OPTICAL INFORMATION RECORDING METHOD AND ITS OPTICAL INFORMATION RECORDING MEDIUM

摘要

PURPOSE:To accurately write or read information with use of a comparatively inexpensive device by having a preliminary process where the projecting bits are formed previously at periodical positions and then a recording process where the prescribed one of these bits is erased or deteriorated by heat to provide the information volume to the positions of remaining bits of the project ed bits. CONSTITUTION:The projecting bits 20 are formed previously at the periodical positions in a preliminary process. Then the prescribed one of those bits 20 is erased or deteriorated by heat in a recording process. While the information value is provided to the positions of remaining bits 20. Thus the remaining bits 20 have prescribed sizes and shapes decided by the conditions of said prelimi nary process regardless of the conditions of said recording process using heat. Here no highly accurate control is required to the heat value needed for erasion or deterioration of the bit 20. Thus it is possible to secure a stable size and shape of an information bit despite deterioration of accuracy of a writing device. Then an accurate reading action is ensured.