| 摘要 |
PURPOSE:To eliminate the distortion and steps of an address signal and a reproduced signal and to extend the amplitudes and to stably follow up tracks by forming rectangular grooves in concentric circles or the spiral of a pitch P and providing two kinds of groove width. CONSTITUTION:Grooves whose section is rectangular are formed in concentric circles or the spiral of the pitch P and two kinds of groove width (0.5-alpha)P and (0.5+beta)P (0.10<alpha<0.30 and 0.15<beta<0.35) are provided, thereby, the quantity of reflected light converged by a converging lens is increased or reduced to give the reproduced signal or the address signal. Thus, the distortion of the address signal or the reproduced signal and steps of the signal waveform accompanied with variable length of the signal are eliminated, and the signal amplitude is long even in case of a high-density signal, and stable track following-up is possible because there are no breaks of a guide groove, and signals are recorded and reproduced with a high density. |
