| 摘要 |
PURPOSE:To enable steep fall of a reproduction signal pulse and consequent unification of a min. pit length and inter-pit space to 1:1 by stopping the irradiation of a laser beam only for the specified short time right after pit formation. CONSTITUTION:The recording layer with a discoid photomagnetic recording medium is a TbFe vertical magnetized film (0.35 deg.Kerr rotating angle) and irradiation of a laser beam is known to be most adequate for recording to the medium. The irradiation of the laser beam is required in order to obtain signals for focusing and tracking. A pickup housing an optical system is designed to make tracking at a uniform-speed with respect to the medium. The irradiation intensity of the laser beam is now changed in order to record information 1010101-. Pulse width in the stage of recording tw=4X10<-7>sec, pulse interval in the stage of non-recording tI=4X10<-7>sec and irradiation stop time tR=1.33X10<-7>sec. Since the time tR is short, no influences are observed at all in focusing and tracking. |
