Patent ID: 7965428

Claim:
A color image forming device, comprising: an optical scanning part; an image carrier where a latent image is formed by the optical scanning part; a developing part configured to develop the latent image of the image carrier; an endless belt configured to move so as to come in contact with the image carrier where the developed image is formed; a plurality of environment detection parts including a humidity detector and a temperature detector provided at least at one of the optical scanning part, the image carrier, the developing part, and the endless belt, the environment detection parts being configured to obtain environmental data; a storage part configured to store a positional error function, the positional error function including at least a temperature function and humidity function, the temperature and humidity functions generating respective positional errors due to changes of values of the environmental data; and a control part configured to calculate a sum positional error amount based on the positional error function and the environmental data, and configured to implement positioning control based on the sum positional error amount, wherein the sum positional error amount includes a sum of the positional errors generated by the temperature function and humidity function.