| 摘要 |
PURPOSE:To prevent abnormality in an image, deterioration of a photosensitive body caused by a charger and an exposing device, and fault of the copying machine by providing a limit value detecting means which detects whether latent image potential detected by a pattern potential detecting means is above a specified limit value or not. CONSTITUTION:A reference pattern latent image 4 is formed on a latent image carrier 1 by a reference pattern latent image formation means 3, and the poten tial of this reference pattern latent image 4 is detected by the pattern potential detecting means 12, and an image forming condition is controlled so that the latent image potential becomes a set value by an image forming condition control means 20. Furthermore, whether the latent image potential is above the specified limit value or not is detected by the limit value detection means 7. Therefore, fault of a potential sensor 12 become easier to discover, and the image forming condition can be prevented from being set based on any errone ous potential information. Thus, abnormality in the image, deterioration of the photosensitive body due to a charger or the exposure device, and fault of the copying machine can be prevented. |
