CUSTOMER REPLACEABLE UNIT DEVICE ELECTRONIC COUNTER FAIL SAFE DEVICE
Original Publication Date: 1998-Dec-31
Included in the Prior Art Database: 2004-Apr-08
Xerox Disclosure Journal
Disclosed is an apparatus for replacing an existing device that prevents Customer Replaceable Units (CRUs) from being refilled by an unauthorized individual. The existing device uses a mechanical counter and solenoid to raise and latch a magnet when the counter reaches a value indicative of a CRU's end of life. A magnetic sensor detects the position of the magnet. However, defeating the magnetic latch mechanism can disable the end of life function, thus allowing an unauthorized refill of the CRU. In the disclosed apparatus, an electronic counter replaces the mechanical counter. The electronic counter utilizes the same inputs and existing electrophotographic printing machine voltage to produce the same outputs as the mechanical counter. Moreover, the electronic counter is more foolproof by virtue of its internal logic.