| 摘要 |
PROBLEM TO BE SOLVED: To provide such a toner residual detecting device in a simple structure as being capable of surely preventing erroneous detection. SOLUTION: A rising portion 57a is formed gradually thinner in a descending order. Light from a projecting portion 58a is thus reflected to the projecting portion 58a side by the rising portion 57a so that the light does not reach the other rising portion 57b via a ranging portion 57c but linearly goes from the projecting portion 58a to a receiving portion 58b. |
