| 摘要 |
PURPOSE: An optical reproduction apparatus is provided to reproduce information from an optical recording medium having grooves and lands alternately provided in a radial direction, information recording areas being formed in both of the grooves and the lands, and at least one prepit region where a groove is not formed. CONSTITUTION: Grooves(84) each having a width of 0.6 nm and a depth of 50 nm and lands(85) each having a width of 0.6 nm are arranged alternately in the radial direction of the medium and recorded marks(81) are formed on the two kinds of areas. In other words, each of the groove and land serves as a recording area. In a prepit area(83), any groove is not formed but pits(82) are disposed on an extension of the boundary between a land and a groove. Each of the pits has a width of 0.35 nm and a depth of 50 nm. The prepit area is divided into a first prepit area(831) and a second prepit area(832). In the first prepit region, pits are disposed on the upper side, as viewed in the drawing, of the center line of the land and in the second prepit area, pits are disposed on the lower side, as viewed in the drawing, of the center line of the land. Accordingly, when an optical spot(21) scans. Therefore, address data recorded in the form of the prepits can duly be reproduced without crosstalk.
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