Abstract: An electrophotographic printing machine of the type in which an electrostatic latent image recorded on a charge retentive surface is developed with toner particles to form a visible image thereof, including; a housing having a supply of toner and developer therein; a donor member for transporting toner from the housing to the development zone; a means for conveying toner to the donor member; blower for generating a negative air stream for carrying toner therein; and a filter for removing the toner from the negative air stream, the filter including filter material and spring blower, connected thereto, for oscillating the filter material to dislodge toner material collected in the filter when the generating means is disabled.

Abstract: An electrostatic filtering system which allows a steady flow of air into a development housing and prevent toner emission therefrom. The system is used in an apparatus for developing a latent image recorded on a surface includes the housing having a supply of toner therein; a donor member arranged in the housing to transport toner to a development zone adjacent the surface; and electrode for detaching toner from the donor member and produce a toner cloud in the development zone; and an air handling system, associated with the housing, for generating a negative air stream in the housing, the air handling system including the electrostatic filtering system for removing the toner from the negative air stream. The electrostatic filtering system includes a baffle mounted in the housing in the negative air stream and a high voltage DC for applying a bias to the baffle thereby creating an electrostatic field between the baffle and the developer for collecting toner emission.

Abstract: An electrophotographic printing machine of the type in which an electrostatic latent image recorded on a charge retentive surface is developed with toner particles to form a visible image thereof, including; a housing having a supply of toner and developer therein; a donor member for transporting toner from said housing to the development zone; means for conveying toner to the donor member; means for generating a negative air stream for carrying toner therein; and a filter for removing the toner from the negative air stream, said filter including filter material and oscillation means, operational connected to said conveying means, for oscillating said filter material to dislodge toner material collected in said filter when said generating means is disabled.

Abstract: In an image forming apparatus, a cleaning device removes toner remaining after image formation. A toner storing section stores the toner collected by the cleaning device. A toner transferring device transfers the toner from the cleaning device and implemented by a powder pump. The powder pump includes a screw pump rotatable to move the toner in its axial direction, and an air feeding arrangement for causing the toner being moved by the screw pump to flow in a dispersed state. The toner transferring device and toner storing section are communicated by a path constituted by a flexible material.

Abstract: A toner sorting device includes a device for taking in used toner conveyed from an image forming apparatus and conveying the used toner in one direction, and a device for sifting the used toner conveyed from the intake device to separate reusable toner from the used toner. The sifting device includes a tubular sieve for separating reusable toner from the used toner and a device for holding the sieve so that the sieve is rotatable. The sieve has an opening for receiving the used toner conveyed from the intake device to be moved into the sifting device and an opening for discharging the remaining toner separated from the reusable toner and remaining inside the sifting device. The toner sorting device further includes a device for collecting the reusable toner separated from the used toner by the sifting device and a device for collecting the remaining toner discharged from the sifting device. The toner sorting device further includes a device for accelerating sifting of the used toner by the sifting device.

Abstract: A method of forming an electrostatic latent image includes printing operation and toner recovering operation. The printing operation includes charging, forming an electrostatic latent image, developing, and transferring operations. The toner recovering operation includes the step of charging the photosensitive drum in timed relation to the rotation of the photosensitive drum after printing operation so that reversely charged toner deposited on the charging roller migrates from the charging roller to the photosensitive drum. The toner migrated from the charging roller to the photosensitive drum is recovered into a developer. An apparatus for forming an image includes a charging roller, photosensitive drum, developing roller, and transfer roller.

Abstract: A development station for an electrostatographic reproduction apparatus wherein pigmented marking particles from a particulate material mixture of pigmented marking particles and magnetic carrier particles are utilized to develop latent image charge patterns on a dielectric member. The development station has a housing adapted to be located adjacent to a dielectric member. The housing defines a reservoir for a particulate material mixture, and an opening facing such dielectric member. A mixer for mixing particulate material, a magnetic brush for applying pigmented marking particles from such particulate material mixture to a latent image charge pattern to develop such charge pattern, and a transport for transporting such particulate material from the mixer to the magnetic brush are located within the housing. A device is provided for collecting contaminating airborne particulate material contamination. The contamination collecting device includes an elongated tube, located externally of the housing.

Abstract: A system for automatically cleaning toner build-up on a roller, such as the fuser pressure roller in an electrophotographic printing device, using the duplexing capability of the device. One embodiment is a method for cleaning a roller in an image forming device. The method includes the steps of: feeding a sheet of print media into the simplex paper path; printing a cleaning pattern on one side of the sheet; routing the sheet through the duplex paper path to invert the sheet; and routing the inverted sheet back through the simplex paper path. When the image forming device includes a fuser, such as with a laser printer, a toner image cleaning pattern is applied to the paper or other sheet media, the toner is fused to the paper, the paper is then routed through a duplexer and back through the fuser. When the cleaning page is fed into the image forming device the second time, it goes through the device with the printed side down.

Abstract: An apparatus for powder cloud development of an electrostatic image in which a donor roll advances toner to a development zone adjacent the image, and in which precipitating electric fields are provided at the entrance and exit of the development zone to redeposit undeveloped toner onto the surface of the doner member, whereby unwanted airborne emissions of toner are substantially reduced.

Abstract: A system for the delivery of a substantially uniform mono-layer of toner to an electrostatic latent image in an imaging member (such as a rotating cylinder) insures proper handling of the toner, and utilizes first and second rollers which function as a polarity filter for toner, allowing only particular charged toner to be transferred from a toner reservoir to the imaging member. The twin roller delivery system comprises first and second rollers mounted for rotation about substantially parallel substantially horizontal axes, so that the peripheral surface of the first roller receives the toner from the substantially open top reservoir, and the second roller receives toner from the first roller and transfers it to the imaging member. The first and second rollers are charged to different electrical potentials, e.g. both being positive with the second roller at a potential that is about 400 volts below the first. The rollers are rotated in opposite directions about the axes of rotation.

Abstract: An apparatus and process for reducing accumulation of toner from the surface of an electrode member in a development unit of an electrostatographic printing apparatus by providing a composition coating including a polymer, lubricant and inorganic material, on at least a portion of the electrode member.

Abstract: In an electrophotographic recording apparatus of the type using a single-ingredient type developer, i.e., toner, a developing device has a developing roller for conveying the toner deposited thereon, and an intermediate roller for conveying the toner transferred theretofrom the developing roller and depositing it on a latent image electrostatically formed on an image carrier to thereby produce a corresponding toner image. During the development of an area of the image carrier other than a latent image area, a bias assigned to the developing roller is switched over to thereby form an electric field different in direction from an electric field assigned to the formation of the toner image between the two rollers. Further, before the rotation of the image carrier is stopped, the bias assigned to the developing roller is again switched in order to form the electric field for the formation of the toner image between the rollers. As a result, a toner layer is formed on the intermediate roller.

Abstract: A toner image processing apparatus performs a printing operation and a cleaning operation. A toner-attracting electrode includes first and second electrodes disposed closer to the charged surface of a photosensitive drum and outside of a path through which the light from the exposing device illuminates the charged surface. During the toner attracting operation, a toner-recovering device causes the toner-attracting electrode to attract the toner particles floating in the air surrounding the exposing device, and reversely charged toner particles and residual toner particles left on the photosensitive drum after the toner image is transferred to the print medium. During the toner-releasing operation, the toner-recovering device causes the toner-attracting electrode to release the attracted toner particles to the photosensitive drum. The toner-attracting operation is performed during the printing operation and the toner-releasing operation is performed during the cleaning operation.

Abstract: The present invention is a method and apparatus for vacuuming toner waste from a toner sump in a xerographic printing machine. A xerographic module in the machine contains a photoconductor, charging devices, a cleaning unit and the toner sump. When the toner sump approaches a full condition, the toner waste must be removed in order to prevent failure of the xerographic module seals. This is accomplished by removing the xerographic module from the machine, opening a sealed toner sump port and attaching a vacuum source to the toner sump port so that the toner waste can be removed with the vacuum source. A disposal adaptor tool sealingly engages the vacuum source to the toner sump at the toner sump port, allowing the toner to removed in a clean glove environment. Once the toner waste is removed from the toner sump, a new toner seal is placed over the toner sump port and the xerographic module is returned to the machine for further use.

Abstract: An image forming apparatus has a plurality of image forming units for forming, on an image receiving member such as a transfer sheet, toner images of a plurality of different colors such as magenta, cyan, yellow and black. Each of the image forming units includes a photosensitive drum serving as an image carrier, a developing device for developing an electrostatic latent image carried by the image carrier to form a color toner image, and a transfer device for transferring the toner image to the image receiving member. The developing device in the image forming unit for forming on the image receiving member the toner image of an (i+1)-th color is of the type capable of simultaneously performing both development and removal of residual toner. The transfer currents T.sub.i and T.sub.i+1 employed by the transfer units which perform transfer of the toner images of an i-th color and the (i+1)-th color satisfy the following condition (1).

Abstract: An image forming apparatus includes a first image-bearing member, latent image-forming unit for forming an electrostatic latent image on the first image-bearing member, developer for developing the electrostatic latent image with a toner to form a toner image, an intermediate transfer member for receiving the toner image by primary transfer and transferring the toner image onto a second image-bearing member by secondary transfer, a charging member for charging a residual toner remaining on the intermediate transfer member after the secondary transfer, and a recovery member for recovering the charged residual toner at a recovery position by voltage application. The intermediate transfer member exhibits a charging characteristic such that it has a surface potential of at most 500 volts as an absolute value at the recovery position.

Abstract: An electrophotographic image forming apparatus has an image forming device for forming a toner image, an image transfer device for transferring a toner image to a sheet, a toner fixing device for fixing the toner on the sheet and a conveying device for conveying the sheet from the image transfer device to the toner fixing device. A toner removing device is positioned in a conveyance path of the sheet from the image transfer device to the toner fixing device for removing toner from back of the sheet. The toner removing device assumes an electrical bias having a polarity opposite that of the toner.

Abstract: The scavenging of a first toner into a second toning station in a DAD-CAD or CAD-DAD process can be reduced by allowing scavenged toner to deposit in the background of single color images. The polarity of the first toner of the scavenged toner is not changed prior to transfer and remains on the image member through transfer from which it is later cleaned. Alternatively, scavenged toner is deposited from a second toning station on the image member while no images are being made and allowed to pass through transfer to be cleaned off.

Abstract: An image forming apparatus having a device for moving a charging roller towards and away from a photoreceptor and a cleaning member for the charging roller. The charging roller moving device moves the charging roller to positions including a first position where the charging roller is in contact with the photoreceptor and is separated from the cleaning member for a charging operation, a second position where the charging roller is in contact with the cleaning member for cleaning the surface of the charging roller and a third position where the charging roller is separated from the photoreceptor and the cleaning member. Even if the apparatus is left unoperated for a long time, the photoreceptor is prevented from being contaminated by the charging roller by placing the charging roller in the third position.

Abstract: In an image forming apparatus, a toner collection mode is executed when a series of image formation modes ends and when the image formation mode is continuously repeated a preselected number of times. A toner image sensing mode for sensing a reflection density from a reference toner image is executed every time the image formation mode is repeated a preselected number of times. The apparatus is capable of surely and efficiently removing toner left on an image carrier after image transfer, and collecting the reference toner image with a developing unit. The reference toner image is prevented from contaminating an image transferring unit and a cleaning unit.

Abstract: Accumulated toner and other particulate contaminants are removed from rollers, such as charging and transferring rollers, and conveyed to a collection receptacle positioned about the rotating path of an image bearing member, such as a photoconductive drum. In one embodiment, accumulated toner removed from a charging roller is recycled for development.