This application claims the benefit of Korean Application No. 98-42488, filed Oct. 12, 1998, in the Korean Patent Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an optical recording medium for an optical near-field recording in which a data erasure and re-recording is possible, and more particularly, to an optical disc of a textured structure preventing a stiction by forming the structure of a number of bumps and craters, with a lubricant film, and a method of manufacturing the optical disc.
2. Description of the Related Art
An optical near-field recording drive combines a hard disc drive technology with an optical recording technology, to thereby enable data to be recorded, erased and reproduced with respect to an optical disc. Here, a near-field means a field where the distance between an optical flying head and a surface of an optical disc is close as much as possible to 20-300 nm. A near-field recording means that data can be recorded and reproduced with respect to the optical disc under the condition that the optical flying head and the optical disc are close as much as possible the above distance. The optical flying head comprises a slider containing a magnetic coil, an objective lens mounted on the slider and a small lens.
FIG. 1 is a view showing an optical disc 14 for an optical near-field recording and an optical flying head 10 comprising a slider 13 containing a magnetic coil, an objective lens 11 and a small lens 12. As shown in FIG. 1, the optical disc 14 comprises a substrate, a reflective film, an insulation film, a recording film and a protective film, in that order from the lowest layer (furthest from the optical flying head 10) to the topmost layer (nearest the optical flying head 10). Here, the material of the substrate is plastic, that of the reflective film is aluminum (Al), that of the insulation film is SiNx, that of the recording film is TbFeCo, and that of the protective film is SiNx. A number of V-shaped grooves are formed on the substrate, and the V-shaped grooves are formed by injection molding. That is, if a fused plastic substrate is injection molded by a stamper for V-shaped grooves, V-shaped grooves are formed on the substrate.
FIG. 2 shows a substrate on which V-shaped grooves are formed. In FIG. 2, the width of the groove is 0.3xcx9c0.4 xcexcm, the depth of the groove is 500xcx9c700 xc3x85 and the width of the land is 0.3xcx9c0.4 xcexcm and the track pitch is 0.6xcx9c0.8 xcexcm.
FIG. 3 shows that the slider 13 of the optical flying head 10 rests on the surface of the optical disc 14. In FIG. 3, a multilayer, including the reflective film, insulation film recording film and protective film, formed on the substrate is not shown and V-shaped grooves are formed on the substrate.
When the above-described optical near-field recording drive (hereinafter called a drive) does not perform recording and reproduction operations of data with respect to the optical disc 14, the slider 13 is positioned at a stop state on the surface (which is not shown but is called a parking zone) of the inner diameter side of the optical disc 14. When the drive performs recording and reproduction operations with respect to the optical disc 14, the optical disc 14 rotates at several thousand RPM (rotations per minute), and the slider 13 is floated from the surface of the optical disc; 14 to be spaced by a distance of 20xcx9c300 nm at the parking zone by a floating force of air swiftly passing between the grooves formed on the bottom of the slider and the surface of the optical disc, and then moves toward the outer diameter side of the optical disc 14.
However, when the optical disc 14 starts to rotate, although the slider 13 should be floated from the parking zone of the optical disc 14, the slider 13 is not floated because of a stiction force acting between the bottom surface of the slider 13 and the surface of the optical disc 14. Thus, a stiction such that the slider 13 does not move off from the parking zone of the optical disc 14 frequently occurs.
As a result, wear, friction and crash occur between the slider 13 and the optical disc 14 due to the above stiction, by which data recording on the optical disc 14 is not only lost but also the optical flying head 10 is damaged.
To solve the above problems, it is an object of the present invention to provide an optical disc in which a textured structure having a number of bumps and craters are formed on a substrate of the optical disc so that a slider of an optical flying head contacts the bumps of the optical disc, thereby reducing a mutual contact area between the optical disc and the slider, and also a lubricant film is formed on a protective film which is formed on the textured structure of the substrate so that a stiction force is reduced, thereby preventing a stiction between the slider and the optical disc, and a method of manufacturing the optical disc.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
To accomplish the above and other objects and advantages of the present invention, there is provided an optical disc for an optical near-field recording using an optical flying head, the optical disc including the substrate having a textured structure with a plurality of craters and bumps; and the multilayer formed on the substrate, on the topmost of which a lubricant film is formed, wherein the optical flying head contacts the bumps.
To further accomplish the above and other objects and advantages of the present invention, there is provided a method of manufacturing an optical disc for an optical rear-field recording using an optical flying head, comprising forming a stamper for a textured structure having a number of craters and bumps; forming a substrate of the textured structure using the stamper; and forming a multilayer on the substrate on which the textured structure is formed, the multilayer having a lubricant film formed on a topmost of the multilayer, wherein the optical flying head is to contact the bumps.