| 摘要 |
PURPOSE:To prevent amiss detection by arranging the detection face of a detection board somewhat upward from the vertical face, and providing a powdery developer stirring rod for turning in contact with said board or a little apart from it. CONSTITUTION:A detection board 3 is inclined at an angle of alpha deg. and with its face directed a little upward, and a powdery developer stirring rod 6 is turned with a space (d) kept to the detection board 3. Its turning is made effective by an intermittent movement, for example, about 30 deg. vibration at intervals of 1-5sec. As a result of an experiment, amiss detection was not caused in the range of 1-0.3mm. (d) space and 2-6 deg. inclination angle (alpha). The developer is prevented from agglomeration and attachment to the detection board 3 by turning the rod 6 made of a flexible material in contact with the board 3, thus permitting vacant spaces or parts 5 low in apparent density to be prevented from being produced out of the developer opposite to the detection face, and presence of the developer not lower than a given level to be detected without any error. |
