| 摘要 |
PURPOSE:To obtain a position on a disk with detection of just signals in a cycle by setting the relation between lengths of the 1st and 2nd signal parts within a cycle of a signal in response to the recording position on the disk. CONSTITUTION:An effective recording area of an optical disk is divided into 196 parts between the innermost circumference and the outermost circumference. Then ¦lambda2-lambda'2¦=0mum and ¦lambda2-lambda'2¦=196mum are set opposite to the most inner and outer circumferences respectively. At the same time, the prescribed value of ¦lambda2-lambda'2¦ is set opposite to a middle area to obtain the value of ¦lambda2-lambda'2¦. Thus the corresponding area on the disk is obtained. For instance, the value of ¦lambda2- lambda'2¦ is set proportional to the recording time, the number of trakcs, etc. obtained at the innermost circumference in order to set said 196 steps opposite to each area on the disk. Furthermore it is possible to obtain such a relation that can be shown by an equation of higher degree than the second degree between the value of ¦lambda2-lambda'2¦ and the position on the disk. |
