| 摘要 |
<p>PURPOSE:To transfer only added and corrected data to the other distant station, and to raise a transfer efficiency by managing data as picture information which has increased the number of editions of an absolute picture number of original picture data, in case when an addition and a correction are executed to an existing picture. CONSTITUTION:Electronic blackboard devices 1, 1' of the own station side and the other distance station side of a difference data transfer system are connected by a communication circuit such as a telephone circuit, etc. Digitizers 2, 2' for inputting handwriting data document input devices 3, 3' for inputting existing data, display devices 4, 4' and keyboard devices 5, 5' are provided on this device 1 or 1', and the respective devices are connected to control devices 6, 6' connected to storage devices 7, 7'. Also, a picture number detecting part, an absolute number managing part, a common mode managing register, etc. are provided on the devices 6, 6'. In this state, in case when an addition and a correction are executed to the existing picture, its data is managed as picture information which has increased the number of editions of an absolute picture number of original picture data, and only added and corrected data are transferred to the other distant station.</p> |
