Abstract: A corona charger includes a case provided in the vicinity of a device to be charged. The case includes an opening facing the device, a discharge electrode, a first charging region, and a second charging region. The discharge electrode provided inside the case and supplied with a voltage so as to generate a corona discharge charges a surface of the device from the opening by supplying the corona discharge to the surface. The first charging region includes no grid electrode at a position upstream of the opening in a surface moving direction of the device. The second charging region includes a grid electrode to which a predetermined voltage is applied at a position downstream of the opening. The voltage applied to the discharge electrode is an alternating current (AC) voltage superimposed on a direct current (DC) voltage.

Abstract: A disclosed gloss-providing sheet for providing high gloss to a toner image on a recording material by being placed on a toner image surface of the recording material, heated so as to fuse toner, and then separated from the recording material after the toner is cooled and solidified includes: a notification portion that changes a visual state thereof when a temperature of the gloss-providing sheet becomes equal to or lower than a glass transition temperature of the toner.

Abstract: An image forming device is disclosed that is able to superpose a smooth sheet on a toner image on a recording sheet after common thermal fusing, perform re-melting and solidification, and then separate the smooth sheet, thereby, forming a high-gloss image easily. The image forming device includes a first fusing unit for the common thermal fusing, and a second fusing unit for fusing the toner image on a recording sheet after the common thermal fusing with a gloss application sheet superposed on the toner image, and a separation unit for separating the gloss application sheet from the recording sheet. The gloss application sheet is superposed on the recording sheet with a side of the gloss application sheet projecting out beyond a side of the recording sheet on a downstream side in the conveyance direction, and the gloss application sheet and the recording sheet are directed into the separation unit while being superposed.

Abstract: An image forming apparatus is disclosed, including a fixing device and a sheet storing member. The fixing device performs both tentative fixing and regular fixing. In at least one embodiment, the fixing device performs tentative fixing for tentatively fixing a toner image on a recording sheet. Further, the fixing device performs regular fixing for further fixing the tentatively fixed toner image by contacting a gloss sheet onto the tentatively fixed toner image on the recording sheet. The sheet storing member temporarily stores the recording sheet bearing the tentatively fixed toner image before the recording sheet is sent to the fixing device for the further fixing.

Abstract: A disclosed image forming apparatus for recording images includes: an image processing unit to create toner image data on four colors of yellow (Y), cyan (C), magenta (M), and black (K) such that toner images have line-shaped periodic structures; and an image forming unit to form the toner images using coloring materials of the four colors and superposing the toner images on a recording medium, wherein the line-shaped periodic structures of the toner images of the four colors are determined based on screen ruling of 200.0, 180.3, 180.3, and 200.0 for Y, C, M, and K colors and screen angles of 0.0, 146.3, 33.7, and 90.0 for Y, C, M, and K colors.

Abstract: An image forming apparatus includes an image carrier; an exposing unit that exposes the image carrier to light to form an electrostatic latent image on the image carrier; a developing unit that has at least a toner, and develops the electrostatic latent image formed on the image carrier as a toner image; a transfer unit that transfers the toner image onto a recording medium; a fixing unit that fixes the toner image transferred on the recording medium; an exposure-energy modulating unit that modulates exposure energy of the exposing unit; and a development-time detecting unit that detects operation time of the developing unit. The exposure-energy modulating unit modulates the exposure energy based on a result of detection by the development-time detecting unit.

Abstract: An image processing apparatus is disclosed that includes a color separating apparatus for converting input image data into C,M,Y data; generating K data from the C, M, Y data; separating the K data into Bk data and Lk data; and generating C?,M?,Y? data by conducting color conversion on any two of the C,M,Y data. Also included is a dither processing apparatus for selectively applying one of two dither matrices to one of the C?,M?,Y? data in accordance with the color of an output image, and applying a predetermined dither matrix having a periodic structure that matches the periodic structure of one of the selectively applied dither matrices to the other two of the C?,M?,Y? data.

Abstract: An image forming apparatus of the present invention forms a light and a dark toner image and superposes them on a sheet for thereby outputting a composite image. The apparatus includes a first and a second developing unit storing dark toner and light toner, respectively, a dark toner and a light toner replenishing device for replenishing the dark toner and light toner to the first and second developing units, respectively, and a toner replenishment control unit storing a dark toner replenishment history and a light toner replenishment history for controlling the operations of the dark toner and light toner replenishing devices.

Abstract: An image forming apparatus is disclosed. A color moire score calculator selects a combination (a dither set) of four dither matrices from plural types of dither matrices stored in a dither matrix storage, and calculates color moire scores of secondary colors and tertiary colors. Dither processing is performed in a pseudo-halftoning part using a dither set having a preferable color moire score.

Abstract: An electrophotographic image forming apparatus of the present invention frees images from various defects including the thinning of horizontal lines, the omission of the trailing edge of an image, background contamination, granularity particular to a halftone image, carrier scattering, and image noise. Further, the apparatus of the present invention solves problems ascribable to patches used to sense image density. Moreover, the apparatus of the present invention faithfully reproduces tonality and has a high developing ability.

Abstract: An apparatus including and a method using a fixing device including a fixing member, a pressure member, a heater, and a pressure controller. The fixing member and the pressure member face with each other to form a nip. The heater heats a surface of the fixing member when the fixing member rotates. The pressure controller is configured to change a pressure generated at the nip, according to an operation of the fixing device.

Abstract: A main vector: m{circumflex over (?)}=(mx, my) and a sub-vector: s{circumflex over (?)}=(sx, sy) determining cyclic structure of a basic matrix are defined, and a positional vector for a pixel configuring the basic matrix Pi{circumflex over (?)}=(Pix, Piy) is defined, where the suffix i denotes an i-th pixel configuring the basic matrix. Then, the pixels configuring the basic matrix are arranged in such a manner as to satisfy the cyclic structure, and transformation of Pi{circumflex over (?)}?Pi{circumflex over (?)}+km{circumflex over (?)}+ls{circumflex over (?)} is carried out where k and l are arbitrary integers, and may be negative values. Then a new shape of the basic matrix is obtained with Pi{circumflex over (?)}+km{circumflex over (?)}+ls{circumflex over (?)} as a new pixel positional vector Pi{circumflex over (?)}.

Abstract: An image forming apparatus includes an image carrier; an exposing unit that exposes the image carrier to light to form an electrostatic latent image on the image carrier; a developing unit that has at least a toner, and develops the electrostatic latent image formed on the image carrier as a toner image; a transfer unit that transfers the toner image onto a recording medium; a fixing unit that fixes the toner image transferred on the recording medium; an exposure-energy modulating unit that modulates exposure energy of the exposing unit; and a development-time detecting unit that detects operation time of the developing unit. The exposure-energy modulating unit modulates the exposure energy based on a result of detection by the development-time detecting unit.

Abstract: An image forming apparatus includes a pseudo half tone processing unit that performs a pseudo half tone process on input image data to generate output image data. An exposure unit executes light modulation of a plurality of light emitting sources based on the output image data. The exposure unit performs writing in such a way that different numbers of light emitting sources are used when writing a character/line image and a picture image or a graphics image. The pseudo half tone processing unit performs pseudo half tone processes with different resolutions on a character/line image and a picture image or a graphics image based on the numbers of the light emitting sources to be used for the writing by the exposure unit.

Abstract: An image forming method including providing a developer including a toner and a magnetic carrier, a developer carrier configured to convey the developer deposited thereon, and magnetic field generating means fixed within the developer carrier, and forming a magnetic field which forms a magnet brush between the image carrier and the developer carrier such that the magnet brush rises, contacts the image carrier and collapses within a range in which the magnetic field is more intense than an electric field capable of separating the toner and the magnetic carrier from each other by using the magnetic field generating means. The magnetic brush rubs the image carrier to thereby develop a latent image formed on the image carrier.

Abstract: An image forming apparatus has at least a photoconductor, a charger, and an irradiator for irradiating a light for optically writing in on the photoconductor to form a latent electrostatic image using a process for electrophotography in which a resolution of the optical writing in operation is 1200 dpi or more. Further, the optical writing operation is performed using a laser beam having a diameter of 35 &mgr;m or less. The photoconductor is provided with at least a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance. The charge transporting layer has a carrier mobility of 1×10−5 cm2·V−1·sec−1 or more under an electric field of 3×105 V·cm−1.

Abstract: An electrophotographic image forming apparatus of the present invention frees images from various defects including the thinning of horizontal lines, the omission of the trailing edge of an image, background contamination, granularity particular to a halftone image, carrier scattering, and image noise. Further, the apparatus of the present invention solves problems ascribable to patches used to sense image density. Moreover, the apparatus of the present invention faithfully reproduces tonality and has a high developing ability.

Abstract: An image forming apparatus of the present invention includes a lubricator for applying a lubricant to an image carrier or a process unit around the image carrier to thereby reduce friction. The apparatus of the present invention insures a uniform halftone image, prevents the trailing edge of an image from being lost, and faithfully reproduces even a horizontal line.

Abstract: An electrophotographic image forming apparatus of the present invention frees images from various defects including the thinning of horizontal lines, the omission of the trailing edge an image, background contamination, granularity particular to a halftone image, carrier scattering, and image noise. Further, the apparatus of the present invention solves problems ascribable to patches used to sense image density. Moreover, the apparatus of the present invention faithfully reproduces tonality and has a high developing ability.

Abstract: An image forming apparatus has at least a photoconductor, a charger, and an irradiator for irradiating a light for optically writing in on the photoconductor to form a latent electrostatic image using a process for electrophotography in which a resolution of the optical writing in operation is 1200 dpi or more. Further, the optical writing operation is performed using a laser beam having a diameter of 35 &mgr;m or less. The photoconductor is provided with at least a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance. The charge transporting layer has a carrier mobility of 1×10−5 cm2·V−1·sec−1 or more under an electric field of 3×10−5 V·cm−1.