Image transfer device, image forming apparatus, and image transferring method

An image forming apparatus, comprising:

• a supply potion to supply a recording medium;
• an image forming portion to form a document image as a developed image on an image carrier;
• and
• a transfer device to transfer the developed image formed on the image carrier onto an endless transfer belt;
• the transfer device including:
• a pair of supporting members arranged separately around which the endless transfer belt is belted movably to form a belt loop;
• a transfer member facing the image carrier via the transfer belt to transfer the developed image formed on the image carrier onto the transfer belt;
• a secondary transfer member located at a secondary transfer position to further transfer the developed image transferred on the transfer belt onto the recording medium supplied from the supply portion;
• and
• a belt pressing member configured to act the transfer belt to increase an area of the transfer belt contacting the image carrier.

An image transferring method, comprising:

• contacting an endless transfer belt which is belted movably around a pair of separate supporting members to form a belt loop, with an image carrier for a color use and an image carrier for a monochrome use;
• transferring a developed image formed on the image carrier for the color use and the image carrier for the monochrome use on the transfer belt;
• separating the transfer belt from the image carrier for the color use, and switching the transfer belt to contact only the image carrier for the monochrome use;
• acting a pressing member to the transfer belt when switching, to increase an area of the transfer belt contacting the image carrier for the monochrome use;
• and
• transferring the developed image formed on the image carrier for the monochrome use onto the transfer belt.