Electrophotographic printing apparatus

Abstract

An electrophotographic printer has a printing mechanism that prints data on a medium on a transport belt and is movable between operative and non-operative positions. The printing mechanism and a main body have mechanical contacts through which the printing mechanism receives electric power from the main body when the printing mechanism is at the operative position. A density sensor is located downstream of the printing mechanism with respect to a direction of travel of the transport belt and detects a density of the surface of the transport belt. A controller causes the printing mechanism to print a test pattern on the transport belt and compares a density of the printed test pattern with a density of print data of the test pattern. If there is a difference in density between the data of test pattern and the printed test pattern, the controller generates a reporting signal.

Dependencies are inferred from the claim text.