magnetic disk so as to be capable of recording and reproducing information, and a tangent line of the magnetic disk provided with the magnetic head. a carriage provided to be slidable in a direction perpendicular to the direction; a drive belt fixed to the carriage and driven in a direction perpendicular to the tangential direction of the magnetic disk; It consists of an access motor provided on the top, and a tension pulley that loops the drive belt and applies tension to the drive belt, and connects the fixing point of the carriage and drive belt to the recording/reproducing point of the magnetic head. Lines and,
The imaginary line connecting the center point of the rotational axis of the access motor that fully drives the drive belt and the rotational center point of the magnetic disk is arranged in parallel, so even if changes in temperature and humidity occur, the rotation of the magnetic disk and drive belt will be maintained. It has the unique effect that expansion and contraction are in the same direction and no off-track occurs due to any temperature change.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to all the drawings.

FIG. 3 is a plan view of the magnetic recording/reproducing apparatus according to the first embodiment of the present invention, FIG. 4 is a side sectional view, and FIG. 5 is a bottom plan view.

This embodiment is an explanatory diagram of a double-sided magnetic recording system in which recording and reproduction are performed on the upper and lower surfaces of a magnetic disk.

In the figure, two guide bars 1 are fixed on a substrate 11.
2 are arranged parallel to each other, and a sliding carriage 13 is engaged to guide the entire guide bar 11. Cal],
An upper side 14 and a lower side 14' of the magnetic head are arranged at two points on the disk 13 so as to sandwich a magnetic disk 15, respectively. Further, two points of the carriage are fixed to a driving belt 16. One end of the driving belt 16 is fixed to a driving pulley 18 that engages with the central rotation axis of the access motor 1a, and the other end is looped around a tension pulley 19, and is given tension by a tension spring 2o.

Moreover, the magnetic disk 16 is housed in a protective case 22, and the magnetic disk 16 is
A part of the protective case 22 is provided with an opening 23, and when inserted, the magnetic heads 14 and 14' come into contact with the surface of the magnetic disk 16 through the opening 23 of the protective case. The magnetic disk 15 is rotated by a drive motor 24 at a predetermined number of rotations around a rotation center Hi to perform recording and reproduction.

Next, the features of the magnetic recording/reproducing apparatus according to the present invention having the above-described structure will be explained with reference to FIGS. 6 and 7.

FIG. 6 is a schematic diagram of the configuration of the conventional floppy disk device shown in FIGS. 1 and 2, and FIG. 7 is a schematic diagram of the configuration of the magnetic recording/reproducing device of the present invention.

In FIG. 6, the center of the floppy disk e,
The dimension to the center Z of the capstan roller 8 that drives the carriage is the dimension between the respective mounting centers on the substrate. The positioning point τ of the floppy disk 6 indicates a track position spaced from the center of the floppy disk by a dimension B. In addition, the dimension C from the center z machining positioning point Y of the capstan roller 8 is the dimension when recording and reproducing the magnetic head of the carriage 3, then D=B0G.
For example, when the environmental temperature of the device changes, the total thermal expansion or thermal contraction of all component materials is 11 + 11 + 65, then D±l, = (B
±62)+(Of:J,).

If the formula does not hold, the dimensional accuracy of the positioning point Y shown in FIG. 6 will not be achieved. However, in many cases, conventional floppy disk devices are made of materials such that the 0 dimension substrate material is made of aluminum die-casting, the B dimension material is a polyester sheet, and the C dimension material is made of synthetic resin. For this reason, the design of this type of structure has conventionally been handled by calculating an approximate value using the coefficient of linear expansion of the component material such that D=B0C always holds even if there is a change in the environmental temperature.

In addition, in the above configuration, the dimensions B and C are not only enlarged due to changes in the environmental temperature, but also the dimensions 8 and C are expanded by moving the positioning point Y with each track. Due to temperature changes,
It had a very weak structure.

Next, the features and effects of the magnetic recording/reproducing apparatus according to the present invention will be explained with reference to FIG.

In FIG. 7, the dimensions from the center point H of the magnetic disc 15 to the track position E of the magnetic disc, and the dimension from the drive center of the drive pulley 18 to the drive belt fixing point F of the carriage 13 are set to be the same dimension JK. In addition, if the substrate mounting dimension iK is set between the magnetic disk center H and the drive center I-E of the drive pulley 18, the expansion and contraction of the material due to environmental temperature changes in the K dimension will affect the substrate, that is, the aluminum die-cast, and the carriage 13, that is, the resin material. The difference in thermal expansion and contraction between the There is almost no effect as an off-track.

Furthermore, thermal expansion and contraction at the environmental temperature of one dimension occurs in the J direction from point 1 and point H, which causes a difference in the dimensional precision of positioning the magnetic head. The material is amber (1
nvar)k, and in order to make the respective linear expansion coefficients of the magnetic disk 16 and the drive belt 16 closely match,
There is almost no off-track of the magnetic head at the center of the magnetic disk caused by environmental temperature changes, and as shown in FIG. 6, there is no significant off-track as the sum of thermal expansion and contraction of the 8 dimensions and the C dimension in the conventional example. Also, the dimensions as shown in Figure 6,
The J dimension of the magnetic disk 16 and the drive belt 16 does not change relatively and no matter what track position the magnetic head is at.
The dimensional difference hardly changes.

Effects of the Invention In the conventional configuration shown in Fig. 6, it is necessary to calculate the off-track balance by taking into account the coefficient of linear expansion of each component, whereas in the configuration of the present invention, the drive goo is (1nvar), off-track balance calculations only need to take into account the linear expansion coefficients of the magnetic disc and drive belt. It has now become possible to provide a magnetic recording and reproducing device that has many advantages and is of high practical value.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a conventional floppy disk device, FIG. 2 is a side view of a conventional floppy disk device, FIG. 3 is a plan view showing an embodiment of a magnetic recording/reproducing device according to the present invention, and FIG. 4 is a plan view of a conventional floppy disk device. 6 is a side view of the same, FIG. 6 is a bottom plan view of the same, FIG. 6 is a schematic diagram of the configuration of a conventional floppy disk device, and FIG. 7 is a schematic diagram of the configuration of a magnetic recording/reproducing device according to the present invention. 13... Carriage, 14, 14'...
...Magnetic head, 15...Magnetic disk, 16...
... Drive belt, 18... Drive pulley. Name of agent: Patent attorney Toshio Nakao and one other person δ
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Claims (1)

[Claims] A magnetic disk provided rotatably, a magnetic head provided on the magnetic disk so as to be capable of recording and reproducing information, and a carriage provided with the magnetic head and provided slidably in a direction perpendicular to a tangential direction of the magnetic disk. , consisting of a drive belt fixed to this carriage and driven in a direction perpendicular to the tangential direction of the magnetic disk, and a drive pulley that drives this drive belt, and a point where the carriage and drive belt are fixed, and a recording point of the magnetic head. The magnetic recording/reproducing device is arranged such that an imaginary line connecting the reproducing points is parallel to an imaginary line connecting an axial center point of a drive shaft that drives the drive belt and a rotation center point of the magnetic disk, the drive pulley A magnetic recording and reproducing device whose material is amber.