Abstract: A donor roll for transporting marking particles to an electrostatic latent image recorded on a surface is provided. The donor roll includes a rotatably mounted body and an electrode member mounted on the body. The donor roll further includes a magnetically permeable core external to the body. The core rotates with the body. The donor roll further includes an electrically conductive material positioned on the core. The material is electrically connected to the electrode member.

Abstract: A color electrophotographic apparatus using a plurality of image forming units. The entire image forming unit group moves by rotation, and a toner image is transferred on an intermediate transfer belt at an image forming position. The intermediate transfer belt is variable in speed, and while the image forming unit group is moving, it is stopped or runs at low speed. The hopper in the image forming unit is divided into two sections. The toner is supplied the image forming position, and when the toner remainder sensor detects no remaining toner, the image forming unit group rotates by one revolution or more, and then the toner remainder is detected again to judge presence or absence of toner remainder. At this time, the toner in the toner hopper is agitated by the agitating member and the shape of the inner wall. After rotary move of the image forming unit group, each image forming unit is initialized sequentially.

Abstract: A developing unit includes a developing tank and a toner hopper. The developing tank is disposed to oppose a recording medium rotatably mounted to an image forming apparatus utilizing electrophotography. A developing member conveys a developer and attaches toner to an electrostatic latent image formed on the recording medium to develop the electrostatic latent image. The toner hopper has a toner supply port for supplying toner to the developing tank through a toner replenishing port formed in the developing tank. The developing tank is detachable in a direction of a rotating shaft of the recording medium, and is movable in a direction perpendicular to the direction of the rotating shaft of the recording medium so as to separate from or oppose the recording medium. The toner hopper has a shutter for opening/closing an opening of the toner supply port.

Abstract: A joint having an OLDHAM state coupling at a leading edge thereof is held movably in a direction which is parallel to a joint axis at a full-color printer body. A coupling gear is substantially connected to a developing roller disposed in each mono-color developing unit, which makes up a revolving type developing device. At the time of developing by one of the mono-color developing units, the joint is capable of moving in parallel to the axis of the joint in the state of being rotated toward the coupling. A projection is further provided at the leading edge of the coupling, and a claw is further provided at the end of the coupling gear. Thereby, smooth engagement between the coupling gear and the coupling is made by the help of the OLDHAM state coupling, the projection and the claw. As a result, the driving force is transmitted from the joint to the developing roller disposed in the developing unit, so that the developing roller can rotate at a predetermined speed and direction.

Abstract: A communication control device connected between an image forming apparatus and a communication line in an image forming apparatus supervising system which connects the image forming apparatus and a host machine by the communication line. Assume that particular data of an image forming apparatus and which is updated day by day should be read periodically. Then, even when the power supply to the image forming apparatus is shut off, a host machine can access the apparatus to read the data which should be read periodically, and receive it. In addition, the data can be preserved until the next time for reading. The data is stored in a first memory until the data is ready for transfer to the host machine, at which time the data is transferred to a second memory and then to the host machine.

Abstract: In an image forming apparatus using a cleaner/toner magazine (CTM) which has a waste toner tank and a fresh toner tank formed integrally with each other, a cleaning device has a cleaning blade which scrapes off toner left on a photoconductive element with an edge thereof. The toner removed by the cleaning blade is magnetically deposited on a rotatable magnet member whose outer periphery is magnetized. A scraper member contacts the magnet member in the waste toner tank and scrapes off the toner from the magnet member which is in rotation. As a result, the toner is collected in a collection space defined in the waste toner tank. A shutter can also be provided to prevent toner from flying about via an opening of the collection space. Such a shutter may include a shutter body, a lever operatively connected to the shutter body, and a spring biasing the lever in a direction in which the shutter body closes.

Abstract: When a developing agent prepared to have a preset toner density is loaded in a developing unit, a comparing reference level for controlling the toner density in the developing agent is changed to a value higher than the preset value in the initial stage of operation and fresh toner is supplied to the developing agent so that the toner density of the developing agent is increased in comparison to the reference level. Thereby, the developed density is prevented from decreasing due to an excess amount of friction charge of the toner.

Abstract: A device is provided for storing a supply of particles for use in a developer unit of an electrophotographic printing machine. The device includes an open ended container defining a chamber in communication with the open end of the container. The particles are stored in the chamber of the container. The device also includes a puncturable seal attached to the open end of the container for sealing the chamber. The container is installable into the developer unit without removal of the seal. The device further includes an internal seal attached to the open end of the container. The internal seal is internal to the puncturable seal. The internal seal has a surface closely conforming to the open end of the container. The internal seal is removable from the open end of the container by displacement of the internal seal into the chamber of the container.

Abstract: An image forming apparatus comprises a rotatable image carrying member, a charger, a scanner unit for forming a latent image at an exposure position on the surface of the image carrying member charged by the charger, a developing device for converting the latent image to a toner image, and a transfer roller for transferring the toner image on the image carrying member to a recording paper by application of a transfer voltage to the toner image. A conductive member is provided on a charger case covering the charger adjacent to the charger and between the charger and the exposure position. The conductive member is positioned close to the surface of the photosensitive drum. Thus, ions (positive charges) generated by the charger are prevented from reaching the exposure position where the latent image is formed.

Abstract: An automatic document feeder includes a controller for actuating and controlling a document forwarder, a document separator, a resist roller pair, and a document conveyor. In response to a copy start signal, the controller energizes the pressing mechanism of the document forward, actuates the forwarding roller, and actuates the document separator to carry the document laid on the document bearing member. During the carriage of the document to bring its front end to the resist roller pair, the controller deenergizes the pressing mechanism of the document forwarder at least once for a predetermined time during a period from the arrival of the front end of the document at the document separator until its arrival at the resist roller pair, thereby releasing the pressure on the documents laid on document bearing member.

Abstract: There is provided an apparatus for conveying a media's size to a printing system. First there is a rotatable shaft. Several cams are formed around the shaft. Each cam has a lobe extending beyond the radius of the shaft. A number of levers, one for each cam, pivot about a pivot point and have a tab that is adjacent to a corresponding cam. An indicator wheel is also attached to the shaft. The indicator wheel has a first set of faces located around the circumference of the indicator wheel, where each face indicates a media size. The indicator wheel has another set of faces that indicate a second set of media sizes. Finally, there is a slidable lever positioned adjacent to the indicator wheel. When the slidable lever is in a first position, only media sizes in the first set are visible and the presently visible size is the size conveyed to the printing system.

Abstract: A book document handing device for an image forming apparatus, and having a function of reading a book document and a function of turning the pages of the document. A scanning unit having the two functions is moved in a reciprocating motion on and along the surface of a book document laid spread on a right and a left document tables, thereby reading the document while turning the pages thereof. A table unit has, in addition to the right and left tables, a mechanism for moving each table up and down independently of the other table, members for fixing the front and rear covers of the book document to the two tables, and slide rails supporting the table unit in such a manner as to be movable in the front-and-rear direction relative to the body of the device.

Abstract: In a copying processing performed several times from the depression of a copy button of a copying machine until the surface potential of the photoreceptor drum is stabilized, a voltage sufficiently high for correcting the rise characteristic of the photosensitive layer on the drum surface is applied to a charger. A main circuit having a controlling portion to realize this corrects the output voltage of the high-voltage generating circuit which applies a high voltage to the charger to a voltage value necessary for the drum surface to be charged at a stable potential level. The main circuit charges the drum surface at the stable potential level necessary for development from copying of the first sheet.

Abstract: A hollow, member which serves as a cylinder having an inner configuration which matches the outer configuration of a magnet roller to be manufactured, is mounted in a metallic mold, and then the metallic mold is clamped. A molten resin containing magnetic particles is injected into the mold cavity of hollow member through a runner. Magnetic lines of force are applied to a roller type resin magnet, and such an application is continued. Before the roller type magnetic resin is fully cured, the mold is opened. Then, the magnetic members of a movable mold member 1 are separated from the magnetic members of a stationary mold member so that the distribution of the magnetic flux passing through the hollow member is changed. When the roller type resin magnet is fully cured by cooling, a magnet roller having two pairs of magnetic poles with different surface magnetic flux densities can be obtained.

Abstract: An apparatus for developing an image with spherical toner particles has a latent image carrier on which a latent image is formed by a potential contrast, a toner transporter having a surface for transporting the spherical toner particles to the latent image carrier and an elastic blade having a surface for passing the spherical toner particles transported by the toner transporter through a gap between the surfaces of the toner transporter and elastic blade for forming a thin toner layer which is charged. The toner transporter is elastically deformed for the surface thereof to be brought into pressure contact with the latent image carrier and develop an electrostatic latent image on the latent image carrier with the thin toner layer which is charged. Surface roughnesses of the elastic blade and of the toner transporter are different from each other. The toner particles are rotated between the elastic blade and the toner transporter and charged electrostatically.

Abstract: An image forming apparatus includes an image bearing member for bearing an electrostatic image; a developer carrying member, opposed to the image bearing member, for carrying a one component developer which is charged to a predetermined polarity by friction between the developer and the developer carrying member; an electric field generating device for generating, between the image bearing member and developer carrying member, an electric field for developing the electrostatic image on the image bearing member with a reverse development method; a regulating member for regulating an amount of the developer on the developer carrying member; and a voltage applying device for applying to the regulating member, a voltage having a polarity opposite the predetermined polarity.

Abstract: A magnetic brush type developing device of the type used for electrophotography includes a developing roller and a carrier recovery roller, each of which includes a non-magnetic sleeve and a permanent magnet disposed within the non-magnetic sleeve. The developing roller is positioned adjacent to a photostatic body bearing an electrostatic latent image. During use the developing roller is rotated to transfer a two-component developing agent, comprised of a carrier and a toner, onto the photosensitive body. The carrier roller faces the photosensitive body and includes a permanent magnet having an orientation and a magnetic force that will cause the carrier component of the two-component developing agent to transfer from the photostatic body to the carrier roller during rotation of the carrier roller.

Abstract: Paper processing equipment such as a laser printer uses a plurality of sensors to detect the presence of paper in the paper path of the equipment. In order to determine the nature of malfunctions indicated by presence or absence of paper at the sensors, data from the sensors is coordinated with information concerning the timing of the data. In one embodiment, a single data signal is used to provide information that a paper supply hopper is empty and that paper is present at an output of a paper sheet pick mechanism. Advantages include simpler operation and the provision of discrete display indicia for different types of malfunctions and paper out conditions.

Abstract: An electromagnetic shutter (40) is comprised of two poles, a south pole (42) and a north pole (44) that are disposed above the surface of a delivery roller element (32). The delivery roller element (32) rotates about a fixed magnet (30) that has various poles. The south pole (42) of the electromagnetic shutter (40) is aligned proximate to the one of the north poles of the magnet (30). When the electromagnetic shutter (40) is activated with the windings (48) and (50) or winding (48) only, the shutter will form a magnetic dam (79) of toner particles which will effectively prevent passage of the toner particles thereby.

Abstract: An image forming apparatus which includes a member to be charged, and a charging member, contactable to the member to be charged and being supplied with a voltage, for charging the member to be charged, wherein the voltage applied to the charging member for image formation contains an oscillation component, wherein a peak-to-peak voltage of the oscillation component in a first period for formation of a predetermined number of initial images is higher than in a second period after the predetermined number of image formations.