| 摘要 |
A disk storage device includes a light source emitting a light, an objective lens for focusing the light on a surface of a recording film of a disk via a protection film protecting the recording film, and a motor for rotating the disk. A detector receives the light reflected by the surface of the recording film and reproduces information recorded on the recording film. The detector is located at a position where the following condition is satisfied: D>/=FxAx alpha where D is the distance between the objective lens and the detector, F is the focal length of the objective lens, A is equal to F/t2 where t2 is the thickness of the protection film, and alpha is a constant equal to or greater than 1.0.
|
