An electrostatic image developer includes a toner containing toner particles, a carrier, and an external additive containing titanium dioxide particles of two types having different refractive indexes, fatty acid metal salt particles, and an abrasive.

A particle conveying device includes a storage portion that stores pressure sensitive adhesive particles that contain at least a binder resin, have a pressure-induced phase transition property, and have a sulfur content in a range of 0.1 mass % or more and 0.5 mass % or less relative to the entire pressure sensitive adhesive particles as measured by X-ray fluorescence; and a conveying member that is disposed in the storage portion and rotates about a shaft that extends in one direction inside the storage portion to thereby convey the pressure sensitive adhesive particles in a direction along the shaft inside the storage portion.

An image forming apparatus, includes: plural image forming units each including an image holding member and configured to form an image that is to be transferred to a recording medium on the image holding member using a dry toner, the number of the plural image forming units being at least five; and plural developing devices each of which is provided in each of the plural image forming units and supplied with the dry toner and a dry carrier, each of the plural developing devices including a dry toner adhering unit that has a length equal to or longer than a length of a long side of an A3 size and to which the dry toner adheres, the dry toner adhering unit being configured to cause the dry toner adhering to the dry toner adhering unit to adhere to the image holding member.

A powder conveying device includes a first conveyor, a first conveyance passage, a fall passage, a second conveyor, and a second conveyance passage. The first conveyor conveys powder in a substantially horizontal direction and is disposed in the first conveyance passage. The powder output from an outlet port of the first conveyance passage is to fall in the fall passage. The second conveyor conveys the powder in the substantially horizontal direction and is disposed in the second conveyance passage that has an inlet port to receive the powder falling in the fall passage. When viewed in a cross section orthogonal to a powder conveyance direction, a cross-sectional area of a space that is not occupied by the first conveyor in the first conveyance passage is larger than a cross-sectional area of a space that is not occupied by the second conveyor in the second conveyance passage.

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 development device including: a developer bearing; a regulation portion; a magnetic field generation member that is provided inside of the developer bearing member, the magnetic field generation member having: a development pole; a first magnetic pole; and a second magnetic pole; wherein the magnetic field generation member has a region satisfying |(Br(θa)−Br(θc))/10|<0.3, wherein Br(θa) is a magnetic flux density in a normal direction relative to the surface of the developer bearing member on a position shifted by −5° from a point nearest to the regulation portion on the developer bearing member around a center of the developer bearing member, and Br(θc) is the magnetic flux density around the developer bearing member on a position shifted by +5° from the point nearest to the regulation portion on the developer bearing member.

A toner of the present invention includes at least a colorant and a resin, has crystallinity CX or 20 or greater, and has a dynamic viscoelasticity characteristic in which a logarithmic value Log G′(50) of storage elastic modulus (Pa) at 50° C. is from 6.5 to 8.0 and a logarithmic value Log G′(65) of storage elastic modulus (Pa) at 65° C. is from 4.5 to 6.0, when the dynamic viscoelasticity characteristic is measured by temperature sweep from 40° C., at a frequency of 1 Hz, at a strain amount control of 0.1%, and at a temperature elevating rate of 2° C./min.

An electrostatic charge image developer includes a toner that includes a toner particle; and a carrier, wherein the toner particle contains a brilliant pigment, an exposed amount of the brilliant pigment contained in the toner particle is from 0.5% to 5%, the carrier has a core particle and a coating layer which covers a surface of the core particle, the coating layer contains a silicone resin and a siloxane oligomer, and a content of the siloxane oligomer is from 0.1 ppm to 500 ppm with respect to a total weight of the coating layer.

An image forming apparatus includes a rotatable image bearing member and a rotatable developing member to carry developer made up of toner particles and carrier particles adhered to surfaces of the toner particles. Where a pressing force pressing the developing member against the image bearing member is F1, a total number of the carrier particles interposed between the toner particles and the image bearing member is N1, and an adhesion Ft between a carrier particle and a toner particle, measured when the carrier particle is pressed against the toner particle with F1/N1 that is a pressing force per unit carrier particle, and an adhesion Fdr1 between the carrier particle and the image bearing member, measured when the carrier particle is pressed against the image bearing member with F1/N1, satisfy Ft≤Fdr1.

According to an aspect of the invention, a developing device includes a developing container that accommodates a two-component developer, a toner concentration detecting unit that detects a toner concentration of the developer by a detecting unit exposed to an inner wall of the developing container, a transport member that is disposed within the developing container and stirs and transport the developer with a transport blade having a pitch that is equal to or less than a size of the detecting unit of the toner concentration detecting unit, and a plurality of gap holding members that is provided at a position facing the toner concentration detecting unit of the transport member and holds a gap such that a tip thereof is abutted against the inner wall of the developing container.