Abstract: An object of the present invention is to provide an image forming apparatus that has an image bearing body, exposing device for exposing the image bearing body, which is charged, based on an image signal and forming an electrostatic latent image on the image bearing body, wherein a pixel density of the electrostatic latent image can be switched, and control device for controlling a responsibility to the image signal of the exposing device when the pixel density is switched.

Abstract: A process cartridge includes an electrophotographic photosensitive member, a developer for developing a latent image formed on the electrophotographic photosensitive member, a developer remaining amount detecting member for detecting a remaining amount of developer in the developer, and a non-volatile memory for memorizing information corresponding to at least the print number of sheets and the developer remaining amount in such a manner that such information can be read out and re-written by an image forming apparatus. The present invention also provides and electrophotographic image forming apparatus to which such a process cartridge can be detachably mounted.

Abstract: A developing apparatus includes a developer bearing member for bearing and carrying developer to a developing area. A developer is borne on the developer bearing member, wherein the developer has a weight average particle size not exceeding 6.5 &mgr;m and contains an external additive of a charging polarity opposite to that of the developer. A voltage application device applies a voltage to the developer bearing member, wherein the voltage including at least a first voltage V1 for acting on the developer in a direction from the developer bearing member toward an image bearing member and a second voltage V2 for acting on the developer in a direction from an image bearing member toward said developer bearing member, and a charged potential VL of the image bearing member, a latent image potential VD a distance H between the developer bearing member and an image bearing member, and wherein the voltages V1 and V2 satisfy a following relationships: |V1−VL|/H≦3.

Abstract: The present invention relates to a developing apparatus in which, assuming that a tangent which is in contact with said detecting member on an opening portion side of a developing container in a vertical direction is a first tangent, and a tangent which is in contact with a rotating locus of a first agitating member on an opposite side of the opening portion in a vertical direction is a second tangent, the first tangent is positioned nearer to the opening portion than the second tangent, and a lower end of said partition member is provided between the first tangent and the second tangent.

Abstract: The present invention relates to a development density adjusting method in which development density is adjusted by varying ratio of application time of a voltage having the first voltage value to application time of a voltage having the second voltage value in one period, and difference between a potential of the developer bearing member and a potential of the electrostatic latent image, when the voltage having the first voltage value is applied to the developer bearing member.

Abstract: A developing apparatus includes a developer carrying sleeve, opposed to an electrostatic image bearing member for carrying a developer; a regulating member for regulating an amount of developer on the developer carrying sleeve, wherein the regulating member cooperates with the developer carrying member to form a nip, and includes a rubber blade having a wear index of 0.03-0.15, and wherein the rubber blade is contacted to the developer carrying member with a contact pressure P (g/cm), wherein 10.ltoreq.P.ltoreq.60.

Abstract: A developing device includes a developer container for accommodating one component magnetic toner; a rotatable toner carrying member, faced to an image bearing member for bearing an electrostatic image to form a developing zone therebetween, for carrying the toner in the container; a magnet member in the toner carrying member; a regulating member, elastically urged to the toner carrying member to form a nip therebetween, for regulating a toner layer thickness on the toner carrying member; wherein the magnet member has a magnetic pole, upstream of the nip with respect to a movement direction of the toner carrying member, for supplying the toner in the container to the toner carrying member, and wherein the magnet member does not generate a magnetic field effective for chain erection of the toner in a range from an upstream end of the nip to a downstream end of the developing zone.

Abstract: A developing apparatus for developing a latent image formed on an electrophotographic photosensitive member include a toner container for containing toner to be used for developing the latent image, a light transmitting member for transmitting light for detecting that an amount of the toner in the toner container is smaller than a predetermined level, a cleaning member for cleaning the light transmitting member, a stirring member reciprocating device for reciprocating a stirring member, and a cleaning member reciprocation device for reciprocating the cleaning member with a degree of displacement larger than that of the stirring member.

Abstract: An image forming apparatus includes a image bearing member having a photosensitive layer, a surface protection layer having fluorine resin material; a charging member contactable to the image bearing member to electrically charge the image bearing member, the charging member is capable of being supplied with an oscillation voltage, and wherein a peak-to-peak voltage of the oscillating voltage applied across a gap between a surface of the charging member and the surface of the image bearing member, is not less than twice a charge starting voltage of the image bearing member in the gap and not more than 1600 volt.

Abstract: A developing unit including a developer container for accommodating a developer, a first window portion which is formed in an upper portion of the developer container and through which light passes, a second window portion which is formed in a lower portion of the developer container and through which light passes, a first wiping member for wiping the first window portion, a second wiping member for wiping the second window portion, and a holding member for holding the first wiping member and the second wiping member at opposite ends of said holding member, wherein the holding member performs a reciprocating operation with respect to a supporting point.

Abstract: A magnetic toner has magnetic toner particles containing a binder resin and a magnetic material, and an inorganic fine powder treated with an organic compound. The magnetic toner has a volume average particle diameter D.sub.v (.mu.m) of 3 .mu.m.ltoreq.D.sub.v <6 .mu.m, a weight average particle diameter D.sub.4 (.mu.m) of 3.5 .mu.m.ltoreq.D.sub.4 <6.5 .mu.m, a percentage M.sub.r of particles with particle diameters of 5 .mu.m or smaller in number particle size distribution of the magnetic toner, of 60% by number<M.sub.r .ltoreq.90% by number, and the ratio of a percentage N.sub.r of particles with particle diameters of 3.17 .mu.m or smaller in number particle size distribution of the magnetic toner to a percentage N.sub.v of particles with particle diameters of 3.17 .mu.m or smaller in volume particle size distribution of the magnetic toner, N.sub.r /N.sub.v, of from 2.0 to 8.0.

Abstract: A process cartridge detachably mountable to an image forming apparatus, wherein the image forming apparatus light emitting means and light receiving means cooperative with the light emitting means to detect amount of toner in a part of the process cartridge, the process cartridge includes an electrophotographic photosensitive member; process means actable on the electrophotographic photosensitive member; a toner container, adapted for being mounted in the part, for containing the toner to be used for developing a latent image formed in the electrophotographic photosensitive member; a light transmitting member, provided in the toner container, for transmitting light emitted from the light emitting means to permit detection of the amount of the toner in the toner container when the process cartridge is mounted to a main assembly of the image forming apparatus; a cover member movable between a protecting position for protecting the electrophotographic photosensitive member and a retracted position wherein the co

Abstract: An electrostatic latent image developing apparatus includes a movable developer carrying member for carrying developer to a developing zone where an electrostatic latent image on an image bearing member is developed. There is an outer coating layer on the developer carrying member wherein the coating layer is of resin in which conductive fine particles are dispersed and which is abraded.

Abstract: A developing apparatus for developping an electrostatic latent image includes a movable developer carrying member facing toward or contacted with an image bearing member in a developing zone. An elastic regulating member for forming a regulated developer layer on the developer carrying member is elastically urged toward the developer to form a nip therebetween, through which the developer is conveyed to the developing zone. Fine particles different from particles constituting the developer are arranged on the surface of the regulating member comprising the nip.

Abstract: A developing apparatus including a developer carrying member for carrying a developer, a magnet disposed in the developer carrying member, and an elastic regulating member contacting the developer carrying member to regulate a thickness of a layer of the developer formed on the developer carrying member. The developer carrying member has a roughened surface over a width thereof larger than a width of the portion of the elastic regulating member contacting the developer carrying member while the magnet forms a magnetic field in a marginal region of the roughened surface of the developer carrying member not contacting the elastic regulating member to remove magnetic developer.

Abstract: A developing apparatus including a developing roller for carrying an one component developer to a developing zone for developing an electrostatic latent image. The developing roller is provided with a surface layer which contains long carbon fibers extending substantially parallel to the axis of the developing roller or extending in a direction inclined relative to the roller axis, and a binder for binding the carbon fibers.

Abstract: A developing apparatus using one component developer includes a developing sleeve for carrying the developer to a developing zone. The developing sleeve has an outer coating layer made of resin material in which electrically conductive fine particles are dispersed.