An image forming apparatus includes an image forming part, a fixer including a heating member and a pressure member, a reverse transport part to forward a recording medium transported from the fixer to the image forming part, a toner image sensor to detect presence of a toner image on the recording medium,...http://www.google.com.au/patents/US7912392?utm_source=gb-gplus-sharePatent US7912392 - Image forming apparatus with glossy image printing mode
