| 摘要 |
PURPOSE:To contrive a simpler medium construction and a higher recording density by a construction wherein at least two optical recording layers provided in a laminate form are separated by a heat insulating layer, and the recording layers comprise a high molecular weight liquid crystal material having a reversibly variable light transmittance or reflectance. CONSTITUTION:Optical recording layers 1a-1c comprising a lightabsorptive coloring matter and heat-insulatinq layers 2a, 2b comprising a material having a low thermal conductivity are alternately provided on a base 3. At the time of recording, the recording layers 1a-1c are heated by irradiation with rays corresponding to the absorption wavelengths of the coloring matters, followed by rapid cooling or slow cooling, whereby the light transmittance or reflectance of each of the layers 1a-1c can be reversibly varied. It is preferable to provide the heat-insulating layers by use of a material having a low thermal conductivity and an excellent thin film forming property, the material being, for example, a heat-or UVcurable resin, and being selected according to the extent of a temperature rise at the time of recording or erasing. It is also possible to use, for the heat-insulating layers, a high molecular weight liquid crystal which has a phase transition temperature higher than those of high molecular weight liquid crystals used for the recording layers and which is not changed even under the temperature rise at the time of recording or erasing. |
