| 摘要 |
<P>PROBLEM TO BE SOLVED: To increase reproduction speed by reducing a burden of adjusting optical path difference accompanying face deflection on an optical disk in acquiring an amplified signal by interference between a reference beam and a beam reflected from a recording medium. <P>SOLUTION: A reference beam is concentrated to irradiate a predetermined reflecting layer in a recording medium, so that the reference beam reflected from the reflecting layer interferes with a signal beam, where the numerical aperture of the reference beam is set smaller than that of the signal beam. <P>COPYRIGHT: (C)2012,JPO&INPIT |
