Image forming apparatus and image forming method for bringing transfer material held at inner face

An image forming apparatus, comprising:

• an image carrier belt for carrying an image;
• a transfer roller including a sheet member having an inner face, and a concave section on a circumferential surface thereof, and a sheet member being configured on a part of the circumferential surface other than where the concave section is, the transfer roller being configured to transfer the developed image onto a transfer material to be in contact with the transfer material supported at the inner face, the concave section being concaved from the sheet member and extending in a direction towards the center of the transfer roller, the inner face being arranged to have an angle with the direction;
• a coating unit being configured to coat an part of the image carrier belt with a coating liquid;
• and
• a control unit being configured to control the area of the image carrier belt being in contact with the sheet member via the transfer material.

An image forming method, comprising:

• stopping a transfer roller including a sheet member having an inner face, and a concave section on a circumferential surface thereof and a sheet member on a part of the circumferential surface other than where the concave section is, at a position where the concave section faces the image carrier belt with a predetermined distance, the concave section being concaved from the sheet member and extending in a direction towards the center of the transfer roller, the inner face being arranged to have an angle with the direction;
• bringing a developer carrier for carrying a liquid developer, which contains toner and a carrier liquid, into contact with a latent image carrier to coat the latent image carrier with the carrier liquid;
• bringing the latent image carrier coated with the carrier liquid into contact with the moving image carrier belt to coat the image carrier belt with the carrier liquid;
• rotating the transfer roller after the image carrier belt is coated with the carrier liquid;
• bringing a transfer material by holding the transfer material at the inner face to an area between the sheet member and the image carrier belt;
• and
• bringing the sheet member and the image carrier belt coated with the carrier liquid into contact via the transfer material by rotating the transfer roller.