In a cartridge, a housing has a developer accommodating portion and includes a first side wall and a second side wall. A coupling member is disposed at a position opposite to the developer accommodating portion with respect to the first side wall. A detection body is disposed at a position opposite to the developer accommodating portion with respect to the second side wall. A first driving force transmission member is positioned at the same side with the coupling member with respect to the first side wall, and transmits driving force from the coupling member to a rotating member. A second driving force transmission member is positioned at the same side with the detection body with respect to the second side wall, and transmits driving force from the rotating member to the detection body.

A developing roller is located nearer a first end than a second end in a first direction. A first boss extends in a second direction and is movable together with a housing. The first boss bears the weight of a developer cartridge when the first boss is supported by a support surface of a first side plate of a drum unit, and is located away from the developing roller in the first direction and the third direction. A first pressure receiving surface is located farther away from the developing roller than the first boss in the third direction. The pressure receiving member receives a pressing force in the third direction from a pressing member of the first side plate of the drum unit. The first boss is located away from the developing roller in the first direction by a first distance. The first pressure receiving surface is located away from the developing roller in the first direction by the first distance or by a second distance smaller than the first distance.

A cartridge includes: a housing; a storage medium; and a holder. The storage medium has an electrical contact surface. The holder is movable relative to the housing. The holder includes: a first holder member; and a second holder member. The first holder member has a pawl portion and is configured to hold the electrical contact surface. The second holder member includes a corner portion. The pawl portion is engageable with the corner portion. The second holder member has a through-hole. An engagement part of the pawl portion engaging with the corner portion is accessible from outside the second holder member through the through-hole in a state where the pawl portion engages with the corner portion.

An example toner cartridge includes a housing to contain toner and having a toner outlet, a conveying member, a shutter to open and close the toner outlet, a driven coupler to rotate the conveying member and having an extension that extends in an axial direction, and a protruding member including a rotational force receiver installed in the extension so as to move to a protruding position in which the rotational force receiver protrudes from the extension and a retracted position in which the rotational force receiver is received into the extension in conjunction with opening and closing operations of the shutter.

A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin; the Mg element in an amount such that the net intensity of x-ray fluorescence from the Mg element in the toner is 0.10 kcps or more and 1.20 kcps or less; and external additives including particles of at least one compound represented by formula (1) and particles of a metal salt of a fatty acid,
MTiO.sub.3  (1)
where M represents at least one selected from the group consisting of Ca, Sr, and Ba.

A toner conveying device for conveying toner, comprising: a first conveying portion; and a second conveying portion conveying the toner conveyed from the first conveying portion. The first conveying portion further includes: a first screw which includes a first rotation shaft and a first blade portion, the first screw including an engaging portion and a first protruded portion on a first end portion; and a first conveying passage forming member having a first inner wall face which forms a first conveying passage. The second conveying portion includes: a second screw which includes a second rotation shaft and a second blade portion, the second screw including an engaged portion and a second protruded portion on a second end portion; and a second conveying passage forming member having a second inner wall face which forms a second conveying passage, and which is connected with the first conveying passage forming member.

A toner particle includes a core particle including a binder resin, and a plurality of fine particles that are smaller than the core particle and that are attached to a surface of the core particle. The fine particles include silica fine particles, and inorganic fine particles having a band gap energy of 2.5 to 7.0 eV and a relative permittivity of 30 to 100. The toner particle has a content of titanium dioxide of less than 1% by mass.

A nozzle insertion member is in a powder container that includes a nozzle insertion opening into which a conveying nozzle is inserted. The nozzle insertion member includes an opening/closing structure to move to an opening position to open the nozzle insertion opening by being pressed by the inserted conveying nozzle, and to a closing position to close the nozzle insertion opening when the conveying nozzle is separated from the nozzle insertion member, and a seal arranged at the nozzle insertion opening and including a through hole into which the conveying nozzle is insertable. The opening/closing structure includes a front cylindrical portion to contact with an inner surface of the through hole, and a slide area formed on another side relative to the front cylindrical portion. W1<W4 is satisfied, where W1 is an inner diameter of the through hole, and W4 is an outer diameter of the slide area.

The present invention provides an image forming apparatus including: a first moving member pressed and moved by an openable/closable member when the openable/closable member is opened, and switching a cartridge from a state where the cartridge is positioned in an image forming position to a state where the positioning is released; and a second moving member pressed and moved by the openable/closable member when the openable/closable member is opened, and moving the exposure member from an exposure position to a retracted position, wherein when the positioning of the cartridge is released, a reaction force applied from the first moving member to the openable/closable member reaches a first peak, when the exposure member is moved to the retracted position, a reaction force applied from the second moving member to the openable/closable member reaches a second peak, and timing of the first peak is different from timing of the second peak.

A toner container includes a toner accommodating body, a nozzle in fluid communication with the toner accommodating body, and a shutter configured to open and close the opening of the nozzle. A projection is positioned at an end portion of the toner container in a direction of the rotational axis, the projection having an inner peripheral surface facing towards the rotational axis. When the toner container is oriented such that the toner accommodating body is above the nozzle, the nozzle is above the projection, and the projection is at a bottommost side of the toner container, (i) the opening of the nozzle is positioned such that toner may be discharged from a lateral side of the toner container that is above the bottommost side, (ii) the projection includes (ii-i) a first surface facing downward, (ii-ii) a second surface facing downward, and (ii-iii) a third surface facing upward, with the first surface, the second surface, and the third surface being positioned outside the inner peripheral surface of the projection and inside the opening of the nozzle in the direction perpendicular to the rotational axis, (iii) the first surface extends such that a distance in the direction of the rotational axis from the first surface to the toner accommodating body decreases along the first surface in the first rotational direction, (iv) the second surface extends such that a distance in the direction of the rotational axis from the second surface to the toner accommodating body decreases along the second surface in the first rotational direction, (v) a distance, measured along a line that is perpendicular to the rotational axis, from the rotational axis to at least a part of the first surface is less than a distance, measured along a line that is perpendicular to the rotational axis, from the rotational axis to a part of the second surface that is closest from the rotational axis, and (vi) at least a part of the third surface is above an uppermost part of the second surface.