| 摘要 |
An image forming device includes a light-receiving element that receives a light having passed through a cartridge. An image forming unit has a first mode for forming images while rotating an agitator at a first speed and a second mode for forming images while rotating the agitator at a second speed that is lower than the first speed. If a value regarding image forming amount counted while the image forming unit is in the second mode is determined to be greater than a predetermined value, the image forming unit changes a rotation speed of the agitator from the second speed to the first speed, and it is determined whether the cartridge should be replaced based on a time ratio, which is a ratio of time duration, in which the light-receiving element receives the detection light within a predetermined duration, to the predetermined time duration. |
