| 摘要 |
<P>PROBLEM TO BE SOLVED: To make quickly sensible an obstacle in an opening part and make controllable a shutter to the safety side. <P>SOLUTION: When a shutter reaches the lower limit position in the closing operation, it is detected by a lower limit position detecting means 7. An opening and closing machine 2 for driving the shutter to open and close is detected by a rotation amount detecting means 6 when it reaches a rotation amount corresponding to the lower limit position of the shutter. A control part 4 controls the shutter to the safety side according to the determination on that an obstacle is present at the lower end part of the opening part when the rotation amount detecting means 6 reaches a rotation amount corresponding to the lower limit position of the shutter under the condition where the lower limit position detecting means 7 does not detect the lower limit position of the shutter. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
