| 摘要 |
PURPOSE:To improve the recording density by removing a foreign matter adhered onto the surface of a side for recording/reproduction on an information recording medium, applying a transparent liquid to the surface of the recording medium so as to form a thin film and overlap a parallel flat transparent plate thereupon thereby recording/reproducing the information. CONSTITUTION:A cleaner section M, a liquid coating section N and an information recording/reproducing section L are provided and an optical card 1 is carried along the guide 11 in the order of M N L in the direction of arrow A. In applying recording/reproduction by the reproduction section L, a radiated light from a semiconductor laser is made incident in the thin film of a liquid part 4 via an optical plate 50 and further incident in a coating layer 101. Since no foreign matter such as dust exists at a boundary between the liquid thin film and the coating layer 101 in this case and the refractive index of the thin film and that of the layer 11 are nearly the same, then even if a flaw 2 exists on the layer 101, the light is not almost scattered. This is applied similarly to the case when the light reflected on the recording layer 102 is travelled toward the optical sensor and the presence of the optical plate 50 allows the beam spot diameter to be decreased sufficiently even when an optical card 1 is made thin to a value such as 0.3-0.8mm.
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