JPS5665167A - Developing device - Google Patents

Abstract

PURPOSE:To detect assuredly the residual amount of the developing agent in a simple constitution, by pushing the residual amount detecting component provided to a developing unit in a free-rocking way with the rotating developing agent stirring component to give a rock to the residual amount detecting component. CONSTITUTION:In the developing unit 5, the stirring component 6 is attached to the shaft 9 which turns in accordance with rotation of the photosensitive drum, and the residual amount detecting component 13 is attached to the free-rocking shaft 14. The component 6, when turning, pushes the component 13 to turn the shaft 9. As no coaxial rotation is given between the components 6 and 13, the engagement is released between these components at the point B where component 6 had rotations to some extent. In case much amount of the developing agent exists, the component 13 stops at the position B and is then reset toward A by the empty weight or the force of spring when the component 13 is at and after B. The component which detects the movement of the shaft 14 is provided at the area of the shaft 14 and outside the unit 5. Thus the residual amount of the developing agent is detected by the pulse signal produced with the detection signal.