OPTICAL DISK WITH GUIDE GROOVE

摘要

PURPOSE:To reduce the number of reading errors of an address signal by making the land part of an optical disk with a guide groove into the preformat part with the large width of a radius direction and a recording part with a small width of the radius direction. CONSTITUTION:The land part 3 is composed of a preformat part F with the large width of a radius direction and a recording part R with the small width of the radius direction. In the preformat part F, the width of the land part 3 of the radius direction is widely formed so that the laser spot for reading cannot be applied to the guide groove as the guide groove in which the depth of a groove 2 is shallow and the width is narrow, and in the recording part R, the end part of the recording part is formed by the angle close to the right angle as the approximately U-shaped guide groove to touch the bottom and thus, the modulation factor of the reflecting light is enlarged. Thus, the number of the reading errors of an address signal is reduced and the control signal such as the tracking error signal and track cross signal with the level of the allowable value or above can be further obtained.