| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical information recording medium having a preformat constitution in which cross talk signals from an adjacent track is reduced, an offset voltage generated in push-pull signals is eliminated and thereby the position of a preformat region is accurately detected when preformat information constituted of prepits is reproduced. SOLUTION: An optical information recording medium has grooves 3 for a tracking and prepit 4 strings. When P is the interval between the grooves 3, the prepit 4 string are formed so that the center line of the each column is deviated to either one of the left or the right side from the line by an approximate distance of P/4. No grooves 3 are formed in a preformat region constituted of the prepit 4 columns. Moreover, a preformat mark, that is made up with mirror mark portions in which the grooves 3 and prepits 4 do not exist, is provided in the preformat region that is constituted of prepit 4 columns. |
