Abstract: An oligoester is obtained by subjecting the following to an esterification reaction: component (A), a glycerin; component (B), a dicarboxylic acid having 2-12 carbon atoms; and component (C), one or more types of fatty acid selected from the group consisting of caprylic acid, ethylhexanoic acid, isononanoic acid, isopalmitic acid and isostearic acid. The esterification reaction involves esterifying 0.65-0.8 moles of the component (B) and 1.2-1.7 moles of the component (C) relative to 1 mole of the component (A). The oligoester has an acid value of 5 mgKOH/g or less, a saponification value of 420-510 mgKOH/g and a hydroxyl value of 60 mgKOH/g or less.

Abstract: A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.

Abstract: An optical fiber-embedded PC steel strand includes a PC steel strand in which a plurality of PC steel wires are twisted together, and an optical fiber. The optical fiber is fixed with a resin in a twist groove that is a groove between two PC steel wires of the PC steel wires, the two PC steel wires being disposed at an outer surface of the PC steel strand and being next to each other. A coefficient of variation in distance between a common tangent of the two PC steel wires that form the twist groove and are next to each other, and a center of the optical fiber is 0.5 or less, as measured in 10 cross sections of the PC steel strand that are perpendicular to a longitudinal direction of the PC steel strand.

Abstract: One aspect of the present invention provides a method for manufacturing a strain wave gear device. The method includes steps of measuring a between pin diameter of an internal gear, measuring an over pin diameter of an external gear, where the external gear is to be placed radially inside the internal gear, configured to mesh with the internal gear, and flexible, measuring a dimension of a bearing, where the bearing is to be placed radially inside the external gear, and flexible, and machining an elliptical cam, where the elliptical cam is to be placed radially inside the bearing, and configured to flex the external gear in a non-circular manner. The elliptical cam is machined based on the measured dimensions of the internal gear, external gear and bearing such that the internal and external gears mesh with each other at a constant position.

Abstract: A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.

Abstract: A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.

Abstract: One aspect of the present invention provides a method for manufacturing a strain wave gear device. The method includes steps of measuring a between pin diameter of an internal gear, measuring an over pin diameter of an external gear, where the external gear is to be placed radially inside the internal gear, configured to mesh with the internal gear, and flexible, measuring a dimension of a bearing, where the bearing is to be placed radially inside the external gear, and flexible, and machining an elliptical cam, where the elliptical cam is to be placed radially inside the bearing, and configured to flex the external gear in a non-circular manner. The elliptical cam is machined based on the measured dimensions of the internal gear, external gear and bearing such that the internal and external gears mesh with each other at a constant position.

Abstract: An image forming apparatus includes a controller, a drum cartridge and a toner cartridge. The controller is configured to perform determining a value of a first initial developing bias for a first toner cartridge based on a cumulative number of drum rotations that is stored in a drum memory of the drum cartridge at the time when the cumulative dot count stored in the toner memory of the first toner cartridge is equal to zero. After determining the first initial developing bias, the controller is configured to perform determining a value of a second initial developing bias for a second toner cartridge based on the cumulative number of drum rotations that is stored in the drum memory at the time when the cumulative dot count stored in the toner memory of the second toner cartridge is equal to zero.

Abstract: Provided is an anthocyanin pigment composition having the following features: (A) an aqueous solution containing the composition and adjusted to pH of 3 with a citrate buffer (pH: 3.0) has a maximum absorption wavelength of 500 to 550 nm in the visible light region; (B) when a pigment-composition-containing aqueous solution containing the composition, 0.2 mass % citric acid, 20 mass % ethanol, and water is prepared so as to have a color value E10%1 cm of 10, 1 mL of the aqueous solution is sealed in a 20-mL vial, and the vial is stored at 50° C. for 5 days and further maintained at 40° C. for 30 minutes, the total amount of methyl mercaptan, dimethyl disulfide, and dimethyl trisulfide in the gas in the sealed space of the vial is 100 pg/mL or less; and (C) the gas in the sealed space of the vial contains 5-methylthiopentanenitrile when the vial is maintained at 40° C. for 30 minutes in (B) above.

Abstract: A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.

Abstract: A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.

Abstract: An image forming apparatus includes a controller, a drum cartridge and a toner cartridge. The controller is configured to perform determining a value of a first initial developing bias for a first toner cartridge based on a cumulative number of drum rotations that is stored in a drum memory of the drum cartridge at the time when the cumulative dot count stored in the toner memory of the first toner cartridge is equal to zero. After determining the first initial developing bias, the controller is configured to perform determining a value of a second initial developing bias for a second toner cartridge based on the cumulative number of drum rotations that is stored in the drum memory at the time when the cumulative dot count stored in the toner memory of the second toner cartridge is equal to zero.

Abstract: A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.

Abstract: An image forming apparatus includes a controller, a drum cartridge and a toner cartridge. The controller is configured to perform determining a value of a first initial developing bias for a first toner cartridge based on a cumulative number of drum rotations that is stored in a drum memory of the drum cartridge at the time when the cumulative dot count stored in the toner memory of the first toner cartridge is equal to zero. After determining the first initial developing bias, the controller is configured to perform determining a value of a second initial developing bias for a second toner cartridge based on the cumulative number of drum rotations that is stored in the drum memory at the time when the cumulative dot count stored in the toner memory of the second toner cartridge is equal to zero.

Abstract: A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.

Abstract: A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.

Abstract: An object of the present invention is to provide a technique of suppressing precipitation of an anthocyanin pigment in a range other than the highly acidic range. The present invention provides an anthocyanin pigment preparation, comprising: an anthocyanin pigment; and an emulsifier, wherein the pH when the anthocyanin pigment preparation is diluted with water or dissolved in water so that a color value becomes 10 is more than 3.

Abstract: An image forming apparatus includes a controller, a drum cartridge and a toner cartridge. The controller is configured to perform determining a value of a first initial developing bias for a first toner cartridge based on a cumulative number of drum rotations that is stored in a drum memory of the drum cartridge at the time when the cumulative dot count stored in the toner memory of the first toner cartridge is equal to zero. After determining the first initial developing bias, the controller is configured to perform determining a value of a second initial developing bias for a second toner cartridge based on the cumulative number of drum rotations that is stored in the drum memory at the time when the cumulative dot count stored in the toner memory of the second toner cartridge is equal to zero.

Abstract: A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.

Abstract: A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.