Image forming apparatus for recycling toner

A color image forming method comprising:

• developing a first latent image with a first developing agent containing a toner and a carrier to form a first toner image;
• transferring the first toner image to a transfer medium at a first toner image transfer section;
• collecting the toner remaining on the image carrier after transferring the toner image;
• developing a second latent image with a second developing agent containing a toner and a carrier to form a second toner image;
• transferring the second toner image to the transfer medium at a second toner image transfer section;
• collecting the toner remaining on the image carrier after transferring the toner image;
• developing a third latent image with a third developing agent containing a toner and a carrier to form a third toner image, transferring the third toner image to the transfer medium at a third toner image transfer section;
• collecting the toner remaining on the image carrier after transferring the toner image,
• developing a fourth latent image with a fourth developing agent containing a toner and a carrier to form a fourth toner image;
• transferring the fourth toner image to the transfer medium at a fourth toner image transfer section;
• collecting the toner remaining on the image carrier after transferring the toner image,
• fixing the first to fourth toner images on the transfer medium by a fixing member,
• wherein, in the second and third image forming station, a contact nip width between the transfer medium and the image carrier is larger than a nip width between the transfer medium and a transfer member having a voltage applied thereto, and a plurality of transfer members are provided, each of the second and the third toner image transfer sections has the transfer efficiency higher than that of the first and the fourth second transfer sections.