| 摘要 |
PURPOSE:To correctly detect a position information code without lowering the speed of seek operation by constituting relation between the mark positions of two position information codes neighboring in the radial direction of an optical disk into specified relation. CONSTITUTION:Two position information codes are placed on the centers 15 of neighboring two tracks (i) and (i+1), and the marks A,B of channel bit positions 4,5 on the track (i) do not change their positions on both the track (i) and the track (i+1). Only the mark C of the channel bit position 6 on the track (i) changes to the channel bit position 3 on the track (i+1), and the positions on the track (i) and the track (i+1) are different by three channel bits portion. Besides, the mark C makes a long mark of length '3' as continuing to other two marks A,B on both the track (i) and the track (i+1). Thus, the correct detection of the position information code becomes possible without lowering the speed of the seek operation. |
