| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of determining the timing of exchange of cartridges on the basis of an appropriate deterioration state. <P>SOLUTION: This image forming apparatus is an apparatus for forming an image on a record sheet and includes a cartridge (developing cartridge 5B) which contains a developer and is configured so as to be replaceable to the apparatus body, a development roller 54 which holds a developer and rotates, a rotation number estimation means 11 which estimates the number of rotations NR of the development roller 54, a dot number counting means 12 which counts the number of dots ND printed on a record paper, a determination means 13 which determines that it is the time to exchange cartridges when the number of rotations NR of the development roller 54 estimated by the rotation number estimation means 11 exceeds a threshold, and a threshold changing means 14 which changes the threshold according to an increase in the number of dots ND counted by the dot number counting means 12. <P>COPYRIGHT: (C)2012,JPO&INPIT |
