Image adjusting method and image forming apparatus

An image adjusting method for an image forming apparatus having

• a feeding unit adapted to feed a sheet,
• an image forming unit adapted to form an image on an image carrier,
• a transfer unit adapted to transfer, to a sheet, the image formed on the image carrier,
• a fixing unit adapted to fix the transferred image onto the sheet, and
• a temperature detection unit adapted to detect a temperature of the fixing unit, the method comprising:
• a feeding interval changing step of widening feeding interval between sheets fed by said feeding unit, when the temperature detection unit detects that the temperature of the fixing unit falls outside a set temperature range;
• an adjustment step of executing adjustment processing to form on the image carrier an adjusting image for adjusting an image forming condition, and adjust the image forming condition on the basis of a result of reading the adjusting image;
• and
• a determination step of determining a timing to execute the adjustment processing,
• wherein when a feeding interval is widened in the feeding interval changing step, a reference value is changed in the determination step, which is used for determining the timing to execute the adjustment processing.