REPRODUCTION-ONLY OPTICAL DISC MEDIUM AND METHOD FOR MANUFACTURING THE SAME

摘要

At a stage in which disc substrates are manufactured in a large volume using a stamper, a zone in which pits / lands are not formed is previously formed as an additional information recording zone within a recording track formed as a series of data recorded by pits / lands. A metal alloy reflective film is coated on an information recording surface including such additional information recording zone (10). After that, a part of the region of the metal alloy reflective film in the additional information recording zone (10) is removed or reduced to form a pit vacant mark (6), thereby recording additional information. This additional information is recorded onto a part of the region of the recording track in the information recording region (in which information is recorded as a series of data formed by pits / lands and which includes a contents area and a control area such as the lead-in). The pit vacant mark (6) is formed as a mark from which a logical value similar to the pits can be obtained when being reproduced.