IMAGE FORMING SYSTEM, AND LATENT IMAGE CARRIER REPLACEMENT TIME DETECTION METHOD

PROBLEM TO BE SOLVED: To detect a replacement time of a latent image carrier such as a photoreceptor with high accuracy at a low cost.SOLUTION: An image forming system comprises a surface potential sensor that intermittently detects residual potential of a photoreceptor in an image forming apparatus that performs image formation by developing a latent image formed on the surface of a replaceable photoreceptor to form a visible image and ultimately transferring the visible image on a recording material. The image forming system stores data of photoreceptor residual potential detected by the surface potential sensor in a non-volatile RAM in a postscriptive manner, and performs processing for detecting a photoreceptor replacement time on the basis of a change in stored photoreceptor residual potential over time.