| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical disk and optical disk device which can surely read an address signal even in an area to which recording mark is overlapped with an address prepit. <P>SOLUTION: The optical disk has guide grooves 5G formed along a circumferencial direction forming a cycle of a pitch p in a radial direction of disk-like substrate, and a prepit formed between the guide grooves along the guide groove, and is constituted so that the address signals assigned to each position of signal face are represented by arrangement of the prepit in accordance with the prescribed rule. The prepit is constituted of a pair of prepits 5A and 5B as a unit formed in both sides of a guide groove respectively. Positions of a pair of prepits are shifted mutually along with the circumferencial direction, and the distance between each of end edges inside between both prepits within end edges of a pair of prepits in circumferencial direction is equal or less than the pitches p of the guide groove. The optical disk device detects return light from optical disks of the above configuration, computes a phase difference signal and uses it for detection of the address signal. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
