Optical disc-like recoding medium and manufacturing method thereof

摘要

An optical disc-like recording medium has on one surface of its transparent substrate a ROM region where a plurality of pits are formed in correspondence with a predetermined information signal, and a RAM region where a plurality of guide grooves for tracking are formed and where an information signal is capable of being recorded. The optical disc-like recording medium transparent substrate is formed with a recording film made of an organic material and arranged to have a light-absorbing effect. Its refractive index is varied in response to illumination of laser light with a predetermined wavelength. Further formed on the recording film is a reflection film made of a metal which reflects light incident thereon. The physical depth of the pits is arranged to be equal to the physical depth of the guide grooves. The optical depths of the pit and guide groove have predetermined values which result from adjusting the thicknesses of the respective portions of the recording film present on the pit and guide groove. The width of the pits is preferable to be greater than the width of the guide grooves by a predetermined value. Optical disks interchangeable with compact disks are thus easily produced.