| 摘要 |
PURPOSE:To detect the inclination of a disk, by arranging two reflection type photocouplers in lines oriented to the outer surface of the disk from its center at a specified interval, and taking out the difference in amount of returning light caused by the inclination of the disk. CONSTITUTION:A disk 1 as a recording medium is rotated at a specified number of rotation by a spindle motor 2. Reflection type photocouplers 4 and 5 are arranged along the direction of the radius of the disk 1. The axial line connecting the light emitting side and the light receiving side of the photocoupler is directed in the direction of the tangent line of the disk, which is perpendicular to said direction of the radius. When the disk 1 is inclined, the difference in distances from the disk 1, which are yielded in the first sensor 4 and the second sensor 5, is obtained as the difference in amounts of light by a comparator 7. Thus the inclination of the disk 1 is detected. |
