Abstract: A device for developing an electrostatic latent image that includes a developing roller which is disposed in a developing housing, holds the developing agent on its peripheral surface, and conveys the developing agent that is held to a developing zone, a feeding roller for feeding the developing agent onto the peripheral surface of the developing roller, and seals that are disposed so as to be opposed to both ends of the developing roller from the downstream side of the developing zone to the upstream side of a developing agent-limiting zone. The device further includes seal lips that are formed in a protruding manner and which extend from one end on the side of the developing zone to an opposite end on the side of the developing agent-limiting zone. The feeding or replenishing roller is positioned so that its end surfaces are in contact with the inner end surfaces of the seals.

Abstract: A device for developing an electrostatic latent image includes a developing housing having a developing chamber and stirrer chamber, a replenishing device for feeding the developing agent onto the peripheral surface of the developing roller, a stirring device disposed in the stirrer chamber to stir the developing chamber, and a developing agent detecting sensor disposed in the developing housing under the stirring device. The stirring device has a rotary shaft, a cleaning member mounted on the rotary shaft at a position corresponding to a development agent detector unit of the developing agent detecting sensor, and a stirrer member mounted on the rotary shaft at the side of the cleaning member. The stirrer member is provided with tilted guide portions for sending the stirred developing agent toward the developing agent detecting sensor.

Abstract: A device for developing an electrostatic latent image including a developing housing having a developing chamber, a stirrer chamber, and a developing agent-feeding port communicating with the stirrer chamber. A developing roller is disposed in the developing chamber to hold, on the peripheral surface thereof, a developing agent in a developing agent-holding zone, and convey the thus held developing agent to a developing zone to apply it to the electrostatic latent image. A replenishing device feeds the developing agent onto the peripheral surface of the developing roller in the developing agent-holding zone. A stirring device disposed in the stirrer chamber stirs the developing agent that is fed through the developing agent-feeding port and sends the stirred developing agent to the developing chamber. A vibration plate having a plurality of developing agent-flow ports is disposed at the developing agent-feeding port of the developing housing, and the stirring device is caused to act on the vibration plate.