Abstract: A developing device includes a developer bearer, a developer regulator disposed opposite the developer bearer across a first gap, and an opposing member having an opposing face disposed opposing the developer bearer across a second gap wider than the first gap. The opposing face is disposed adjacent to and upstream from the developer regulator in a direction of rotation of the developer bearer. The opposing face is inclined relative to an orthogonal plane direction orthogonal to a side face of the developer regulator. The opposing face is inclined to progressively reduce a distance from the developer bearer to the opposing face in a direction of rotation of the developer bearer. A difference between the second gap and the first gap is not greater than 1.75 times as large as the first gap.

Abstract: A powder amount detector includes a vibration plate secured to a powder container to contain powder and positioned at a predetermined position in a stationary state, a shaft to rotate inside the powder container, a contact member attached to the shaft, a vibration detector to detect vibration of the vibration plate, and a detection result processor to determine an amount of the powder in the powder container according to a detection result generated by the vibration detector. The contact member is to flip the vibration plate to cause the vibration plate to repeat elastic deformation and reversion to vibrate. The contact member is to exit an area opposed to the vibration plate after the contact member flips the vibration plate by the time the vibration plate returns to the predetermined position.

Abstract: A powder supply device that includes a powder reservoir including a rotator having a rotation shaft, to store powder supplied from a powder container; and a powder amount detector. The powder amount detector includes a detected member disposed in the powder reservoir, a contact member attached to the rotation shaft, to contact the detected member to vibrate or move the detected member, a detector to detect vibration or a displacement of the detected member, and a detection result processor to detect the amount of the powder in the powder reservoir based on detection by the detector. The powder supply device further includes a controller to supply the powder from the powder container to the powder reservoir based on detection by the powder amount detector. The controller rotates the rotator in discharging the powder from the powder reservoir and supplying the powder from the powder container to the powder reservoir.

Abstract: A developing device includes a developer bearer to carry, by rotation, developer to a developing range, a casing including a developer container to contain the developer and housing the developer bearer, a gap retainer adjacent to the developer container and downstream from the developing range in a rotation direction of the developer bearer, an opposing wall opposing an end face of the gap retainer in an axial direction of the developer bearer, a first seal disposed between the end face of the gap retainer and the opposing wall, and a contact portion disposed adjacent to an end portion of the gap retainer in the axial direction of the developer bearer. The gap retainer secures a predetermined gap between the developer bearer and the gap retainer. The contact portion contacts, via a second seal, the gap retainer in a direction intersecting the axial direction of the developer bearer.

Abstract: A powder amount detector includes a vibration plate secured to a powder container to contain powder and positioned at a predetermined position in a stationary state, a shaft to rotate inside the powder container, a contact member attached to the shaft, a vibration detector to detect vibration of the vibration plate, and a detection result processor to determine an amount of the powder in the powder container according to a detection result generated by the vibration detector. The contact member is to flip the vibration plate to cause the vibration plate to repeat elastic deformation and reversion to vibrate. The contact member is to exit an area opposed to the vibration plate after the contact member flips the vibration plate by the time the vibration plate returns to the predetermined position.

Abstract: A developing device includes a developer bearer, a casing including a bearing support and a developer container, a developer conveyor to transport, by rotation, developer in the developer container, a bearing to fit in the bearing support and support a shaft of the developer conveyor rotatably on the casing, and a heat conductor made of a material higher in thermal conductivity than the bearing support and including a heat absorbing portion to contact the bearing and absorb heat from the bearing and a heat dissipating portion to release the heat. The bearing includes an outer ring secured to the bearing support, an inner ring to rotate together with the shaft of the developer conveyor, and a ball disposed between the outer ring and the inner ring. The heat conductor is disposed to contact the outer ring of the bearing and contactless with the inner ring and the ball.