u201c h u201d has become extremely small it can be indicated by the following equation 7 regarding the fifth sampling clock of u201c h u201d as reckoned from the left of the figure it can be conjectured from an edge detection signal that an u201c h u201d period has not ended therefore the fifth sampling clock number of u201c h u201d as reckoned from the left of the figure can be indicated by the following equation 8 when the ppm signals are sampled at the sampling points indicated above the influence of the discrepancy of the pulse widths can be made less than in the related art example and the ppm signals can be reliably sampled thus the ppm signals can be correctly reproduced the ppm signals are correctly sampled as stated above whereby these ppm signals can be correctly reproduced incidentally this invention is not restricted to the embodiments but it can also be performed in various modifications within a scope not departing from the purport thereof especially in third embodiment the sampling points may be altered during the signal reproduction depending upon conjectured results and the sampling points may well be altered at fixed time intervals during the signal reproduction although the embodiment according to the present invention has been described above the present invention is not limited to the above mentioned embodiments but can be variously modified constituent components disclosed in the aforementioned embodiments may be combined suitably to form various modifications for example some of all constituent components disclosed in one of the embodiments may.