| 摘要 |
PURPOSE:To prevent deterioration of reproduced signal quality by forming a recording medium allowing glass transition point of the recording medium, its temperature raised by photoirradiation at the time of recording, and its temperature raised by photoirradiation at the time of reproduction to satisfy specified conditions. CONSTITUTION:The recording medium 2 satisfies Tr<Tg<Tw, where Tg is its glass transition point, Tw is its temperature raised by photoirradiation at the time of recording, and Tr is its temperature raised by photoirradiation at the time of reproduction. The temperature Tr is lower than that Tr and mobility in the polymer chain of the polymer solid around the organic compound is suppressed and the photochromic reaction of the organic compound is restricted, thus permitting the difference of light absorbances between the recorded area and the nonrecorded area to be kept constant even at the time of repeating reproduction of the optical memory element, and accordingly, deterioration of quality of the reproduced signal to be avoided. |
