| 摘要 |
PURPOSE: To provide a good erasing characteristic in a phase changing medium without using plural heads for erasing information. CONSTITUTION: A 2-beam laser 52 for emitting two beams is arranged in a laser pen 70, and the emitted beams are reflected by a dichroic mirror 59, and are converged via an objective lens 62 into two erasing beams 72, 73 on an optical disk 64. Emitted light of another laser 51 is traveled via a compound prism 55 to go straight through the dichroic mirror 59 and is converged via the objective lens 62 onto the optical disk 64 as a recording and reproducing beam 65. As a result, recording is performed on the optical disk 64 consisting of the phase changing medium after erasing operation in twice, so that erasing of information is improved. In addition, by reducing a bit error rate, recording density is also improved. |
