Abstract: A developing unit of a liquid electrophotographic printer includes a developing roller, for forming a development gap with a photoreceptor web where developer is filled and developing an electrostatic latent image formed on the photoreceptor web, a squeegee roller installed at the rear end of the developing roller for closely pressing the photoreceptor web to squeegee surplus developer, and a cleaning mechanism for removing toner particles of the developer adhering to a surface of the squeegee roller using an electrical force. Since the toner particles adhering to the squeegee roller are removed, contamination of a developed image is prevented and a clean image can be printed.

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 developing unit of a liquid electrophotographic printer includes a developing roller, for forming a development gap with a photoreceptor web where developer is filled and developing an electrostatic latent image formed on the photoreceptor web, a squeegee roller installed at the rear end of the developing roller for closely pressing the photoreceptor web to squeegee surplus developer, and a cleaning mechanism for removing toner particles of the developer adhering to a surface of the squeegee roller using an electrical force. Since the toner particles adhering to the squeegee roller are removed, contamination of a developed image is prevented and a clean image can be printed.

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: 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.

Abstract: A technique for supplying ink in a liquid printer, for example, includes an apparatus containing: an ink reservoir containing ink; a supply pump for pumping ink into the ink reservoir; a manifold coupled to the supply pump via an ink supply pipe and through which ink is injected to a gap between a developing roller and a photoreceptor web, and an ink storing portion installed between the ink supply pipe and the manifold and having a sectional area greater than that of the ink supply pipe so that a change in pressure of ink supplied to the manifold from the ink supply pipe is minimized.

Abstract: A developing device, of a wet type printer, provided with a reservoir for holding developer liquid. A developing roller is installed at an upper region of the reservoir, and contacts a photosensitive belt. A cleaning device for cleaning the developing roller, is in contact with the developing roller. An auxiliary reservoir is installed below the developing roller, and within the reservoir, to hold a predetermined amount of the developer liquid in which the lower portion of the developing roller is immersed to a predetermined depth. The cleaning device is installed within the auxiliary reservoir to be immersed in the developer liquid and is provided with a rotating shaft and a brush installed around the circumferential surface of the rotating shaft. The developing roller is effectively cleaned, by the cleaning device, and particles adhering to the developing roller are easily removed. The removed particles are then recovered and used again in subsequent printing operations.

Abstract: A development roller cleaning apparatus includes a cleaning blade installed with an end contacting an outer surface of a development roller for removing an excess developer liquid therefrom, and a guide for guiding an excess developer liquid removed by a squeegee roller installed downstream from the development roller to the end of the cleaning blade.

Abstract: A development apparatus for a liquid electrophotographic printer includes a development roller for supplying a developer liquid to a photoreceptor belt on which a latent electrostatic image is formed, a plurality of squeegee rollers for removing excess developer liquid sticking to the photoreceptor belt, at least one cleaning device having a rotary body rotatably installed in proximity with at least one of the plurality of squeegee rollers, and a plurality of blades installed on the perimeter of the rotary body at a predetermined spacing, in contact with the surfaces of the respective squeegee rollers, and a rotation mechanism for selectively bringing one of the plurality of blades into contact with the surface of each squeegee roller. Therefore, when one blade is worn, the worn blade can be replaced with a new one without dismantling the development apparatus, and thus the life of the development apparatus is prolonged.

Abstract: An image printing apparatus includes a photoreceptor belt on which a latent electrostatic image is formed, and a plurality of development devices for developing the latent electrostatic image formed on the photoreceptor belt. Each of the development devices has a development roller for coating a developer liquid on the photoreceptor belt, and a squeegee roller for removing excess developer liquid from the photoreceptor belt. A roller driving means drives the squeegee rollers, and an elevating means elevates the development devices. The plurality of development devices are supported by a pair of frames that are spaced apart a predetermined distance from each other. The roller driving means commonly drives the squeegee rollers of the development devices. The frame elevating means displaces the pair of frames, such that the squeegee rollers are simultaneously in contact with or out of contact with the photoreceptor belt.

Abstract: A method for driving development devices of an image forming apparatus including the steps of: (a) simultaneously rotating gear cams of the respective development devices for colors Y (yellow), M (magenta), C (cyan) and K (black); (b) determining whether the frame of the development devices is lifted to a preset position; (c) rotating a developing roller; (d) coating a developer liquid on an image portion of a photoreceptor belt; (e) determining whether the image portion has passed through a transfer roller or not; (f) simultaneously rotating the gear cams of the respective development devices for colors Y, M, C and K if the image portion has passed through the transfer roller; (g) determining whether the distance between the frame and the photoreceptor belt is a preset value; (h) simultaneously stopping the gear cams of the respective development devices for colors Y, M, C and K if the distance between the frame and the photoreceptor belt is the preset value; and (i) simultaneously removing drip lines by sim

Abstract: In a squeeze roller assembly of a wet type developer of an electrophotographic printer, a shaft is rotatably installed in a frame. A first roller is fixed on the shaft for filming solid toner from a developing liquid onto a photosensitive belt. Second rollers are rotatably installed on the same shaft at both sides of the first roller. The first roller, attached to the central portion of the imaging surface of a photosensitive belt, rotates in the same direction as that of the conveying direction of the photosensitive belt. The second roller rotates in a direction opposite to the direction of the photosensitive belt by an inverse rotator. Therefore, it is possible to reduce the required installation space by having the first and second rollers share a common shaft as a rotating axis.