OPTICAL INFORMATION RECORDING MEDIUM

摘要

PURPOSE:To widen the allowance width of the intensity of light to eras marks and to increase an erasing rate by using materials which are heated up to approximately the same temp. by light for erasing the marks to constitute the mark parts formed by irradiation of light on a recording layer and the ambient parts thereof. CONSTITUTION:Recording tracks 8 are irradiated with light to change unrecording parts 10 to the state of the marks 9 as information recording. The recording tracks 8 formed with the marks 9 are irradiated with light and are changed to the state of the unrecording parts 10. The specific rising temp. and cooling rate intrinsic to the material having some allowance width are necessary for the recording layer 3 to attain the state of the unrecording parts 10. The range satisfying the conditions under which both the states attain the state of the unrecording part 10 is narrowed if the rising temps. vary in the state of the marks 9 and the state of the unrecording parts 10. The materials which are heated up to approximately the same temp. by irradiation of erasing light are, therefore, used for the marks 9 and unrecording parts 10 of the recording layer 3, by which the erasing rate of the information recording medium is increased and the allowance range of the intensity of the erasing light is widened.