Abstract: A toner supply device for supplying toner to a developing unit, includes: a toner cartridge for storing toner; and a toner feed device disposed adjacent to the toner cartridge and composed of a casing for reserving the toner supplied from the toner cartridge and first and second toner agitator shafts for agitating and conveying the toner inside the casing, and is constructed such that the toner feed device agitates the toner supplied from the toner cartridge first, then feeds the agitated toner to the developing unit.

Abstract: An exhaust gas recirculation passage connects an exhaust passage with an intake passage. A cooling device is mounted to the exhaust gas recirculation passage for cooling exhaust gas in the exhaust gas recirculation passage. An EGR valve adjusts a flow passage area of the exhaust gas recirculation passage. An exhaust gas quantity (EGR quantity) in the exhaust gas recirculation passage is feedback-controlled by manipulating an opening degree of the EGR valve based on a measurement value of an airflow meter. Existence or nonexistence of an abnormality in the cooling device is diagnosed based on whether a measurement value of the opening degree of the EGR valve contains a component corresponding to compensation for reduction of the EGR quantity due to degradation of cooling performance of the cooling device.

Abstract: An object of the present invention is to provide a remaining amount of toner detecting apparatus capable of highly accurately detecting the remaining amount of toner with a simple configuration, a toner cartridge in which the remaining amount of toner is highly accurately detected with a simple configuration, and an image forming apparatus which enables the operator to easily recognize time to resupply toner and is capable of forming an image of high image quality. A holding member (22) is flexible, one end (22a) in the longitudinal direction is connected to a stirring member (11), and the other end (22b) in the longitudinal direction holds a detection auxiliarymember (21) disposed in a housing (8). Consequently, the holding member (22) and the detection auxiliary member (21) rotate as the stirring member (11) rotates.

Abstract: A developing device is arranged such that Dg<ds<3 Dg, and 3 Dg<dc<6 Dg, where ds is an end gap, Dg is an upstream gap, and dc is a center gap. The gap ds is a gap between a developer tank 4 and either end portion of a developing roller 1 in the downstream of a transportation direction of the developing roller 1. The end portion of the developing roller 1 is an end portion thereof with respect to a rotation direction of the developing roller 1. The gap Dg is a gap between the developing roller 1 and a doctor blade. The gap dc is a smallest gap between the developer tank 4 and the center portion b of the developing roller 1. With this arrangement, it is possible to prevent the toner scattering appropriately in the developing device for use of a two-component developer containing toner and carrier.

Abstract: Elastic members are fixed at one end to the housing of an image forming apparatus while their distal ends extend into the framework of the developing unit. When a toner cartridge is fitted to the framework of a developing unit, the distal ends of the elastic members abut the top surface of the toner cartridge, so that the elastic members are compressed to produce repulsive force, which in turn causes the developing unit to rotate clockwise about a support so as to bring the developer roller into pressing contact with a photoconductor.

Abstract: A process cartridge includes a toner unit including a toner containing space and a toner supply space. A development unit including rollers. There is a holding frame having a fixture section for the development unit and an accepting section for the toner unit. The process cartridge is constructed arrangement in which the toner is fixed in a predetermined position in the accepting section of the holding frame or which the toner unit is detachably installed in a predetermined position in the accepting section of the holding frame.

Abstract: A toner cartridge includes: a toner storage chamber; a toner collecting chamber; a partitioning wall for separating these chambers; a cylindrical return pipe penetrating through the partitioning wall with a conveyer screw arranged therein and is configured so that when the amount of untransferred toner collected into the toner collecting chamber exceeds the height of the return pipe, the untransferred toner is conveyed by the rotation of the conveyer screw to be returned into the toner storage chamber.

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: Elastic members are fixed at one end to the housing of an image forming apparatus while their distal ends extend into the framework of the developing unit. When a toner cartridge is fitted to the framework of the developing unit, the distal ends of the elastic members abut the top surface of the toner cartridge, so that the elastic members are compressed to produce repulsive force, which in turn causes the developing unit to rotate clockwise about a support so as to bring the developer roller into pressing contact with the photoconductor.

Abstract: A toner cartridge includes: a toner storage chamber; a toner collecting chamber; a partitioning wall for separating these chambers; a cylindrical return pipe penetrating through the partitioning wall with a conveyer screw arranged therein and is configured so that when the amount of untransferred toner collected into the toner collecting chamber exceeds the height of the return pipe, the untransferred toner is conveyed by the rotation of the conveyer screw to be returned into the toner storage chamber.

Abstract: A process cartridge of the present invention includes a toner unit including a toner containing space and a toner supply section; a development unit including a developing device; and a holding frame having a fixture section for the development unit and an accepting section for the toner unit. Moreover, the process cartridge of the present invention is constructed selectively in a first arrangement in which the toner unit is fixed in a predetermined position in the accepting section of the holding frame or in a second arrangement in which the toner unit is detachably installed in the predetermined position.

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: For realizing a satisfactory and stable developing process, the charge state of a developer and the density of toner particles contained in the developer is kept constant in the developing process. A developing roller to be driven rotationally is provided in a developing tank containing a developer. The developer is sucked magnetically using the magnetic force of a magnet provided in a developing sleeve composing the developing roller. The developer is then fed into a developing area opposed to a photosensitive member, then collected into the developing tank after the developing process is ended. The magnet is composed of an odd number of magnetic poles; developing pole, feeding pole, magnetic force distribution adjusting pole, developer sucking pole, developer separating pole, auxiliary collecting pole, and collecting pole. Between the sucking pole and the developing pole, an even number of poles are disposed. Between the developing pole and the separating pole are disposed an even number of poles.

Abstract: A developing device having a reduced size in the horizontal direction and in which a developing agent is transported with stirring along a circulating route inside a developing tank to effectively mix newly added toner therewith and stir the mixture. A developing tank for storing developing agent therein is horizontally divided with a partition member thereby providing an upper chamber and a lower chamber. A developer roller and a stirring roller are disposed in the lower chamber. Two screw rollers are disposed in the upper chamber. An inlet opening is formed between an end of the partition member and a regulating member for restricting a layer if the developing agent adsorbed to the developing roller. A developing agent removed by the restricting member is fed through an inlet opening to the screw rollers in the upper chamber. The developing agent is mixed with fresh toner supplied through a supply inlet and transported with being stirred by the screw roller in its axial direction.

Abstract: A developing apparatus comprises a development housing containing developer and disposed opposite to a carrier for carrying a latent image, and a developing roller rotatably provided in the development housing and rotatively driven in a predetermined direction. The developer in the development housing is carried by the developing roller and the developer carried by the developing roller is applied to the carrier through an opening formed in the development housing. A rotation speed F.beta. of the developing roller is higher than a movement speed F.alpha. of the carrier. A gap .beta. between an opening downstream side wall portion of the development housing and the developing roller is greater than a gap .alpha. between the opening downstream side wall portion and the carrier.

Abstract: Impurities contained in a developer are captured and prevented from mixing into the developer again, thereby to avoid lowering of image quality due to the impurities. Such impurities include aggregates of the developer formed in a developing apparatus, insufficiently charged toner particles, defectively charged toner particles having an opposite polarity to a predetermined polarity, and defective carrier particles lacking in strength for being held by a developing magnet roller. A recess is provided between peaks of magnetism located in a lower portion of a developing magnet roller. The recess has an air pressure substantially equal to an air pressure (atmospheric pressure) in the developing apparatus, so that air in the developing apparatus and the recess does not flow only in one direction. Impurities contained in the developer circulating around the developing roller cannot be magnetically held in the lower half of the developing roller because of centrifugal force and gravity.

Abstract: The invention is characterized by efficiently and quickly loosening an aggregation of toner material formed in a toner cartridge. A toner cartridge has an L-shaped toner agitating member disposed in a main body thereof having a discharge port for feeding toner at the front surface of the main body. Since the toner agitating member is supported so as to pivot like a conical pendulum, a support pin fixed to a bottom surface of the main body passes through a through hole having a greater diameter than that of the support pin. The support pin has an engagement portion attached thereto for prevention of disengagement of the toner agitating member therefrom. A plate-like portion of the toner agitating member defines an agitating plate, a distal end of which extends toward the discharge port of the main body.