Main Scan Registration (Image Vertical)

The paper that has been corrected for skew is fed to the LE (leading edge) shift unit [A] for image registration in the main scan direction.

The LE shift unit is equipped with a CIS (Contact Image Sensor) [B] that detects the position of the edge of the paper. The reading of the paper edge by the CIS is used to calculate the amount of deviation from the correct position, and then the amount of movement by the LE shift unit required to correct the position of the paper is calculated. The LE shift unit moves slightly to the front or rear so the image will be positioned correctly on the paper.

At this time the paper is held only by the LE shift unit. The paper is still free because the nip of the registration timing roller is open.

If paper longer than A4 SEF (297 mm) has been fed, the TE (trailing edge) shift unit [C] moves with the LE shift unit to correct paper registration in the main scan direction.

The LE registration shift motor [A] moves the LE shift unit to the front and rear. The LE shift unit HP sensor [B] determines the home position of the LE shift unit where the shift unit resides while it is idle.

The TE registration shift motor [C] moves the TE shift unit to the front and rear. The TE shift unit HP sensor [D] determines the home position of the TE shift unit where the shift unit resides while it is idle.