Abstract: An image transferring device for use in image forming equipment prevents an image from being omitted in a trailing edge portion of a paper sheet in the event when pre-transfer discharge is applied to a photoconductive element prior to image transfer. The pre-transfer discharge is not effected on an image portion of a photoconductive element that is associated with a trailing edge portion of a paper sheet where a discharge due to separation will be caused by the vibration of the trailing edge portion of the paper sheet.

Abstract: A method of removing a film which undesirably forms on a photoconductive element or similar image carrier of an image forming apparatus such as an electrophotographic copier, printer or facsimile machine. The method is implemented by a cleaning device having a cleaning sleeve which removed toner particles remaining on the image carrier after image transfer. In a film removing mode which is executed when an image forming mode for forming a toner image on the image carrier is not under way, the cleaning sleeve is rotated at a lower speed than in an ordinary cleaning mode so as to feed a greater amount of cleaning agent to a cleaning region. The rotation speed of image carrier and that of the cleaning sleeve are controlled in such a manner as to feed a predetermined adequate amount of cleaning agent for the removal of a film to the cleaning region at all times.

Abstract: A developing device developes an electrostatic latent image formed on a rotatable electrostatic latent image support member. The developing device includes a rotatable first toner transport member in contact with an electrostatic latent image support member and a rotatable second toner transport member in contact with an electrostatic latent image support member. Toner layers are formed on the peripheral surface of the first toner transport member and the second toner transport member. The electric conductivity of the first toner transport member is different from that of the second toner transport member.

Abstract: An image forming apparatus comprises an original table for carrying an original with an image thereon, an original cover for covering the original table along with the original thereon, image carriers, an optical scanning system for optically scanning the original on the original table and forming an image corresponding to the image of the original on the image carrier, two optical detectors which is are simultaneously moved for scanning the original table with the original thereon. The two optical detectors independently detect at predetermined positions the presence or absence of the original on the original table, and output signals indicative of the presence or absence of the original at the predetermined positions. The apparatus also includes a discriminating circuit for discriminating the size of the original by finding out the logical sum of the signals from the two detectors.

Abstract: The present invention provides a method of controlling toner concentration in a developing apparatus that uses a two-component developer consisting of a carrier and a toner, wherein the change in toner concentration in the developing container containing the developer is not taken out as it is to carry out the toner concentration control, but an approximately periodic waveform component is lapped over the detection signal to produce a waved detection output oscillated with the detection signal between the center, then the detection output and the control standard level corresponding to a prescribed toner concentration level are compared, and a level signal "Hi" and a level signal "Lo" plus a proportional pulse signal whose pulse width changes approximately proportionally between the level signals "Hi" and "Lo", that is, three types of signals are obtained from the comparison output, thereby making the toner supply operation different in conformity with the type of the signal.

Abstract: An image forming apparatus includes an image forming section for forming an image on a sheet, a main convey mechanism for delivering the sheet to outside the image forming apparatus through the image forming section, and a reconvey mechanism for separating the sheet from the main convey mechanism at the downstream side of the image forming section, and merging the separated sheet to the upstream side of the image forming section. The reconvey mechanism has a gate for separating the sheet from the main convey mechanism to the reconvey mechanism, and a detector for detecting the jam of the sheet in the reconvey mechanism. The image forming apparatus also includes a control circuit and the like for preventing the separation of the sheet by the gate, and then delivering the sheet following the jammed sheet to outside the image forming apparatus.

Abstract: In an input scanner provided with a document input, a sheet feeding path for transporting documents to a scanning station and to a document output; a scanning station having at least a first scanning element, normally fixed in position relative to the sheet feeding path, and supporting a full width array of photosensitive sensors with a coresponding optical arrangement for directing light from the document to the sensors, there is provided an arrangement for bringing the optical arrangement and sensors of the scanning element to a calibration sensing position for detection of a calibration target provided in a fixed position within the input scanner, while retaining the scanning element at a fixed position relative to the sheet feeding path.

Abstract: An apparatus in which a latent image recorded on a belt extending in a direction transverse to a horizontal plane is developed with a developer material. At least two developer rollers are mounted, at least partially, in the chamber of a housing storing a supply of developer material. The developer rollers are spaced from one another and have different diameters. The spacing between each of the developer rollers and the diameters of each of the developer rollers is selected so that a plane tangential to the lowermost region of each of the developer rollers is substantially parallel to the horizontal plane.

Abstract: A residual toner cleaning device for removing the residual toner on a photosensitive drum of an image forming apparatus of the invention is provided with an elastic roller in contact with said photosensitive drum and rotatable to remove said residual toner from said photosensitive drum, regulating means encompassing at least a portion of said elastic roller and having a compressing portion which compresses said elastic roller and a releasing portion for releasing said elastic roller from the compression to release the residual toner carried by said elastic roller, and toner collecting means for collecting the toner released by said elastic roller. The elastic roller ejects the toner toward the toner collecting means by the restoring force of the elastic roller released from the compression by the compressing portion of the regulating means, and the toner collecting means collects the toner.

Abstract: A fusing apparatus operable at a desired fusing temperature through a run period when toner images on a receiver or copy sheet are fused, using up a required and first amount of heat, and through a standby period when the apparatus is awaiting a run period. The fusing apparatus includes a device for selectively dissipating, during the standby period, a desired and second amount of heat approximating the required and first amount of heat used up during the run period. The heat dissipating device thus prevents "droop" or a dropping from the desired fusing temperature, by causing heat flow from the apparatus to remain relatively constant during both run and standby periods. Additionally, such dissipation also advantageously cools the apparatus, thereby preventing the occurrence of heat-related fusing defects such as copy curling, blistering, and image offset.

Abstract: A pre-programmable multiple pause points system for a post-collation copying system for a copier with associated plural sorter bins and a recirculating document handler (RDH) in which a set of document sheets may be loaded, recirculated, and copied for making a plural number of identical consecutive copies per document per circulation and outputting them to selected sorter bins for collation. This system is particularly adapted for a system of "limitless sorting" in which the plural identical copies are job subsets collated in a variable limited number of sorter bins normally substantially less than the total number of bins and wherein the total job is completed with further RDH document circulations and further job subsets productions.

Abstract: A transferring device for transferring on a record paper a toner image formed onto an image forming member is disclosed. The transferring device comprises a transfer belt with a dielectric layer formed on a conduction belt member; a driving device for running the transfer belt; a transfer roller for contacting the transfer belt to an image forming member with pressure; a corona charges arranged at a position opposite to the transfer belt for charging the transfer belt with a charge having a polarity opposite to the charging polarity of the toner; a grid electrode arranged between the corona charger and the transfer belt; a plurality of bias sources connected to the grid electrode for biassing the grid electrode at respective potentials; and a change-over circuit for changing over the connection between the grid electrode and the bias source, whereby the grid potentials are selectively changed over in accordance with the characteristics of a record paper to be used.

Abstract: A control apparatus for controlling concentration of toner incorporated in developing material in a developing unit by means of controlling a toner replenishment to supply the toner in accordance with a toner concentration detected by a toner concentration detecting sensor in a first state wherein the detecting signal of the sensor is normal and to supply the toner by a constant volume at the predetermined period in a second state wherein the detecting signal of the sensor is abnormal.

Abstract: Apparatus for applying developer material to a latent electrostatic image wherein flow of developer material is controlled accurately and without clogging. A rotary feed mechanism delivers developer material from a sump to a magnetic brush, and includes a drive mechanism axially aligned with and drivingly engaged with the feed mechanism. A metering device between the sump and the magnetic brush rotates about an axis substantially co-axial with the rotary feed mechanism between (1) an open position communicating the magnetic brush and the sump and (2) a closed position substantially isolating the magnetic brush from the sump. A drive solenoid is spaced from the metering device, and the drive mechanism is positioned axially between the solenoid and the metering device. The metering device is drivingly connected to the solenoid while at the same time avoiding interference with said drive mechanism since the connecting means extends radially outwardly around the drive mechanism.

Abstract: A copying apparatus operable in a two-side copy mode has two exclusive switchback transport paths which are selectively usable for refeeding paper sheets each carrying an image on one side thereof from a refeed tray. One of the switchback transport paths is assigned to paper sheets of size A4 and smaller sizes which are fed sideways, while the other is assigned to paper sheets of sizes greater than A4.

Abstract: A sheet having an image of a document formed by a copying unit on one side is sequentially stacked in a stacking section of a two-sided/multiple copy unit. Such sheets are picked up by pick-up rollers one by one and conveyed to the copying unit by a plurality of conveying rollers which are arranged along a conveying path. A detection switch is provided on the conveying path to detect abnormality which may occur during conveyance of the sheet. If such abnormality is detected by the switch, then a door is opened by the operator and a caught sheet is removed from the rest of the machine. Upon the closure of the door, the door switch detects that the door is closed. At this time, the sheet is picked up from the stacking section by the pick-up roller prior to a copying operation by the copying unit and conveyed past a conveying path to a location near the copying unit.

Abstract: An original document detecting device includes at least a pair of elements made up of a light emitting element and a light receiving element oppositely arranged on both sides of an original placing platform which is used for placing an original document, for example, on a copying machine. When no original document is present on the platform, the light receiving element receives the light from the light emitting element. When an original document is placed on the platform, the light is interrupted because of the presence of the original document. The detecting apparatus is provided for detecting whether the light is received by the light receiving element or the light is interrupted by an original document. Because the light is interrupted, the presence or absence of the original document is detected.

Abstract: An image forming apparatus includes a detector for detecting light intensities of light from a light source, and a discrimination unit for obtaining the relative ratio of chroma signals of light with two or more wavelengths at the light intensities of the light source detected by the detector, to thereby discriminate life expiration of the light source. Data of the relative ratio of chroma signals of light with two or more wavelengths at a time of life expiration of the light source is obtained in advance. Thereafter, the light intensity of the light source is detected to obtain the actual relative ratio of the chroma signals of light with two or more wavelengths. Based on these data, the life expiration of the light source is discriminated.

Abstract: A fixing roller used in an electrophotographic device includes a coupling with a drive key that engages an end of a pressing roll that contains a key groove. Disposed between the coupling and the end of the pressing roll is a spacing member. This spacing member decreases the rate at which the key groove and the drive key deteriorate when two fixing rollers are used as pair to fix toner on a printed page. The spacing member is made of plastic, a sintered metal alloy, or other material. Also, the spacing member is lubricated to further prevent friction and the key groove of the pressing roll is lined with an abrasion resistant material to further prevent deterioration of the drive key and the key groove.

Abstract: A transfer member, for example, a transfer drum utilizes a vacuum applied through vacuum holes to the drum surface for holding a receiving sheet. A toner image is transferred to the sheet under the urging of an electric field. To prevent non-transfer over the vacuum holes, the holes are filled or covered with a conductive material that is sufficiently conductive to maintain the electric field over the holes and sufficiently porous to maintain the vacuum at the surface. For example, a polyurethane foam material can be used for the material in or over the vacuum holes.