JPH03185688A - disc cartridge - Google Patents

Abstract

PURPOSE:To stably perform recording and reproduction by providing a ring shape projecting member which suppresses the waving in the vertical direction to a disk surface, opposite to the inner circumference surface part and the outer circumference surface part of a rotating disk, at the upper and lower side of the inside of a cartridge case. CONSTITUTION:A floppy disk 4 is housed so it can be freely rotated in a cartridge case 1. An outer circumference side ring plate 2 for regulating the disk surface waving of the outer circumference side of the floppy disk 4 is provided on the upper and lower sides. An inner circumference side ring plate 3 for regulating the disk surface waving of the inner circumference side of the floppy disk 4 is provided. The outer circumference side ring plate 2 which is placed opposite to the prescribed position of the inner circumference side from the outermost circumference of a disk magnetic surface to the outer circumference side, and the inner circumference side ring plate 3 which is placed opposite to the prescribe position of the outer circumference side from the innermost circumference of the disk magnetic surface, are provided. Thus, the surface waving of the rotating disk become very small and flat, so the head touch is further improved, and the recording/reproducing properties can be improved remarkably.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a disk cartridge that rotatably stores a magnetic disk such as a floppy disk, and more specifically, it is suitable for suppressing surface runout of a rotating magnetic disk. The present invention relates to a magnetic disk cartridge in which a ring-shaped projection member is provided on the inner surface of a cartridge case.

[Conventional technology]

Magnetic recording methods are being applied in a wide range of fields as a rewritable recording method for information.

In magnetic recording, in order to increase recording efficiency, the distance between the magnetic head and the recording medium must be minimized, and in order to improve the durability of the head and the medium, it is necessary to improve the sliding contact between the magnetic head and the disk. I need to improve my "touch". For this purpose, the flatness of the magnetic recording medium becomes a problem. In particular, since the floppy disk is flexible, it is easily deformed during the manufacturing process, and the flatness of the floppy disk is likely to be impaired.

In addition, in the case of floppy disks with metal thin film magnetic layers, which have recently been expected to be used as high-density recording media,
Due to the difference in thermal expansion coefficient between the metal thin film and the substrate film during the manufacturing process, curling tends to occur on the disk surface, resulting in a decrease in recording efficiency and poor contact between the head and the medium, reducing durability. It was the cause. Therefore, as a method to improve the flatness of floppy disks, research and development is being carried out on surface-stretched magnetic disks in which a recording medium with one surface stretched is fixed to a disk-shaped rigid support. E.E., Transaction on Magnetics, M.N.
21, Volume 5 (September 1983), pages 1511 to 1514 (IEEE, Trans, Magne
tics, MAG21. Nn5 (SEPTEMB
ER1983) pp1511-1514)). A magnetic disk with an elongated surface undergoes less deformation during rotation than a conventional floppy disk, but when it comes into contact with a magnetic head, it applies a large surface pressure to the head, and the disk surface is elongated with uniform tension. The problem was that it was difficult.

On the other hand, inside the disk cartridge, a narrow ring plate of the same size as the floppy disk diameter is provided only on the outer circumferential side of the rotating disk, which suppresses the vertical runout of the disk surface. (IEICE, IEICE Technical Report, Vol. 88. MR-13 (1)
(988), pp. 39-46). However, although this method can suppress the surface runout of the floppy disk to some extent, it is designed to suppress only the runout of the outer circumference of the disk, so it is difficult to prevent fine waviness from the inner circumference of the disk caused by attaching a hub. The drawback was that it was difficult to regulate. In order to solve this drawback, it is possible to make the ring plate into a disk shape and restrict the entire surface of the disk, but this increases the load torque applied to the spindle motor of the disk drive and tends to cause uneven rotation of the motor. There was a problem that magnetic recording and reproducing characteristics deteriorated.

[Problem to be solved by the invention]

As mentioned above, with conventional magnetic disks with stretched surfaces, the deformation of the medium during rotation is reduced, but when contacting the magnetic head, the surface pressure applied to the head increases, and it is difficult to stretch the disk surface evenly. The problem was extremely difficult. In addition, in a disk cartridge that has a structure in which a ring plate of approximately the same size as the outer circumferential diameter of the floppy disk is installed on the inner surface of the disk cartridge to suppress vertical vibration of the disk surface, fine waviness that occurs on the inner circumferential side of the floppy disk can be suppressed. It has been difficult to precisely control the vibration of the disk.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art, and to provide a disk cartridge that rotatably stores a magnetic disk such as a floppy disk. A ring-shaped protrusion member suitable for suppressing surface runout of the disk at the inner and outer circumferential portions is provided to flatten the magnetic disk, improve head touch, and provide excellent recording/reproducing characteristics and durability. An object of the present invention is to provide a highly reliable magnetic disk cartridge that can perform stable recording and reproduction by reducing the load on a torque motor of an apparatus.

[Means to solve the problem]

In order to achieve the above object of the present invention, in a disk cartridge having a structure having a flat space in which a flexible magnetic disk with one or both sides of which is an information recording surface is rotatably housed, a rotatable magnetic disk is provided on the inner surface of the cartridge case. A ring-shaped protrusion member (for example, a ring plate, etc.) having a shape configured to suppress vibration in a direction perpendicular to the disk surface that occurs when the disk rotates, is arranged opposite to the inner peripheral surface and the outer peripheral surface of the disk, By using a disk cartridge having a structure in which the disks are provided above and below with the disk interposed therebetween, it is possible to restrict the surface runout of the rotating disk to the minimum possible level.

In the disc cartridge of the present invention, the vertical gap between the upper and lower ring-shaped projection members for preventing vibration of the disc, which are provided on the inner surface of the cartridge case to face the inner peripheral surface and the outer peripheral surface of the rotating disc, is 5 discs. It is preferable that the thickness be subtracted from 0.03 to 0.3an+, and if this gap exceeds O,:3nwn, the effect of controlling the surface runout of the disk cannot be sufficiently obtained. If it is less than .03 mm, the friction between the ring-shaped protrusion member and the rotating disk will increase, and the motor of the disk sliding device will likely have uneven rotation, making the recording and reproducing characteristics unstable, which is not preferable.

In the disk cartridge of the present invention, the width of the ring-shaped protrusion member provided on the inner surface of the cartridge case is the width of the ring-shaped protrusion member for controlling surface runout on the inner circumference side of the disk, from the innermost circumference of the disk magnetic surface to the outer circumference. The width of the ring-shaped protrusion member for controlling surface runout on the outer circumferential side of the disk is preferably 1 to 2% with respect to the disk diameter, from the outermost circumference of the disk magnetic surface to the inner circumferential side. If the value is 1 to 2% of the disk diameter, it is possible to sufficiently control the surface runout of a rotating disk.

〔Example〕

An embodiment of the present invention will be described below in more detail based on the drawings.

FIG. 1 is a sectional view showing the structure of a magnetic disk cartridge manufactured in an example of the present invention, and FIG. 2 is a view taken along the line A--A of the disk cartridge shown in FIG. In the figure, a 5-inch diameter floppy disk 4 is rotatably housed in a cartridge case 1. On the upper and lower inner surfaces of the cartridge case 1, there are an outer ring plate 2 for regulating the disk surface runout on the outer circumference side of the floppy disk 4, and an inner circumferential ring plate 2 for regulating the disk surface deflection on the inner circumference side of the floppy disk 4. The side ring plates 3 are arranged such that the outer ring plates 2 and 5 face each other at a predetermined position from the outermost circumference to the inner circumference of the disk magnetic surface, and the outer ring plate 5 faces from a predetermined position from the innermost circumference to the outer circumference of the disk magnetic surface. An inner ring plate 3 is provided. In this embodiment, when the upper jacket and lower jacket of the cartridge case 1 are combined, the vertical gap between the outer ring plate 2 and the inner ring plate 3, which are provided at predetermined positions, is the width of the floppy disk. The width of each ring plate is set so that the gap obtained by subtracting the thickness of 4 is approximately 0.1 nyn or less, and the width of each ring plate is approximately 2 + m +
Closed.

(Comparative Example 1) Except for removing the outer ring plate 2 for regulating disk surface runout on the outer circumference side of the floppy disk 4,
A disk cartridge was produced in the same manner as in the above example.

(Comparative example 2) A commercially available cartridge case was used as is.

In addition, in the commercially available cartridge case, the gap between the upper jacket and the lower jacket was about 2 m.

Inside the disk cartridge produced in the above-mentioned Examples and Comparative Example 1.2, a 5-inch diameter floppy disk (on a polyimide film substrate with a thickness of 50/ffi), which is a metal thin film type magnetic recording medium for perpendicular magnetic recording, was installed. To,
A medium in which a perpendicularly magnetized film made of a Co-Cr alloy with a thickness of 0.2/ffi was formed, a Si thin film with a thickness of 0.02μ was formed by sputtering, and a lubricant was further applied,
Three types of magnetic disk cartridges were manufactured by storing the disks in a rotatable manner. A recording/reproduction test was performed on these using a commercially available 5-inch floppy disk deck (FDD), and the output (dB) was measured. Note that the output (dB) was evaluated using the case where a commercially available cartridge case was used (Comparative Example 2) as a standard (0...zero). In addition, the durability is
Number of passes (X10) until output (dB) decreases by 2dB
0O).

Furthermore, regarding the surface runout during disk rotation, the maximum runout width (p) was measured using a photonic sensor. The results are shown in Table 1.

Margin 1 below Table 1 As is clear from Table 1, the floppy disk housed in the cartridge case produced in the example of the present invention has reduced surface runout and further improved recording/playback characteristics and durability. I know that there is.

〔Effect of the invention〕

As explained in detail above, the magnetic disk of the present invention housed in a disk cartridge having respective ring-shaped protrusions provided oppositely at predetermined portions on the inner circumferential surface side and the outer circumferential surface side of the rotating disk, Since the surface runout of the rotating disk is extremely small and flat, the head touch is further improved, the recording/reproducing characteristics and durability are significantly improved, and highly reliable recording and reproducing characteristics of the magnetic disk can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of the internal structure of a disk cartridge manufactured in an example of the present invention, and FIG.
The AA arrow view of the disk cartridge of a figure is shown. 1... Cartridge case 2... Outer ring plate 3... Inner ring plate 4... Floppy disk

Claims (1)

[Claims] 1. In a cartridge case having a flat space in which a magnetic disk is rotatably housed, the disk is placed on the inner surface of the cartridge case so as to face the inner circumferential surface and the outer circumferential surface of the rotating disk. 1. A disk cartridge, characterized in that ring-shaped projection members for suppressing surface runout that occur during rotation of the disk cartridge are provided at predetermined positions on the upper and lower inner surfaces of the cartridge case via the disk. 2. In the disk cartridge according to claim 1, the vertical gap between the ring plate-like protruding members provided at the upper and lower inner surfaces of the cartridge case via the magnetic disk is equal to the thickness of the disk. 0.
A disc cartridge characterized in that the diameter is in the range of 0.03 to 0.3 mm.