| 摘要 |
PURPOSE:To perform record/reproduction by means of a conventional apparatus without hindrance, even if the thickness of an optical disk changes, and to prevent dust from entering by adding a transparent member with suitable thickness to the optical path of an optical head provided at an optical disk cartridge or optical disk drive. CONSTITUTION:An optical disk 3 with 3.5 inch diameter and 0.6mm substrate thickness having a recording film or reflecting film is stored in a cartridge body 1. A hub 4 to be connected to a motor 8 for rotating the disk 3 is stuck to the disk 3. Light outgoing from an optical head 7 passes as convergent light through the open window 5 of the cartridge 1 and then through the 0.6mm thick substrate of the disk 3 to reach the recording film 2. Normally, the thickness of the substrate is 1.2mm and the lens of the optical head is designed in the manner of conforming thereto so that aberration, etc., are made small. Therefore, the purpose of the title apparatus can be achieved when the thickness of the transparent member 9 of the window 5 is 0.6mm so that the thickness of the member 9 and thickness(0.6mm) of the substrate of the disk 3 amount to 1.2mm in all. |
