Patent ID: 7502571

Claim:
A sheet transportation control method in which abnormal sheet transportation is detected based on the timing of detection of a sheet by each one of plural sheet sensors disposed along a transportation path along which said sheet is transported and based on a set time determined in advance, and sheet transportation is stopped upon detection of said abnormal sheet transportation, comprising: a step of determining a change of said set time; in response to determining said change of said set time, a step of entering an operation mode to change said set time to a post-change new set time, said operation mode comprising: a step of determining said post-change new set time by performing: a step of introducing and transporting a first standard sheet at a predetermined speed; a step of determining said post-change new set time based on the timing of detection of said first standard sheet by each sheet sensor during transportation of said first standard sheet at said predetermined speed; a step of changing said set time to said new set time determined; a step of confirming said new set time by introducing and transporting a second standard sheet at a predetermined speed and judging an absence of an abnormal sheet transportation based on said new set time; and a step of exiting said operation mode based upon judging said absence in said step of confirming.