Abstract: In a color image forming apparatus, an image retainer, a charger, a plurality of developing devices and a cleaner are made in one unit. The unit is dismountably supported in a housing so that the unit can be moved out from a first position at which the unit is set in the housing to a second position at which jam disposition is conducted. When the unit means is placed at the second position, a part of the apparatus is used to cover the image retaining surface at the transfer section.

Abstract: An electrophotographic photoreceptor is disclosed. The photoreceptor comprises a conductive substrate and a photosensitive layer provided on the substrate. The photosensitive layer comprises titanylphthalocyanine having a peak at a Bragg angle 2.theta. of 27.2.degree..+-.2.degree. in the Cu-K.alpha. X ray-diffraction spectrum thereof and an alkyldiol which has 3 to 12 carbon atoms and the two hydroxyl group is bonded to carbon atoms arranged at different position in the molecular thereof. The amount of the diol is 0.1 to 1000 parts by weight per 100 parts by weight of the titanyl-phthalocyanine.

Abstract: An electrophotographic photoreceptor is disclosed. The photoreceptor comprises a conductive support and a photosensitive layer provided thereon. The photosensitive layer contains a carrier generation material and a compound represented by the following formula 1, 2 or 3; ##STR1## wherein R.sub.1, R.sub.11 and R.sub.21 are each a hydrogen atom, an alkyl group, an alkoxy group, a cycloalkyl group, an alkenyl group, an aryl group, and aryloxy group or a heterocylic group; R.sub.2 to R.sub.9, R.sub.12 to R.sub.19 and R.sub.22 to R.sub.29 are independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a cycloalkyl group, an aryl group or a heterocyclic group, said groups represented by R.sub.1 to R.sub.9, R.sub.11 to R.sub.19 and R.sub.21 to R.sub.29 each may have a substituent selected form a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a thioether group, an acyl group and sulfonamido group.

Abstract: The invention provides a method of forming an image on a photoreceptor indicating a maximum value of the differential coefficient to the exposure in the light decay curve thereof. The method comprises charging the surface of the photoreceptor; exposing uniformly the surface of the photoreceptor at the same time or substantially at the same time with the step of the charging; forming a latent image on the surface of the photoreceptor by a dot-wise image exposure; and developing the latent image on the surface of the photoreceptor.

Abstract: An electrophotographic photoreceptor is disclosed. The photoreceptor contains in a light sensitive layer thereof a titanylphthalocyanine having specific crystalline characteristics as defined in the specification and a polycyclic quinone pigment or a bisazo pigment as defined in the specification. The photoreceptor has a high sensitivity over a broad wavelength region, especially near-infrared range. It is suitably used for a laser printer.

Abstract: There is disclosed the electrophotoreceptor having excellent adhesiveness between the support and the photoconductive layer and capable of providing copied images of good quality without the reduction in a sensitivity and the increase in a residual potential. The electrophotoreceptor is characterized by that the photoconductive layer contains a silicone-modified butyral resin represented by the following Formula I: ##STR1## wherein R.sub.1 to R.sub.4 each represent an alkyl group, an aryl group and a hydroxyl group; the molar ratio l:m:n:j is 30 to 98:1 to 10:1 to 50:1 to 50; n.gtoreq.j; k is 1 to 1000; an x is 300 to 10000.

Abstract: An electrophotographic photoreceptor having a light-sensitive layer on an electroconductive base is disclosed, the improvement wherein the light-sensitive layer is formed from a dispersion in which a titanyl phthalocyanine pigment having at least two predominant peaks of the Bragg angle 2.theta. at 9.6.degree..+-.0.2.degree. and 27.2.degree..+-.0.2.degree. in a diffraction spectrum obtained with characteristic x-rays of Cu K.alpha. at a wavelength of 1.54 .ANG. is dispersed in a dispersion medium that contains at least one of branched ester and alcohol solvents as a chief component.

Abstract: A photoreceptor that has at least a subbing layer and a light-sensitive layer formed on an electro-conductive supports is disclosed. The improvement is that said subbing layer is formed of a copolymer comprising ethylene, vinyl acetate and an unsaturated carboxylic acid and/or vinyl alcohol.

Abstract: A photoreceptor including a carrier transporting layer containing a carrier transporting material and a binder material, and a carrier generating layer containing a carrier generating material and a binder material, the layers being placed one over the other in order of mention, characterized in that said carrier generating layer contains a metal-free phthalocyanine having main peaks of Bragg angles 2.theta. at least at 7.5 degrees.+-.0.2 degrees, 9.1 degrees .+-.0.2 degrees, 16.7 degrees.+-.0.2 degrees, 17.3 degrees.+-.0.2 degrees, and 22.3 degrees.+-.0.2 degrees in relation to CuK.alpha. characteristic X rays (wavelength 1.541 .ANG.), and in that said carrier generating layer also contains a carrier transporting material.

Abstract: An electrophotographic photoreceptor useful for negative electrification is disclosed. The photoreceptor comprises on an electroconductive substrate, a photo-sensitive layer containing a compound represented by general formula [A]: ##STR1## wherein, R.sub.1 represents a hydrogen atom or a substituent; R.sub.2 represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group; Ar.sub.1 represents a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group; Ar.sub.2 represents a substituted or unsubstituted phenylene group or a substituted or unsubstituted naphthylene group; Ar.sub.3 and Ar.sub.4 independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted phenyl group or a substituted or unsubstituted naphthyl group; and n represents an integer of 0 or 1; and a compound containing in its chemical structure a hindered phenolic structure unit.

Abstract: A photoreceptor for electrophotography containing a titanyl phthalocyanine compound which has major peaks in terms of Bragg's 2.theta. angle to the CuK.alpha. characteristic X-ray (wavelength at 1.541 .ANG.) at least at 9.4.+-.0.2 degrees, 11.7.+-.0.2 degrees, 11.7.+-.0.2 degrees, 15.0.+-.0.2 degrees, 23.5.+-.0.2 degrees, 24.1.+-.0.2 degrees and 27.3.+-.0.2 degrees is disclosed.

Abstract: Disclosed is a photoreceptor for electrophotography comprising a carrier generation layer and a charge transport layer. The organic charge generating substance has, at the time of positive charging, a photosensitivity less than the photosensitivity at the time of negative charging.

Abstract: An electrophotographic image forming method is disclosed. The method comprises the steps of developing an electrostatic image formed on an image-forming member with a particulate toner for forming a toner image and transferring said toner image onto a receiving material, in which the image-forming member has a surface-improving layer comprised principally of amorphous silicon, and the toner has a weight average particle size within the range of from 1 .mu.m to 6 .mu.m and contains a constituent having a weight average particle size of not more than 5 .mu.m which accounts for not less than 20% by weight of the whole amount of the toner. An electrophotographic copy bearing a high-resolution and high-quality image can be stably obtained by this method.

Abstract: Disclosed is a photoreceptor for electrophotography comprised of a charge carrier generating material and charge transport material wherein one charge generating material is a metal phthalocyanine or a metal-free phthalocyanine. The layer containing the generator material also contains an organic amine.

Abstract: A photoconductive screen includes a conductive screen substrate with many perforations therein, an insulating layer formed substantially on one side of the screen substrate, a biasing conductive layer substantially covering the insulating layer, and a photoconductive layer substantially covering the conductive layer. An image of electrostatic charges can be formed on the screen to control a flow of charged particles for formation of an electrostatic latent image in a chargeable layer under exposure to the flow of charged particles.

Abstract: A photoreceptor for positive charging is disclosed, said photoreceptor comprising a carrier generating material which is stable against both heat and light, has high carrier generating efficiency and provides good photoconductivity over a wide wavelength range and a specific carrier transport material combined in such a manner that the shape of surface potential curves remains essentially constant over a cyclic operation and contributes to the formation of a visible image of high quality in each cycle by reducing the "memory effect", minimizing the residual potential and extending the cycle life.

Abstract: Disclosed is a light-sensitive member for electrophotography, having a charge generating phase formed by coating a dispersion comprising a charge generating substance, which contains in said charge generating phase an amine in an amount of 20-fold moles or less per mole of said charge generating substance and the solvent. Also disclosed are useful methods for the preparation of such a light-sensitive member.

Abstract: There is disclosed an electrophotographic photosensitive member comprising a photosensitive layer comprising a combination of a carrier generating layer and a carrier transporting layer provided on an electroconductive support, the carrier generating layer containing a bisazo compound and the carrier transporting layer containing a styryl compound and/or an amine derivative, a hydrazone compound or a carbazole derivative.The electrophotographic photosensitive member according to the present invention has a high sensitivity and can form constantly good visible images.

Abstract: A highly sensitive photoreceptor for electrophotography that forms a sharp image during repeated use is disclosed. It comprises an electrically conductive support having successively formed thereon a photoconductive photosensitive layer and a protective layer for that photosensitive layer, said photosensitive layer comprising an organic photoconductive material and said protective layer comprising an amorphous silicon carbide or amorphous silicon nitride containing a hydrogen atom and/or a fluorine atom. A method of forming a latent electrostatic image and an electrophotographic process using such photoreceptor are also disclosed.

Abstract: An electrophotographic element having a carrier generating layer and a carrier transport layer, which carrier transport layer contains an arylamine derivative and an amine substituted styryl compound, is disclosed.