Abstract: An object is to obtain a white ink which is easy to redisperse and is re-dispersible by being shaken several tens of times with weak force at most, or alternatively, without being shaken. As a solution, a white ink composition is provided which contains 50.0% by mass or less of a titanium oxide pigment treated with silica, alumina, and contains an organic compound in a solid content of the white ink composition, and contains 5.0 parts by mass or more of an alkali-soluble resin whose weight-average molecular weight is 28,000 to 100,000 relative to 100 parts by mass of the titanium oxide pigment, and further contains a water-dispersible resin and water.

Abstract: An object is to obtain an ink set capable of forming images of excellent image quality even when an acidic atmosphere, arising from use of a volatile acid in a pretreatment solution, is present in the vicinity of ink nozzles, etc. As a solution, an ink set containing a pretreatment solution and an ink composition is provided, wherein: the pretreatment solution contains an organic acid having a boiling point of 120° C. or lower at 1 atmospheric pressure; and the ink composition contains a pigment and an alkali-soluble resin having an acid value of 200 mgKOH/g or higher or crosslinked substance thereof accounting for 1.8% by mass or more in the ink composition, and further contains a water-dispersible resin and water.

Abstract: A cartridge includes a photosensitive drum supported by a frame, a coupling positioned at an end of the photosensitive drum, with the coupling being configured to receive a driving force for rotating the photosensitive drum. A lever is movably supported by a part of the frame at a position that is adjacent to the end of the photosensitive drum, with the lever being movable between a first position and a second position. As viewed along the axis of the photosensitive drum, an end of the lever is a first distance from the axis of the photosensitive drum when the lever is in the first position, and the end of the lever is a second distance from the axis of the photosensitive drum when the lever is in the second position, with the second distance being greater than the first distance.

Abstract: To accomplish engagement between a coupling member and a drive transmission member of main assembly. A drum unit includes a photosensitive drum and a coupling member which is provided adjacent to an end portion of the photosensitive drum and which is connected with the photosensitive drum so as to be capable of drive transmission. the coupling member is inclinable relative to a rotational axis of the photosensitive drum, and an inclination angle relative to photosensitive drum is reduced with rotational driving operation.

Abstract: An object is to provide a prebiotic which efficiently proliferates a butyrate-producing bacterium. An oligosaccharide which is composed of ?-D-mannuronic acid and/or ?-L-guluronic acid and which has an unsaturated form of ?-D-mannuronic acid residue or ?-L-guluronic acid residue at the non-reducing end or a salt thereof is used as an active ingredient of a prebiotic composition for a butyrate-producing bacterium. The oligosaccharide can be produced by causing an alginate lyase to act on alginic acid and/or a salt thereof or a hydrolysate thereof and thus obtaining a degradation product of alginic acid.

Abstract: A cartridge includes a container, a light guide including incident and emergent portions, and a cover including outer and inner surfaces. When a direction directing from the outer surface toward the inner surface is a first direction, and a direction in which the incident and emergent portions are arranged is a second direction, (i) the outer surface is recessed toward a downstream side of the first direction between the incident and emergent portions, (ii) a first end of a bottom of the recessed portion on an incident portion side is positioned on a side downstream with respect to the first direction, of a second end of the bottom on an emergent portion side, and (iii) the bottom is curved so as to be recessed toward the downstream side of the first direction between the first and second ends relative to an imaginary rectilinear line connecting these ends.

Abstract: A cartridge includes a photosensitive drum and a developing roller, with the developing roller being configured to develop a latent image formed on the photosensitive drum with toner. The cartridge also includes a first electrical contact electrically connected to the charging roller and the second electrical contact electrically connected to the developing roller. As viewed along the axis of the photosensitive drum, the first electrical contact and the second electrical contact are positioned on opposite sides with respect to a line that passes through an axis of the photosensitive drum and an axis of the developing roller.

Abstract: A process cartridge includes a photosensitive drum supported by the frame. A coupling is operatively connected to the photosensitive drum such that a driving force can be transferred from the coupling to the photosensitive drum, and a developing roller is supported by the frame. A first gear is operatively connected to the photosensitive drum and the developing roller such that the driving force can be transmitted from the coupling to the developing roller. A second gear is positioned at a side of the process cartridge, with the second gear having a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge, and with a tip of at least one of the exposed teeth facing an axis of the photosensitive drum.

Abstract: A process cartridge includes a frame and a photosensitive drum supported by the frame, with the photosensitive drum being rotatable about an axis thereof. A coupling is operatively connected to the photosensitive drum such that a driving force can be transferred from the coupling to the photosensitive drum. A developing roller is supported by the frame, with the developing roller being rotatable about an axis thereof. A gear is positioned at a side of the process cartridge, with the gear being rotatable about an axis thereof. The gear has a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge, and with a tip of at least one of the exposed teeth facing the axis of the photosensitive drum. As measured in the axial direction of the photosensitive drum, the teeth of the gear are shorter than the projection of the coupling.

Abstract: A driving-force transmission member includes a coupling portion that includes a driving-force transmission surface and that transmits a driving force to a cartridge coupling, a first helical gear portion that engages with a driven gear of a cartridge to transmit the driving force, and a second helical gear portion that engages with a drive gear to receive the driving force. The portions rotate integrally with each other when the driving-force transmission member rotates about the axis of rotation. The driving-force transmission surface is shaped with a twist in the same direction as the driving-force transmission member. Helical teeth of the first helical gear portion are shaped with a twist in the same direction as the driving-force transmission surface. Helical teeth of the second helical gear portion are shaped with a twist in a direction opposite to the twist direction of the helical teeth of the first helical gear portion.

Abstract: A process cartridge includes a frame, a photosensitive drum supported by the frame, and a developing roller supported by the frame. A coupling is operatively connected to the photosensitive drum, with the coupling being rotatable about an axis thereof, and with the coupling being positioned (i) at a first end of the photosensitive drum, (ii) coaxial with the photosensitive drum, and (iii) at a side of the process cartridge. A helical gear is positioned at the side of the process cartridge, the helical gear being rotatable about an axis thereof, the helical gear having a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge. As measured in an axial direction of the photosensitive drum, at least a part of the exposed teeth of the helical gear is positioned farther from the second end of the photosensitive drum than a tip of a projection of the coupling is positioned from the second end of the photosensitive drum.

Abstract: A cartridge includes a photosensitive drum supported by a frame, a coupling positioned at an end of the photosensitive drum, with the coupling being configured to receive a driving force for rotating the photosensitive drum. A lever is movably supported by a part of the frame at a position that is adjacent to the end of the photosensitive drum, with the lever being movable between a first position and a second position. As viewed along the axis of the photosensitive drum, an end of the lever is a first distance from the axis of the photosensitive drum when the lever is in the first position, and the end of the lever is a second distance from the axis of the photosensitive drum when the lever is in the second position, with the second distance being greater than the first distance.

Abstract: A cartridge includes a photosensitive drum, the movable member movable relative to the photosensitive drum to control an inclination angle of a drive transmission member. The movable member is movable between a first position for reducing an inclination angle of the drive transmission member relative to the photosensitive drum and a second position retracted from the first position. By this, driving connection can be smoothly carried out.

Abstract: To provide a structure for the process cartridge for receiving input of driving force from outside thereof. The main assembly of the electrophotographic image forming apparatus includes a driving output member provided with an output gear portion and an output coupling portion. The process cartridge that can be mounted to and dismounted from the main assembly of the electrophotographic image forming apparatus includes a photosensitive member, an input coupling portion provided at the end of the photosensitive member and capable of coupling with the output coupling portion, and an input gear portion capable of meshing with the output gear portion.

Abstract: A process cartridge includes a frame, a photosensitive drum supported by the frame, and a developing roller supported by the frame. A coupling is operatively connected to the photosensitive drum, with the coupling being rotatable about an axis thereof, and with the coupling being positioned (i) at a first end of the photosensitive drum, (ii) coaxial with the photosensitive drum, and (iii) at a side of the process cartridge. A helical gear is positioned at the side of the process cartridge, the helical gear being rotatable about an axis thereof, the helical gear having a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge. As measured in an axial direction of the photosensitive drum, at least a part of the exposed teeth of the helical gear is positioned farther from the second end of the photosensitive drum than a tip of a projection of the coupling is positioned from the second end of the photosensitive drum.

Abstract: A cartridge includes a photosensitive drum, the movable member movable relative to the photosensitive drum to control an inclination angle of a drive transmission member. The movable member is movable between a first position for reducing an inclination angle of the drive transmission member relative to the photosensitive drum and a second position retracted from the first position. By this, driving connection can be smoothly carried out.

Abstract: A photosensitive member unit detachably mountable to a main assembly of an image forming apparatus, the image forming apparatus including a first main assembly side helical gear portion and a second main assembly side helical gear portion which are coaxially rotatable, the photosensitive member unit includes a photosensitive member rotatable about a rotational axis thereof; a first unit side helical gear portion for meshing engagement with the first main assembly side helical gear portion; and a second unit side helical gear portion for meshing engagement with the second main assembly side helical gear portion, wherein a twisting direction of a tooth of the second unit side helical gear portion is the same as the twisting direction of a tooth of first unit side helical gear portion, wherein a helix angle of the tooth of the second unit side helical gear portion is larger than a helix angle of the tooth of the first unit side helical gear portion, and wherein the first unit side helical gear portion and the se

Abstract: An aspect is to provide a prebiotic for growing a butyrate-producing bacterium. A prebiotic composition for a butyrate-producing bacterium includes alginic acid and/or a salt thereof having an average molecular weight of 10000 or less.

Abstract: A cartridge mountable to and dismountable from a main assembly of an image forming apparatus includes a memory, a guide configured to guide a portion-to-be-guided provided in the main assembly and to guide a main assembly contact provided in the main assembly to a memory contact of the memory when the cartridge is mounted in the main assembly, and a grip portion. The guide is provided at a bottom of the cartridge when the cartridge is hung by gripping the grip portion and constitutes a part of a supporting portion configured to support the cartridge when the cartridge is placed on a horizontal placement surface. The guide has a chamfered surface formed by being chamfered. When the cartridge is supported at the supporting portion, the chamfered surface opposes the horizontal placement surface, and a surface of the memory contact is inclined with respect to the horizontal placement surface.

Abstract: A process cartridge includes a frame having a slit and a recess formed therein at a side of the process cartridge. A photosensitive drum is supported by the frame, with the photosensitive drum being rotatable about an axis thereof, the photosensitive drum including a first end and a second end opposite to the first end. A developing roller is also supported by the frame, the developing roller being rotatable about an axis thereof. A coupling is operatively connected to the photosensitive drum, with the coupling being rotatable about an axis thereof. A helical gear is positioned at the side of the process cartridge, with the helical gear being rotatable about an axis thereof. The helical gear has a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge.