Abstract: A uniform image is obtained by matching the sliding friction force, the moving speed and the developing agent in a developing region of two developing rollers and an electric characteristic of a photosensitive body used for image development. Two developing rollers rotating in directions opposite to each other are used, the moving direction of the first developing roller being opposite to the moving direction of the photosensitive body, and a circumferential speed ratio of a circumferential speed of the first developing roller to a circumferential speed of the photosensitive body is within a rage of 0.5 to 2.5; and the moving direction of the second developing roller is equal to the moving direction of the photosensitive body, and a circumferential speed ratio of a circumferential speed of the second developing roller to a circumferential speed of the photosensitive body is within a range of 1.5 to 3.5.

Abstract: A toner for recording electrostatic image having a volume-average particle diameter of from 6 to 10 .mu.m, which exhibits a compression stress of from 50 to 500 kgf/cm.sup.2 at the middle temperature between room temperature and the glass transition temperature of the toner, and a compression stress of from 0.2 to 10 kgf/cm.sup.2 at the middle temperature intermediate between the glass transition temperature and the softening temperature of the toner.

Abstract: In an image forming apparatus forming an electrostatic latent image on a surface of a photosensitive body by exposing the charged photosensitive body, developing the latent image using a toner to form a toner image, transferring the toner image to a image holding body, and erasing the remaining charge on the surface of the photosensitive body after completion of the transferring, the photosensitive body is formed of a base material consisting of As.sub.2 Se.sub.3 or a-Si, and wherein the wavelength .lambda..sub.0 of the writing light used for the exposure is limited to a wavelength not larger than 780 nm, the wavelength .lambda..sub.1 of charge erasing light used for the charge erasing is limited to a wavelength smaller than 680 nm, and the time T.sub.1 from completion of the exposure to initiation of the development is limited within the range of 70 milliseconds to 300 milliseconds.

Abstract: Image fixing device for use in electrophotographic apparatus, capable of suppressing gloss of fixed toner image, thus stably producing images of high quality and high level of fixing intensity over a long period of time. The fixing device is composed of a belt-type heating member and a pressing roller which are contacted with each other and rotate to form therebetween a nip through which a paper supporting unfixed toner image is passed to have the toner image fixed to the paper. The belt-type heating member comprises a metallic endless belt having fine irregularities formed on its surface and a surface layer made of a resin. The surface roughness of the fine irregularities ranges between 10 and 45 .mu.m, when measured by a ten-point averaging method.

Abstract: Image fixing device for use in electrophotographic apparatus, capable of suppressing gloss of fixed toner image, thus stably producing images of high quality and high level of fixing intensity over a long period of time. The fixing device has a fixing roller and a pressing roller which are contacted with each other and rotate to form therebetween a nip through which a paper supporting unfixed toner image is passed to have the toner image fixed to the paper. The fixing roller has a cylindrical core having fine irregularities formed on its surface and a surface layer made of a resin. The surface of the cylindrical core has a greater elastic modulus than that of the surface layer.

Abstract: Image fixing device for use in electrophotographic apparatus, capable of suppressing gloss of fixed toner image, thus stably producing images of high quality and high level of fixing intensity over a long period of time. The fixing device has a fixing roller and a pressing roller which are contacted with each other and rotate to form therebetween a nip through which a paper supporting unfixed toner image is passed to have the toner image fixed to the paper. The fixing roller has a cylindrical core having fine irregularities formed on its surface and a surface layer made of a resin. The surface of the cylindrical core has a greater elastic modulus than that of the surface layer.

Abstract: Image fixing device for use in electrophotographic apparatus, capable of suppressing gloss of fixed toner image, thus stably producing images of high quality and high level of fixing intensity over a long period of time. The fixing device has a fixing roller and a pressing roller which are contacted with each other and rotate to form therebetween a nip through which a paper supporting unfixed toner image is passed to have the toner image fixed to the paper. The fixing roller has a cylindrical core having fine irregularities formed on its surface and a surface layer made of a resin. The surface of the cylindrical core has a greater elastic modulus than that of the surface layer.

Abstract: A electrophotographic image fixing device fixes a toner image on a substrate. The substrate is passed between two pressing rollers disposed in opposition to each other to fix toner images on the substrate. The pressing rollers includes a surface constructed from an elastic material layer such that the elastic material layer can be deformed approximately 0.5-1.5% in terms of thickness. The pressing force against the toner applied side of the substrate is adjusted to 0.3-1 kg/cm.sup.2. As a result, an image with excellent toner fixing strength can be formed on a substrate such as an envelope without wrinkling the substrate during the fixing operation.

Abstract: A photosensitive element for electrophotography has an electrically conductive substrate and a layer structure thereon comprising a charge generating substance and a charge transport substance. An improved charge transport substance is a derivative of triphenylamine in which at least 80% of the electrons in the highest occupied molecular orbital are located on the triphenylamine skeleton. Examples of such compounds have the following formula: ##STR1## wherein X is a an optionally substituted heterocyclic radical containing at least one ring nitrogen, Q is a single bond or --C.dbd.C--, and Z.sub.1, Z.sub.2 and Z.sub.3 are H, lower alkyl or alkoxy, aryl, NO.sub.2, CF.sub.3, --N(R').sub.2, --S--C.sub.6 H.sub.5 or --S(R').sub.2.

Abstract: Disclosed is an electrophotographic photoreceptor in which an organic lubricant is provided on the surface of an organic photoconductive layer or on a protective layer formed on the organic photoconductive layer. Elements of the organic lubricant are partly exposed from the surface of the organic photoconductive layer or the protective layer while the remainder portions of the elements are embedded or fixed by chemical reaction in the surface region of the photoconductive layer or the protective layer so that the exposed portions of the elements of the organic lubricant provides a lubricating surface layer. The lubricating surface layer supresses wear of the photoreceptor thereby enabling the photosensitive layer to withstand a long repeated use without impairing electrophotographic characteristics.

Abstract: The present invention provides an electrophotographic toner, particularly with a good transferability and a good flowability, which comprises a binder resin and a coloring agent, the binder resin containing a lactone-modified epoxy resin, obtained by subjecting all or a portion of secondary hydroxyl groups of epoxy compounds having hydroxyl groups in the molecules to ring opening polymerization of lactone.The present invention further provides an electrophotographic toner with a good transferability, a good flowability and a good offset resistance and also with a fixability of transferred images, which comprises a binder resin and a coloring aent, the binder resin containing:(1) a lactone-modified epoxy resin, obtained by subjecting all or a portion of secondary hydroxyl groups of epoxy compounds having hydroxy groups in the molecules to ring opening polymerization of lactone,(2) styrene-butadiene rubber, and(3) polyester resin.

Abstract: A dark or black print article is ink-jet printed with a white ink composition comprising at least a white pigment having a particle size of less than 3 .mu.m, a solvent and a binder resin with a good print stability. The white ink composition has a good dispersion stability, a good redispersability, and no nozzle clogging.

Abstract: In a method of developing triboelectric magnetic toner, an electrostatic latent image is formed on a substance, the latent image is developed by a magnetic brush method using a ferrite carrier of semiconductivity and a triboelectric magnetic tonor, and the developed toner image is transferred to a transfer member and fixed.By adding the semiconductive ferrite carrier, a lump of tonor is broken with a mechanical force of the carrier so as to increase the flowability of the tonor and to prevent the agglomeration of the tonor due to dielectric charging.

Abstract: Electrophotographic copying is carried out by electrostatically forming a latent image on a recording medium, supplying a magnetic toner of single component system containing at least a resin and fine particles of forromagnetic material on a non-magnetic sleeve provided with a permanent magnet roller having a plurality of magnetic poles therein, transporting the magnetic toner into a gap between the recording medium and the non-magnetic sleeve, attaching the magnetic toner to the recording medium, thereby developing the latent image into a visible image, electrostatically transferring the toner image thus formed on the recording medium onto a transfer sheet, and fixing the transferred image, thereby obtaining a final image, wherein the magnetic toner has a resistivity of more than 5.times.10.sup.15 .OMEGA.cm and a relative dielectric constant of less than 3.0.

Abstract: Magnetic toner employable as a developer for electrophotographic duplication system consisting of the steps of developing electrostatic latent image on a carrier, overlaying a copying sheet on said carrier of developed image, and transferring the developed image to said sheet, characterized by containing magnetic fine particles of a electric resistivity from 10.sup.9 .about.10.sup.16 .OMEGA..multidot.cm (at 4000 V/cm DC) and dielectric constant from 2.6.about.5.