| 摘要 |
PURPOSE:To surely read the information signals of a signal recording part with a simple device by marking the signal indicating the recording capacity of the information signals of this recording part in the peripheral part inner or the peripheral part outer than the signal recording part on the main surface of the disk. CONSTITUTION:Symbols 6 are marked in the positions where the distances from the center of a disk substrate 1 are approximately equal to a stamper number 3. The symbols 6 indicate the recording capacity of the information signals of the signal recording part 2, i.e., the time when the information signals can be recorded in this recording part 2. The dots constituting the symbols 6 are formed by surface satinizing by means of a stamper or others and are formed as black dots in the case of printing. The symbols 6 are constituted of two pieces of the dots if, for example, the time when the information signals can be recorded in the recording part 2 is 60 minutes. The symbols are constituted of three pieces of the dots in the case of 74 minutes. The symbols 6 are surely identified by a simple device, such as photosensor. |
