Abstract: A developer agitator of an image forming device capable of improving the electrification rate of a developer is disclosed. The developer agitator includes a rotatable shaft and an agitating wing disposed on the circumferential surface of the shaft. The agitating wing has an uneven part formed to increase the contact area with a developer. The developer agitator can obtain an electrification rate of the developer required for high speed printing, thereby allowing the image forming device to be operated at a high speed.

Abstract: A toner path opening and closing apparatus of an image forming device includes a first shutter elastically supported by a first elastic member to open and close a first toner path, and a second shutter elastically supported by a second elastic member having an elastic modulus smaller than the first elastic member to open and close a second toner path by the first shutter. After the second toner path is opened by the first shutter, the first is opened, so that the first and second toner paths communicate with each other. The first toner path is a toner supplying pipeline to which a toner is supplied from a toner cartridge, and the second toner path is a toner injecting port disposed in a developing unit.

Abstract: An image forming apparatus and control method, the image forming apparatus including: a first image bearing body and a second image bearing body aligned to form predetermined color images; a transfer belt supported by a driving roller and a driven roller, to transfer images onto a printing medium; a first primary transfer roller installed on the opposite side of the first image bearing body, having the transfer belt in-between; a second primary transfer roller movably installed on the opposite side of the second image bearing body, having the transfer belt in-between, to engage/disengage the transfer belt with/from the second image bearing body by selectively changing the traveling track of the transfer belt; a driving unit to drive the second primary transfer roller to engage/disengage with/from the transfer belt; and a belt length adjusting unit to control the traveling distance of the transfer belt to be constant.

Abstract: A toner path opening and closing apparatus of an image forming device includes a first shutter elastically supported by a first elastic member to open and close a first toner path, and a second shutter elastically supported by a second elastic member having an elastic modulus smaller than the first elastic member to open and close a second toner path by the first shutter. After the second toner path is opened by the first shutter, the first is opened, so that the first and second toner paths communicate with each other. The first toner path is a toner supplying pipeline to which a toner is supplied from a toner cartridge, and the second toner path is a toner injecting port disposed in a developing unit.

Abstract: An image developing unit and an image forming apparatus having the same. The image forming apparatus includes a body, an image developing unit including a frame having a developer supply part into which a developer is introduced, a developing roller rotatably installed on a developing roller support part provided in the frame, and a developer supply auger mounted in the developer supply part so as to provide the developing roller with the developer and formed with a reduction part having a reduced circumferential width, and an image transferring unit to transfer a visible image formed in the image developing unit onto a printing medium, wherein the developer supply auger is installed on the frame such that the reduction part is positioned corresponding to the developing roller support part. An interval between central axes of the developing roller and the developer supply auger becomes narrow, so that a developer is stably supplied to the developing roller.

Abstract: A developer agitator of an image forming device capable of improving the electrification rate of a developer is disclosed. The developer agitator includes a rotatable shaft and an agitating wing disposed on the circumferential surface of the shaft. The agitating wing has an uneven part formed to increase the contact area with a developer. The developer agitator can obtain an electrification rate of the developer required for high speed printing, thereby allowing the image forming device to be operated at a high speed.

Abstract: An image forming apparatus and control method, the image forming apparatus including: a first image bearing body and a second image bearing body aligned to form predetermined color images; a transfer belt supported by a driving roller and a driven roller, to transfer images onto a printing medium; a first primary transfer roller installed on the opposite side of the first image bearing body, having the transfer belt in-between; a second primary transfer roller movably installed on the opposite side of the second image bearing body, having the transfer belt in-between, to engage/disengage the transfer belt with/from the second image bearing body by selectively changing the traveling track of the transfer belt; a driving unit to drive the second primary transfer roller to engage/disengage with/from the transfer belt; and a belt length adjusting unit to control the traveling distance of the transfer belt to be constant.

Abstract: Disclosed are a sludge prevention apparatus of a tube member and an image forming apparatus provided with such a sludge prevention apparatus. The sludge prevention apparatus comprises a sludge stirring member located in a tube member to be movable, so that the sludge stirring member stirs the developer sludge deposited or as being deposited in the tube member, the liquid developer being discharged from or flowing into a developer storage chamber through the tube member; and an operating member installed in the developer storage chamber to correspond to the sludge stirring member in such a manner that the operating member operates the sludge stirring member to stir the developer sludge. The sludge prevention apparatus and the image forming apparatus with the same can prevent the tube member from being blocked by the developer sludge deposited in the tube member.

Abstract: A digital copy machine, including a display panel to display at least one menu to allow for a setting up of a copy function and to display a layout of copy output, a display controller which changes a screen displayed on the display panel according to a selection of a user and, when a function is set up by the user, performs control to display the layout of the copy output on the display panel based on the set-up copy function.

Abstract: Disclosed are a sludge prevention apparatus of a tube member and an image forming apparatus provided with such a sludge prevention apparatus. The sludge prevention apparatus comprises a sludge stirring member located in a tube member to be movable, so that the sludge stirring member stirs the developer sludge deposited or as being deposited in the tube member, the liquid developer being discharged from or flowing into a developer storage chamber through the tube member; and an operating member installed in the developer storage chamber to correspond to the sludge stirring member in such a manner that the operating member operates the sludge stirring member to stir the developer sludge. The sludge prevention apparatus and the image forming apparatus with the same can prevent the tube member from being blocked by the developer sludge deposited in the tube member.

Abstract: A wet color image forming apparatus and method of using the same is provided. The wet color image forming apparatus includes a transfer belt, which is formed of a plurality of layers including a surface layer contacting a sheet of paper. A hardness of the surface layer is reduced by removing carbon from a material constituting the surface layer. The apparatus also includes a transfer roller which applies pressure to the transfer belt to transfer the color image formed on the transfer belt onto the sheet of paper.

Abstract: A liquid image forming system including a photosensitive body on which an electrostatic latent image is formed, a developing roller which forms a contact nip with the photosensitive body, and a metering member which is closely adhered to the developing roller and regulates the developing agent to a predetermined thickness. The system includes an intermediate transfer medium onto which the image formed on the photosensitive body is transferred via a first transfer nip, and a transfer roller which forms a second transfer nip with the transfer medium. A pressure applied to the contact nip is less than 1.2 times a pressure of the metering member on the developing roller. A pressure applied to the first transfer nip is less than 1.2 times the pressure applied to the contact nip. A pressure applied to the second transfer nip is less than 1.5 times the pressure applied to the first transfer nip.

Abstract: A liquid image forming system including a photosensitive body on which-an electrostatic latent image is formed, a developing roller which forms a contact nip with the photosensitive body and develops the electrostatic latent image with a developing agent having a predetermined color, and a metering member which is closely adhered to the developing roller and regulates the developing agent stained on the outer surface of the developing roller to a predetermined thickness. The system further includes an intermediate transfer medium onto which the image formed on the photosensitive body is transferred via a first transfer nip, and a transfer roller which forms a second transfer nip with the intermediate transfer medium and transfers the image onto a printing medium passing between the intermediate transfer medium and the second transfer nip, from the intermediate transfer medium. A pressure applied to the contact nip is less than 1.2 times a pressure of the metering member on the developing roller.

Abstract: A photosensitive belt installation device of an electrophotographic image forming apparatus that includes a soft cartridge which rolls up for storage, and an installation guide member which selectively attaches to the image forming apparatus. When unrolled, the cartridge, allows the simple installation of a photosensitive belt into the imaging forming apparatus. The soft cartridge is a flexible cartridge having a shape of the endless track of a belt unit of the imaging forming apparatus, and is open on both sides. The unrolled soft cartridge supports the photosensitive belt during installation, as one open side of the soft cartridge is fitted over a sloping surface of the installation guide member attached to the front frame of the belt unit. The soft cartridge is completely pushed around the belt unit along a sloping surface of the installation guide member. The photosensitive belt remains around the belt unit as the soft cartridge is pulled out.

Abstract: An ink feeding valve of a wet type electrophotographic printer, capable of basically preventing operational error and incapability of valve due to ink attachment, includes: a valve body having a pipeline for interconnecting the concentrated ink tank with the developing solution tank; a rod assembly disposed in the pipeline of the valve body so as to be vertically moved for selectively opening/closing the pipeline; an elevating section for vertically moving the rod assembly; and a corrugated tube disposed in the pipeline of the valve body for partitioning the pipeline into an inner ink passage and an outside elevating section operating chamber, and for preventing ink flow into the elevating section operating chamber. Since the ink passage and the elevating section operating chamber are isolated from each other by the presence of a corrugated tube, the plunger and spring located in the elevating section operating chamber are efficiently operated without having problems caused due to ink attachment.

Abstract: A photosensitive belt installation device of an electrophotographic image forming apparatus that includes a soft cartridge which rolls up for storage, and an installation guide member which selectively attaches to the image forming apparatus. When unrolled, the cartridge, allows the simple installation of a photosensitive belt into the imaging forming apparatus. The soft cartridge is a flexible cartridge having a shape of the endless track of a belt unit of the imaging forming apparatus, and is open on both sides. The unrolled soft cartridge supports the photosensitive belt during installation, as one open side of the soft cartridge is fitted over a sloping surface of the installation guide member attached to the front frame of the belt unit. The soft cartridge is completely pushed around the belt unit along a sloping surface of the installation guide member. The photosensitive belt remains around the belt unit as the soft cartridge is pulled out.

Abstract: A photoreceptor web for a liquid electrophotographic printer on which a predetermined image is developed at a development unit and the developed image is transferred to a transfer unit to be printed on a sheet of paper, in which a total length of the photoreceptor web is 32±0.25 inches. The total length of the photoreceptor web is set to include a plurality of image zones in which an image to be printed on a sheet of paper is developed, an interval zone provided between the image zones as allowance zone, a drip line removing zone provided to avoid frictional contact with a squeegee roller of the development unit when the drip line is removed, a seam portion formed by combining both end portions of the photoreceptor web for forming a closed path, and a mark zone where a mark for detecting the seam portion is provided. Thus, the photoreceptor web does not occupy excess installation space in the printer and development, transfer and drip line removing operations are performed smoothly.

Abstract: A squeegee roller for a liquid electrophotographic printer includes a steel core and an elastic rubber layer coated on an outer circumferential surface of the steel core. The elastic rubber layer forms a squeegee nip by contacting a photoreceptor web, thereby to make a toner of the excess developer, which is developed in an area for an electrostatic latent image of the photoreceptor web, into a thin film in the area for electrostatic latent image and to squeeze the remaining carrier. The roughness (Ra) of a surface of the elastic rubber layer satisfies the condition, 1.5 &mgr;m≦Ra≦2.5 &mgr;m.

Abstract: A developer cleaning method for a liquid electrophotographic printer is achieved by developing an electrostatic latent image by supplying developer supplied from an injection nozzle to a photoreceptor medium via a development roller, removing drip developer formed on the photoreceptor web between a squeegee roller and the development roller, removing developer remaining between the injection nozzle and the development roller, and reducing an electrical potential of the development roller after development so that toner particles included in the drip developer are transferred to the development roller due to a difference in electrical potential.

Abstract: An ink leakage prevention system, for a liquid electrophotographic printer having a development tray, which includes a chassis, installed at a main body of the printer, a development tray, installed at the lower portion of a development unit and is detachable from the main body of the printer, wherein the developing tray accommodates developer left over after being used by the development unit for developing and which has a discharge portion for discharging the accommodated developer, a drain tray installed at the chassis to drain the developer discharged from the development tray into a circulation tank, and a discharge portion opening/shutting means for closing the discharge portion when the development tray is separated from the drain tray and for opening the discharge portion when the development tray is coupled to the drain tray.