JPH06195919A - Magnetic disk cartridge and its production - Google Patents

Abstract

PURPOSE:To easily stick the center core and magnetic disk sheet of the magnetic disk cartridge to a correct position. CONSTITUTION:The flange part 1b of the blind cylindrical center core 1 having the flange part 1b at its top end face is circumferentially provided with plural pieces of small through-holes 1d for injection of adhesives at the time of sticking the above-mentioned center core and the magnetic disk sheet 2 having an inside hole 2a to be fitted into the cylindrical part 1c of the center core. The rear surface of the flange part 1b of the center core and the front surface of the magnetic disk sheet 2 are pressed to each other and thereafter, the instant-set adhesives are injected between the flange part 1b and the magnetic disk sheet 2 via the small through-holes 1d for injection of the adhesives, by which the center core 1 and the magnetic disk sheet 2 are stuck.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention incorporates a disc-shaped magnetic disk sheet having a small diameter and a very thin thickness, and the magnetic disk sheet is rotated and used for recording and reproduction. The present invention relates to a magnetic disk cartridge and a method for manufacturing the same, and more particularly to a technique for adhering a magnetic disk sheet and a center core. (Prior Art) Conventionally, a floppy disk has been developed in which a magnetic head records digital information on a recording medium in which a magnetic material is coated on both sides of a flexible polyester sheet disk, and it is easy to handle and low cost for a computer. Is widely used as a recording medium. In recent years, a so-called micro floppy disk has been introduced to the market, which is further miniaturized and hardened by plastic resin for the case, and a shutter member is provided at the magnetic head opening to improve the handling, reliability, and dust resistance. Started to be played. On the other hand, in a still camera, a floppy disk is further miniaturized by taking advantage of the usefulness of such a floppy disk and the reusability of a recording medium which is not in a silver salt film by magnetic recording, that is, a disk. It has been proposed to further reduce the diameter and thickness of a recording medium, and to reduce the size of the housing, and to use a hardened magnetic disk cartridge at high speed as a recording and reproducing medium. A still camera with a magnetic recording system having a size of a 35 mm camera has been developed. In such a miniaturized magnetic disk cartridge, a large amount of information is recorded on a small-diameter magnetic disk, so that the recording density becomes very high. Therefore, when the magnetic disk is slightly deformed or displaced, the magnetic head and the magnetic disk During this period, irregularity occurs in the electromagnetic conversion read output due to so-called spacing loss due to poor contact, which causes distortion in the information to be recorded and reproduced, and there is a high possibility that good recording and reproduction will be difficult. On the other hand, this magnetic disk cartridge has a fitting hole in the center of a magnetic disk like a conventional floppy disk and is supported by a member on the machine side from both directions on the side of the magnetic disk drive. Is provided with a center core fitted to the rotary shaft inserted from one side. In order to transmit the rotation of the center core to the magnetic disk, it is necessary to fix the both together, and various measures have been taken to prevent the magnetic disk from being deformed during the fixing. For example, as shown in FIG. 3, there is an inner hole 1a at the center of the bottom surface and a flange portion 1 at the outer circumference of the upper surface.
a bottomed cylindrical center core 1 having b and a disk-shaped magnetic disk sheet 2 having an inner hole 2a, a lower surface of the flange portion 1b of the center core 1 and a peripheral edge of the inner hole 2a of the magnetic disk sheet 2. A method is used in which the ring-shaped double-sided adhesive member 3 interposed between the upper surface and the upper surface is used for adhesion, and the cylindrical portion 1c of the center core 1 is fitted into the inner hole 2a for assembly. This method also enables automatic assembly by a robot. However, in this method, an adhesive member such as the double-sided adhesive tape 3 must be used, and the pressure at the time of adhesion causes unevenness in the thickness direction of the adhesive tape, which causes wrinkles on the magnetic disk, and the adhesive tape 3 is automatically formed. To be fixed concentrically on the lower surface of the flange portion 1b of the center core 1 or the peripheral edge of the inner hole 2a of the magnetic disk sheet 2 without concentric displacement, the adhesive tape is attached to the center core 1 and the disk sheet 2. There is a problem in terms of cost and productivity due to the fact that it is easy to erroneously adhere to each other before the completion of assembly, in which case it is difficult to correct the position of the seat and the center core. (Object of the Invention) In view of the above circumstances, the present invention is a magnetic disk cartridge having a simple structure in which the center core and the magnetic disk sheet can be easily adhered to correct positions without using a double-sided adhesive tape. And a method for producing the same. (Structure of the Invention) In order to achieve the above object, a magnetic disk cartridge according to the present invention comprises a bottomed cylindrical center core having a flange portion on its upper end surface, and an inner hole fitted into the cylindrical portion of this center core. A magnetic disk cartridge comprising a magnetic disk assembly having a magnetic disk sheet, which is rotatably housed, in which a plurality of through holes for injecting an adhesive are provided in a circumferential direction, and the adhesive injection. It is characterized in that it is provided with an instant adhesive which is injected through the small through hole and is interposed at least between the lower surface of the flange portion and the upper surface of the inner peripheral edge of the magnetic disk sheet. In order to achieve the above-mentioned object, a method for manufacturing a magnetic disk cartridge according to the present invention has a bottomed cylindrical center core having a flange portion on an upper end surface thereof, and a magnetic hole having an inner hole fitted into the cylindrical portion of the center core. A method of manufacturing a magnetic disk cartridge comprising a magnetic disk assembly composed of a disk sheet rotatably accommodated, wherein a plurality of through holes for injecting an adhesive are provided in a circumferential direction in a flange portion of the center core,
After the lower surface of the flange portion of the center core and the upper surface of the magnetic disk sheet are brought into contact with each other, an instantaneous adhesive is injected between the flange portion and the magnetic disk sheet through the adhesive injection through hole. Then, the center core and the magnetic disk sheet are bonded to each other. (Effect of the Invention) According to the magnetic disk cartridge and the method of manufacturing the same of the present invention, the instant adhesive is injected from the plurality of adhesive injection through-holes provided in the flange portion of the center core in the circumferential direction. By doing so, the center core and the magnetic disk sheet are bonded to each other, so that a double-sided adhesive tape that has been conventionally used is not required, and it is extremely easy to concentric with the magnetic disk sheet while suppressing the distortion of the magnetic disk sheet. The present invention can reduce the cost and improve the productivity because the center core can be assembled in a shape, and the magnetic disk sheet and the center core can be centered and then bonded to each other so that media deformation due to misalignment can be reduced. The contribution is extremely large. (Examples) Examples of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing an embodiment of a magnetic disk cartridge according to the present invention, and FIG. 2 is an assembled vertical sectional view on the center line of FIG. 1 (the same as the conventional example shown in FIG. 3). Or equivalent parts are indicated by the same symbols). As shown in FIGS. 1 and 2, the magnetic disk assembly is
A magnetic disk sheet having an inner hole 1a in the center of the bottom surface and a bottomed cylindrical center core 1 having a flange portion 1b on the outer periphery of the upper surface and an inner hole 2a into which the cylindrical portion 1c of the center core 1 is fitted. 2 in combination, the lower surface of the flange portion 1b of the center core 1 and the inner hole 2 of the magnetic disk sheet 2
The upper surface of the peripheral portion of a is brought into contact. A plurality of through holes 1d for injecting an adhesive are formed in the flange portion 1b in the circumferential direction, and the through holes 1d are instantly bonded with a proper viscosity such as Aron Alpha (manufactured by Toa Chemical Industry Co., Ltd.). By injecting a small amount of the agent with a syringe or the like, the lower surface of the flange portion 1b and the inner hole 2 of the magnetic disk sheet 2
This instant adhesive permeates between the upper surface of the peripheral portion of a and is instantly fixed. The magnetic disk assembly thus assembled is rotatably housed in the cartridge. In this housed state, the rotating shaft on the magnetic disk drive side fits with the center core 1 to rotate the center core 1. When the center core 1 is rotated, the magnetic disk sheet 2 adhered to the center core 1 also rotates, whereby recording and reproduction can be performed on the magnetic disk sheet.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of each component of the magnetic disk assembly of the present invention, and FIG. 2 is a sectional view showing an embodiment of the magnetic disk assembly of the present invention. FIG. 3 is a perspective view showing each component of the conventional magnetic disk assembly. DESCRIPTION OF SYMBOLS 1 ... Center core 1a ... Inner hole 1b ... Flange part 1c ... Cylindrical part 1d ... Adhesive injecting small hole 2 ... Magnetic disk sheet 2a ... Inner hole

Claims (1)

(1) Rotating a magnetic disk assembly comprising a cylindrical center core with a bottom having a flange portion on the upper end surface and a magnetic disk sheet having an inner hole that fits into the cylindrical portion of the center core. In a magnetic disk cartridge that is freely accommodated, at least a plurality of adhesive injection through-holes are provided through the flange portion and the adhesive injection through-holes. A magnetic disk cartridge comprising an instant adhesive interposed between the lower surface of the flange portion and the upper surface of the inner peripheral edge of the magnetic disk sheet. (2) A magnetic disk assembly comprising a bottomed cylindrical center core having a flange portion on the upper end surface thereof and a magnetic disk sheet having an inner hole that fits into the cylindrical portion of the center core is rotatably accommodated. In the method for manufacturing a magnetic disk cartridge, a plurality of through holes for injecting an adhesive are circumferentially provided in the flange portion of the center core, and the lower surface of the flange portion of the center core and the upper surface of the magnetic disk sheet are brought into contact with each other. After that, an instant adhesive is injected between the flange portion and the magnetic disk sheet through the adhesive injection through-hole to bond the center core and the magnetic disk sheet. Manufacturing method of magnetic disk cartridge.