JPS572049A - Copying machine - Google Patents

Abstract

PURPOSE:To prevent a decline of a copying speed, by detecting the size of a form which is used at the time of continuous copying, and changing over its copying cycle to one copying operation by one rotation of a photosensitive drum or to one copying operation by two rotations, in accordance with said detection result. CONSTITUTION:Copying paper P having different sizes is put in paper feed cassettes 141 and 142. Now, in case the paper feed cassette 141 has been selected, a switch 45 is closed, NOR circuits 46, 48 are not realized, and copying by the cassette 141 is executed. An original table 2 is returned by a signal from a return switch 4, a photosensitive drum 8 is stopped at a constant position at every copying operation, and one copying operation is executed at every one rotation of the drum 8. Subsequently, when a paper feed cassette 142 for large-sized paper has been selected, the switch 45 is opened, the NOR circuit 48 is realized, and when the continuous copying operation is executed, the original table 2 is returned by a signal from a return switch 5, and since the drum 8 is returnd to its constant position earlier than the original table 2 is returned to its original position, the drum 8 is made to run idle by one rotation. Accordingly, at every two rotations of the drum 8, one copying operation is executed.