Abstract: The developing device X includes: toner T that contacts an electrostatic latent image on a photosensitive drum D; a charging roller 4 for charging the toner through contact; and an ultraviolet irradiator 5 for charging the toner by shining ultraviolet light onto a sleeve 41 of the charging roller from a position on the back of the sleeve 41 via a roller 42. The sleeve of the charging roller contains material that changes its molecular structure under ultraviolet irradiation by the ultraviolet irradiator in such a manner to charge the toner. Deterioration of a charged member (toner) can be prevented, and so is fusion of the charged member with the charging means. Reliability in the developing process proves.

Abstract: According to a toner and a manufacturing method of the present invention, the toner, which is composed of a binding resin component precipitated in particle shapes with a coloring agent component dispersed in the binding resin component, is produced by dissolving the binding resin component in a supercritical fluid (a SCF), blending the coloring agent component in the SCF, and lowering solubility of the binding resin component for precipitating the binding resin component in the particle shapes. Even when the coloring agent content is increased, by the SCF, the toner can maintain dispersibility of the coloring agent component in the binding resin component precipitated in the particle shapes, meanwhile coloring power is also maintained thereby. Therefore, the toner can promote miniaturization of an image forming apparatus using the toner.

Abstract: A color image forming apparatus fixes a superimposed multi-color toner image, heat-fused at a heating section of an intermediate transfer belt, onto a recording material at a fixing nip section at which a pressing roller presses against the intermediate transfer belt. The fixing nip section is provided at the downstream end of the heating section in a turning direction of the intermediate transfer belt. The present apparatus can accelerate a fixing rate while maintaining stable fixing properties for a multi-layer toner image of a color image having different layer thicknesses with any kind of recording papers under any operation condition, and requires a shorter warm-up period while attaining excellent heat efficiency.

Abstract: In a fixing device, a sheet of paper carrying an image formed with pre-fixed toner is transported to a fixing nip region in which (1) a fixing roller heated by a heating roller outside of the fixing roller and (2) a pressure roller come into contact, so that the toner is melted and fixed on the sheet of paper. The heating roller is controlled so that a surface portion of the fixing roller in the vicinity of an exit of the fixing nip region constantly has a set temperature during the transport of the sheet of paper through the fixing nip region. By thus arranging a fixing device, the resultant fixing device features a short warm-up period, high thermal efficiency and uniform temperature distribution, capability of fixing color toner without application of oil, durability and safety, a simple structure and a low manufacturing cost, no curling of paper after fixation, and applicability to high-speed printing.

Abstract: In a toner image fixing roller covered with a fluororesin layer, to evenly apply anti-offset agent to the roller surface and to increase sharpness of edge-portions of a toner image fixed on recording paper, a fixing roller consists of a core, elastic body layer and a fluororesin layer. The fluororesin layer contains filler (silicone oil or silicone powder) having affinity to anti-offset agent.

Abstract: A fixing method for fixing an unfixed toner image formed on a recording material by transporting the recording material to a contact portion between a fixing roller and a pressurizing mechanism for pressurizing the surface of the fixing roller is arranged such that the fixing roller surface temperature and the pressurizing mechanism surface temperature at the contact portion while the recording material is being transported therethrough are controlled to fall within a non-offset region in which a sufficient fixing strength for fixing toner onto the recording material can be ensured without generating a high temperature offset, said non-offset region being defined by a critical border line obtained from a function of a fixing roller surface temperature and a pressurizing mechanism surface temperature. According to the described fixing method, an occurrence of an offset can be prevented without an application of an oil, and a toner fixing inferior can be prevented.

Abstract: Toner attracted onto an electronic latent image formed on the surface of a photosensitive drum is transferred onto a transfer sheet, using a transfer bias from a transfer bias roller. A transfer belt for transporting the transfer sheet includes an anisotropic conductive layer composed of conductive members and an insulating member. The anisotropic conductive layer is conductive only in the thickness direction thereof and insulating in the other directions. This makes it possible to offer a transfer device that can prevent a transfer electric field from spreading and toner from being projected, and that boasts excellent sheet transportability.

Abstract: A developing device for developing, by using a developer, a latent image formed on a surface of an image data forming member including a developer accommodating section for accommodating the developer; a first developer retaining member for receiving the developer from the developer accommodating section and transporting the developer; a second developer retaining member for receiving the developer from the first developer retaining member and making the developer adhere to the latent image formed on the image data forming member; a conductive member opposed to the second developer retaining member with an appropriate space interposed therebetween; a first voltage applying member for applying a voltage between the first developer retaining member and the second developer retaining member; a second voltage applying member for applying a voltage between the second developer retaining member and the surface of the image data forming member; and a third voltage applying member for applying a voltage between the s

Abstract: An electrophotographic image forming apparatus for transferring a visible toner image formed on a photoconductive body onto an intermediate transfer body primarily and transferring the toner image transferred on the intermediate body onto a paper secondarily is disclosed. In the electrophotographic image forming apparatus, the toner remaining on the photoconductive body is removed by a first cleaner blade after the primary transfer, and the toner remaining on the intermediate transfer body is removed by a second cleaner blade after the secondary transfer. A contact pressure of the second cleaner blade to be applied to the intermediate transfer body is set to be larger than a contact pressure of the first cleaner blade to be applied to the photoconductive body.

Abstract: A full color copying machine which includes intermediate transfer medium whereon toner images having respective color components, formed on a photoreceptor are transferred to form one color toner image, and a screen filter disposed so as to be freely inserted or removed in or from a path of exposure light, which filters the exposure light for exposing the photoreceptor into a pattern of lines. A plurality of color toner images obtained by executing a plurality of copying processes based on a plurality of exposures applied to an original document are superposed on the intermediate transfer medium to form a color toner image. The copying machine further includes a screen mode for inserting a screen filter into a path of exposure light and a normal mode for removing the screen filter from the path of exposure light.

Abstract: A transfer unit including: a transfer belt onto which toner images are formed; a backup roller on which said transfer belt is applied, the metallic surface of said backup roller being coated with a dielectric film; a metallic transfer roller that is disposed opposite to said backup roller across said transfer belt and to which a predetermined transfer voltage is applied, said transfer roller pressing copy paper against said backup roller with said transfer belt placed therebetween so that said toner images formed on said transfer belt are transferred onto said copy paper to be transported between said transfer roller and said transfer belt; and a back plate that is located in the vicinity of said backup roller and that contacts the back surface of said transfer belt, whereby an electric field for transferring a toner image by a low transfer voltage can be created, thereby preventing the transfer belt from dielectric breakdown.

Abstract: A method of cleaning a photosensitive member in an electrophotographic apparatus in which an electrophotographic operation is performed by charging the photosensitive member with a predetermined voltage, exposing the charged photosensitive member so as to form a latent image thereon and developing the latent image by use of toner, includes the steps of charging the photosensitive member with a half tone level voltage which is smaller than the predetermined voltage, and developing the charged photosensitive member by use of toner without exposing the charged photosensitive member, so as to form a uniform half tone toner image thereon. The cleaning method also includes the step of scraping off the toner of the uniform half tone toner image from the photosensitive member by a blade abutting thereto.

Abstract: A transfer roller device for transferring onto a copy paper sheet a full color toner image formed on an intermediate transfer belt. A rear-surface electrode roller disposed at the opposite side to a transfer roller with the intermediate transfer belt positioned in between, is divided into a plurality of cylinder members, and at least one of the cylinder members corresponding to the size of a copy paper sheet is separately connected to ground. With the arrangement, occurrence of an excess current through a portion of the intermediate transfer belt carrying no copy paper sheet thereon is eliminated, thereby preventing a filming phenomenon. In another arrangement, a plurality of rear-surface electrode rollers are disposed at respective positions associated with a plurality of respective copying speeds which are set according to copy paper sheets. Thus, a voltage to be applied between the transfer roller and the rear-surface electrode roller is maintained constant regardless of different copying speeds.

Abstract: In a transfer method of a colored image, the process speed is initially properly set in accordance with the size of a copy paper sheet to be used. The transfer voltage is then changed in accordance with the process speed. After these processes, a colored toner image formed on a photoconductor is first transferred onto an intermediate transfer medium and then further transferred onto the copy paper sheet.

Abstract: A toner transfer device which transfers toner on a photoconductor to an intermediate transfer belt applied on a plurality of rollers, wherein at least part of the surface of the photoconductor moves in an arc while being pressed against the intermediate transfer belt, the toner transfer device comprising: a pair of transfer rollers disposed along the intermediate transfer belt between two of the rollers in such a manner that the part of the surface of the photoconductor which moves in an arc is positioned between the transfer rollers, at least part of each transfer roller being located outside each of two tangents, one of the tangents touching the photoconductor and one of the two rollers, the other tangent touching the photoconductor and the other roller, thereby allowing a certain length of the intermediate transfer belt between the two transfer rollers to be pressed against the part of the surface of the photoconductor moving in an arc; and a means for applying voltage to the transfer rollers, the voltage

Abstract: A copying apparatus having a prescanning function for obtaining density data to adjust copy parameters includes a correction function which eliminates the data obtained from a portion of a predetermined color, from the density data detected on a prescanning process. The density data can be restricted within a predetermined range. The predetermined range can be easily set by the user.

Abstract: A light source device for use in a color copying machine comprises a plurality of light source lamps having different efficiencies respectively and means for lighting any number of light source lamp or lamps among said plural light source lamps depending on the luminous energy of the respective blue, green and red spectrums and/or the spectral sensitivity of the photosensitive member for said respective spectrums.

Abstract: A developing method using non-magnetic, one-component toner, characterized in that the non-magnetic, one-component toner charged either positively or negatively is retained in cloud-like state in a space facing a photoreceptor drum surface with an electrostatic latent image formed thereon and that an alternating electric field is applied to the zone between the space and the photoreceptor drum surface to cause toner particles to fly about, thus developing the latent image.