Image forming apparatus capable of prompting for replacement of at least one of a charging roller and a cleaning blade

An image forming apparatus comprising:

• an image forming portion which comprises
• an image carrier including a photosensitive layer on a surface of the image carrier,
• a charging device which causes the surface of the image carrier to be electrically charged,
• an exposure device which exposes to light the surface of the image carrier electrically charged by the charging device, and forms an electrostatic latent image on the surface of the image carrier,
• a developing device which develops the electrostatic latent image into a toner image by using a developer,
• a transfer device which transfers the toner image from the surface of the image carrier to a transfer-receiving member, and
• a cleaning device which cleans the surface of the image carrier;
• and
• a control portion which controls an operation of the image forming portion, wherein:
• the charging device includes a charging roller which is in contact with the surface of the image carrier;
• the cleaning device includes
• a cleaning blade which slidably contacts the surface of the image carrier, and
• an adjustment portion which adjusts a linear pressure of the cleaning blade exerted on the surface of the image carrier;
• and
• the control portion executes, when a rate of increase of an outer layer resistance value of the charging roller which is caused by a decrease in a function of the cleaning blade is greater than or equal to a first rate, linear pressure adjustment control of controlling the adjustment portion to increase the linear pressure of the cleaning blade exerted on the surface of the image carrier.