| 摘要 |
PURPOSE:To obtain an optical information recording medium having an organic coloring matter recording layer capable of highsensitivity recording and high-contrast reproduction, by providing on a substrate a recording layer comprising a mixed coloring matter of a main cyanine coloring matter with an auxiliary cyanine coloring matter. CONSTITUTION:A recording layer comprises a main cyanine coloring matter and an auxiliary cyanine coloring matter. The main cyanine coloring matter is so selected that an absorption peak wavelength thereof is approximately equal to the wavelength of a laser light used for recording and reproduction. For example, where a semiconductor laser light with a wavelength of 790 nm is used, the main cyanine coloring matter is selected to show an absorption peak in a wavelength range of 790+ or -20 nm. The auxiliary cyanine coloring matter is so selected that it has both an indole ring and a pyrrole ring, the number of methine groups between the indole ring and the pyrrole ring thereof is less than that of the main cyanine coloring matter, and a reflection peak wavelength region thereof agrees substantially with the absorption peak wavelength region of the main cyanine coloring matter. By this construction, the reflectance of the recording layer at the absorption peak wavelength is markedly enhanced, and highcontrast recording and reproduction characteristics can be obtained. |
