For paper fed from the tray 2, tray 3, tray 4 or LCT, loop forming has not been complete before a sheet enters the registration roller because the rise timing of load to perform registration is earlier than the rise timing of load to form a loop.

The registration sensor (PS1) is not unblocked even after the lapse of a given period of time after the paper has turned ON the tray 2 vertical transport sensor (PS19).

Misfeed at vertical transport section

For paper fed from the LCT, the image write start signal permit continues to be disabled for a predetermined period of time after the timing of the image write start signal output.

The leading edge of the paper does not turn ON the vertical transport sensor (PS133) even after the lapse of a given period of time after the LCT starts to feed paper.

Misfeed at LCT feed/vertical transport section

For paper fed from the tray 4, the image write start signal permit continues to be disabled for a predetermined period of time after the timing of the image write start signal output.

The leading edge of the paper does not turn ON the tray 4 vertical transport sensor (PS123) even after the lapse of a given period of time after the tray 4 starts to feed paper.

Misfeed at tray 4 feed section