| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce costs by miniaturization of a device and reduction of the number of parts while attaining precise recording and reproducing of information utilizing an SIL (solid immersion lens). <P>SOLUTION: This device is provided with a collimator 30 which collimates a luminous flux outgoing from a light source to be a parallel luminous flux; an objective lens which is for irradiating an optical recording medium with the parallel luminous flux, which is composed of a lens 10 satisfying NA<1 and the SIL 11 and whose numerical aperture is >1; and photodetectors 27 and 29 which photodetect only the luminous flux of NA<1 of the objective lens in reflected light from the optical recording medium 12. The photodetectors 27 and 29 are arranged so as to photodetect the luminous flux collected by the collimator 30. <P>COPYRIGHT: (C)2007,JPO&INPIT |
