Image forming apparatus

An image forming apparatus comprising:

• a developing unit to form an electrostatic latent image and allow an image to be formed by a developing agent supplied to the electrostatic latent image;
• an intermediate transfer body having an image forming area and two test pattern forming areas arranged at both sides of the image forming area to be parallel with the image forming area in a primary scanning direction, wherein the image is transferred from the developing unit to the image forming area and the two test pattern forming areas, wherein the two test pattern forming areas include a first test pattern forming area formed on one side of the image forming area and a second test pattern forming area formed on the other side of the image forming area;
• and
• a transfer roller allowing the image transferred to the image forming area of the intermediate transfer body to be transferred to a printing medium,
• wherein a maximum transfer length, which is a maximum length of the transfer roller allowing transfer of the image to the printing medium is less than a maximum image forming length, which is a maximum length of the developing unit allowing the image to be developed,
• wherein the transfer roller is positioned so that the maximum transfer length of the transfer roller corresponds to the image forming area of the intermediate transfer body, which is outside of the two test pattern forming areas of the intermediate transfer body.