Abstract: A liquid developer for high-quality image reproduction and a method of preparing the liquid developer. The liquid developer exhibits good pigment dispersion by the introduction of organosol. The liquid developer contains fine toner particles of a uniform size with a volume-average to number-average particle diameter ratio of 1.5-2.5, and thus can produce high-resolution images. The liquid developer preparation method is environmentally friendly, simple, and cost effective because no cosolvent is used, thus eliminating the need for a cosolvent removal process.

Abstract: A wet type electrophotographic image forming apparatus comprises a photosensitive medium, a light exposure device, a developing device, a transfer device, a fuser device, an oxidation catalyst device, a temperature sensor, a power supply device and a control device. The oxidation catalyst device comprises an oxidation catalyst carrying body and a heater, and removes vapor of developer solution from the fuser device by utilizing oxidation decomposition. The control device receives data about the temperature detected from the temperature sensor, and variably controls the temperature of the oxidation catalyst device in accordance operational modes such as warm-up mode, standby mode and print mode. Considering the fact that the oxidation catalyst device has higher efficiency at optimum activation temperature, appropriate temperature control can guarantee increased oxidation efficiency of the oxidation catalyst device.

Abstract: A delivery unit and method for removing carrier vapor in a wet-type printer. The delivery unit includes a delivery guide, delivery rollers and a duct for collecting carrier vapor generated from a paper by the latent heat on the paper passing through the delivery guide in order to prevent the carrier vapor from leaking outside of the printer. The carrier vapor collection duct includes upper and lower housings connected to each other to form a predetermined space therein. The upper housing has a vent on one side thereof and an air inlet on the opposite side. A fan is mounted on the vent. The carrier vapor is collected in the duct of the delivery unit and then sent to the catalyst unit by the fan to be oxidized. Accordingly, the delivery unit can prevent the white carrier vapor generated from the paper passing through the delivery unit from leaking outside the printer.

Abstract: A method of controlling an oxidation catalyst device for a wet-type electrophotographic image forming apparatus. The oxidation catalyst device comprises a duct for guiding air present within the inside of a fixation device, which applies heat and pressure to a paper deposited with a developer consisting of ink and liquid carrier, to the outside of the fixation device, a fan for forcibly discharging the air in the inside of the fixation device, a heater for heating the air discharged from the fixation device, and an oxidation catalyst device-carrying body for facilitating oxidation resolution reaction of the carrier vapors entrained in the air as being discharged. The rotational driving step of the fan comprises a first step of driving the fan at a rotational speed of N1, during which the oxidation catalyst carrying body is warmed up, and a second step of driving the fan at a rotational speed of N2, during which the carrier vapors are heated and resolved.

Abstract: A developing unit using a high concentration ink includes a developing solution supply unit supplying the developing solution containing the high concentration ink, a developing roller, whose lower half is soaked in the developing solution of the developing solution supply unit, absorbing the developing solution by a surface tension, and a photosensitive drum contacting the developing roller, receiving the developing solution absorbed on a surface of the developing roller and developing a latent electrostatic image formed on a surface of the photosensitive drum. Accordingly, as much as about 100% of a binary ink development (BID) is achieved, thereby providing a high quality image.

Abstract: A liquid electrophotographic image forming apparatus using an ink developing solution having a high concentration where a non-volatile carrier is used as a dispersion solvent includes a photosensitive body, a charge unit increasing a potential of the photosensitive body to a charge potential, an exposure unit projecting a beam onto the photosensitive body and forming a latent electrostatic image, a developing solution supply unit supplying a developing solution to the photosensitive body, the developing solution having a high concentration where a non-volatile carrier is used as a dispersion solvent, a developing unit receiving the developing solution having the high concentration to form a developing film having the high concentration and to develop the latent electrostatic image, a transfer unit contacting the photosensitive body and moving the developed image to a recording medium, and a fixing unit fixing the transferred image in the recording medium at a temperature lower than a flash point of the non-vo

Abstract: An exhaust system of a liquid electrophotography printer includes: an exhaust line to discharge air inside an engine cell to an outside thereof; at least one exhaust fan, which is installed inside the exhaust line to generate and move the air inside the engine cell; a heating coil to heat the air to be discharged through the exhaust line to ignite impurities contained in the air; and an oxidative catalyst filter to filter and deodorize the impurities. The heating coil may be installed inside the exhaust line and coated with platinum on the outer surface. The oxidative catalyst filter may be installed inside the exhaust line, and may be a metallic honeycomb carrier coated with a catalyst mixture, or a non-woven heating mat coated with a catalyst mixture. The heating coil and the oxidative catalyst filter are typically sequentially installed adjacent to each other.

Abstract: A gas exhausting apparatus for use in a wet electrophotographic image forming device includes an exhaust duct, an exhaust fan, and an air purification unit. The exhaust duct forms an air flow passage from an inside of a device to an outside of the device. The exhaust fan inhales air from the inside of the device through the exhaust duct and exhausting the air through the exhaust duct to the outside of the device. The air purification unit removes impurities included in the air inhaled by the exhaust fan.

Abstract: A wet-type electrophotographic printer having a photocatalystic filter includes a discharge passage through which air inside a printer body is discharged out, at least one discharge fan positioned inside the discharge passage to guide the air inside the printer body, and a photocatalystic filter positioned inside the discharge passage and having a photocatalystic body coated with a photocatalyst, a plasma electrode and a plasma generator to filter and deodorize the air inside the printer body. Accordingly, a bad smell and air pollution from evaporation of a liquid carrier can be solved, and an excellent printing quality is provided.

Abstract: A wet type electrophotographic printer having a catalyst oxidation filter therein includes a discharge passage to discharge air inside of a printer body to the outside, a blower in the discharge passage to guide the air inside of the printer body, and a catalyst oxidation filter arranged in the discharge passage. The catalyst oxidation filter includes a matrix coated with an oxidation catalyst, to deodorize the air which is guided to the discharge passage as the air is passed therethrough.

Abstract: A liquid developer for high-quality image reproduction and a method of preparing the liquid developer. The liquid developer exhibits good pigment dispersion by the introduction of organosol. The liquid developer contains fine toner particles of a uniform size with a volume-average to number-average particle diameter ratio of 1.5-2.5, and thus can produce high-resolution images. The liquid developer preparation method is environmentally friendly, simple, and cost effective because no cosolvent is used, thus eliminating the need for a cosolvent removal process.

Abstract: An image fusing unit of a liquid electrophotographic unit for fusing an image developed by a developer which is a mixture of toner particles and liquid solvent and transferred onto a sheet of paper includes a charging portion installed on a transfer path of the paper for applying electric potential in a direction in which the toner is in close contact with the paper, a drying portion for drying the image by directly contacting and heating the paper, and a fusing portion for fixing the image to the paper by heating and pressing the paper. Thus, the efficiency of heat can be improved by drying in the direct contact method. Also, by closely pressing the toner against the paper prior to drying, the disadvantage according to the contact type drying method, that is, the toner adheres to a contact member, can be solved.

Abstract: A developing unit using a high concentration ink includes a developing solution supply unit supplying the developing solution containing the high concentration ink, a developing roller, whose lower half is soaked in the developing solution of the developing solution supply unit, absorbing the developing solution by a surface tension, and a photosensitive drum contacting the developing roller, receiving the developing solution absorbed on a surface of the developing roller and developing a latent electrostatic image formed on a surface of the photosensitive drum. Accordingly, as much as about 100% of a binary ink development (BID) is achieved, thereby providing a high quality image.

Abstract: A liquid electrophotographic image forming apparatus using an ink developing solution having a high concentration where a non-volatile carrier is used as a dispersion solvent includes a photosensitive body, a charge unit increasing a potential of the photosensitive body to a charge potential, an exposure unit projecting a beam onto the photosensitive body and forming a latent electrostatic image, a developing solution supply unit supplying a developing solution to the photosensitive body, the developing solution having a high concentration where a non-volatile carrier is used as a dispersion solvent, a developing unit receiving the developing solution having the high concentration to form a developing film having the high concentration and to develop the latent electrostatic image, a transfer unit contacting the photosensitive body and moving the developed image to a recording medium, and a fixing unit fixing the transferred image in the recording medium at a temperature lower than a flash point of the non-vo

Abstract: An image fusing unit of a liquid electrophotographic unit for fusing an image developed by a developer which is a mixture of toner particles and liquid solvent and transferred onto a sheet of paper includes a charging portion installed on a transfer path of the paper for applying electric potential in a direction in which the toner is in close contact with the paper, a drying portion for drying the image by directly contacting and heating the paper, and a fusing portion for fixing the image to the paper by heating and pressing the paper. Thus, the efficiency of heat can be improved by drying in the direct contact method. Also, by closely pressing the toner against the paper prior to drying, the disadvantage according to the contact type drying method, that is, the toner adheres to a contact member, can be solved.

Abstract: In one aspect, a carrier recovery apparatus of a liquid electrophotographic printer includes a drying unit, a cooling unit for cooling and condensing carrier vapor evaporated by the drying unit, a condenser for condensing the carrier vapor which has not been condensed by the cooling unit, and a carrier recovery container. In another aspect, a carrier recovery apparatus of a liquid electrophotographic printer includes a drying unit, a first cooling unit for cooling and condensing carrier vapor evaporated by the drying unit, a second cooling unit for cooling the carrier which has passed through the first cooling unit, a condenser for condensing the carrier vapor which has not been condensed by the first and second cooling units, and a carrier recovery container. Accordingly, the efficiency of condensing carrier vapor is improved. As a result, the recovery percentage of a carrier increases, and the duration of a filter is extended.

Abstract: In one aspect, a carrier recovery apparatus of a liquid electrophotographic printer includes a drying unit, a cooling unit for cooling and condensing carrier vapor evaporated by the drying unit, a condenser for condensing the carrier vapor which has not been condensed by the cooling unit, and a carrier recovery container. In another aspect, a carrier recovery apparatus of a liquid electrophotographic printer includes a drying unit, a first cooling unit for cooling and condensing carrier vapor evaporated by the drying unit, a second cooling unit for cooling the carrier which has passed through the first cooling unit, a condenser for condensing the carrier vapor which has not been condensed by the first and second cooling units, and a carrier recovery container. Accordingly, the efficiency of condensing carrier vapor is improved. As a result, the recovery percentage of a carrier increases, and the duration of a filter is extended.

Abstract: A method of removing a photosensitive belt of a printing apparatus from rollers of a belt unit. In this method, since the photosensitive belt is circulated with at least one roller slanted with respect to the others so that the photosensitive belt moves in a lengthwise direction of the rollers and part of the photosensitive belt is projected through the belt passage, and then the photosensitive belt is removed by pulling the portion projected through the belt passage, the worker can remove the photosensitive belt without a separate removing device and damage of parts in the printing apparatus and an accident due to carelessness can be fundamentally prevented.

Abstract: To prevent banding occurring by a change in the speed of the photoreceptor medium generated when the leading edge and trailing edge of a sheet of paper pass through a transfer nip formed between a transfer roller and a fusing roller, an image banding reduction method of a photoreceptor medium of an indirect transfer type image forming apparatus is achieved by (A) separating the transfer roller and the fusing roller a predetermined distance from each other before the leading edge of paper enters the transfer nip, (B) approximating the transfer roller and the fusing roller after the leading edge of paper has entered the transfer nip, and maintaining the gap of the transfer nip in a normal state, and (C) separating again the transfer roller and the fusing roller a predetermined distance from each other before the trailing edge of paper is exhausted from the transfer nip.

Abstract: A method of removing a photosensitive belt of a printing apparatus from rollers of a belt unit is disclosed. In this method, since the photosensitive belt is circulated with at least one roller slanted with respect to the others so that the photosensitive belt moves in a lengthwise direction of the rollers and part of the photosensitive belt is projected through the belt passage, and then the photosensitive belt is removed by pulling the portion projected through the belt passage, the worker can remove the photosensitive belt without a separate removing means and damage of parts in the printing apparatus and an accident due to carelessness can be fundamentally prevented.