Image forming apparatus

An image forming apparatus for forming an image using an image forming unit and a control unit, the image forming apparatus comprising:

• the image forming unit including a latent image carrier carrying a latent image on the rotating surface thereof, a latent image writing unit writing an electrostatic latent image on the surface of the latent image carrier, and a developer carrier developing the electrostatic latent image with a developer carried on the rotating surface thereof while forming a developing electric field between the electrostatic latent image on the latent image carrier and the surface of the developer carrier in a developing area where the latent image carrier and the surface of the developer carrier are opposite each other with a predetermined developing gap therebetween;
• the control unit performing processing of controlling driving of the image forming unit or processing of varying an image forming condition of the image forming unit;
• an information storage unit which stores first deflection information, second deflection information, writing sensitivity information, and image forming condition information, the first deflection information representing the relationship between the surface movement amount of the latent image carrier and the deflection amount in a direction of variation in the developing gap, at a place within the developing gap from the circumferential surface of the latent image carrier, the second deflection information representing the relationship between the surface movement amount of the developer carrier and the deflection amount in a direction of variation in the developing gap at a place within the developing gap from the circumferential surface of the developer carrier, the writing sensitivity information representing the relationship between the surface movement amount of the latent image carrier and latent image writing sensitivity, and the image forming condition information representing the relationship between the surface movement amount of at least one of the latent image carrier and the developer carrier and an image forming condition for generating deviation in an opposing direction to deviation from a reference value attributable to the deflection of the latent image carrier, the deflection of the developer carrier, and errors in the circumferential direction of latent image writing sensitivity of the latent image carrier in a developing electric field intensity;
• an information input unit which inputs the first deflection information and the second deflection information;
• and
• a surface potential detection unit which detects the surface potential of the latent image carrier,
• wherein the control unit is configured such that, during an image forming operation, processing is performed for changing the image forming condition to a value based on the surface movement amount of one of the latent image carrier and the developer carrier on the basis of the image forming condition information;
• and when the image forming operation is not carried out, if at least one of the first deflection information and the second deflection information is input by the information input unit, processing is performed for calculating the image forming condition for generating the deflection in the opposing direction on the input information to update the image forming condition information;
• and if the first deflection information is input by the information input unit, processing is performed for forming an electrostatic latent image at each latent image writing intensity of the stepwise varying latent image writing intensities, obtaining the relationship between the potential of the electrostatic latent image and the latent image writing intensity on the basis of the sequential detection result of the potential of the electrostatic latent image by the surface potential detection unit at each of a plurality of places in the circumferential direction of the latent image carrier, and constructing the writing sensitivity information on the basis of the relationship.