| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a toner empty detector for a developing device, capable of accurately detecting toner empty when concentration decrease is low in comparison with the case of a conventional system. <P>SOLUTION: The toner empty detecting device includes: a changed amount calculating means 4 that calculates a relative changed amount based on newly detected concentration information and past detected concentration information among changes with time in concentration detected by a concentration detecting means 3; and a toner empty determination means 5 that determies that a toner storage means 2 is empty when the relative changed amount calculated by the changed amount calculating means 4 tends to decrease below a predetermined reference. The changed amount calculating means 4 resets the calculated relative changed amount when the relative changed amount tends to increase. <P>COPYRIGHT: (C)2007,JPO&INPIT |
