MONITORING SYSTEM WITH DUPLEX MEMORY FOR PRESS FOR ELECTROPHOTOGRAPHY USING REPLACEABLE CARTRIDGE

摘要

PURPOSE: To realize design which can not be substantially altered while keeping the simplicity of a non-volatile memory. CONSTITUTION: This monitoring system for a replacable unit such as toner cartridges 12, 14 and 16 in an electrophotographic copying machine 10 includes an electronic counting memory and an electronic flag memory on the unit. The counting memory holds the counted value of every one print formed by the cartridge. The flag memory includes a series of bits which can be changed from a 1st state to a 2nd state but can not be changed from the 2nd state to the 1st state. The bits in the flag memory are changed at the intervals previously fixed in accordance with the number of prints formed by the cartridge. The flag memory is used to inspect a superscription formed by unauthorized operation of the counting memory.