Abstract:
A magneto-optic record medium of narrow tracking pitch for producing a stable tracking servo signal with a reduction in the influence of crosstalk and crosslight which comprises recording/reproducing tracks and sample servo wobble pits each of which is provided between two adjacent tracks and shared by the two adjacent tracks.
Abstract:
An optical disc tracking control device capable of performing stable tracking. The device includes a signal detection section for detecting a tracking error signal and a wobble signal from a light spot, a velocity detection section for detecting a relative moving velocity of the light spot and the track, a polarity judgment section for judging that the light spot position is between grooves when the wobble signal amplitude value is equal to or below a predetermined value in the vicinity of the zero cross point of the tracking error signal, a moving direction detection section for detecting the moving direction of the light spot with respect to the track from the increase/decrease direction of the tracking error signal when the moving velocity is within a predetermined range and polarity is judged to be between grooves, and a control section for reducing the moving velocity and performing tracking according to the moving velocity and the moving direction.
Abstract:
A magneto-optical recording medium including a recording film (10) having a reproduction layer (13), an intermediate layer (14), and a recording layer (15) on an optical disc substrate. The recording film (10) is a magnetic film magnetically connected and having magnetic anisotropy in the direction vertical to the film surface. A recording magnetic domain formed on the recording layer (15) is transferred onto the reproduction layer (13). Recording information is reproduced by movement of the magnetic domain wall. The recording layer (15) has a columnar structure orientated substantially in the vertical direction. Thus, it becomes possible to perform a high-speed reproduction of a signal below the diffraction limit of the light spot for recording/reproducing the information and significantly improve the recording density and the transfer speed. Even when recorded at a high density, it is possible to form a stable recording magnetic domain.
Abstract:
A method of forming a film on an optical disk comprising (a) the step of carrying an optical disk substrate into a vacuum chamber, (b) the step of disposing the optical disk substrate to face a target provided in the vacuum chamber and including a film−forming material, and (c) the step of forming a specified film on a fixed or rotating−on−axis or revolving optical disk substrate by a sputtering method using the target, wherein a relation a > 2D is satisfied where a is a target radius and D the radius of the optical disk substrate, thereby forming a higher−density−compatible, homogeneous film on an optical disk.