Abstract:
A method of preparing a master disc being arranged with a structure, comprising the step of configuring said structure so that said structure measurably changes during preparation of at least one replica from said master disc. A master disc being arranged with a structure, wherein said structure is configured to measurably change during preparation of a replica from said master disc and a method for identifying a father disc used to prepare a replica, wherein said father disc is prepared from a master disc being arranged with a structure configured to measurably change during preparation of said father disc from said master disc, said method comprising the steps of measuring a corresponding structure on said replica and analyzing the measurement to identify said father disc.
Abstract:
Method (260) and apparatus (110, 220) for compensating for differences in translation path geometries of transducers (1 12) used to access a data storage medium (100). A compensation profile is generated in relation to radial error between a first translation path geometry (134, 152) of a first transducer and a different, second translation path geometry (144, 154) of a second transducer. A control circuit (116, 170, 200) directs the first transducer to write data to a rotatable data storage medium in relation to the compensation profile to emulate the second translation path geometry. In some embodiments, the control circuit comprises a data signal clock generator ( 172), a motor rotation clock generator ( 174), and a transducer radial translation clock generator (176). A nearest pulse detector (202) identifies a closest clock signal pulse to a once-per-revolution (OPR) rotational reference (182), and the control circuit adjusts a frequency of the associated clock signal coincident with said closest pulse.
Abstract:
The present invention relates to a laser beam recorder for mastering an optical medium, including a laser for producing a laser beam, means for focusing the laser beam on a surface of the optical medium, and an acousto-optic modulator. According to the present invention, an amplitude and a frequency of an electric signal applied to the acousto-optic modulator is controlled in a way that both, the intensity and a deflection angle of the focused laser beam are controlled by the single acousto-optic modulator.
Abstract:
Au moins une zone en creux est formée dans un empilement (3) d'au moins une couche supérieure (2) et une couche inférieure (4). La couche supérieure (2) est structurée pour former au moins une première région en creux traversant ladite couche supérieure (2). La première région en creux est prolongée par une seconde région en creux formée dans la couche inférieure (4), par gravure à travers un masque de gravure formé sur la couche supérieure (2) structurée. Le masque de gravure est formé par une couche en résine (8), positivement photosensible à un rayonnement optique (9) d'une longueur d'onde prédéterminée, exposée audit rayonnement optique (9), à travers l'empilement (3) et révélée. Les couches inférieure (4) et supérieure (2) de l'empilement (3) sont respectivement transparente et opaque à ladite longueur d'onde prédéterminée, de sorte que la couche supérieure (2) structurée sert de masque d'insolation pour la couche en résine photosensible (8).