To provide an image forming device which prevents fraudulent alteration of the working life of a replaceable cartridge with a small capacity memory provided thereon.
The image forming device forms images by using a unit mounted thereon and to detect the lifetime thereof. The unit includes: a first memory of a data width enough to store the used amount of the unit; and a second memory which has two or more flags showing either one of a first and a second states and allowing the change from the first state, while prohibiting the reverse change of the state.The image forming device includes: a means to count up the used amount stored in the first memory in accordance with the use of the unit and to reset the first memory when it exceed a maximum value and to change the first state of one of the flags in the second memory to the second state; and a means to determine the remaining life of the unit based on the used amount stored in the second memory and to report the results.
| JP2001249530A | 2001-09-14 |
Akinaka Takano
Kenichiro Sano
Eiichi Shiragashi
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