Patent classifications
G03G21/1814
ELECTROPHOTOGRAPHIC ROLLER, PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS
An electrophotographic roller includes: a mandrel and an elastic layer on the mandrel, and having a crown shape in which a diameter decreases from a central position O in a longitudinal direction of the mandrel toward an end portion. When a position of the end portion in the longitudinal direction of the elastic layer is defined as X2, a position between the ) and the X2 is defined as X1, a distance between the O and the X1 is defined as L1, and a distance between the X1 and the X2 is defined as L2, L1=0.6×(L1+L2). When outer diameters of the electrophotographic roller at O, X1 and X2 are defined as Do, DX1 and DX2, respectively, and Z1=(Do−DX1)/2 and Z2=(DX1−DX2)/2 are defined, Z1, Z2, L1 and L2 satisfy (Z2/L2)<1.931×(Z1/L1).
Carrier for forming electrophotographic image, developer for forming electrophotographic image, electrophotographic image forming method, electrophotographic image forming apparatus, and process cartridge
A carrier for forming an electrophotographic image is provided. The carrier comprises a core particle and a resin layer coating the core particle. The resin layer contains a chargeable particle A, a conductive particle B, a dispersing agent, and a defoaming agent.
Drum cartridge and image forming apparatus
A drum cartridge including a photosensitive drum, a drum frame configured to retain the photosensitive drum and to accept a developing cartridge including a toner memory, which stores information concerning the developing cartridge, a first connector electrically connectable with the toner memory in the developing cartridge under a condition where the developing cartridge is attached to the drum frame, a relay board electrically connectable with the first connector, a second connector electrically connectable with a connector in an image forming apparatus and with the toner memory through the relay board, and a thermistor electrically connectable with the relay board, is provided.
Conductive roller, transfer device, process cartridge, and image forming apparatus
A conductive roller includes a support member, an elastic layer disposed on an outer peripheral surface of the support member, and an outer layer disposed on an outer peripheral surface of the elastic layer. The elastic layer includes a cylindrical elastic foam and has a Young□s modulus of 150 kPa or less.
ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, TONER CARTRIDGE, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS
An electrostatic charge image developing toner includes: a toner particle containing a binder resin; and an external additive containing alumina particles having a volume average particle diameter of more than 5 nm and 80 nm or less and silica particles having a volume average particle diameter of 10 nm or more and 90 nm or less, and in the toner particle, a Net intensity N.sub.A of a total of an alkali metal element and an alkaline earth metal element, measured by fluorescence X-ray analysis, is 0.10 kcps or more and 1.30 kcps or less, and a ratio (Ws/Wa) of a content Ws of the silica particles to a content Wa of the alumina particles is more than 0.5 and less than 35.
ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, TONER CARTRIDGE, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS
An electrostatic charge image developing toner contains: a toner particle including a core portion containing a binder resin and a release agent that has a melting temperature Tm of 80° C. or less, and a coating layer that coats the core portion and contains an amorphous polyester resin, and the toner particle has a cross section in which one or more and three or less domains of the release agent are present in the core portion, the one or more and three or less domains having a circle-equivalent diameter of 1 μm or more and 3 μm or less, the toner particle has a volume average particle diameter of 4.2 μm or more and 5.8 μm or less, and a ratio of a thickness of the coating layer to a maximum diameter of the toner particle is 1% or more and 25% or less in the cross section.
ELECTROSTATIC CHARGE IMAGE DEVELOPER, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS, AND IMAGE FORMING METHOD
An electrostatic charge image developer contains: a toner containing a toner particle and an external additive; and a carrier containing a magnetic particle and a resin layer covering the magnetic particle; and the toner particle has a surface property index value of 1.0 or more and less than 2.0; and the carrier has a surface having a ratio B/A of a surface area B to a plane view area A of 1.020 or more and 1.100 or less, the plane view area A and the surface area B being obtained by three-dimensional analysis of the surface of the carrier.
ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, METHOD FOR PRODUCING ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER, TONER CARTRIDGE, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS, AND IMAGE FORMING METHOD
An electrostatic charge image developing toner includes a toner particle containing a binder resin and a releasing agent, and the following requirement (1) is satisfied in cross section observation of the toner particle: requirement (1): the number of a releasing agent domain having a long diameter of 500 nm or more and 1,000 nm or less is 7 or more on average per toner particle.
ELECTROSTATIC CHARGE IMAGE DEVELOPER, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS, AND IMAGE FORMING METHOD
An electrostatic charge image developer containing: a toner containing a toner particle and an external additive; and a carrier containing a magnetic particle and a resin layer covering the magnetic particle, in which the toner particle has a surface property index value of 2.0 or more and 2.8 or less; and the carrier has a surface having a ratio BIA of a surface area B to a planar view area A of 1.020 or more and 1.100 or less, the planar view area A and the surface area B being obtained by three-dimensional analysis of the surface of the carrier.
TONER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE, ELECTROSTATIC CHARGE IMAGE DEVELOPER, TONER CARTRIDGE, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS
A toner for developing an electrostatic charge image includes toner particles that include a binder resin, a releasing agent, a brilliant pigment, and an aminocarboxylic acid compound.