| 摘要 |
PURPOSE:To prevent a sensor surface from getting dirty by dropping an attached toner and prevent a photosensitive body from being damaged, when jammed paper sheets are removed, by fitting a target image density sensor in such a way that the sensor which is positioned in the vicinity of the photosensitive body, can be retreated from the photosensitive body at the time of the upper side portion being subjected to one side opening. CONSTITUTION:When a paper transport passage and a photosensitive drum 3 are exposed by conducting opening by conducting turning to the upper side with an upper side partial turning shaft of a copying machine as a center, paper sheets jammed around them become easy to be removed. A leverlike sensor support member 20 whose one end supports a photo sensor 22, is provided, and the other end of the member 20 is fitted rotatably around a support shaft 21 at the lower portion of a rail 6. Accordingly, under the condition of the upper side portion being opened, the member 20 comes to the condition of being suspended from the shaft 21 at its other end due to self weight, and the sensor 22 at its one end comes to a position separated from the drum 3. When the upper side portion is closed, first, a member 20 butting piece 23 tip butts against a roller support member 13b, and the member 20 rotates anti-clockwise, and the sensor 22 faces accurately to the center of the drum 3, and the density of a target image formed on its surface comes to be able to be inspected surely. |
