Image forming apparatus with positively-charged single layer type electrophotographic photoreceptors

An image forming apparatus, comprising:

• first and second image carriers that are configured by positively-charged single layer type electrophotographic photoreceptors;
• first and second developing devices that supply toner of developers to circumferential surfaces of the first and second image carriers respectively;
• first and second charging members that come into contact with the circumferential surfaces of the first and second image carriers, respectively, to charge the circumferential surfaces of the first and second image carriers;
• a voltage application portion that applies a charging bias to each of the first and second charging members;
• first and second destaticizing portions that destaticize the circumferential surfaces of the first and second image carriers respectively;
• an image carrier driving portion that rotates the first and second image carriers;
• and
• a controller that controls an operation for charging or destaticizing the circumferential surfaces of the first and second image carriers, wherein
• the controller switches between a first mode for operating the first developing device and the second developing device while rotating the first image carrier and the second image carrier so as to form an image on both the first image carrier and the second image carrier, and a second mode for operating only the first developing device while rotating the first image carrier and the second image carrier so as to form an image only on the first image carrier;
• and in the second mode, applies the charging bias and operates the second destaticizing portion for the second image carrier without operating the second developing device, and applies the charging bias and operates the first developing device and the first destaticizing portion for the first image carrier.