Patent ID: 6721113
Filing Date: 2004-04-13
Classification: G11B

Abstract:
A method of recognizing a master disk positioning mark by having a center of a magnetic medium of a magnetic recording disk matching and closely touching a center of a soft magnetic pattern concentrically set around a center of a master disk in order to magnetically transfer servo information written in the soft magnetic patterns to a magnetic recording layer on a surface of the magnetic recording disk by externally applying a magnetic field to the master disk, which is a non-magnetic substrate, and on which the linear and cyclical soft magnetic patterns of independent soft magnetic materials are embedded on a surface or a part of the surface of the magnetic disk, touching or close to the magnetic recording disk, comprising the steps of:setting a positioning mark formed for recognition of a position on the master disk, irradiating the positioning mark by a beam of a light source, image-recognizing a reflected light from around the positioning mark using an optical reception sensor, and positioning the master disk based on the recognition of the image; and limiting a wavelength of a light used to recognize the positioning mark to a specific range such that the intensity of the reflected light from a diamond-like carbon (DLC) film of an upper surface of the master disk can be minimized, and a ratio of the intensity of the reflected light from a surface of a lower substrate of the master disk to the intensity of the reflected light from the positioning mark can be maximized.