OPTICAL RECORDING MEDIUM DRIVE DEVICE AND RECORDING METHOD

摘要

An optical recording medium drive device includes a combining prism for combining a first laser beam for recording emitted from a first light source and a second laser beam for recording emitted from the first light source, an objective for focusing the first and second laser beams from the combining prism onto an optical recording medium, a first light detecting means for detecting reflected light of the first laser beam from a recording layer, a second light detecting means for detecting reflected light of the second laser beam from a guide layer, a magnification changing element disposed along the optical path of the second laser beam between the second light source and the combining prism and adapted for diverging or converging the second laser beam incident on the objective, a first focusing error signal generating means for generating a first focusing error signal indicating the error between the focused spot position of the first laser beam and the recording layer according to the output signal from the first light detecting means, a second focusing error signal generating means for generating a second focusing error signal indicating the error between the focused spot position of the second laser beam and the guide layer according to the output signal from the second light detecting means, a first focusing control means for controlling the objective in the optical-axis direction according to the first focusing error signal, a second focusing control means for controlling the degree of divergence or convergence of the second laser beam by the magnification changing element according to the second focusing error signal.