| 摘要 |
PURPOSE:To distinguish easily a signal information pit from another information pit in which other information is recorded, by forming the signal information pit with a higher reflectance than that given from a tracking guide. CONSTITUTION:A metallic thin film of Te, Se, etc. is used to a record layer 5 of a substrate made of a synthetic resin, etc. A tracking guide 6 and a signal information pit 7 are formed spirally or concentrically on the layer 5. The pit 7 has a higher reflectance than the light given from the guide 6 when the information is read by an optical head. The depth (a) of the guide 6 is set at lambda/8; while the depth (b) of the pit 7 is set at lambda/16, respectively. |
