A toner container information acquiring method includes: measuring a toner amount contained in a resin forming a toner container; and acquiring information regarding mechanical strength of the toner container based on the measured toner amount.

There are demands for stable connections of contact points between a process cartridge, including a development device, and an image forming device. A development contact point, a first contact point, and a second contact point are disposed in this order on the inside in a perpendicular direction with respect to an insertion direction in which a development device is inserted into an image forming apparatus.

An amount-of-remaining-toner detecting device includes: a toner housing portion in which a toner bottle is housed, the toner bottle having a bottle body that is cylindrical and in which toner is housed, and a cap that is attached to one end of the bottle body in an axial direction of the bottle body and from which the toner housed in the bottle body is discharged; and circuitry configured to detect an amount of remaining toner in the toner bottle housed in the toner housing portion. The toner housing portion includes a first pair of electrodes facing each other with the bottle body interposed between the first pair of electrodes, and a second pair of electrodes facing each other with the bottle body interposed between the second pair of electrodes, at respective positions closer to the cap than the first pair of electrodes are. The circuitry detects the amount of remaining toner in the bottle body, based on at least one of a capacitance value between the first pair of electrodes or a capacitance value between the second pair of electrodes.

A remaining-toner-amount detecting device includes: first sensor disposed at a supply channel for a toner; a second sensor disposed at a location different from the supply channel; detection processing that compares a capacitance detected by the first sensor with a determination threshold value to detect a toner end; and a memory that stores a capacitance detected by the second sensor in an initial period as initial reference data, and a capacitance detected by the second sensor after part replacement as post-replacement reference data. The detection processing circuitry sets, based on the initial reference data, the determination threshold value as an initial determination threshold value in the initial period, and re-sets the determination threshold value, from the initial determination threshold value, to a value based on the post-replacement reference data, as a post-replacement reference data after the part replacement.

A resin member includes a base material and a resin molded body disposed on the base material, the resin molded body containing a main component constituted by an ethylene-vinyl acetate copolymer resin and a carbon black. The resin molded body has two or more peaks within a range of 25° C. to 80° C. in an endothermic curve obtained through measurement performed by heating from 25° C. to 150° C. at 5° C./min with a differential scanning calorimetry (DSC) apparatus.

A developing apparatus includes: a developer tank that contains a developer; and conveyance members that convey the developer while agitating the developer. The conveyance members include a first screw and a second screw. The developer tank includes: a first storage chamber in which the first screw is provided; a second storage chamber in which the second screw is provided; a partition that separates the first storage chamber from the second storage chamber; and a flow area that opens the partition to flow the developer between the first storage chamber and the second storage chamber; a developer detection sensor that detects an amount of the developer thereof; a discharge port that discharges the developer; and a discharge guide that guides the developer to the discharge port. The developer detection sensor detects that the developer tank is full according to the amount of the developer.

A remaining toner amount detection device includes four electrodes and a controller. Each electrode has an arc shape along an outer circumferential surface of a toner bottle, and the four electrodes are spaced a certain distance apart in a circumferential direction so as to surround the toner bottle. The controller detects a remaining toner amount inside the toner bottle by using the four electrodes. The controller determines whether at least one of a first electrostatic capacity value between one pair of adjacent electrodes and a second electrostatic capacity value between the other pair of adjacent electrodes falls within a threshold range. In response to determination that at least one of the electrostatic capacity values falls within the threshold range, the controller detects a remaining toner amount inside the toner bottle based on an electrostatic capacity value, and outputs the detected remaining toner amount.

A replaceable unit for an electrophotographic image forming device according to one example embodiment includes a housing having a reservoir for storing toner. A rotatable shaft is positioned within the reservoir and has an axis of rotation. A first magnet and a second magnet are connected to the shaft and rotatable around the axis of rotation in response to rotation of the shaft. The first magnet and the second magnet pass near at least a portion of an inner wall of the housing forming the reservoir during rotation of the first and second magnets. An amount of angular offset between the first magnet and the second magnet varies depending on an amount of toner in the reservoir.

A developing device includes a developing container, a detecting unit including a base portion and a detecting portion, a feeding path, a feeding screw, and a recessed portion provided on a side wall of the developing container. The recessed portion is disposed so as to project toward the feeding screw in the feeding path. The side wall includes a projected region projected toward the screw portion in the feeding path by the recessed portion and a region other than the projected region. The feeding screw includes a first screw portion opposing the projected region and a second screw portion opposing the region other than the projected region. The first screw portion includes a rotation shaft which includes a portion having a shaft diameter smaller than a shaft diameter of a rotation shaft of the second screw portion.

A developing apparatus includes: a developer tank that contains a developer; and conveyance members that convey the developer while agitating the developer. The conveyance members include a first screw and a second screw. The developer tank includes: a first storage chamber in which the first screw is provided; a second storage chamber in which the second screw is provided; a partition that separates the first storage chamber from the second storage chamber; and a flow area that opens the partition to flow the developer between the first storage chamber and the second storage chamber; a developer detection sensor that detects an amount of the developer thereof; a discharge port that discharges the developer; and a discharge guide that guides the developer to the discharge port. The developer detection sensor detects that the developer tank is full according to the amount of the developer.