Abstract: An apparatus for connecting and disconnecting a developing bias power supply in an image forming system. A plurality of developers are operated in sequence to develop an electrostatic latent image formed on a photosensitive body in a predetermined color. An electro-magnetic clutch, which corresponds to each of the developers, connects and disconnects driving of each of the developers. A deceleration gear assembly is rotated according to a rotation of a gear of the developer connected to the electro-magnetic clutch. A connection unit, which is driven by the deceleration gear assembly, rotates and connects/disconnects the developing bias power supply to/from each of the developers.

Abstract: A method of conducting for transaction between a seller and a purchaser through a computer by automatically switching the auction from a bulletin mode into a chatting mode includes the steps of inputting registration information of an article for sale from a seller and then outputting schematically the registration information on information window to the purchaser; inputting bids for the article to the computer selected from the information window; calculating the beginning of the chatting mode in accordance with initiating factor for the article based on the bids and then outputting to activating the chatting mode for the article; and completing the action for the article and then selecting a successful bidder for the article.

Abstract: A waste toner collecting apparatus of an electrophotographic image forming device includes a photoreceptive drum having a first slit formed on an outer circumferential surface thereof in a lengthwise direction, through which waste toner removed from the outer circumferential surface of the photoreceptive drum by a cleaning blade contacting the outer circumferential surface thereof passes to be contained therein, and a slit opening/shutting unit which selectively opens and shuts the first silt. Thus, the image forming device can be made compact, and generation of dust can be prevented.

Abstract: A method for forming an image in an electrophotographic printer. The method includes the steps of rotating a developing roller at the same linear velocity as that of a photosensitive medium in a state where the developing roller is separated from the photosensitive medium, moving a developer so that the developing roller is in contact with the photosensitive medium, and changing the linear velocity of the developing roller to be faster than that of the photosensitive medium after contact and proceeding with the developing process, rotating the developing roller at the same linear velocity as that of the photosensitive medium after completing the developing process, and moving the developer so that the developing roller is separated from the photosensitive medium.

Abstract: A developing apparatus of an electrophotographic printer for developing an image on a photoreceptive drum includes a disc rotating independently of the photoreceptive drum at both sides of the photoreceptive drum and having at least one cam groove formed on an outer circumferential surface thereof. A developing unit includes a housing containing developer and a developing roller supported by both sidewalls of the housing and having a shaft contacting the outer circumferential surface of the disc. An elastic member is provided at a rear surface of the housing and presses the developing apparatus toward the photoreceptive drum. Thus, since the disc having at least one cam groove is provided on the outer circumferential surface and rotates independently of the photoreceptive drum, the developing roller can be detached from the photoreceptive drum at a predetermined pressure.

Abstract: Disclosed herein is a self-diagnosis type welding carriage control system for automatically controlling welding conditions and implementing an oscillation motion. The welding carriage control system includes a main controller for a database, a remote control panel controller, a welding machine and condition controller, motion controllers for oscillation and travel motions, and a digital signal processing controller for managing memories for the respective controllers. The controllers are each provided internally with a central processing unit, and a dual port random access memory so as to share neighboring central processing units and memories through a versa module eurocard bus.

Abstract: An apparatus for connecting and disconnecting a developing bias power supply in an image forming system. A plurality of developers are operated in sequence to develop an electrostatic latent image formed on a photosensitive body in a predetermined color. An electro-magnetic clutch, which corresponds to each of the developers, connects and disconnects driving of each of the developers. A deceleration gear assembly is rotated according to a rotation of a gear of the developer connected to the electro-magnetic clutch. A connection unit, which is driven by the deceleration gear assembly, rotates and connects/disconnects the developing bias power supply to/from each of the developers.

Abstract: A waste toner collecting apparatus of an electrophotographic image forming device includes a photoreceptive drum having a first slit formed on an outer circumferential surface thereof in a lengthwise direction, through which waste toner removed from the outer circumferential surface of the photoreceptive drum by a cleaning blade contacting the outer circumferential surface thereof passes to be contained therein, and a slit opening/shutting unit which selectively opens and shuts the first silt. Thus, the image forming device can be made compact, and generation of dust can be prevented.

Abstract: A photosensitive drum for a printing apparatus includes a drum body, and a photosensitive film attached to an outer circumference of the drum body, the photosensitive film being wound around the outer circumference of the drum body to have an overlapped portion of a predetermined width at both ends thereof.

Abstract: A developing apparatus of an electrophotographic printer for developing an image on a photoreceptive drum includes a disc rotating independently of the photoreceptive drum at both sides of the photoreceptive drum and having at least one cam groove formed on an outer circumferential surface thereof. A developing unit includes a housing containing developer and a developing roller supported by both sidewalls of the housing and having a shaft contacting the outer circumferential surface of the disc. An elastic member is provided at a rear surface of the housing and presses the developing apparatus toward the photoreceptive drum. Thus, since the disc having at least one cam groove is provided on the outer circumferential surface and rotates independently of the photoreceptive drum, the developing roller can be detached from the photoreceptive drum at a predetermined pressure.

Abstract: A method for forming an image in an electrophotographic printer. The method includes the steps of rotating a developing roller at the same linear velocity as that of a photosensitive medium in a state where the developing roller is separated from the photosensitive medium, moving a developer so that the developing roller is in contact with the photosensitive medium, and changing the linear velocity of the developing roller to be faster than that of the photosensitive medium after contact and proceeding with the developing process, rotating the developing roller at the same linear velocity as that of the photosensitive medium after completing the developing process, and moving the developer so that the developing roller is separated from the photosensitive medium.

Abstract: Disclosed herein is a self-diagnosis type welding carriage control system for automatically controlling welding conditions and implementing an oscillation motion. The welding carriage control system includes a main controller for a database, a remote control panel controller, a welding machine and condition controller, motion controllers for oscillation and travel motions, and a digital signal processing controller for managing memories for the respective controllers. The controllers are each provided internally with a central processing unit, and a dual port random access memory so as to share neighboring central processing units and memories through a versa module eurocard bus.

Abstract: A sheet coating apparatus including a storage tank in which a coating liquid having charged coating particles dispersed therein is contained, a development roller rotatably installed to be immersed in the coating liquid, a voltage source for applying a voltage to the development roller, a coating roller rotatably installed in a state in which it is partially immersed in the coating liquid while maintaining a predetermined development gap relative to the development roller, and a compression roller for pressing a sheet passing between the compression roller and the coating roller toward the coating roller while securely rotating with respect to the coating roller. The coating particles adhere to the surface of the coating roller at the development gap due to an electric force to then be coated on the sheet passing between the coating roller and the compression roller.

Abstract: An apparatus for measuring the concentration of developer in a liquid printer, the apparatus includes a housing, a developer film forming device installed in the housing for forming a developer film, and a sensing device including a light source unit for emitting colored light corresponding to a range of wavelengths for which the light transmissivity is relatively low to a developer film of a selected color developer, and a photodetector installed corresponding to the light source unit and receiving the light emitted by the light source unit and transmitted through the developer film. Thus, a thin developer film is formed and the concentration of developer is measured by emitting light in a range of wavelengths for which the selected color developer has a relatively low light transmissivity to the developer film. The affect by the toner mixed with other color is relatively less and the concentration of developer can be measured close to the actual concentration although the developer is contaminated.

Abstract: A sheet coating apparatus including a storage tank in which a coating liquid having charged coating particles dispersed therein is contained, a development roller rotatably installed to be immersed in the coating liquid, a voltage source for applying a voltage to the development roller, a coating roller rotatably installed in a state in which it is partially immersed in the coating liquid while maintaining a predetermined development gap relative to the development roller, and a compression roller for pressing a sheet passing between the compression roller and the coating roller toward the coating roller while securely rotating with respect to the coating roller. The coating particles adhere to the surface of the coating roller at the development gap due to an electric force to then be coated on the sheet passing between the coating roller and the compression roller.

Abstract: A developer contamination measuring apparatus of a printer includes a first pipe portion having a first gap and a second pipe portion having a second gap, a light emitting unit radiating light to the first pipe portion and the second pipe portion, a light detecting unit detecting light reflected or transmitted from the first pipe portion and the second pipe portion to output first and second light receiving signals, respectively, and a developer contamination measuring unit controlling the light emitting unit, and calculating the degree of a contamination due to mixing of other developing materials with the developer from the first and the second light receiving signals. Thus, the degree of contamination of a developer mixed with other developing materials can be precisely calculated, and the developer can be replaced, when the calculated amount of contamination exceeds a predetermined allowable contamination level, to thereby prevent deterioration of print quality.

Abstract: An apparatus for measuring the concentration of a liquid developer of an image processor includes: a housing; a rotating roller disposed inside the housing, a driving source for rotating the roller; a developer supplier for supplying the developer to the roller such that a developer film can be formed as the roller rotates, and a sensor for sensing an amount of light transmitted through the developer film by directing light to the developer film and receiving the light transmitted through the developer film.

Abstract: An apparatus for eliminating excess ions in a developer used for a liquid electrophotographic printer, including a photoreceptor medium, a laser scan unit for forming an electrostatic latent image by emitting a laser beam to the photoreceptor medium, and a developing unit for developing an electrostatic latent image area of the photoreceptor medium using a developer which is a mixture of a toner and a liquid carrier. The apparatus includes: a settling unit provided at one side of the developing unit for settling the toner of the developer supplied from the developing unit in a short time using an electrical force; a developer input/output controller installed between the developing unit and the settling unit for selectively controlling the input/output of the developer; and an excess ion eliminating unit for eliminating excess ions included in the developer in an upper portion of the settling unit.

Abstract: A developer concentration detection apparatus is provided, which includes a base member in which a developer accommodation space is formed, an electrode plate member installed in the base member so that a toner included in a developer in the developer accommodation space is electrically charged, a hollow transparent conductive tube which is rotatably supported in the state where at least part thereof is submerged in the developer in the developer accommodation space and the surface thereof can be charged, a light emitting element installed in the transparent conductive tube, and a light receiving element installed spaced from the surface of the transparent conductive tube, for detecting light generated from the light emitting element. The developer concentration detection apparatus can detect measurement of the developer concentration, thereby providing the result of assuring an optimal printing quality.

Abstract: A concentration measuring device, in an electrographic printer, for measuring the concentration of developer liquid supplied from a mixing container to a development device. The concentration measuring device includes a variable thickness body installed between the mixing container and the development device for changing the thickness of a developer liquid passage for light to transmit; a light emitting device installed a predetermined distance from one side of the variable thickness body for emitting light; and a light detector installed a predetermined distance from the other side of the variable thickness body for detecting the light from the light emitting device and measuring the concentration of developer liquid according to the amount of received light.