Realization of Synchronous Writing and Reading in Optical ROM and RAM

Abstract

Using quality engineering methodology, we successfully developed a concurrent ROM-RAM disk. The concurrent ROM-RAM disk is a new type of optical disk that enables synchronous writing and synchronous reading of ROM and RAM information. In order to obtain functionally sufficient read and write performance from concurrent ROM-RAM media, many control factors were extracted and optimized, related to pit shape, the substrate, the recording film, and the optical disk as a whole. To speed up the development process, parameter design was iterated using evaluations of functionality as a yardstick. Cross-talk noise from ROM pits during the reading of RAM data, which was the major error factor,was successfully suppressed in a short time.