| 摘要 |
PURPOSE:To produce a uniform and highly accurate original board for information storage medium in a simple method with high yield and a low cost, by forming simultaneously the depressed/projected parts for both tracking guidance and signal information to said material board which can read the information by means of the laser light. CONSTITUTION:For instance, Te, Al, etc. are vapor deposited to a glass substrate 20 to form a signal information producing layer 23, and a positive photoresist is formed on the layer 23 to obtain a layer 25 which functions as a tracking guidance forming layer 24. Then the laser light 27 is exposed spirally or concentrically by an objective lens 26, and the exposed part 28 is removed after development and fixing. Then Te is vapor deposited to form a light reflecting layer 29 and then to form a depressed part 22 for tracking guidance. Then the substrate is turned, and at the same time the lens 26 is moved in response to the eccentricity of a depressed part 21 which is formed by means of the reflected light given from the layer 29. Then the focal point of the light 27 is traced on the part 22. At the same time, the volume of the light 27 is increased at a part corresponding to a signal information pit in order to remove both layers 29 and 23. Thus the part 21 is formed for the signal information pit. Thus a uniform and highly accurate original board is obtained for an information storage medium. |
