JP2001084727A - Disk cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk cartridge which can eliminate generation of burrs in a cartridge case and consequently prevent deterioration of disk-recording and reproduction characteristics. SOLUTION: In the disk cartridge, resin is injected into a cavity 3, in a state with leading end faces of push pins 4 retreated slightly from the surface of a fixed mold, thereby forming projecting parts 5a to the inner face of a cartridge case 5 at a position opposite to the push pins of an area opposite to a recording disk 11. The push pins will not sink in the cartridge case 5, and as a result generation of burrs can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk cartridge having a cartridge case made of a synthetic resin molded body and a recording disk rotatably housed in the cartridge case, and more particularly to a cartridge case thereof. .

[0002]

2. Description of the Related Art A cartridge case of a disk cartridge usually comprises an upper case and a lower case, which are formed of a synthetic resin molded body. FIG. 4 is a diagram showing an initial state of a push-out pin at the time of resin molding of a conventional cartridge case, and FIG. 5 is a diagram showing a contact state between a tip end of the push-out pin after resin molding and the cartridge case.

As shown in FIG. 4, a fixed mold 1 and a movable mold 2 are opposed to each other at a predetermined interval, and a molten synthetic resin is injected into a cavity 3, which is a gap therebetween. At this time, the tip of the push pin 4 on the fixed mold 1 side is flush with the surface of the fixed mold 1. In this figure, resin is injected into the cavity 3 from the left side, and after molding, as shown in FIG. 5, the movable mold 2 is opened to extrude a plurality of cases 5 (upper case or lower case) as a molded product. Extruded by the pin 4 and separated from the fixed mold 1.

[0004]

In the prior art, when the movable mold 2 is opened and the case 5 is pushed out by the push-out pin 4, the resin is still soft. Therefore, as shown in FIG. Slightly sinks into the cartridge case 5.

On the other hand, since the cartridge case 5 has through holes, recesses, ribs and the like and is complicated in shape, even if the case 5 is pushed out by a plurality of pushing pins 4, it is difficult to push it out evenly. It may be pushed out at an angle to the surface of the fixed mold 1.

In this case, as described above, since the tip of the push pin 4 is recessed into the inner surface of the case 5, when the case 5 separates from the edge of the tip of the push pin 4, the burr is partially formed on the inner surface of the case 5. May occur. When a disk cartridge is assembled using this case 5, the pointed end of the burr comes into contact with the surface of a rotating disk (optical disk, magnetic disk), causing scratches, which adversely affects the recording and reproducing characteristics of the disk. There was a problem. In particular, in the case of an optical disk, when a scratch is generated on the transparent substrate by the tip of the burr, the laser beam is irregularly reflected by the scratch and causes optical noise.

[0007] The present invention solves such disadvantages of the prior art and eliminates the occurrence of burrs on the inner surface of the cartridge case.
It is another object of the present invention to provide a disk cartridge capable of preventing deterioration of recording and reproducing characteristics of a disk.

[0008]

In order to achieve the above object, the present invention provides a disk having a cartridge case made of a synthetic resin molded article and a recording disk rotatably housed in the cartridge case. The cartridge is characterized in that a low convex portion is formed at a position where the pushing pin pushes the inner surface of the cartridge case and a region facing the recording disk.

In the present invention, the resin is injected into the cavity while the tip end surface of the push pin is slightly retracted from the surface of the fixed mold, thereby pushing out the area inside the cartridge case and facing the recording disk. Since the projections having a low diameter and substantially the same diameter as the push-out pins are formed at the pin-facing positions, the push-out pins do not sink into the inner surface of the cartridge case. Eliminates scratches on the disk surface.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing an initial state of an extruding pin at the time of resin molding of the cartridge case of the present invention, FIG. 2 is a view showing an abutting state between a tip of the extruding pin after resin molding of the cartridge case and a resin molded product, and FIG. FIG. 3 is an exploded perspective view of the disk cartridge of the present invention.

The resin molding process of the cartridge case will be described with reference to FIGS. As shown in FIG. 1, at the time of resin molding, the tip end surface of the extrusion pin 4 is slightly retracted from the surface of the fixed mold 1, and is located at the position of the tip end of the extrusion pin 4 when viewed from the surface of the fixed mold 1. Has a recess 6 formed therein.

When the molten resin is poured into the cavity 3 in this state, as shown in FIG.
Is formed at a position facing the recording disk at a position facing the push pin, the protrusion 5a having the same area (approximately the same diameter as the push pin 4) as the tip surface of the push pin 4, for example, about 0.1 mm. Is done.

When the movable mold 2 is opened and the push-out pin 4 is used to push out the cartridge case 5 (the convex portion 5a), the tip of the push-out pin 4 is pushed into the cartridge case 5 because the resin is still soft. The push pin 4 does not sink into the inner surface of the cartridge case 5 to the extent that the outer periphery of the protrusion 5a is crushed as shown by the broken line.

Therefore, even if the cartridge case 5 is pushed out while being inclined, no partial burr is generated. As a result,
Good recording and reproducing characteristics can be maintained without damaging the substrate surface of the optical disk.

The disk cartridge shown in FIG. 3 contains an optical disk 11 between an upper case 5-1 and a lower case 5-2 which are resin molded products. A shutter 12 is provided so as to straddle the upper case 5-1 and the lower case 5-2. The shutter 12 is moved by a slider 13 and is elastically urged by a return spring 14 toward the home position, that is, the closed position. .

In the figure, a suitable number of the above-mentioned projections 5a are provided on the inner surface of the lower case 5-2, at positions corresponding to the push pins in a region facing the recording disk 11. Although this projection 5a is not shown in the drawing, the upper case 5-
1 is also provided on the inner surface. Although the protrusion 5a is slightly crushed by the push pin 4, it does not sink into the inner surface of the cartridge case 5, so that no sharp burrs are generated.

In the above embodiment, an optical disk is used as a recording disk. However, the present invention is not limited to this, and can be applied to other disk cartridges using a magnetic disk, a hard disk, or the like.

[0018]

According to the present invention, the resin is injected into the cavity while the tip end surface of the push pin is slightly retracted from the surface of the fixed die, whereby the inner surface of the cartridge case faces the recording disk. Since the protrusion is formed at the position of the region facing the push pin, the push pin does not sink into the cartridge case, and as a result, the occurrence of burrs is suppressed. Therefore, the surface of the recording disk is not damaged, so that it is possible to provide a disk cartridge capable of always obtaining good recording and reproducing characteristics.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an initial state of an extruding pin during resin molding of a cartridge case according to an embodiment of the present invention.

FIG. 2 is a diagram showing a contact state between a tip end of an extruding pin after resin molding of the cartridge case and the cartridge case.

FIG. 3 is an exploded perspective view of a disk cartridge using the cartridge case.

FIG. 4 is a diagram showing an initial state of a push pin at the time of resin molding of a conventional cartridge case.

FIG. 5 is a view showing a contact state between a tip end of an extruding pin after resin molding of the cartridge case and the cartridge case.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed mold 2 Movable mold 3 Cavity 4 Extrusion pin 5 Cartridge case 5-1 Upper case 5-2 Lower case 5a Convex part 6 Recess 11 Recording disk 12 Shutter 13 Slider 14 Return spring

Claims (2)

[Claims] 1. A disk cartridge comprising a cartridge case made of a synthetic resin molded body and a recording disk rotatably housed in the cartridge case, an area on the inner surface of the cartridge case and facing the recording disk. A convex portion is formed at a position pushed by the pushing pin. 2. The disk cartridge according to claim 1, wherein said recording disk is an optical disk.