| 摘要 |
PROBLEM TO BE SOLVED: To rapidly and efficiently read out the data from a data recording area of an optical recording medium even when a tracking signal from a control information recording area isn't read precisely due to contamination, etc., on the optical recording medium. SOLUTION: An O/E conversion part is provided with a photointerruptor 13 and an edge detection circuit 14 detecting an edge of its output signal, PD 123a, 123b outputting a binarized tracking signal from diffracted light beams from the control information recording area of the optical recording medium and the edge detection circuit 15 of a control CGH(computer generated hologram) signal detecting the edge of the signal and outputting a timing signal. Then, this device comprises mainly counters 17, 18 counting the number of edges of the signal outputted from the edge detection circuit 14, a control part 19 generating the tracking timing from the results of the reset operation of the counters 17, 18 and the image recognition, an image pickup element 122 capturing the image of the data CGH and an image recognition part 20 recognizing the image captured by the image pickup element 122 the main parts. |
