Abstract: An iron powder developer carrier for electrophotography having at least the outer surface thereof coated with iron oxide. The iron oxide has a particle size of 50 to 200.mu., an apparent density of 1.5 to 2.5 g/cm.sup.3 and a specific surface area of 0.01 to 0.3 m.sup.2 /g.A process for the preparation of iron powder developer carriers for electrophotography, which comprises the steps of subjecting a starting iron powder to a primary calcination treatment in an inert gas atmosphere without using a binder, pulverizing and classifying said calcination product to prepare an intermediate iron powder, reducing the intermediate iron powder in a reducing atmosphere and washing the intermediate iron powder, and subjecting the intermediate iron powder to an oxidizing calcination treatment.

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.

Abstract: A developing apparatus for developing an electrostatic latent image on a charge receptor comprising a developing member for supplying toner to the electrostatic latent image on the charge receptor and an image forming means arranged in developing direction downstream of said developing member, said image forming means including an electrode to which a voltage is applied so as to form an alternating electric field between said charge receptor and said electrode, and means for applying said voltage to said electrode.

Abstract: The present application relates to a novel toner for developing electrostatic latent images. The toner contains a colorant and a resin wherein the resin contains at least one particular type of polymer which has a Mw/Mn ratio of from 3.5 to 40 wherein the Mn value is about between 2,000 and 30,000.

Abstract: In an electrostatic copying apparatus of the type in which a magnetic toner is applied to an image holder such as a drum from a developing roller which in turn receives the toner from a supply roller, a source of relative positive and negative voltages is alternately applied to the developing roller. This produces electric fields which move the toner from the supply roller to the developing roller and then to the image holder with the desired relative polarities.

Abstract: A two-cycle electrophotographic copying apparatus includes a rotatable charge retaining member, a charging device, an exposure mechanism, a developing device and a transferring device sequentially arranged around the charge retaining member in the direction of its rotation. During a first rotation of the charge retaining member, a toner image of an original is formed, and during the second rotation of the charge retaining member, the remaining toner is cleaned from the charge retaining member to prepare it for its next succeeding copying operation.

Abstract: A toner for developing an electrostatic latent image comprising a resin prepared by emulsion polymerization of a first polymer to yield a first emulsion, emulsion polymerization of a second polymer to yield a second emulsion, mixing said first and second emulsions and coagulating said mixture, wherein said second polymer has characteristics different from those of said first polymer.

Abstract: In the developing apparatus for producing an electrostatic latent image on a charge retaining member such as a drum, a rotating member for producing a shifting magnetic field is used to transport magnetic toner from a toner source to a developing area on the drum. The amount of toner so transported is regulated by the present invention by a magnetizable member positioned adjacent the rotating member in front of the developing area, the magnetizable member being characterized by a curved surface on which a shifting magnetic field is induced by the said rotating member and which attracts excess toner from the latter.

Abstract: A charging method of an electrostatic image developer which makes it possible to electrically charge an insulating one-component developer or a two-component developer consisting of a toner and a carrier to a desired charged state and which comprises introducing the developer into a charging space between a pair of sheet-like charging members opposing each other in which space an alternating field is formed, and oscillating the developer by means of the alternating field for charging it. A developing method of a non-contact or contact system which develops the electrostatic image by use of the developer charged electrically by the above-mentioned charging method.

Abstract: A magnetic toner comprising nuclear particles comprising lyophilic magnetic particles and a resin having a low softening point is disclosed. Each of the nuclear particles is surrounded by a resin wall.

Abstract: In the transfer of a toner image from a transfer medium such as a belt to transfer material such as paper, heating and fixing of the toner is required. According to the present invention, two sources of heat are used, one applied to the transfer medium and the other to the paper, the heat applied to the transfer medium being insufficient to melt or fuse the toner, with the heat applied to the paper being greater than necessary for fusing. When the hot paper contacts the underheated transfer medium the temperature of the latter is then and only then increased to the fusing temperature and the transfer and fixing of the toner image upon the paper takes place.

Abstract: A developing apparatus comprising a developing agent conveyor for conveying a developing agent, said developing agent conveyor including a multiplicity of pairs of electrodes each composed of a first electrode and a second electrode faced to said first electrode through a charging space so that an alternating electric field is generated in said charging space by the coactions of said first and second electrodes.

Abstract: The present invention relates to a method of fixing a toner image onto a paper bearing said image with the use of a particular toner containing a colorant and a resin wherein the resin contains at least one particular type of polymer which has a Mw/Mn ratio of about 3.5 to 40 wherein the Mn value is between about 2,000 and 30,000.

Abstract: An iron powder developing carrier for developing an electrostatic latent image, a manufacturing method thereof, a developer containing said developing carrier and a method of forming a visible image by using said developer.Said iron powder developing carrier has the apparent density from 1.5 to 2.5. Said manufacturing method comprises the steps of sintering a raw iron powder having been ground to particles of not larger than 50 microns in diameter without using any binder agent at the temperature from 900.degree. to 1200.degree. C. to form an sintered body, grinding and classifying said sintered body into an intermediate iron powder having the particle diameter from 50 to 200 microns, then treating said intermediate iron powder to oxidize at the temperature from 280.degree. to 390.degree. C., and adjusting the resultant iron powder so as to have the apparent density from 1.5 to 2.5.

Abstract: Disclosed are carrier compositions for electrophotographic developers comprising core particles coated with a mixture of a resin and an organic surfactant having at least one carbon-fluorine bond and at least one functional group having an affinity for the resin. An intermediate resin layer may be present on the core particles, which themselves may be metal, glass or silicon dioxide, e.g.

Abstract: A color transfer copying process for forming a colored image corresponding to an original by repeating prescribed times the procedures of projecting a reflected ray image from the original to be copied on a photosensitive material uniformly charged by a charging electrode through a filter to form an electrostatic latent image on the photosensitive material, converting the latent image to a toner image by using a powdery developer containing a coloring toner and transferring electrostatically the toner image onto a transfer sheet, while using selectively blue, green and red filters.

Abstract: According to the present invention, there is provided a toner for developing electrostatic latent images, which includes a colorant, an amine-addition resin and, if desired, the resin miscible with the amine-addition resin. The above mentioned amine-addition resin is further obtained by interacting an epoxy group-containing resin and an aliphatic primary or secondary amine.

Abstract: A toner for developing electrostatic images which contains a particular addition condensate and a colorant wherein said addition condensate is present in an amount of from 1 to 100 parts by weight and said colorant in an amount of from 1 to 10 parts by weight of said toner.

Abstract: Apparatus for cleaning residual toner from an electrostatic recording medium is provided wherein a brush is located adjacent the medium and a toner seizer is located adjacent the brush to remove toner carried by the brush.

Abstract: A toner for developing electrostatic latent images which comprises a colorant, a styrene type resin containing a styrene component in an amount of more than 25% by weight based on the sum of a resin component of the toner and an alkylene-bis fatty acid amide represented by the following general formula: ##EQU1## wherein R.sub.1 and R.sub.2 stand for saturated or unsaturated aliphatic hydrocarbon residues having at least 10 carbon atoms, R.sub.3 and R.sub.4 are a hydrocarbon atom or a group --COR.sub.5 in which R.sub.5 is a saturated or unsaturated aliphatic hydrocarbon residue, and n is a positive integer.