Image forming apparatus and method of controlling image forming apparatus

A method of controlling an image forming apparatus equipped with a photoconductor, an exposure device including a polygon mirror configured to deflect a light beam to expose the photoconductor, a developing device configured to supply a toner to the photoconductor exposed by the light beam deflected by the polygon mirror, a transfer device configured to transfer the toner on the photoconductor onto a sheet, and a sheet tray configured to accommodate multiple sheets,

• wherein the method comprises:
• when printing is started and when an elapsed time from a time when the polygon mirror starts rotating to a time when a rotation speed of the polygon mirror has reached a determination speed which is slower than a target speed is less than a first time, feeding the sheet from the sheet tray before the rotation speed reaches the target speed;
• and
• when the elapsed time is equal to or greater than the first time, feeding the sheet from the sheet tray after the rotation speed has reached the target speed.

An image forming apparatus, comprising:

• a photoconductor;
• an exposure device including a polygon mirror configured to deflect a light beam to expose the photoconductor;
• a developing device configured to supply a toner to the photoconductor exposed by the light beam deflected by the polygon mirror;
• a transfer device configured to transfer the toner on the photoconductor onto a sheet;
• a sheet tray configured to accommodate multiple sheets;
• a feed roller configured to feed the sheets accommodated in the sheet tray;
• and
• a controller,
• wherein, when start printing, the controller is configured to:
• start rotating the polygon mirror;
• when a rotation speed of the polygon mirror reaches a determination speed, that is slower than a target speed, within an upper limit time after the polygon mirror starts rotating, start feeding the sheet from the sheet tray with the feed roller before the rotation speed reaches the target speed;
• and
• when the rotation speed does not reach the determination speed within the upper limit time after the polygon mirror starts rotating, start feeding the sheet from the sheet tray with the feed roller after the rotation speed reaches the target speed.