G11B2220/232

Optical disc and method for judging whether optical disc is placed reversely

A method is provided for judging whether a double-sided optical disc is placed reversely. Firstly, the disc is loaded. Then, a first optical pickup head emits a first laser beam to a first specified area of the disc and receives a first reflected laser beam. A second optical pickup head emits a second laser beam to a second specified area of the disc and receives a second reflected laser beam. If the first reflected laser beam generates an alternate brightness and darkness change and the second reflected laser beam does not generate the alternate brightness and darkness change, the disc is not placed reversely. If the first reflected laser beam does not generate the alternate brightness and darkness change and the second reflected laser beam generates the alternate brightness and darkness change, the disc is placed reversely.

Optical disc and method for judging whether optical disc is placed reversely

A method is provided for judging whether a double-sided optical disc is placed reversely into an optical disc drive. The optical disc drive includes a first control module and a second control module. The first control module includes a first optical pickup head. The second control module includes a second optical pickup head. Firstly, the double-sided optical disc is loaded. Then, the first optical pickup head of the first control module emits a laser beam to a specified area of the double-sided optical disc and receives a reflected laser beam from the specified area. If the reflected laser beam generates an alternate brightness and darkness change, the double-sided optical disc is not placed reversely. If the reflected laser beam does not generate the alternate brightness and darkness change, the double-sided optical disc is placed reversely.