Abstract: An image forming apparatus is provided, which includes: a photosensitive member; an exposure member; a support frame supporting the exposure member; a gap keeping member; a pressing member; and an adjustment member. The adjust member is disposed between the exposure member and the support frame and configured to adjust a gap between the exposure member and the support frame to allow the exposure member to move in an optical axis direction.

Abstract: A process cartridge includes (a) an image carrier for carrying a developer image; (b) a transfer roller for transferring the developer image onto a recording medium; (c) a winding preventer for preventing the recording medium from winding around the transfer roller; and (d) a cover which covers the transfer roller and which has an opposed surface opposed to the transfer roller. The winding preventer has a contact surface extending from the opposed surface toward the transfer roller, such that a leading edge of the recording medium is held in contact with the contact surface when the recording medium is pulled into between an outer circumferential surface of the transfer roller and the opposed surface of the cover. The opposed surface includes an immediately upstream portion which is immediately upstream of the contact surface as seen in a rotational direction of the transfer roller. An angle formed between the contact surface and the immediately upstream portion is acute.

Abstract: A stepper motor controller that controls acceleration of a stepper motor so that, once the stepper motor is stabilized at 500 pps, acceleration of the motor is increased to 667 pps for four steps, during which time the speed of the stepper motor reaches about 900 pps. Then, acceleration of the stepper motor is increased to 1,000 pps, allowing the motor to increase to that speed without degeneration of the speed. In other words, when the stopper motor nears the maximum possible speed at an acceleration of 667 pps, the next acceleration is applied. In this way, acceleration of the stepper motor can be changed between levels having a great difference in driving frequency without causing the stepper motor to degenerate.