| 摘要 |
PURPOSE:To accurately reproduce duplicated recording with a simple constitution by dividing a reflected light corresponding to the superimposing recording of a magneto-optical medium recorded with pit information into two, using a 4-split sensor or the like to apply light receiving processing and reproducing the information or the like based on light diffraction and a Kerr rotational angle. CONSTITUTION:Pit information is recorded on a base made of a material such as an acrylic material and a magneto-optical substance such as Gd, Tb or Fe is coated to the recording medium 1 and the recording/erasure is applied freely by a light. The reflected light from the medium 1 by the irradiation of a cylindrical light laser luminous flux by a cylindrical light forming means 7 or the like is divided into two by the beam splitter 13 of a suboptical system 3 and they are made respectively incident on the main light sensor 16 and sublight sensor 17 of a 4-split light sensor. Then the pit information reproduction in response to the tracking control and the diffracted light detection in response to the tracking control and the diffracted light detection based on the heterodyne processing by the signal via the sensor 16 and the reproduction of superimposed optical recording information based on the focus control and the Kerr angle rotation via the sensor 17 are applied. Thus, the superimposing recording is reproduced accurately with the simple constitution. |
