| 摘要 |
PURPOSE:To keep the uniqueness of original data. CONSTITUTION:Image data stored in an optical disk of a filing system 10 on the transmission side is copied by an output means 4, and information related to the time for copy or output is added to output the copy data. Copy data is stored in a memory 6 of a filing system 20 on the reception side. A CPU 7 reads information related to the time from copy data stored in the memory 6 and erases copy data, which a prescribed time passes after copy or output of, or makes this copy data unaccessable. |
