| 摘要 |
PROBLEM TO BE SOLVED: To obtain an inexpensive skew measuring device, for measuring the skew of a two-layer disk, having simple constitution with which a skew measuring time is shortened and moreover correct skew measuring is executed. SOLUTION: The device is provided with first and second parallel laser beam generating means LP1, LP2 projecting first and second parallel laser beams having different wavelengths each other on the desired same circumference of a semi-light-transmissive film and a light total reflecting film and first and second position sensors PS1, PS2 receiving respective reflecting laser beams from the desired position on the respective desired circumference. Position detecting signals of respective reflecting laser beams from respective desired positions of the semi-light-transmissive film and the light total reflecting film are obtained as the skew values of the semi-light-transmissive film and the light total reflecting film.
|
