| 摘要 |
PROBLEM TO BE SOLVED: To prevent image halftone roughness and reduction in image density by arranging a residual toner detecting means in a main body case, to locate the detecting surface of the residual toner detecting means in a circular toner flowing region where the flowing of toner is active. SOLUTION: The residual toner detecting sensor 27 is arranged in the main body case 22, so that the detecting surface (head surface 27a) of the sensor 27 crosses a horizontal line HL1 passing through the press-contact position of a developing roller 23 with a layer thickness regulating member 25 and is located in the circular toner flowing region S1 formed by the developing roller 23, a supplying roller 24 and the layer thickness regulating member 25, at the time of executing a printing operation. Thus, the toner T is not heaped on the detecting surface 27a and not solidified therearound, so that the residual toner can be accurately detected. Therefore, it is unnecessary that the installation height of the residual toner detecting sensor 27 is forcibly made high and futility such as the fact that the toner remains in the main body case 22, without being used can be eliminated. |
