| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical recording medium which can prevent copying of information, such as a program based on a a copyright, and data, and can control reproduction of copied information in order to protect the right of an information provider. <P>SOLUTION: The optical recording medium has one or more tracks of low-reflectivity regions where information is unreadable at least at one point in a radial direction at ≥1 mm in a track direction in the information recordable region of the disk-shaped optical recording medium having a recording layer capable of recording and reproducing information on a substrate having concentric or spiral grooves or in the ROM section of the disk-shaped optical recording medium which has a region (ROM section) previously recorded with the information by concentric or spiral rugged pits formed on the substrate and the information recordable region (RAM section and) is formed with the recording layers in the ROM section and the RAM section. The average reflectivity of the above low-reflectivity region is ≤1/2 of the average reflectivity of the other regions. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
