Image forming apparatus, toner image transfer and fixing method, and computer-readable recording medium having recorded thereon toner image transfer and fixing program

A toner image transfer and fixing method on a sheet by an image forming apparatus including:

• a photoconductive member configured to carry a toner image;
• an endless annular intermediate transfer belt onto which the toner image is transferred from the photoconductive member;
• an endless annular transfer and fixing belt onto which the toner image is transferred from the intermediate transfer belt;
• and a fixing and pressing roller configured to nip and convey the sheet in cooperation with a belt surface of the transfer and fixing belt,
• the method comprising:
• heating, with a heating device, the toner image on an outer circumferential surface of the transfer and fixing belt between a first toner image transfer position for transfer from the intermediate transfer belt onto the transfer and fixing belt and a second toner image transfer position for transfer from the transfer and fixing belt onto the sheet in a moving direction of the belt surface of the transfer and fixing belt and, at the same time, heating, with the heating device, the sheet conveyed to the second toner image transfer position;
• nipping and pressing the heated sheet with the transfer and fixing belt, which carries the heated toner image, and the fixing and pressing roller to transfer the toner image on the transfer and fixing belt onto the sheet and fix the toner image;
• adjusting, with a heat insulating plate located between the heating device and the sheet conveyed to the second toner image transfer position, a heat transmission amount from the heating device to the sheet;
• detecting a thickness of the sheet conveyed to the second toner image transfer position;
• and
• adjusting a position of the heat insulating plate on the basis of a detection result of the thickness of the sheet to thereby adjust the heat transmission amount from the heating device to the sheet.