| 摘要 |
PURPOSE:To prevent a scanner from running away by detecting whether the measured value of the output pulse number of an encoder falls within a range of prescribed value of upper and lower limits or not to notify the malfunction of a controller of a motor. CONSTITUTION:When a main power source is turned ON, a set value predetermined in a timer is set, and a motor 15 for a scanner is driven through a drive circuit 15 at the predetermined speed. A counter 14 counts the number of pulses output from an encoder 18 in the meantime. Then, the counted value N of the counter 14 is compared with the upper limit N1 and the lower limit N0 to judge whether it satisfies N0<=N<=N1 or not. If the condition is not satisfied, it is regarded as a malfunction to inhibit the following operation of a copying machine. |
