| 摘要 |
PURPOSE:To provide an optical recording medium having favorable weatherability and signal quality together with high sensitivity and being stable, by providing a crystalline recording layer comprising tellurium, tellurium nitride and selenium as main constituents. CONSTITUTION:A recording layer 21 is provided on a base 1, and recording laser light is focused on the recording layer 21 through the base 1, whereby a pit 22 is formed. A guide groove or grooves are provided for ensuring accurate recording through formation of such pits 22 in a concentric or spiral pattern at regular intervals. When light is incident on the groove, the width of which is about the diameter of a laser beam, the light is diffracted, so that the spatial distribution of the intensity of the diffracted light is changed as the center of the beam is deviated from the groove. A servo system is arranged to detect the change and cause the laser beam to be incident on the center of the groove. With selenium incorporated in the recording layer, the melting point of the whole system of the layer is lowered, and with the layer made to be crystalline, formation of a small hole in the beginning stage of formation of the pit takes place at a relatively low temperature, resulting in a higher sensitivity. Weatherability is enhanced through interactions of tellurium, tellurium nitride and selenium, and since the recording layer is crystalline, a favorable signal quality can be stably obtained. |
