Image forming apparatus and image forming method for controlling image formation based on a temperature of a fusing rotating body

An image forming apparatus comprising:

• an image forming unit configured to form a toner image on an image carrier;
• a transfer unit configured to transfer the toner image on the image carrier to a recording medium;
• a fusing rotating body that is heated by a heating unit;
• a pressure rotating body that contacts the fusing rotating body to form a fusing/nipping portion between the fusing rotating body and the pressure rotating body, the fusing rotating body and the pressure rotating body forming a fusing rotating body pair;
• a fusing device configured to cause the recording medium to pass through the fusing/nipping portion and configured to fuse the toner image on the recording medium onto the recording medium;
• a temperature detecting unit configured to detect a temperature on a surface of the fusing rotating body;
• a control unit configured to cause the fusing rotating body pair to be rotated in response to an image formation request, detect an amount of decrease in the temperature of the fusing rotating body surface at a predetermined time with the
• temperature detecting unit, and extend a time between the image formation request and an arrival of the recording medium with the toner image formed thereon at the fusing/nipping portion when the temperature decrease amount is greater than a threshold value;
• and
• wherein the control unit is configured to raise a fusing target temperature, which is a target in controlling a heating amount of the heating unit when the toner image is fused on the recording medium, to a fusing target temperature higher than normal, when the temperature decrease amount is greater than the threshold value.

An image forming apparatus comprising:

• an image forming unit configured to form a toner image on an image carrier;
• a transfer unit configured to transfer the toner image on the image carrier to a recording medium;
• a fusing rotating body that is heated by a heating unit;
• a pressure rotating body that contacts the fusing rotating body to form a fusing/nipping portion between the fusing rotating body and the pressure rotating body, the fusing rotating body and the pressure rotating body forming a fusing rotating body pair;
• a fusing device configured to cause the recording medium to pass through the fusing/nipping portion and configured to fuse the toner image on the recording medium onto the recording medium;
• a temperature detecting unit configured to detect a temperature on a surface of the fusing rotating body;
• a control unit configured to cause the fusing rotating body pair to be rotated in response to an image formation request, detect an amount of decrease in the temperature of the fusing rotating body surface at a predetermined time with the temperature detecting unit, and extend a time between the image formation request and an arrival of the recording medium with the toner image formed thereon at the fusing/nipping portion when the temperature decrease amount is greater than a threshold value;
• and
• wherein the control unit is configured to change a standby target temperature, which is a target in controlling a heating amount of the heating unit in a standby status, to a standby target temperature that is higher than normal, when the temperature decrease amount is greater than the threshold value.