| 摘要 |
PURPOSE:To perform a recording operation and a verify operation at the same time by constituting the device to be capable of detecting a differential push-pull signal and a verify signal at the same time. CONSTITUTION:Light emitted from a laser diode 1 is split into 0th-order light and + or -1st-order light by a grating 3. These split laser beams are spot-focused on an information recording medium 6 respectively via a beam shaping prism 4 by an objective lens 5. This prism 4 is disposed in an inclined position to the grating 3. Consequently, the light beam spot converged on the medium 6 is formed in an asymmetrical position to a 0th-order beam spot in the middle. By this method, a tracking control is performed by detecting the differential push-pull signal in using a 1st sub-beam and a main beam, and also information is recorded by the main beam, and moreover, immediately after recording, the information can be reproduced by using a 2nd sub-beam. |
