| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a phase change optical disk of CAV type in which a deterioration of a reproduced signal is small and the erasing residue of an amorphousness is small even on the outer periphery of the phase change optical disk in multiple rewriting without generating a recrystallization even when information is recorded on the inner periphery of the phase change optical disk. <P>SOLUTION: The phase change optical disk of CAV type includes a substrate, and a first protective layer, a first heat stabilized layer, a recording layer, a second heat stabilized layer, a second protective layer, an absorptivity control layer and a thermal diffusion layer sequentially provided from a laser beam input side. In this phase change optical disk, the composition ratio of the recording layer material is a range surrounded by composition points B3 (Bi<SB>3</SB>, Ge<SB>46</SB>, Te<SB>51</SB>), C3 (Bi<SB>4</SB>, Ge<SB>46</SB>, Te<SB>50</SB>), D3 (Bi<SB>5</SB>, Ge<SB>46</SB>, Te<SB>49</SB>), D5 (Bi<SB>10</SB>, Ge<SB>42</SB>, Te<SB>48</SB>), C5 (Bi<SB>10</SB>, Ge<SB>41</SB>, Te<SB>49</SB>) and B5 (Bi<SB>7</SB>, Ge<SB>41</SB>, Te<SB>52</SB>) on a triangular composition diagram. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
