| 摘要 |
PROBLEM TO BE SOLVED: To achieve high resolution while maintaining the compatibility and portability of an optical disk by allowing a disk case to be at least partially transparent for the used wavelength of recording/reproducing light and allowing the disk case and the optical disk to approach the used wavelength or less of the recording/reproducing light. SOLUTION: A disk case 41 is in sealed structure and is provided with a transparent part 44 with a refractive index of 2.0 for recording/reproducing light. An optical system is provided with an objective lens 47 and a Solid Immersion Lens 43 with the same refractive index of 2.0 as that of a light incident part at a tip part and the Lens 43 adheres to the transparent part 44. Floating force is applied to a rotating optical disk 42 by a groove 45 on the inner wall of the disk case being formed at a part excluding the transparent part 44, and the distance between the recording film surface of the optical disk 42 and the transparent part 44 is controlled to, for example, 50-90 nm, thus preventing a recording medium from directly touching the air outside and preventing the inner wall of the disk case and a recording carrier from being contaminated by dust for improved reliability. |
