| 摘要 |
PURPOSE:To improve the tracing capability of a digital signal reproducing device, by providing a faulty section having no reflacting film or recording film on a digital signal recording and reproducing disk. CONSTITUTION:A reflecting film 8 is formed after sticking a masking base body 7 to the surface of a resin substrate 2. Then the masking base body 7 is removed and a section 9 where no reflecting film 8 is formed is obtained. The masking base body 7 can be prepared to have excellent dimensional accuracy in advance by laser beam machining or ultrasonic cutting method. The test disk manufactured by this method is equipped with a faulty section 9' having three different widths in the direction track and no reflecting film. When the width in the direction of track of a faulty section having no reflecting film is changed in the shape of a stairway, the tracing capability of s digital signal reproducing device can be tested successively and, therefore, it is useful for improving the tracing capability of the reproducing device. |
