Abstract: An image forming apparatus and method cause a connecting/conveying device to convey a recovered toner from a cleaner part to recovered toner housing means to house therein the recovered toner, and cause control means to control recovered toner supply means and new toner supply means in accordance with a toner concentration ratio in a developing device, which is detected by toner concentration ratio detecting means, to supply the recovered toner, which is stored in the recovered toner housing means, and a new toner, which is stored in new toner housing means, to the developing device.

Abstract: An image forming apparatus and method cause a connecting/conveying device to convey a recovered toner from a cleaner part to recovered toner housing means to house therein the recovered toner, and cause control means to separately control recovered toner supply means and new toner supply means to supply the recovered toner, which is stored in the recovered toner housing means, and/or a new toner, which is stored in new toner housing means, to the developing device. The control means restricts the supply of the recovered toner from the recovered toner housing means to the developing device when the no-residual-amount detecting means detects no residual amount of the new toner in the recovered toner housing means.

Abstract: A powder pump includes a stator and a rotor. The stator has a through-hole formed with two grooves extended in a stator spiral form. The rotor is rotated inside the through-hole of the stator. The rotor extends in a rotor spiral form such that spaces for accommodating a powder are formed between an outer circumferential surface of the rotor and an inner circumferential surface of the through-hole of the stator. The rotor is rotated to move the spaces and to transfer the powder. A cross-sectional engagement amount formed in the stator. An outer diameter engagement amount is formed in the rotor. When the rotor has a cross-sectional diameter RA millimeters and an outer diameter RB millimeters, and the through-hole of the stator has a least inner diameter SN millimeters and a largest inner diameter SX millimeters, RA, RB, SN, and SX are defined to satisfy formulas of RA−SN≧0.4 and RB−(SN+SX)/2≧0.4.

Abstract: To provide a Si photosensitive member and an image forming apparatus which prevents toner adherence at the time of cleaning and forms an excellent image, an electrophotographic photosensitive member comprising a photoconductive layer including amorphous Si and a surface protective layer which are formed on an electroconductive substrate has a difference in the height of concave and convex corresponding to 90% and 50% of a cumulative frequency of the height of concave and convex with respect to the most deepest point of surface roughness concave and convex within a range of 10 &mgr;m×10 &mgr;m of the photosensitive member as a standard which is set within a range of 3 nm to 200 nm.

Abstract: A toner recycling device of an electrophotographic image forming apparatus conveys collected used toner to a developing device of the image forming apparatus. The toner recycling device includes a powder conveying pump that is driven to convey the collected used toner to the developing device of the image forming apparatus when an integrated value of predetermined numerical values, each based on a number of picture elements of an image to be formed, is equal to or greater than a constant value, and an adding device that adds a predetermined constant value to the integrated value when driving of an image bearing member of the image forming apparatus is detected.

Abstract: In an image forming apparatus, a developing unit includes an inlet cover for opening and closing a toner inlet formed in an outer casing of the developing unit, and an outlet cover for opening and closing a toner outlet. A toner cartridge includes a toner feeding roller for selectively opening and closing a toner feeding port formed in an outer casing of the toner cartridge, a recovery cover for opening and closing a toner recovery port formed in an outer casing of the toner cartridge in relative movement with the outlet cover during mounting and removal with respect to the developing unit, and a supporting projection for restricting and opening and closing one end of the inlet cover during mounting and removal of the toner cartridge with respect to the developing unit. As a result of this arrangement, a user does not have to perform additional steps to open and close the toner feeding path and the toner recovery path, and accordingly can use the image forming apparatus with more convenience.

Abstract: An image forming apparatus and method cause a connecting/conveying device to convey a recovered toner from a cleaner part to a recovered toner housing to house therein the recovered toner, and cause a controller to control a recovered toner supply and a new toner supply in accordance with a toner concentration ratio in a developing device, which is detected by a toner concentration ratio detector, to supply the recovered toner, which is stored in the recovered toner housing, and the new toner, which is stored in the new toner housing, to the developing device. The controller separately controls the recovered toner supply and the new toner supply in accordance with the contents detected by the toner concentration ratio detecting means, to cause to change the combination of the amounts of the recovered toner and new toner to be supplied to the developing device.

Abstract: Toners resided after transferring toner images on a photosensitive member are collected and reused as recycled toners once returned to developing devices. A mixture ratio of the recycled toner to a specific color toner in each of the developing devices is controlled below a limiting color mixture ratio to suppress reduction in image quality due to the toner collected from an image carrier and reused as the recycled toner. The limiting color mixture ratio is defined as a color mixture ratio of a recycled toner to a color toner when a tone variation in another image reaches to a permissible limitation level.

Abstract: An image forming apparatus of the present invention includes a plurality of image carriers sequentially arranged in a direction of paper conveyance. Developing devices each form a toner image of particular color on one image carrier associated therewith. Cleaning devices each remove residual toner left on the surface of the associated image carriers after the transfer of the toner image to the recording medium. A toner recycling device is provided between the cleaning device located at the most upstream position in the direction of paper conveyance and the developing device associated therewith, but not provided between the cleaning device located at the most downstream position the developing device assigned therewith. With this configuration, the apparatus obviates troubles ascribable to the mixture of toner of different colors occurring in the most downstream developing device.

Abstract: A toner cartridge having toner agitating and mixing properties. The structure insures image quality without increasing in complexity of the structure as well as capable of being compacted. A used toner recycling opening for dropping used toner by gravity is formed in an upper wall of a cartridge main body storing fresh toner. A toner agitator and a toner supply device with an opening for supplying mixed toner to a developing apparatus are arranged within the cartridge main body. The toner can be sufficiently mixed and agitated on a cartridge main body side without depending on a developing apparatus side, and the toner cartridge is prevented from being large-sized. In particular, since the used toner drops by gravity, a taking-in structure of this used toner is simplified, and a mixing work of the used toner with fresh toner is made irrespective of a moving direction of the toner agitator. Also, there are two film sealing members for sealing the used toner recycling and toner supply openings.

Abstract: An image forming apparatus of the present invention includes a recycle toner conveying device for returning toner collected in a cleaning step to a developing device as recycled toner. A waste toner conveying device conveys the collected toner to a waste toner container as waste toner. A switching device selects either one of the recycle toner conveying device and waste toner conveying device. Toner can therefore be efficiently recycled in accordance with the degree of color mixture of the collected toner. In addition, It is possible to estimate the amount of toner to enter due to reverse transfer and therefore to increase the proportion of toner recycling while reducing the influence of color mixture on the toner to be recycled.

Abstract: An image forming apparatus includes an image bearing member on which an electrostatic latent image is formed, the image bearing member including a protective layer on a surface thereof, a developing device configured to develop the electrostatic latent image with toner to which an external additive is added to form a toner image, and a toner replenishing device configured to contain the toner and to supply air to the toner to replenish the developing device with the toner.

Abstract: In accordance with the present invention, in an image forming apparatus of the type developing a latent image formed on an image carrier, which moves at a linear velocity of 400 mm/sec or above, with a developer containing toner grains having a volume mean grain size of 5 &mgr;m to 10 &mgr;m and 60 number percent to 80 number percent of which has a grain size of 5 &mgr;m or below, the developer contains carrier grains having a weight mean grain size of 65 &mgr;m or below. When use is made of toner with a small grain size, the apparatus successfully obviates background contamination, toner scattering and sleeve contamination without regard to operation speed or environmental conditions.

Abstract: An image forming apparatus including a photoconductor, and a developing unit having a developing sleeve for carrying a developer and a developer regulating plate for regulating the amount of the developer carried on the sleeve, wherein the developer is composed of a carrier and a toner, wherein that portion of the toner which has a particle diameter of 2.0-4.0 &mgr;m accounts for 30-70% of a total number thereof, and wherein the developer regulating plate is grounded so that when the developing sleeve is applied with a bias voltage, an electric field is formed between the developer regulating plate and the developing sleeve, whereby toner deposits on the developing sleeve are transferred to the developer regulating plate.

Abstract: A toner container has a partitioning wall disposed therein for partitioning the toner container whilst allowing communication between partitioned compartments. A waste toner collecting port for receiving the waste toner collected by the cleaning unit of an image forming apparatus is formed in the waste toner collection compartment. A toner agitating element for mixing waste toner with unused toner is arranged inside the partitioned waste toner collection compartment partitioned in the toner container.

Abstract: A recovered toner classifier includes a rotatable cylindrical-shaped filter and a fur brush having a brush spirally provided on an outer peripheral surface of a rotation shaft. A non-brush region is continuously formed from the inlet of the filter for the recovered toner through the outlet of the filter for discharging the disposal toner along the axis line of the rotation shaft. The fur brush integrally rotates with the rotation shaft with a tip portion of the brush is in press-contact with an inner peripheral surface of the filter. A screw conveyer having a screw on a portion of the rotation shaft on a side of the inlet of the filter for the recovered toner is provided to convey the recovered toner to the inlet of the filter for the recovered toner.

Abstract: Toner processing systems and electronic display devices and methods are described. In one embodiment, a toner processing system comprises an enclosure and an electrostatic toner recovery assembly supported within the enclosure for electrostatically recovering unfused toner from a print media surface. A toner development assembly is supported within the enclosure proximate the electrostatic toner recovery assembly and is configured to receive recovered toner from the electrostatic toner recovery assembly for reuse on the print media surface.

Abstract: In image forming apparatuses producing recycled toner from residual toner and recycling the recycled toner, the toner composition changes, and the toner properties worsen, because the external additive contained in the collected residual toner that is collected with a cleaning portion decreases during the image formation. The residual toner that has been collected with the cleaning portion is conveyed through a conveyance path to a collected residual toner storage, and external additive is supplemented from an external additive cartridge, and mixed with being stirred to produce recycled toner. In a fresh toner storage, fresh toner and recycled toner are stirred, and when the amount of toner in a developing portion drops below a predetermined amount, toner is conveyed from the fresh toner storage through a conveyance path to the developing portion. The toner that has been conveyed to the developing portion is supplied to a photosensitive drum.

Abstract: A toner recycling device of an electrophotographic image forming apparatus conveys collected used toner to a developing device of the image forming apparatus. The toner recycling device includes a powder conveying pump that is driven to convey the collected used toner to the developing device of the image forming apparatus when an integrated value of predetermined numerical values, each based on a number of picture elements of an image to be formed, is equal to or greater than a constant value, and an adding device that adds a predetermined constant value to the integrated value when driving of an image bearing member of the image forming apparatus is detected.

Abstract: A powder classifying device that classifies powder includes a mesh member having meshes, and a brush roller formed with hair-like members and configured to rotate in sliding contact with the mesh member at a predetermined portion in a circumferential direction of the brush roller to push the powder conveyed in a radial direction of the brush roller against the meshes so that the powder is classified into powder passing through the meshes and powder not passing through the meshes.

Abstract: A method and apparatus for electrophotographic image forming are provided incorporating an improved toner recycling unit. This recycling unit is devised such that the selectable switching between toner recycling and non-recycling modes be continually carried out according to the decision based on the present amount of paper dusts measured by a paper dust measuring unit provided in a paper dust removal unit. The image forming apparatus incorporating the toner recycling unit is therefore capable of efficiently recycling the toner recovered from a cleaning unit without removing contaminants such as paper dusts and toner aggregates included in the recycled toner, thereby preventing the emergence of undesirable picture image anomalies such as whisker images and black dots.

Abstract: Monocolor image forming unit includes a developing device and an image carrier cleaning device arranged around an image carrier. A plurality of such the monocolor image forming unit is arrayed laterally along the rotary transport direction of an intermediate transfer member of the belt type to configure a tandem image forming device. In the tandem image forming device, a synthesized toner image is formed on the intermediate transfer member and transferred to a recording medium to form a multicolor image thereon. Among the plurality of monocolor image forming unit contained in the tandem image forming device, at least two monocolor image forming unit each include a toner recycling device for conveying toner collected at the image carrier cleaning device to the developing device.

Abstract: Image forming unit has a photosensitive drum unit and a developing unit. The photosensitive drum unit has drum shafts extending outward from opposite sides thereof. The developing unit has a through-hole and a drum shaft mounting groove for receiving the drum shafts, and developing unit rotary shafts extending outward from opposite sides thereof. An engagement lever and a toner returning cylinder are provided in the photosensitive drum unit, and a shutter is provided in the developing unit. The toner returning cylinder and the shutter are disposed between the waste toner tank of the photosensitive drum unit and the toner returning pipe of the developing unit so that they are detachable and separable from each other. Further, a mechanism is provided for pressing the developing roller onto the photosensitive drum when the photosensitive drum unit is mounted to the developing unit or when the photosensitive roller is driven.

Abstract: A color image forming apparatus includes a plurality of image forming sections independent of each other. The image forming sections store respective toner of different colors that are chargeable to the same polarity. All the toner are implemented by the same binder resin and provided with the same particle size distribution. Further, developing units each storing toner of particular color are identical in specification. When two-ingredient type developers are used, the developers contain an identical carrier. The apparatus recycles the toner of different colors to the respective developing units. The alien color toner collected in each developing unit is prevented from remaining by being chargeable to the same polarity.

Abstract: A transporting member for transporting toner by its rotation is provided inside a first transporting passage, and that a transporting member provided inside a second transporting passage is moved in a vertical direction through a converter for converting the rotation of the transporting member provided inside the first transporting passage into reciprocation.

Abstract: To provide an amorphous Si photosensitive member and an image forming apparatus which form favorable images by preventing toner adhesion at a cleaning time. A photoconductive layer 102 containing amorphous Si is formed on an electrically conductive substrate 101 so that a surface of a photosensitive member has an average inclination &Dgr;a within a range of 0.12 to 1.0, more preferably 0.15 to 0.8 within a range of 10 &mgr;m×10 &mgr;m, and an electrically conductive substrate has surface roughness Ra within the range of 10 &mgr;m×10 &mgr;m is lower than 9 nm, preferably lower than 6 nm.

Abstract: An electrophotographic apparatus which forms an electrostatic latent image on a photoreceptor includes a developing device configured to accommodate a two-component developer including toner and carrier and to develop the electrostatic latent image with the developer. Toner which has been used for developing the electrostatic latent image is recycled to the developing device so as to be used again. The developing device includes a developer conveying path so as to convey the recycled toner therethrough. A screening member having openings to screen the recycled toner is arranged in the developer conveying path.

Abstract: A toner cartridge having excellent toner agitating and mixing properties, capable of ensuring improved image quality without increasing in complexity of the structure as well as capable of being compacted. A used toner recycling opening for dropping used toner by gravity is formed in an upper wall of a cartridge main body storing fresh toner. A toner agitator and a toner supply device for supplying mixed toner to a developing apparatus are arranged within the cartridge main body. The toner can be sufficiently mixed and agitated on a cartridge main body side without depending on a developing apparatus side, and the toner cartridge is prevented from being large-sized. In particular, since the used toner drops by gravity, a taking-in structure of this used toner is simplified, and a mixing work of the used toner with fresh toner is efficiently made irrespective of a moving direction of the toner agitator.

Abstract: An imaging apparatus is disclosed that conveys toner smoothly from its cleaning unit to a toner collector and efficiently recovers toner residual on its photoconductive drum circumferential surface. A toner recovery device for the imaging apparatus is provided with a cleaning unit 34 for removing toner residual on the surface of the photoconductive drum 30, a toner-conveying device 71 for conveying recovered toner, and a developing unit 32 to which the recovered toner is conveyed. The inner circumferential bottom surface of a toner conveyance container 72 for the toner-conveying device 71 slopes downward from the cleaning unit 34 toward the developing unit 32.

Abstract: A toner carrier is included in an image forming apparatus wherein the electrical resistance between a shaft of the toner carrier and a surface which covers the shaft is different depending on the polarity of the voltage applied between th shaft and the surface. A resistance characteristic is thereby obtained having a resistance that allows prescribed current to flow from the shaft side to the surface side and which makes current flow from the surface side to the shaft side difficult. This prevents leakage current being received from the surface of the photosensitive drum. The amount of charging up of the toner therefore does not drop and a prescribed amount of charging up can be maintained, which means that fog of the image background surface does not occur. Furthermore, because there is no voltage dependence at the toner carrier surface from the shaft side, stable image density can be achieved, enabling high image quality to be achieved.

Abstract: An image forming apparatus includes an image bearing member on which an electrostatic latent image is formed, the image bearing member including a protective layer on a surface thereof, a developing device configured to develop the electrostatic latent image with toner to which an external additive is added to form a toner image, and a toner replenishing device configured to contain the toner and to supply air to the toner to replenish the developing device with the toner.

Abstract: A toner replenishing device includes a toner conveyance path for connecting a toner storing device with a developing device, a toner conveying device for conveying the toner from the toner storing device to the developing device along the toner conveyance path, and an air supplying device connected to the toner conveyance path vie an air supply path for supplying the toner storing device with air from a bottom of the toner storing device so as to agitate the toner pooling in the toner storing device.

Abstract: An color image forming apparatus is disclosed which forms an electrostatic latent image on a photosensitive drum with the use of a charger and laser beam for light exposure, develops the electrostatic latent image into a visible image by a developing unit with the use of a liquid developer with a coloring material of very fine particles mixed in an insulating solvent and transfers the visible image to a recording sheet with the use of a transfer roller with a heater reincorporated therein.

Abstract: An image forming apparatus includes a developing unit having a photoreceptor, for making an electrostatic latent image on a surface of the photoreceptor visible as a toner image. A toner hopper stores toner to be supplied to the developing unit and a cleaning device removes and recovers the toner remaining on the surface of the photoreceptor after the toner image has been transferred onto a recording material. A toner transporting passage is connected between the cleaning device and the toner hopper, through which the toner recovered by the cleaning device is returned to the toner hopper. A toner exhausting port is disposed at a part of the toner transporting passage, from which the toner being returned from the cleaning device side is exhausted outside the toner transporting passage. An opening and closing member selectively opens or closes the toner exhausting port, wherein an inner diameter of the toner exhausting port is made larger than that of the toner transporting passage.

Abstract: To solve problems that the amount of reuse toner increases with time recovery of reuse toner is efficiently achieved while forming an image of high quality. In a toner replenishing apparatus, toner recovered by a cleaning unit is conveyed via conveying device and contained in a recovery toner container. When an amount of the recovery toner exceeds a predetermined capacity of the recovery toner container, the recovery toner flows into a fresh toner container over an upper edge of a partition wall. Fresh toner and recovery toner are replenished to a developing unit via a fresh toner replenishing roller and a recovery toner replenishing roller, respectively, and the ratio between fresh toner and recovery toner is selected so that the fresh toner occupies a larger part than the recovery toner. This ratio is controlled on the basis of the cumulative rotation time of a photoconductor drum counted by a counting device.

Abstract: In image forming, the ratio of foreign substances mixed in the recycled toner which is removed from the photoreceptor drum surface by means of the cleaning device is computed as one of the characteristics of the recycled toner, based on the paper size, the image area and the transfer efficiency. If the recycled toner has a high ratio of foreign substances mixed therein and is determined to have a low quality, collection of the recycled toner into the developing unit is temporarily interrupted and a fixed amount of toner is conveyed from the developing unit to the cleaning device so as to improve the quality of the recycled toner. In this way, recycled toner of a low quality is prohibited from being used for subsequent image forming operations so as to prevent degradation of the image quality.

Abstract: A developing unit and an image forming apparatus includes drive and control mechanisms for the conveyance of collected toner and fresh toner in an uncomplicated structure and an uncomplicated toner supplying roller structure for the reduction in manufacturing cost. Fresh toner and collected toner stored in housing parts of a toner housing are discharged from an outlet via openings formed in a partitioning member for forwarding to a developing section by a toner supplying roller disposed to confront the outlet. The toner supplying roller is provided in common to fresh toner and collected toner. The toner supplying roller includes a single rotary shaft and a plurality of composite members which are fit into the rotary shaft. Each of the composite members has a cylindrical hollow body and a cylindrical elastic body which is fit onto the outer peripheral surface of the hollow body. The composite members are disposed correspondingly to the housing parts.

Abstract: In an image forming apparatus and a controlling method thereof, the image forming apparatus comprises conveyer mechanisms for conveying collected toner to a waste part or a recycling part, and a controller for controlling the conveyer mechanism and a developer supplying device according to image forming conditions. When the image forming condition exceeds a predetermined reference level, the controller decreases a recycling rate of the collected toner. If the recycling rate becomes high as a result of the controlling, the controller decreases an amount of supplying the developer so as to lower toner density. Thus, reference toner density in the developer is controlled, thereby, high quality images can be maintained, and the controller can be simplified.

Abstract: A developing agent filtering apparatus includes a filtering arrangement for filtering magnetic toner from the mixture of the magnetic toner and foreign matter. The filtering arrangement includes a pair of magnetic field generating members, and a filter for regulating a shifting movement of the foreign matter from one of the pair of magnetic field generating members to the other; and a switch for changing the configuration of a magnetic field generated by the pair of magnetic field generating members. The switch switches a relative position between the pair of magnetic field generating members between a first position where opposite magnetic polarities of the pair of magnetic field generating members are opposed to each other and a second position different from the first position.

Abstract: A cleaning device comprises: a first conveying member disposed further upstream in the rotating direction of a photoconductor drum than a cleaning blade, and constructed to rotate in non-contacting relationship to the photoconductor drum to convey residual toner that was removed by the cleaning blade; a second conveying member disposed parallel to the first conveying member and constructed to rotate in non-contacting relationship to the first conveying member; a first bias power supply for applying to the first conveying member a bias voltage having a polarity opposite to the proper polarity of the developer applied for development; and a second bias power supply for applying to the second conveying member a bias voltage having the same polarity as the proper polarity.

Abstract: A toner supplying device for supplying toner contained in a toner container to a developing device of an image forming apparatus includes a toner container insertion part configured to receive at least two inserted toner containers from a front side of the toner supplying device. A toner container holder detachably holds the toner containers inserted into the toner container insertion part. A toner container selection control device selects an arbitrary toner container from among the at least two toner containers held by the toner container holder and causes the selected toner container to discharge toner from an opening thereof while stopping a discharge of toner from an opening of the other toner containers.

Abstract: An image-forming method uses an assembly having a first toner replenishing hopper, a toner storage room, a nonmagnetic cylindrical rotating member provided with a first mixed magnetic field-generating device, a first magnetic blade, a nonmagnetic cylindrical development sleeve provided with a second fixed magnetic field generating device, a second magnetic blade, an electrostatic image holding member, a cleaning device and a second toner-replenishing hopper. At least certain of the foregoing components are set to have specific positional relationships with one another so that the recovered magnetic toner is efficiently reused together with the fresh magnetic toner.

Abstract: An image forming apparatus capable of collecting toner left on an image carrier after image transfer during an electrophotographic process, and returning the toner to a developing unit for reuse in the form of an air-toner mixture is disclosed. A toner conveying device includes a screw pump and a hopper portion positioned upstream of the screw pump in the intended direction of toner conveyance. When the collected toner accumulating in the hopper portion reaches a preselected amount, the toner conveying device is caused to start and stop operating at a specific timing.

Abstract: An image forming apparatus including a plurality of filters for obtaining reusable toner from used toner scraped off of an image carrier. Also included is a reusable toner container for storing the reusable toner, and a toner transfer device for transferring the reusable toner stored in the reusable toner container to a developing device so that the reusable toner is reused by the developing device. The plurality of filters have a different mesh-size and are positioned in a used toner stream in an order based on the different mesh-size.

Abstract: A photoreceptor for forming an electrophotography is disclosed. The photoreceptor comprises a photosensitive layer in an area excluding both edges in the axial direction on a cylindrical aluminum support and silicon oil on the surface of both edges which have no photosensitive layer on the cylindrical aluminum support.

Abstract: A toner cartridge includes a container body having a toner transport passage, and a toner transporter disposed in the toner transport passage for transporting toner from one end portion toward the other end portion of the toner transport passage while agitating the toner along the toner transport passage. The container body has a toner discharge port provided at the other end portion of the toner transport passage, and a recycle toner entry port provided at the one end portion of the toner transport passage. When the toner cartridge is mounted at a predetermined position, the toner discharge port is positioned opposite a toner feed port provided in a developing device, while the recycle toner entry port is positioned opposite a recycle toner drop port provided in a recycle toner carrier.

Abstract: A toner replenishing device for an image forming machine has a hopper housing with a toner agitating passageway and a toner carrying passageway, a toner agitator disposed in the toner agitating passageway for agitating recovered toner and fresh toner supplied to the toner agitating passageway and lifting them to the toner carrying passageway, and a toner carrier disposed in the toner carrying passageway for carrying the recovered toner and the fresh toner agitated and lifted by the toner agitator. The toner agitator has a first paddle disposed in a first end part of the toner agitating passageway, and a second paddle disposed on the other end part side of the toner agitating passageway and adjacent to the first paddle. The first paddle has the function of sending the toner to the other end part side of the toner agitating passageway, while the second paddle has the function of sending the toner to the first end part side of the toner agitating passageway.

Abstract: In an electrophotographic image forming apparatus including a toner recycling mechanism, a collected toner conveying device is free from troubles particular to a conventional device using a screw pump and an air pump and conveying toner and air mixture via an elastic tubing, i.e., the wear of a stator due to aging and a decrease in the delivery pressure of the pump ascribable to the wear. A control device controls, based on the cumulative operation time, an operation of the screw pump and an operation of the air pump. This provides the toner conveying device with durability, reliability and simple construction while insuring toner conveyance and reducing cost.

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: An electrophotographic printer has a toner recycling mechanism with a belt conveyor that transports toner from a toner collection chamber, in which toner removed from the photosensitive drum of the printer is collected, to a toner delivery chamber, from which toner is returned to the developing unit of the printer. The belt conveyor is disposed in a channel that loops around the ends of roller shafts in the printer, and does not increase the width of the printer. The toner recycling mechanism is easily assembled, and can be driven without motion irregularities.