| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of suppressing a developer leakage from a cartridge and of appropriately judging the timing of exchange of cartridges according to a use condition. <P>SOLUTION: The image forming apparatus is an apparatus designed to form an image on a record sheet, and comprises a development roller 54 which holds a developer and rotates, a cartridge (developing cartridge 5B) configured so as to be replaceable to the apparatus body, and rotation number estimation means 11 which estimates the number of rotations NR of the development roller 54, sheet number counting means 12 which counts the number of sheets on which an image is formed (number of prints NP), determination means 13 which determines that it is the time to exchange cartridges when the number of rotations of the development roller 54 estimated by the rotation number estimation means 11 exceeds a threshold, and threshold changing means 14 which changes the threshold according to an increase in the number of prints NP counted by the sheet number counting means 12. <P>COPYRIGHT: (C)2012,JPO&INPIT |
