An electrophotographic belt includes a biaxially stretched cylindrical film as a base layer, wherein the biaxially stretched cylindrical film includes crystalline polyester, amorphous polyester and carbon black, a content of the carbon black with respect to the biaxially stretched cylindrical film is 2.0% by mass or more, and a surface resistivity measured on the surface of the biaxially stretched cylindrical film in an environment of 23° C. and 50% RH is 1×10.sup.3 Ω/square or higher and 1×10.sup.13 Ω/square or lower, and A/B is 3.00 or smaller, where A (Ω/square) represents a surface resistivity of the biaxially stretched cylindrical film after the film is left to stand for 24 hours in an environment of 23° C. and 50% RH, and B (Ω/square) represents a surface resistivity of the biaxially stretched cylindrical film after the film is left to stand for 24 hours in an environment of 30° C. and 80% RH.

A transfer unit, provided in an image forming apparatus having an image bearing member to bear a toner image, includes an endless belt, a transfer member, a collecting member, a storage container, a conveyance member, and a detection unit. The transfer member transfers the toner image from the image bearing member to the endless belt. The collecting member recovers toner remaining on the endless belt. The conveyance member rotates to convey toner from an inflow port inside the storage container. The detection unit detects a load which the conveyance member receives when rotating. The rotational axis direction is a direction which is perpendicular to neither a movement direction of the endless belt nor a width direction perpendicular to the movement direction of the endless belt. The conveyance member includes a force receiving portion configured to receive a force from the toner conveyed in a state the conveyance member is rotating.

An endless belt includes: a resin; and electrically conductive particles, wherein an integrated discharge amount is 350 μC or less. The integrated discharge amount is determined by disposing an electrode at a position spaced 60 μm apart from the outer circumferential surface of the belt, applying a voltage to the electrode, and measuring the amount of discharge for a period of 1 second after the voltage reaches 1300 V.

An electrophotographic belt having an endless shape and including an endless-shaped base layer, an elastic layer on an outer peripheral surface of the base layer, and a surface layer on the outer peripheral surface of the elastic layer, and the surface layer contains a urethane resin as a binder, polytetrafluoroethylene particles, and a compound having a perfluoropolyether structure and an oxyalkylene structure.

A belt device includes a belt assembly, a pressing force adjuster, and an optical sensor. The belt assembly includes multiple rollers and a belt stretched by the multiple rollers and is rotatable about a rotation axis of one of the multiple rollers. The pressing force adjuster rotates the belt assembly about the rotation axis and adjusts a contact pressure of the belt pressed against an object. The optical sensor is disposed opposite to the one of the multiple rollers, and a position of the optical sensor relative to the rotation axis is fixed while the belt assembly is rotated by the pressing force adjuster.

A transfer device includes an intermediate transferor and primary transfer sections. The primary transfer sections each includes a primary transferor. The primary transfer sections include a most-upstream primary transfer section and a most-downstream primary transfer section. One of the primary transfer sections is a special-color primary transfer section switchable between the most-upstream primary transfer section and the most-downstream primary transfer section. The primary transferor of each of the most-upstream primary transfer section and the most-downstream primary transfer section is switchable between a contact position at which the primary transferor contacts the latent image bearer and a separation position at which the primary transferor is separated from the latent image bearer. With only the primary transferor of the special-color primary transfer section at the separation position, the primary transferor of any other primary transfer section than the special-color primary transfer section is arranged at the contact position to transfer an image.

An intermediate transfer belt includes a base layer that has ionic conductivity and is a thickest layer out of multiple layers making up the intermediate transfer belt with respect to the thickness direction of the intermediate transfer belt, and an inner layer having electronic conductivity and a lower electrical resistance than the base layer.

The belt conveyance device includes a plurality of rollers, a belt, a meandering correction part, and an adjustment part. The rollers are disposed at intervals each other and rotate around axes. The belt is disposed around the plurality of rollers and travels. The meandering correction part shifts one end portion in an axial direction of a tension roller included in the plurality of rollers in a radial direction within a predetermined range to correct a meandering of the belt. The adjustment part shifts the other end portion in the axial direction of the tension roller in the radial direction such that a position of the one end portion of the tension roller is variable under a state where the meandering of the belt is corrected.

An electrophotographic belt including: a base layer, an elastic layer formed on the base layer, and a surface layer formed on the elastic layer. The surface layer contains a binder resin and polytetrafluoroethylene particles. A content of the polytetrafluoroethylene particles is 200 parts by mass or more with respect to 100 parts by mass of the binder resin. The polytetrafluoroethylene particles have a number average particle diameter of 200 nm or less.

An endless belt includes a base material layer containing a polymer material and conductive particles, wherein, in an image obtained by observing a cross section taken along a thickness direction of the base material layer with an atomic force microscope, a proportion of a total area Ap of cross sections of all the conductive particles is 9.0% or more and 14.5% or less with respect to a total cross-sectional area At of the base material layer, and a proportion of a total area Ab of cross sections of conductive particles having an area of 0.01 μm.sup.2 or more among cross sections of the conductive particles is 28.0% or more and 65.0% or less with respect to the total area Ap of cross sections of all the conductive particles.