Printer apparatus with sheet supply selecting means

摘要

An image forming apparatus including a mechanism for forming a visual image on a sheet of paper and a plurality of sheets supply mechanisms each including a sheet storage cassette detachably incorporated therein. A detector for detecting the attaching operation of the sheet storage cassettes in each of the sheets supply mechanisms is also provided. An automatic selecting circuit, which is responsive to the detector, automatically selects the sheets supply mechanisms for which the attaching operation has been detected by the detector. A signal is generated to disable the automatic selecting circuit. The disabling signal enables operation without a cassette attached to the sheets supply mechanism irrespective of the sheet size selected.