| 摘要 |
PURPOSE:To maintain always the specified developing gap during development regardless of the presence or absence of the load of a magnet roll or the fluctuation thereof by constituting the magnet roll in such a manner that the moment in the direction reverse from the energizing direction of an energizing means hardly acts on a lever. CONSTITUTION:A developing device 21 is provided with the magnet roll 2 having a magnet roll gear 3, a gap holding roller 4, etc., and is supported on the lever 14 turntable around a fulcrum 11. The lever 14 is energized counterclockwise by the energizing means 13 such as sponge rubber to press the roller 4 to a photosensitive drum 101. The magnet roll 2 is driven by a drive gear 12 via the magnet roll gear 3 to transport a toner. Development is thus executed. Said roll is disposed in such a position where the fulcrum 11 is located near the common tangent of the basic circle of the gears 12, 3. The action of the moment in the direction reverse from the energizing direction of the energizing means 13 on the lever 14 is thereby substantially prevented and always the specified developing gap (a) is maintained regardless of the presence or absence of the load on the magnet roll 2 and the fluctuation thereof. |
