Abstract: A transfer device of the type having a belt which is stretched around a driving roller and an electric potential-applied driven roller, whereby the transfer device transfers a toner image from an image carrier onto a recording paper, and conveys the recording paper. The cleaning device is positioned so that its blade contacts the belt at a point a little downstream of the point where the belt separates from the driving roller.

Abstract: A camshell type photoelectric color image printer includes a photoreceptor for holding a latent image on its surface, a charger for charging the surface of the photoreceptor, a laser writer for forming a latent image on the charged surface of the photoreceptor, plural developers for developing the latent image with color toners, a transfer drum for holding a recording sheet on which the developed latent image is transferred, a cleaner for cleaning residual toner on the photoreceptor, and a cartridge which holds the photoreceptor, the developers, the cleaner and the transfer unit. The developers are located under the photoreceptor, and the cartridge is removable from the color image printer. An upper part of the color image printer is movable relative to the main body of the printer.

Abstract: A toner density control device of an electrophotographic recording apparatus in which development is conducted by a plurality of developing units with two-component developer wherein a toner density detecting device can detect the density of toner loaded in the plurality of developing units according to the variation of magnetic permeability of the developer. The detecting device is composed of a sensor provided to each developing unit, and a signal processing unit to process the output of the sensor selected by a selector. And toner is supplied according to the difference between the detected value of the detecting device and the reference value which is previously established.

Abstract: A developing apparatus for supplying a developer to a photoreceptor so that an electrostatic latent image on the photoreceptor is developed with the developer. The developing apparatus comprises a developer conveyer, having a rigid surface, for conveying the developer to a developing zone; a developer layer-thickness regulator, shaped like a bar and having a rigid surface portion of the curvature radius between 0.5 mm and 15 mm, for regulating the thickness of the developer to be conveyed to the developing zone; and a supporter for supporting the developer layer-thickness regulator.

Abstract: A color image forming apparatus for forming a plurality of toner images on a rotating image retainer, wherein the image retainer, a group of developing devices disposed below the image retainer and a cleaning device disposed above the image retainer are integrated to constitute a process unit, toner recovered by the cleaning device is stored in the process unit, and the image retainer can be removed from the process unit.

Abstract: A method of forming a multicolor toner image on an electrostatic latent image carrying member wherein developer containing a carrier and toner is transported to a developing region on a cylindrically shaped outer sleeve member of a developer transporting unit. Inside the sleeve there is provided at least one pair of magnets, the magnetic poles of which face the inner surface of the sleeve and are so arranged as to be rotatable, relative to each other, around the center axis of the sleeve. The amount of transported toner is regulated so that the amount of toner on the sleeve [mt], in mg/cm.sup.2, the peripheral speed of the image surface [V.sub.d ] and the peripheral speed of the sleeve member [V.sub.sl ] satisfy the following formulas:.vertline.V.sub.sl /V.sub.d .vertline..times.mt.gtoreq.0.4 mg/cm.sup.2.vertline.V.sub.sl /V.sub.3 .gtoreq.

Abstract: An electrophotographic image forming apparatus for forming an image on a recording sheet comprises a photosensitive drum for holding a toner image thereon, in developer for forming the toner image on the photosensitive drum, an image transfer device for electrostatically transferring the toner image from the photosensitive drum to the recording sheet, and a sheet separator for separating the recording sheet from the photosensitive drum as the recording sheet advances. The sheet is controlled to generate a discharge voltage which includes separator at least alternating currents at various duty factors.

Abstract: The present invention provides a method of regulating the thickness of developer layer formed on a developer-transporting means by transporting the layer to a layer thickness-regulating means disposed so as to face with the developer transporting means, pressing the layer by the layer thickness-regulating means so that the layer thickness-regulating distance of the pressing portion between the layer thickness-regulating means and the developer-transporting means can be made substantially equal to the diameter of single developer particle, and allowing the layer to pass through the pressing portion while keeping the layer thickness-regulating distance substantially equal to the diameter of single developer particle.

Abstract: A method and an apparatus to prevent toner particles on the surface of the photoreceptor from splashing when a multilayer image of toner particles is formed by repeating of an electrophotographic process including electrification, exposure and development of the surface of the photoreceptor. An electric field is established by electrode means between it and the photoreceptor to repel toner particles from the electrode means at least when the photoreceptor is exposed subsequent to the first exposure.

Abstract: An improved electrostatic image-developing process is disclosed, wherein said process comprises,a step of supplying a developer comprising carrier and toner to a developer transporting means which includes a cylindrical development sleeve (3) for carrying by rotation said developer (D) to the close proximity of an electrostatic latent image formed on an image-carrying member (1) disposed opposite thereto, the outer diameter of said cylindrical development sleeve (3) being 15 mm to 30 mm, and a magnetic roller (4) provided inside said cylindrical development sleeve, said roller having not less than ten magnetic poles, a step of forming a thin layer of said developer on the surface of said developer transporting means (3) so that the maximum thickness of the developer layer is smaller than the minimum distance (H) between the surface of said developer transporting means (3) and the surface of said electrostatic image-carrying member (1),a step of carrying said developer to a close proximity of the electrostatic

Abstract: A developer layer forming apparatus having a developer carrying member having a magnet therein and a plate-shaped elastic member having a rubber surface thereon, wherein the rubber surface is in pressure contact with the developer carrying member and one end of the rubber surface projects from the pressure contact point to the upstream of the developer carrying member in the revolving direction. The plate-shaped elastic member is constructed by superposing a metal or a synthetic resin and a rubber material.

Abstract: An image forming apparatus having a cleaning device arranged on the outer periphery of an image retainer, and bringing into and out of abutment against the image retainer, wherein the cleaning device comprises a first cleaning member and a second cleaning member arranged downstream of the first cleaning member in the moving direction of the surface of the image retainer. A cleaning operation of the second cleaning member against the image retainer is conducted according to a time at which the cleaning operation of the first cleaning member against the image retainer is conducted.

Abstract: A cleaning device for removing residual toner from an image support member after transferring a developed image therefrom including a fur-brush moveable in contact with the image support, a toner separating projection for knocking toner free from the fur-brush, a cylindrical member having a toner receiving opening adjacent the fur-brush and a rotatable toner transporting member therein, and a magnetic field arranged from the outside of the cylindrical member, the toner transporting member preferably being in the form of a spiral wire rotated in contact with the inside wall of the cylindrical member for transporting toner collected thereon to a reservoir at one end.

Abstract: A developing method for an electrostatic latent image comprises the steps of applying and retaining a layer of developer on a supporting sleeve, conveying the developer on the supporting sleeve to a development area, and regulating the quantity of the developer on the supporting sleeve by a developer regulating device before the developer is conveyed to the development area. The regulating step includes impressing a bias voltage so as to establish a field between the supporting sleeve and the regulating device in order to selectively retain developer on the supporting sleeve which has a desired polarity and quantity of charge for development. The developer regulating device may be a sleeve rotated in a direction opposite to the direction of rotation of the supporting sleeve, and has a bias voltage impressed thereon.

Abstract: A method of and apparatus for developing an electrostatic latent image wherein an oscillating electric field is formed between a developing member and an electrostatic latent image receptor in synchronism with the rotation of the developing member. A voltage having a waveform obtained by periodically superposing a pulse-like voltage is applied on the developing member.

Abstract: A method and apparatus for cleaning toner from the surface of an electrostatic image holder wherein a film member comprising superposed insulating and conductive layers is positioned close to an electrostatic image holder so that the insulating layer of the film member faces the image holder. At least one of a d.c. voltage and an a.c. voltage is applied between the electrostatic image holder and the film member, the toner from the surface of the electrostatic image holder being removed and transferred onto the surface of the insulating layer of the film member. The toner from the surface of the insulating layer of the film member may be removed by a removing means. Also, an electrostatic charge eliminator is provided for eliminating the electrostatic charge from the surface of the insulating layer after removal of the toner therefrom.

Abstract: A brush cleaning device for electrophotographic reproducing apparatus of the type wherein a fur brush is contacted against an image receptor for removing magnetic toner remaining thereon, comprises a nonmagnetic cylindrical sleeve disposed near the fur brush, and a magnetic member disposed inside the cylindrical sleeve to attract the toner onto the surface of the sleeve. At least one of the cylindrical sleeve and the magnetic member is made to rotate, and the cylindrical sleeve is formed with a spiral projection on its surface. A flicker member for dispersing magnetic toner removed from the image receptor onto the cylindrical sleeve is provided. A cleaning member is arranged at the downstream end portion of the cylindrical sleeve for cleaning magnetic toner carried on the cylindrical sleeve by the spiral projection.

Abstract: A developing means for an electrostatic latent image has, within a non-magnetic developer transport member, plural magnets arranged in series in a defined area between a develops layer thickness regulating member and a developing area opposite an image forming member so as to generate a magnetic flux distribution having a pair of homopolar peaks for eliminating a density uneveness of the developer layer on said transport member.

Abstract: An electrostatic image is developed by selectively extracting colored grains of one polarity from a mixture containing colored grains having opposite polarity to each other in the presence of an alternating field followed by development of the electrostatic image by the selectively extracted colored grains.

Abstract: The invention is directed to a developing method for electrophotography in which an insulating magnetic toner contacts an electrostatic image carrier to develop an electrostatic latent image. A magnetic bias is applied to restrain movement of the magnetic toner toward the image carrier and an alternating electric field is applied to the toner, all subject to the condition V/d.gtoreq.0.1.nu. in which V represents the effective voltage impressed upon the toner, d represents the clearance in millimeters between the image carrier and a developing sleeve, and .nu. represents the frequency in kilohertz of the alternating electric field.