| 摘要 |
PURPOSE:To enable search to be executed in a shorter time even when disk track pitches are uneven by dividing the number of recording tracks and detecting the positional information of the disk surface and the frame number at a dividing point thereof. CONSTITUTION:The frame number of video signals is searched at every frame interval DELTAn and the positional information is fetched from a generator 3 and written in a memory 11. When a search instruction is given from outside, its target frame number N is inputted and a frame number larger than this number N is detected from the memory 11. A positional information L for the number N is found to drive a drive circuit 9 at a high speed. When the positional information outputted from the generator 3 is equal to L, the high speed movement of a thread feed motor 2 is terminated. At this time, a search mode is set and the targeted frame number N is searched. As a result, when the disk track pitch is not uniform, the positional information of the targeted number N can be computed with higher accuracy to assure high speed accessing.
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