| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect a developer detection time and a developer replenishing ending time by one sensor etc. <P>SOLUTION: An upper limit detecting member 31 is stored in each developing device 221, extends from one window hole 221a up to the upper limit toner position showing the prescribed upper limit amount of toner in the developing device 221, shields the light emitted from a light emitting part so that a light receiving part 182 may not receive the light when the toner amount in the developing device 221 reaches the upper limit, and when the toner amount in the developing unit 221 does not reach the upper limit, guides the light emitted from the light emitting part 181 so that it may be received by the light receiving part 182. A lower limit detecting member 32 is stored in each developing device 221, extends from the other window hole 221a up to the lower limit position, that is, a position where the prescribed toner amount in the developing device 221 is below the lower limit, reflects the light emitted from the light emitting part 181 toward the light receiving part 182 so that the light may be received by the light receiving part 182 when the toner amount in the developing device 221 is below the lower limit, and when the toner amount in the developing device 221 is equal to or exceeding the lower limit, shields the light emitted from the light emitting part 181 so that it may not be received by the light receiving part 182. <P>COPYRIGHT: (C)2008,JPO&INPIT |
