Sheet cutting apparatus and image forming apparatus

An image forming apparatus, comprising:

• an image forming section configured to form an image on a sheet;
• a sheet conveyance section configured to convey the sheet on which an image is formed by the image forming section to the downstream side of a specific sheet conveyance direction;
• a guillotine type cutter configured to move between a cutting position where the sheet conveyed by the sheet conveyance section and formed with an image by the image forming section is cut and a home position above the cutting position;
• a motor;
• a drive mechanism configured to transfer a drive force from the motor to the cutter to move the cutter between the home position and the cutting position;
• a drive control section configured to enable the cutter to fall from the home position to the cutting position and then return the cutter to the home position;
• a determination section configured to determine whether or not a predetermined time lapses after the image forming processing is completed by the image forming section based on the drive control section;
• a return control section configured to return the cutter to the home position if the determination section determines that a given period of time elapses from the time when the last image forming processing by the image forming section is ended;
• a counter configured to count the drive times the drive control section drives the cutter;
• and
• a set period changing section configured to change the given period of time based on the drive times counted up by the counter;
• wherein the set period changing section shortens the given period of time in response to an increase in the drive times counted by the counter.