Abstract: An image forming apparatus includes a potential detection portion that determines a surface potential of an image bearing member on the basis of an applied voltage value of a detection voltage applied to a voltage application member by a voltage application portion and a detected current value detected by a current detection portion in response to the applied voltage, and a control unit that sets an image formation condition for performing image formation in order to form a toner image on the image bearing member on the basis of the surface potential determined by the potential detection portion. When the surface potential is determined by the potential detection portion, the voltage application portion applies the detection voltage after applying, to the voltage application member, a voltage having an opposite polarity to an image formation voltage that is applied to the voltage application member during image formation.

Abstract: An image heating apparatus for heating an image formed on a recording material includes: a cylindrical rotatable member including a base layer and an electroconductive layer; a core inserted into the rotatable member; and a coil wound helically around the core inside the rotatable member, wherein an AC magnetic field is formed by passing an AC current through the coil to generate heat in the electroconductive layer through electromagnetic induction heating. The base layer has a volume resistivity higher than a volume resistivity of the base layer. The electroconductive layer generates heat through a full circumference thereof by a current flowing in a circumferential direction of the rotatable member independently of rotation of the rotatable member.

Abstract: A fixing apparatus for fixing a toner image on a recording material through a nip includes a sleeve; a nip forming member contacting an inner surface of the sleeve; a halogen heater provided in the sleeve; and a back-up member cooperating with the nip forming member to form the nip through the sleeve, wherein a surface of the nip forming member which contacts an inner surface of the sleeve is convex in a direction of approaching the back-up member, from each of opposite end portions thereof toward a central portion thereof with respect to a generatrix direction of the sleeve.

Abstract: An image heating device includes a rotatable image heating member including an elastic layer and a surface layer in which a filler is dispersed; and a fixed pressing member which is contacted to a surface of the rotatable image heating member and forms a nip, between itself and the rotatable image heating member, in which a recording material for carrying an image is to be nip-conveyed. The surface of the rotatable image heating member has a shape such that projections are distributed by the filler so that a coefficient of dynamic friction ?(hot) relative to said fixed pressing member when a surface temperature of the rotatable image heating member is a temperature during image heating and a coefficient of dynamic friction ?(cold) relative to the fixed pressing member when the surface temperature is a normal temperature satisfy, ?(hot)<1.2×?(cold).

Abstract: An image heating device includes a rotatable image heating member including an elastic layer and a surface layer in which a filler is dispersed; and a fixed pressing member which is contacted to a surface of the rotatable image heating member and forms a nip, between itself and the rotatable image heating member, in which a recording material for carrying an image is to be nip-conveyed. The surface of the rotatable image heating member has a shape such that projections are distributed by the filler so that a coefficient of dynamic friction ?(hot) relative to said fixed pressing member when a surface temperature of the rotatable image heating member is a temperature during image heating and a coefficient of dynamic friction ?(cold) relative to the fixed pressing member when the surface temperature is a normal temperature satisfy, ?(hot)<1.2×??(cold).