In the first potential difference adjustment mode, the fogging toner amount is predicted from a toner charge amount and a fogging toner current sensed by a current sensing portion with a zero surface potential on the image carrying member. In the second potential difference adjustment mode, the carrier development amount is predicted from a toner concentration, a carrier charge amount calculated based on the toner charge amount, and a carrier development current sensed by the current sensing portion with a zero surface potential on the image carrying member.

An image forming apparatus may include a conveyor conveying continuous paper. The apparatus may also include a speed detector that contacts the continuous paper conveyed by the conveyor to detect a conveyance speed of the continuous paper. The apparatus may also include a hardware processor that controls the conveyor based on a detection result detected by the speed detector so that the conveyance speed of the continuous paper reaches a target value. The hardware processor may adjust the target value based on at least one of information about the continuous paper and information about a job.

An image inspection device includes: an illumination part extending in a width direction of a medium, which intersects a medium transport direction, so as to face a medium transport path, and configured to radiate light on an image formed on a surface of the medium; a reading part configured to read reflected light from the image as image inspection information; and a cooling part configured to cool an entire area of the illumination part in the width direction of the medium. The cooling part includes one blowing part provided on one side in the width direction of the medium and configured to suck and blow outside air, a first guide extending in the width direction of the medium and configured to guide the air blown from the blowing part to a flow path extending in the width direction of the medium, and a second guide configured to guide the air, guided by the first guide, in the medium transport direction to a space where the illumination part is disposed, and distribute the air such that an air volume is uniform over the entire area of the illumination part in the width direction of the medium.