PURPOSE: To prevent toner and electrostatic charges from remaining on the surface of a photosensitive body by applying the highest voltage after the head edge of transfer paper reaches a transfer part and turning OFF a transfer unit after the tail edge of the transfer paper leaves the transfer part.
CONSTITUTION: The head edge of the transfer paper reaches the transfer part of a photosensitive body a time Ta after the clutch of a register roller is turned ON. For the purpose, the transfer unit is turned ON a time Tb before the head edge of the transfer paper reaches the transfer paper and the transfer output is gradually increased. At this time, the transfer unit is controlled so that the transfer output reaches a prescribed output in a time Tc. The tail edge of the transfer paper reaches the transfer part a certain time Td after a register sensor detects the tail edge of the transfer paper at the tail edge part of the transfer paper. Therefore, the transfer output begins to be decreased in a time Te a little bit shorter than the time T and is turned OFF in a time Tf so that the transfer unit is turned OFF after the tail edge of the transfer paper finishes passing through the transfer part. Thus, the transfer output is adjusted at the head edge part and tail edge part of the transfer paper.
YAMANAKA TOSHINAKA
WAKAMOTO KOJI
HARADA YOSHIKAZU
