Abstract: An electrophotographic apparatus includes a photosensitive member for bearing an image, the photosensitive member having a photosensitive layer and a charge injection surface layer outside of the photosensitive layer; a charging member, contactable to the photosensitive member, for electrically charging the photosensitive member; and wherein the charge injection layer has a volume resistivity which is larger at a surface than inside thereof.

Abstract: An image forming apparatus includes an image bearing device, a charger contactable to the image bearing device for effecting contact charging of the image bearing device, the charger being supplied with a voltage having a DC component and an AC component, and the charger being provided with an electrode for receiving the voltage; wherein the following is satisfied: when an electric field formed between the image bearing device and the electrode is not more than .vertline.E/d.sub.SD .vertline. (V/m), a resistance of the charger per unit area of contact between the image bearing device and the charger is larger than20E/(wCV.sub.DC) (.OMEGA.m.sup.2)and is larger than the resistance when the electric field is more than .vertline.(E+V.sub.DC)/d.sub.SD .vertline. (V/m)where E(V) is an amplitude of the AC component; w(rad) is an angular velocity of the AC component; d.sub.SD (m) is a minimum distance between the electrode and the image bearing device; C(F/m.sup.

Abstract: A charging member for charging a member to be charged, includes a magnet member and a surface electroconductive layer for supporting electroconductive magnetic particles, the layer being supported by the magnet member and rotating together with the magnet member in a region supporting the magnetic particles.

Abstract: The image forming method comprises, electrostatically charging an image bearing member using a contact charging assembly, forming an electrostatic latent image on the image bearing member thus charged, developing the electrostatic latent image with a magnetic toner to form a toner image and transferring the toner image to a transfer medium, wherein the charging assembly comprises a magnetic brush formed from conductive magnetic particles magnetically bound, and the charging assembly comes into contact with the image bearing member to charge the surface of the image bearing member by directly injecting charges into the electron level present on the surface of the image bearing member and the magnetic toner has a value of .sigma..D..delta. of 150 or less, where the value is obtained by multiplying i) a magnetization quantity .sigma. (Am.sup.2 /kg) in a magnetic field of 1K oersted as measured by a vibration magnetometer, ii) a weight average particle diameter (D.sub.4) D (.mu.

Abstract: A charging device for charging a member to be charged, includes a charging material for charging the member to be charged, the charging material including a layer of particles capable of being supplied with a voltage and contactable to the member to be charged, wherein the particle layer comprises first particles having a volume resistivity of not less than 6.0.times.10.sup.3 Ohm.cm and less than 1.0.times.10.sup.5 Ohm.cm and second particles having a volume resistivity of not less than 6.3.times.10.sup.5 Ohm.cm mixed with the first particles.