| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to execute recording and reproducing with a light of wavelength selected from the range from 770 to 830nm and to execute reproducing even with a light of wavelength selected from the range from 630 to 690nm. SOLUTION: This recording medium is constituted by laminating a recording layer contg. at least a dye and a reflection layer on a transparent substrate. The reflectivity of the unrecorded part to a light of wavelength λ1 selected from the range from 770 to 830nm of the recording layer, is defined as R1 , the reflectivity of the recorded part, as R2 , the reflectivity of the unrecorded part to light λ/2 of wavelength selected from the range from 630 to 690nm as R3 and the reflectivity of the recorded part, as R4 , are specified to R1 >=65%, R2 /R1 <=0.40, R3 >=15%, R4 /R3 <=0.45. |
