| 摘要 |
<p>PURPOSE:To improve the operability at data read by providing a start header of a prescribed frequency in an audible frequency band to a data format to find out easily the head of data. CONSTITUTION:A start header 1 representing the head of data is formed by 12,000 waves of data having 2,400Hz each, document data comprising a document management data and document data is provided, and an end data part 3 representing the end of data is formed by 6,000 waves of data having a frequency of 1,200Hz each. Further, the start header 1 and the end header 3 are formed by frequencies of 2,400Hz, 1,200Hz respectively, which differ by one octave, and the start/end of data are judged by reproducing the data when the header whose frequency differs from the end data by one octave within an audible frequency band is consecutive for several seconds in general. Thus, the start position of data is found out easily.</p> |
