Abstract: An organic photoconductive (OPC) unit of an image forming apparatus and a gear assembly arranged in the OPC unit. The gear assembly includes a drum gear formed on a flange of an OPC drum, a cleaning gear driven by a receiving power from the drum gear, and at least one idle gear interposed between the drum gear and the cleaning gear and transmitting the rotational force of the drum gear to the cleaning gear. Therefore, it is possible to drive a plurality of additional rollers with a single power source, and easy to connect the OPC drum with the gears when the OPC drum is fitted into the OPC unit. In addition, because the gear assembly is constructed in a compact form, it is possible to reduce the volume of the OPC unit.

Abstract: A photoreceptor unit includes a photoconductive drum assembly, a housing to enclose the photoconductive drum assembly to be rotatable therein, a handgrip rotatably formed on the housing, and a stopper to prevent the housing with the photoconductive drum assembly from becoming lopsided toward its preponderant side of the housing with respect to a center of rotation of the handgrip when the housing is lifted up by the handgrip.

Abstract: An organic photoconductive (OPC) drum assembly including a pipe-shaped drum body with open sides, first and second flanges connected to both sides of the drum body, a shaft penetrating the drum body and rotatably supporting the flanges, and a pair of bearings inserted between each flange and the shaft. A driving gear to receive power is integrally formed with one of the first and second flanges.

Abstract: A developing apparatus of an electric photographic printer supplying a two-element developing agent to develop an electrostatic latent image formed on a photosensitive medium includes: a housing; a developing agent supplying roller; a developing agent mixing roller; a developing sleeve to transfer mixed developing agent to the photosensitive medium through a developing area formed between the developing sleeve and the photosensitive medium; a fixing magnet disposed inside of the developing sleeve to have a plurality of magnetic poles arranged from the developing area in a circular direction about a center of the fixing magnet; and a magnetic bar disposed on an inside surface of the housing to face one of the magnetic poles of the fixing magnet through the developing sleeve to form a magnetic force brush preventing the developing agent from being scattered as the developing agent passes through the developing area.

Abstract: A squeezing device of a wet printer for separating a liquid carrier element that is not used for forming an image from ink supplied to the photosensitive belt, includes a squeezing roller mounted to be opposite to the photosensitive belt, a bias applying unit for biasing the squeezing roller with a certain potential, and a plurality of backup rollers mounted side by side to be opposite to the squeezing roller across the photosensitive belt placed between the plurality of backup rollers and the squeezing roller, in order to extend a contact width between the photosensitive belt and the squeezing roller. A printer to which the squeezing device of a wet printer is applied secures a sufficient charging time of the photosensitive belt and lowers a voltage for generating a townsend discharge, to thereby enhance charging performances and printing qualities.

Abstract: A waste toner collecting apparatus using a disposable OPC drum utilizes an inside space of the disposable OPC drum as a waste toner container to collect waste toner. The waste toner collecting apparatus comprises a waste toner removing unit contacting one side of the OPC drum to remove the waste toner from the OPC drum, first transport unit transporting the waste toner, which is removed by the waste toner removing unit from the OPC drum, in one direction, a second transport unit transporting waste toner, which is transported by the first transport unit, to one side of a storage unit, and a screw member moving the waste toner, which is moved to one side of the storage unit, to the other side of the storage unit to store the waste toner within the storage unit from the one side to the other side without leaving an unused hollow space. A user can conveniently remove the waste toner by replacing only the OPC drum instead of individually replacing the OPC drum and the waste toner container.

Abstract: An OPC unit exchanging apparatus of a printer includes an organic photo conductor (OPC) unit; a developing cartridge including a developing roller and contacting the OPC unit; a separating unit to separate the OPC unit and developing cartridge by a predetermined distance; a locking unit to settle the developing cartridge at the predetermined distance away from the OPC unit; an unlocking unit to unlock the developing cartridge locked by the locking unit; and a returning unit to return the developing cartridge so that the developing cartridge contacts the OPC unit.

Abstract: A developing apparatus of an electric photographic printer supplies a two-element developing agent to develop an electrostatic latent image formed on a photosensitive medium.

Abstract: A squeezing device of a wet printer for separating a liquid carrier element that is not used for forming an image from ink supplied to the photosensitive belt, includes a squeezing roller mounted to be opposite to the photosensitive belt, a bias applying unit for biasing the squeezing roller with a certain potential, and a plurality of backup rollers mounted side by side to be opposite to the squeezing roller across the photosensitive belt placed between the plurality of backup rollers and the squeezing roller, in order to extend a contact width between the photosensitive belt and the squeezing roller. A printer to which the squeezing device of a wet printer is applied secures a sufficient charging time of the photosensitive belt and lowers a voltage for generating a townsend discharge, to thereby enhance charging performances and printing qualities.

Abstract: A developing solution feeder of a wet type electrophotographic color printer includes a plurality of circulation tanks for storing the developing solution to be fed to a developing unit; a plurality of injection nozzles for jetting the developing solution stored in the circulation tanks to a developing gap of the developing unit; a plurality of ink storage tanks and a carrier storage tank for respectively storing the condensed ink of a certain color and a carrier to be fed to the circulation tanks, respectively; a waste tank for collecting the waste developing solution produced from the circulation tanks; a refill cartridge for the supplementation of the condensed ink or the carrier; developing solution refilling/waste developing solution collecting means for refilling the ink storage tanks or the carrier storage tank with the condensed ink or the carrier, respectively, and for evacuating the waste developing solution collected in the waste tank to the empty refill cartridge; and ink injecting/constant feedin

Abstract: An ink supply apparatus of a printer includes an ink supply container for containing ink which includes a memory module for recording information about the ink contained in the ink supply container, a plurality of exposed terminals formed at the outer circumferential surface of the ink supply container, and a plurality of internal signal lines for internally connecting the exposed terminals and the memory module. Further, an ink injection portion, at which the ink supply container is installed, is provided at the printer and includes a connection terminal portion electrically connected to the exposed terminals when the ink supply container is installed. When the ink supply container is installed at the ink injection portion, information can be exchanged between the controller and the memory module.

Abstract: An ink supply apparatus of a printer includes an ink supply container for containing ink which includes a memory module for recording information about the ink contained in the ink supply container, a plurality of exposed terminals formed at the outer circumferential surface of the ink supply container, and a plurality of internal signal lines for internally connecting the exposed terminals and the memory module. Further, an ink injection portion, at which the ink supply container is installed, is provided at the printer and includes a connection terminal portion electrically connected to the exposed terminals when the ink supply container is installed. When the ink supply container is installed at the ink injection portion, information can be exchanged between the controller and the memory module.

Abstract: A liquid developer refilling system of a liquid electrophotographic printer for supplying any one of concentrated inks and a carrier to corresponding one of ink storage tanks and a carrier storage tank installed in the printer, and a method thereof. The system includes: a main frame provided with a common installation portion; an auxiliary frame installed to be movable with respect to the main frame; a cartridge installed at the installation portion and provided with a discharge hole through which a concentrated ink or carrier is discharged by compressed air; a fastener for fixing the cartridge installed at the installation portion to the main frame; a valve unit provided with a plurality of valves which can be selectively matched with the discharge hole and installed to be movable with respect to the auxiliary frame; and a valve raising/lowering mechanism which raises or lowers the auxiliary frame with respect to the main frame to connect or disconnect a corresponding valve to or from the discharge hole.

Abstract: An ink delivery system of a liquid electrophotographic color printer which supplies liquid developers of predetermined concentration, each of which is a mixture of a toner and a liquid carrier, to a plurality of respective developing units, and which recovers the carrier using a drying/condensing unit which absorbs and evaporates the carrier remaining on the photosensitive medium after development. A plurality of circulation tanks store respective developers to be supplied to a corresponding developing unit. Respective concentration measuring devices measure the concentration of the developers. A waste tank receives waste developer produced in the plurality of circulation tanks, and includes a waste developer agitating device for agitating the waste developer. A plurality of ink storage tanks store concentrated inks of predetermined colors to be supplied to the respective circulation tanks, and include respective ink agitators driven by a single driving source.

Abstract: An ink supply apparatus for a wet electrophotographic printer. The ink supply apparatus includes a housing having an installation portion, an ink cartridge installed in the housing, for supplying ink to a developing unit, a detachable refill cartridge loaded in the installation portion, for supplying ink to the ink cartridge, and an ink supply device for supplying ink to the ink cartridge from the refill cartridge.

Abstract: A valve unit for a hermetic reciprocating compressor comprises a valve plate adapted to be attached to the end of a piston cylinder. A discharge passage is formed through the valve plate, and a valve assembly is mounted within a stepped recess formed in an outer side of the valve plate for opening and closing the discharge passage. The outlet end of the discharge passage is situated within the recess and is spaced inwardly from the outer side so that the length, and hence the volume, of the discharge passage is reduced. Hence, the amount of compressed gas remaining in the discharge passage at the end of a piston stroke is correspondingly reduced, so that a vacuum can be formed in the piston chamber more quickly as the piston is retracted.