| 摘要 |
PURPOSE:To change relative moving speed between a recording medium and an information writing/reading part, and simultaneously, to prevent the jumping phenomenon of an information recording position by changing the relative moving speed by changing some prescribed value into another different prescribed value while keeping a definite correlation. CONSTITUTION:A relative moving speed changing means to change the relative moving speed between the information writing/reading part and the recording medium is constituted of a head carrying shaft 56 the pitches of whose helically cut grooves 56a are different for a front and a back directions. Then, the relative moving speed is changed by this relative moving speed changing means by changing some prescribed value '1' into another different prescribed value '2'. Thus, even if the relative moving speed is changed, the definite correlation is kept, and the jumping phenomenon of the information recording position is never caused. |
