SHUTTER CONTROLLER, DISC DEVICE, AND COMPUTER PROGRAM FOR DETERMINING THAT DISC IS CAUGHT

摘要

A disc device having a shutter at a disc insertion opening, in which a state where a disc is caught by the shutter can be reliably determined. The determination that a disc is caught is used when a shutter is closed in a disc device equipped with a shutter for opening/closing a disc insertion opening. The position of the shutter is detected in a closing process of the shutter of the disc device. Then, a shutter position index H<SUB>C</SUB> defined by a predetermined expression is calculated (step S201) as a first shutter position index H<SUB>C</SUB>. After that, a predetermined threshold a and the difference between the first shutter position index H<SUB>C </SUB>and a second shutter position index H<SUB>C-1</SUB>,<SUB/>which is<SUB/>calculated before the first shutter position index H<SUB>C</SUB> is calculated, are compared (step S203) to determine whether or not the disc is caught by the shutter.