Patent ID: 8090278

Claim:
An image forming apparatus including a process cartridge including at least a developing section and an image bearing body, comprising: an exposing section that irradiates a surface of an image bearing body with light to form dots for an electrostatic latent image on the image bearing body in accordance with print data; a developing section that deposits a developer material to the electrostatic latent image; a calculating section that calculates a number of the dots formed on the image bearing body; a rotation calculating section that calculates a number of rotations of the image bearing body for forming the number of dots on the image bearing body in accordance with the print data; a developer discarding section that removes the developer image from the image bearing body; a controller that makes a decision to determine whether the number of dots formed on the image bearing body is larger than a first reference when the number of rotations is larger than a second reference; and a timer that detects a time during which the image bearing body rotates to form the dots for the electrostatic latent image in accordance with the print data; wherein if the number of dots formed on the image bearing body is less than the first reference, said controller controls said exposing section to form an electrostatic latent image of a pattern on the image bearing body such that the electrostatic latent image of the pattern is equivalent to a difference between the first reference and the number of dots formed on the image bearing body, and then said developing section deposits the developer material to the electrostatic latent image of the pattern, and finally said developer discarding section removes the developer material deposited to the electrostatic latent image of the pattern from the image bearing body; and wherein said controller calculates a print duty based on the time and the number of rotations of the image bearing body in forming the dots for the electrostatic latent image in accordance with the print data, the print duty being a ratio of the number of rotations of the image bearing body per unit time to a maximum number of rotations of the image bearing body per unit time in continuous printing.