Abstract: A printer for printing endless paper webs on both sides has two printing stations with a web turnover station therebetween. The paper web is fed in parallel side-by-side to the two printing stations which are on the same rollers. The drive of the web through the printer is by a positive drive, using pins to engage holes in the paper web, for example, into the first printing station. The drive of the paper web thereafter is by friction drive to permit slippage in the drive to compensate for variations in paper length during heating, etc. The slippage is controlled by brakes or other drag inducing devices acting on one or both of the two portions of the paper web.

Abstract: A plurality of electrostatic images are formed on a moving tensioned belt formed with an electrically conductive base having a non-conductive image-carrying surface layer. The images are developed by passing the belt through toner development stations, each of which includes a development unit including a magnetic roller and a backing member, in opposed position to the magnetic roller, over which the belt passes. Under non-ideal conditions, the image quality in terms of image density and uniformity of image density and rendition of sharp image transitions, is substantially improved by applying an alternating electrical field between the magnetic roller and the belt, with a peak-to-peak voltage greater than 800 volts.

Abstract: An image-forming apparatus using a rubber blade having a rubber hardness of not smaller than 73.degree. for cleaning the residual toner on the photosensitive material drum, wherein a maximum rotational deviation r (mm) of said photosensitive material drum satisfies the following formula,0.15.gtoreq.r.gtoreq.((a.multidot.sin .theta.).sup.2 +b.sup.2).sup.1/2 -bwhereina: length (mm) one-half of the blade length,b: radius (mm) of the drum,.theta.: angle subtended by a line of the drum surface in parallel with an imaginary center axis of the drum and by a tangential line of contact between the rubber blade and the photosensitive material drum.This apparatus exhibits excellent cleaning performance, permits the photosensitive layer to be evenly scraped over the whole surface of the photosensitive material drum and, hence, makes it possible to stably form image for extended periods of time.

Abstract: An image forming apparatus includes a movable image bearing member; an electrostatic image forming device for forming an electrostatic image on the image bearing member, the electrostatic image forming device including a charging member, contactable to the image bearing member, for charging the image bearing member; developing device for developing the electrostatic image with toner to form a toner image on the image bearing member; a transfer device for transferring the toner image onto the transfer material from the image bearing member, wherein the developing device is capable of cleaning the image bearing member to remove residual toner from the image bearing member, without provision of cleaning device for removing the residual toner from the image bearing member at a position upstream of the charging member and downstream of the transfer device with respect to a moving direction of the image bearing member; and a charge application device, provided upstream of the charging member and downstream of the t

Abstract: An image forming apparatus has an image bearing member, a developing agent image formed on the image bearing member, and transferring device for transferring the developing agent image onto a recording member. The image bearing member is cleaned, and the developing agent removed therefrom is stored in a container. A detection is performed as to whether or not the quantity of developing agent in the container has reached a predetermined state, and once the result of such detection becomes positive, the number of prints made thereafter is counted. The result of the detection and the result of the count are stored in a memory along with the container, and the image forming operation is controlled in accordance with the stored information. In another embodiment, the memory is stored in an attachable cartridge. The attachable cartridge has an image bearing member, a charger, a developing device, and a cleaning device.

Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus includes an electrophotographic photosensitive drum; a charging member for charging the electrophotographic photosensitive drum; a grounding contact, provided coaxially with the electrophotographic photosensitive drum at one longitudinal end side of the electrophotographic photosensitive drum, for electrically grounding the electrophotographic photosensitive drum to the main assembly, when the process cartridge is mounted to the main assembly; a charging bias contact, provided at the other longitudinal end side of the electrophotographic photosensitive drum, for receiving a charging bias to be applied to the charging member from the main assembly of the apparatus when the process cartridge is mounted to the main assembly, wherein the contact is disposed on a surface which is substantially a top surface when the process cartridge is mounted to the main assembly.

Abstract: An image forming apparatus includes a photosensitive unit and a developing unit, at least one of which is arranged rotatable about a parallel support shaft. In a state that the both units are mounted on an apparatus main body, a developing roller gear (driven gear) of the developing unit is in mesh with a drive gear provided on the photosensitive unit. A drive force is transmitted from the drive gear to the developing roller gear. The developing roller gear and the drive gear are arranged such that a drive force acting on a pitch point has an extension line passing through a center of the parallel support shaft.

Abstract: A toner developing quantity detection unit operates a plurality of electrostatic recording units to transfer Y, M, C and K color component toner marks onto a belt. A toner developing quantity correction unit detects toner developing quantities per unit area of color toners on the basis of detection signals of the color component toner marks on the belt optically detected by a sensor. The toner developing quantity correction unit corrects the toner developing quantities so as to allow the toner consuming quantities of the plurality of electrostatic recording units to be substantially the same level, on the basis of the thus detected toner developing quantities.

Abstract: A photosensitive drum unit for an electrostatographic printing apparatus is disclosed. The drum unit includes a drum tube formed with at least one opening at one axial end thereof. A flange member is configured to be inserted into the opening in the drum tube. The flange member is provided with a support hole into which a shaft pin is inserted for supporting the drum tube and flange member. An earth plate is formed with projections or claws that extend radially outward from a peripheral edge of the earth plate such that the projections contact with an inner peripheral surface of the drum tube. The earth plate is also formed with a pair of contact pieces extend axially away from the earth plate and also extend toward one another. The contact pieces are spaced apart from one another by a predetermined distance but are also configured to contact and engage a portion of the shaft pin.

Abstract: An image forming apparatus includes an image bearing member, latent image forming device for forming an electrostatic image on the image bearing member, the latent image forming device having a charging member contactable to the image bearing member to electrically charge the image bearing member, and the charging member being supplied with a voltage which includes an oscillation component, a developing device for developing the electrostatic latent image with toner into a toner image, the developing device being capable of removing residual toner from the image bearing member, a transfer device for transferring the toner image from the image bearing member onto a transfer material, and a frequency control device for controlling a frequency of the oscillation component so that the frequency is higher when at least a part of such an area of the image bearing member as is going to be a non-image area is charged than when such an area of the image bearing member as is going to be an image area is charged.

Abstract: A developing unit having a preheating apparatus capable of ensuring good quality of printing by providing a preheating apparatus inside of a developing unit which stores a toner and maintains the toner at a predetermined temperature and humidity, includes: a toner storage unit for storing toner; a toner supply roller for supplying the toner; a photoconductive unit; a developing roller for transmitting the toner supplied by the toner supply roller to an electrostatic latent image formed on a surface of the photoconductive unit; a main body having the toner storage unit, the toner supply roller, the developing roller and the photoconductive unit; and a preheating unit disposed inside of the toner storage unit for properly maintaining the temperature of the toner.

Abstract: Methods of recycling printer cartridges use special rail-type clips for reassembly of complementary halves of a printer cartridge, the clips comprising cutouts or gaps spaced along the length thereof which accommodate protrusions near the edges being joined. The invention allows for recovering these cartridges and avoiding the cost of discarding a fairly costly machine element while additionally avoiding the processing costs for rendering the cartridge into inert, non-polluting waste.

Abstract: In a fixing oil coating apparatus for coating oil to an outer circumferential surface of a fixing roller for fixing a toner image of a recording sheet, the apparatus has an oil coating roller including a cylindrical porous member impregnated with oil therein, and a brush-shaped oil applying member fixed on an outer circumferential surface of the porous member. The brush-shaped oil applying member is brought into contact with the outer circumferential surface of the fixing roller so that the oil is coated to the fixing roller.

Abstract: A photoreceptor assembly and a xerographic cassette for a printing or copying machine, the cassette including a photoreceptor drum, a drum cleaner, a waste toner container, for storing waste toner; and a waste toner conveyor for conveying waste toner cleaned off said photoreceptor drum by the cleaner into the waste toner container characterized in that the waste toner container is positioned in the interior of the photoreceptor drum and is reversibly removable therefrom. The conveyor typically includes a flexible helical wire which acts as an auger. Once filled with waste toner, the waste toner container is removed from the drum and is replaced by a fresh container.

Abstract: An image forming apparatus includes an image bearing member; a charging member, contactable to the image bearing member, for being supplied with a voltage to electrically charge the image bearing member, the charging member having a resistance which is larger when it is supplied with a voltage of 50V than when it is supplied with a voltage of 500V; developing device for developing with toner an electrostatic image formed on the image bearing member using charging operation of the charging member, the developing means being capable of removing the toner from the image bearing member; wherein the voltage is an oscillating voltage, and a ratio T.sub.up of time period when a voltage level thereof is in a side of a charging polarity of the charging member beyond an average voltage in one period of the oscillating voltage to a length of time of one period of the oscillating voltage, and a ratio T.sub.

Abstract: An image forming apparatus has a plurality of image holding components set along a transportation path of a recording sheet, each image holding component being operable at a full-color mode and a monochrome mode and an image holding component used for forming a black image being located nearest to the driving source.

Abstract: An ink delivery system for a liquid electrophotographic color printer including a plurality of circulation tanks connected to respective development units containing developer liquids, a plurality of jet portions disposed between the respective circulation tanks and the respective development units, for jetting the ink in the circulation tanks to development gaps in the respective development units, a plurality of ink cartridges having concentrated ink of different colors and detachably installed in a printer body, a plurality of concentrated ink supply paths through which the concentrated ink is supplied to the corresponding circulation tanks, a carrier tank containing a carrier and fixed in the printer body, a carrier supply path through which the carrier in the carrier tank is supplied to the respective circulation tanks, a waste ink disposal tank connected to the respective circulation tanks by an ink exhaust path, for collecting the waste ink in the circulation tanks, and a filtering mechanism installed

Abstract: Registering a first image on a first side of a substrate with a second image on a second side. A motor driven document transport advances a substrate to a transfer station that transfers the first image onto the substrate. The substrate is then inverted and the document transport moves the inverted substrate back to the transfer station to receive a second image. A sensor detects a leading edge and a trailing edge of the substrate, while an encoder operatively connected to the motor produces a predetermined number of pulses per revolution. A counter counts the number of encoder pulses between the leading edge and the trailing edge. The controller then determines the width of the substrate from the number of counted encoder pulses and from the distance the substrate advances per encoder pulse. The controller then controls the document transport to position the substrate at the transfer station such that the second image is registered with the first image.

Abstract: An image forming apparatus which allows easy recognizing of jammed paper and easy removing of the jammed paper and further easy recognizing of an interior of a machine main body. An image is formed on a photosensitive drum, and a transfer unit is disposed to contact an outer circumferential surface of the photosensitive drum. The transfer unit includes a transfer belt for transporting transfer paper electrostatically absorbed thereon and guiding the transfer paper to a fixing unit. An outer cover supports the transfer unit so as to move the transfer unit in a direction of separating the transfer unit from the photosensitive drum when the outer cover is opened and for guiding transfer paper discharged from a fixing unit.

Abstract: An image forming apparatus has two units which are engageable with a photoconductive element and provided with a substantially identical configuration. Various electrophotographic process devices including a developing device and a cleaning device and to be arranged around the photoconductive element are selectively arranged in the two units. The photoconductive element is passed over two rollers such that part of the element forms parallel flat portions. The two units and the photoconductive element are rotatable integrally with each other.