Image forming apparatus

An image forming apparatus comprising:

• a fixing device including:
• a heating member;
• a heat source configured to heat the heating member;
• a rotating member configured to rotate and to be in contact with the heating member;
• and
• a temperature sensor configured to detect the temperature of the heating member,
• a sheet feeding unit configured to feed a recording sheet toward the fixing device;
• and
• a control device configured to control the heat source and the sheet feeding unit,
• wherein the control device is configured to perform a sheet feed control:
• in which the feeding timing of a first recording sheet by the sheet feeding unit is set to a first timing if a temperature gradient of the heating member for a predetermined period from a print-instruction receiving time is larger than a first threshold value;
• and
• in which the feeding timing of the first recording sheet by the sheet feeding unit is set to a second timing later than the first timing if a temperature gradient of the heating member for the predetermined period is equal to or less than the first threshold value, and
• wherein, in the sheet feed control, the control device changes the first threshold value to a smaller value as the temperature of the heating member at the print-instruction receiving time increases.