Abstract: A transfer power supply apparatus of an image forming machine which can maintain a predetermined degree of the quality of an image on a print medium even when the temperature of the surrounding environment varies. The image forming machine includes a voltage computation unit computing an appropriate voltage corresponding to resistance of an intermediate transfer medium, an output voltage generator generating a transfer voltage according to a signal output from the voltage computation unit, and a switching unit selectively applying a voltage output from the output voltage generator, wherein the switching unit connects a voltage output from the output voltage generator to a transfer roller when the image created on the intermediate transfer medium is transferred to a print medium, and connects a voltage output from the output voltage generator to a transfer backup roller when the image is not transferred to the print medium.

Abstract: A color image forming apparatus which, in a sequential order for each of plural colors of a composite color image, charges plural photosensitive bodies, exposes electrostatic latent images on the plural photosensitive bodies, develops latent images on the photosensitive bodies into color images, and transfers the color images to sequentially form images of each of the plural colors one on another to form the composite color image and transcribing the composite color image onto a printing medium. The color image forming apparatus includes: plural charging units which perform the charging process for each of the plural colors; plural exposing units which perform the exposing process for each of the plural colors; plural developing units which perform the developing process for each of the plural colors; and plural transfer units which perform the transfer process for each of the plural colors.

Abstract: A color image forming apparatus which, in a sequential order for each of plural colors of a composite color image, charges plural photosensitive bodies, exposes electrostatic latent images on the plural photosensitive bodies, develops latent images on the photosensitive bodies into color images, and transfers the color images to sequentially form images of each of the plural colors one on another to form the composite color image and transcribing the composite color image onto a printing medium. The color image forming apparatus includes: plural charging units which perform the charging process for each of the plural colors; plural exposing units which perform the exposing process for each of the plural colors; plural developing units which perform the developing process for each of the plural colors; and plural transfer units which perform the transfer process for each of the plural colors.

Abstract: An electrophotographic image forming apparatus and a method of controlling development includes a current measuring unit to measure a developing current flowing between a developing roller and a photosensitive medium, and a controlling unit to calculate at least one of a thickness of a photosensitive film of the photosensitive medium, a thickness of a developer on a surface of the developing roller, and the quantity of development on the surface of the photosensitive medium using the measured developing current, and then display information concerning replacement of consumables, or control a developer supply vector and a development vector on a basis of the calculated value.

Abstract: A developing method of a liquid type electrophotographic image forming device includes forming an image area corresponding to an electrostatic latent image by scanning light onto a surface of a photosensitive drum that is charged to a predetermined electric potential, attaching a developer on a surface of a developing roller by applying a first bias voltage to a deposit roller and a second bias voltage to the developing roller, developing the image area on the photosensitive drum using the developer attached to the developing roller, and turning off the second and first bias voltages applied to the developing roller and the deposit roller, respectively, when a non-image area of the photosensitive drum contacts the developing roller.

Abstract: An image forming system of an electrophotographic printer. The system includes a photosensitive body on which an electrostatic latent image is formed, a developing unit which develops the electrostatic latent image with a developer, a transfer body onto which the developed image is transferred, a first image charging unit which charges the image so as to increase an electric adhesive force of the image transferred onto the transfer body, a second image charging unit which charges the image so as to reduce the electric adhesive force of the image transferred onto the transfer body in the rear of the first image charging unit, and a transfer unit which transfers the image passing through the first and second image charging units onto paper.

Abstract: A developing device for a liquid electrophotographic image forming apparatus is provided. The developing device may have a developing roller, which supplies ink to a photosensitive body on which an electrostatic latent image is formed and develops the electrostatic latent image. The apparatus may include an ink reservoir in which ink supplied to the developing roller is accommodated, and an ink removal unit, which removes ink remaining in the ink reservoir after a development operation is performed. The ink removal unit may comprise an ink removal member rotatably installed in the ink reservoir that exhausts ink through a through hole formed under the ink reservoir. A driving member rotates the ink removal member. An ink cartridge stores ink exhausted through the through hole.

Abstract: An electrophotographic image forming apparatus and a method of controlling development includes a current measuring unit to measure a developing current flowing between a developing roller and a photosensitive medium, and a controlling unit to calculate at least one of a thickness of a photosensitive film of the photosensitive medium, a thickness of a developer on a surface of the developing roller, and the quantity of development on the surface of the photosensitive medium using the measured developing current, and then display information concerning replacement of consumables, or control a developer supply vector and a development vector on a basis of the calculated value.

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: A liquid developer imaging system and a method using the system for developing an image, including a cartridge for containing a developing solution; a developing container for receiving the developing solution supplied from the cartridge via a predetermined supply line; a developing roller partly submerged in the developing solution contained in the developing container, installed to be rotated facing a photosensitive object; and a metering blade for scraping off the developing solution coated on the surface of the developing roller to a predetermined thickness, is provided. According to the system, a developing supply structure can be considerably simplified because a high-density developing solution is directly used in developing an image without a process of diluting the solution, and an image can be developed to have high definition because the concentration of the developing solution coated on the developing roller is regularly controlled by a metering blade.

Abstract: A color image forming apparatus which, in a sequential order for each of plural colors of a composite color image, charges plural photosensitive bodies, exposes electrostatic latent images on the plural photosensitive bodies, develops latent images on the photosensitive bodies into color images, and transfers the color images to sequentially form images of each of the plural colors one on another to form the composite color image and transcribing the composite color image onto a printing medium.

Abstract: An image forming apparatus for and a method of compensating for development mass per area includes a photosensitive body on which an electrostatic latent image for an image is formed, a charger charging the photosensitive body, a developing unit developing the electrostatic latent image of the photosensitive body, a measuring unit measuring a charge current flowing through the photosensitive body from the charger, a comparator comparing the charge current with a reference current, and a controller controlling a developing unit control variable so as to compensate for a variation in a thickness of the photosensitive body according to an output of the comparator. A time indicator of a display informs a user whether the photosensitive body has to be replaced, and deterioration of an image quality caused by a decrease in the thickness of the photosensitive body can be prevented when a potential of the developing unit is controlled.

Abstract: An image forming system of an electrophotographic printer. The system includes a photosensitive body on which an electrostatic latent image is formed, a developing unit which develops the electrostatic latent image with a developer, a transfer body onto which the developed image is transferred, a first image charging unit which charges the image so as to increase an electric adhesive force of the image transferred onto the transfer body, a second image charging unit which charges the image so as to reduce the electric adhesive force of the image transferred onto the transfer body in the rear of the first image charging unit, and a transfer unit which transfers the image passing through the first and second image charging units onto paper.

Abstract: An image forming apparatus for and a method of compensating for development mass per area includes a photosensitive body on which an electrostatic latent image for an image is formed, a charger charging the photosensitive body, a developing unit developing the electrostatic latent image of the photosensitive body, a measuring unit measuring a charge current flowing through the photosensitive body from the charger, a comparator comparing the charge current with a reference current, and a controller controlling a developing unit control variable so as to compensate for a variation in a thickness of the photosensitive body according to an output of the comparator. A time indicator of a display informs a user whether the photosensitive body has to be replaced, and deterioration of an image quality caused by a decrease in the thickness of the photosensitive body can be prevented when a potential of the developing unit is controlled.

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: A liquid developer imaging system and a method using the system for developing an image, including a cartridge for containing a developing solution; a developing container for receiving the developing solution supplied from the cartridge via a predetermined supply line; a developing roller partly submerged in the developing solution contained in the developing container, installed to be rotated facing a photosensitive object; and a metering blade for scraping off the developing solution coated on the surface of the developing roller to a predetermined thickness, is provided. According to the system, a developing supply structure can be considerably simplified because a high-density developing solution is directly used in developing an image without a process of diluting the solution, and an image can be developed to have high definition because the concentration of the developing solution coated on the developing roller is regularly controlled by a metering blade.

Abstract: A liquid electrophotographic color image forming apparatus includes a main charger for charging a surface of a photoreceptor web to a predetermined charging electric potential, an optical scanning unit for scanning light onto the photoreceptor web to form an electrostatic latent image, and developing rollers for yellow, cyan, magenta and black colors, sequentially installed in a direction that the photoreceptor web circulates, for developing the electrostatic latent image using developer for each color. Further included are auxiliary chargers for cyan, magenta and black colors, installed downstream of each of the developing rollers, for additionally charging the photoreceptor web, the electric potential of which is lowered after development for each of yellow, cyan and magenta colors.

Abstract: An electrophotographic printing apparatus having a structure so that differences between surface energies of components of the electrophotographic printing apparatus contributing to image transfer are maintained within predetermined ranges, and an image transferring method thereof. The electrophotographic printing apparatus includes a photosensitive medium, developing units, a drying roller and a transfer unit having a transfer roller, whereby the peeling force (PFD) of the drying roller is in a range of 0 gram force per inch (gf/inch)≦PFD≦300 gram force per inch (gf/inch), the peeling force (PFO) of the photosensitive medium is in a range of 0 gram force per inch (gf/inch)≦PFO≦80 gram force per inch (gf/inch), and the peeling force (PFT) of the transfer roller is in a range of 200 gram force per inch (gf/inch)≦PFT≦500 gram force per inch (gf/inch), respectively, when the peeling forces are measured.

Abstract: A liquid electrophotographic color image forming apparatus includes a main charger for charging a surface of a photoreceptor web to a predetermined charging electric potential, an optical scanning unit for scanning light onto the photoreceptor web to form an electrostatic latent image, and developing rollers for yellow, cyan, magenta and black colors, sequentially installed in a direction that the photoreceptor web circulates, for developing the electrostatic latent image using developer for each color. Further included are auxiliary chargers for cyan, magenta and black colors, installed downstream of each of the developing rollers, for additionally charging the photoreceptor web, the electric potential of which is lowered after development for each of yellow, cyan and magenta colors.

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.