| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem of a conventional hologram recording medium, in which erroneous detection is caused when part of position sensing incident light penetrates a lower substrate and becomes reflection disturbance light from an upper substrate and accurate access to recorded information is prevented by the erroneous position sensing and reproduction cannot be carried out in some cases. <P>SOLUTION: A minute rugged structure diffusely reflecting light is arranged in a part of an upper substrate for a hologram recording medium, and part of position sensing light incident from a lower substrate and transmitted through the substrate is reflected diffusely. Consequently, erroneous detection of a position sensing signal is prevented and accurate position sensing can be carried out. <P>COPYRIGHT: (C)2009,JPO&INPIT |
