Oki Data Corporation

Nobutoshi Chigira

Mitsuru Kishimoto

Shigenori Koido

Noboru Ooishi

Kiyoshi Ikeda

Kazuhiko Nagaoka

Masahiko Shimosugi

Toyokazu Shiraishi

Yuko Mine

An image-forming apparatus includes image-forming sections, a density detector, and a controller. Each image-forming section has an exposing unit and a developing unit. The image-forming section prints an image of a density detection pattern having a plurality of pattern segments of different duties. The image is printed on a print medium under a predetermined printing condition. The density detector outputs detection values indicative of densities of the plurality of pattern segments printed on the print medium. The controller determines a correction value based on the detection values and corresponding target values of density to modify the printing condition for the image-forming sections. The correction value may be a correction to the amount of light to be emitted from the exposing unit. The correction value may be a correction to the developing voltage to be supplied to the developing unit. The correction value may be weighted.

Image forming apparatus having different dots per unit area densities

An image-recording apparatus has a plurality of image-forming sections. Each image forming section has a transfer point where a corresponding toner image is transferred from a photoconductive drum onto a print medium when the print medium passes through the transfer point. Each of the image-forming sections includes a surface that opposes the print medium and an electrically conductive film to which a high concentration of carbon black is contained and which is provided on the surface. The surface is downstream of the photoconductive drum with respect to a direction of travel of the print medium. The surface and print medium are spaced apart by a distance in the range of 1 to 3 mm and the electrically conductive member has a sheet resistance value of 15 k&OHgr;/&square; to 10 M&OHgr;/&square;.

Image recording apparatus having electrically conductive members for preventing charge migration

An ink jet recording apparatus has at least one ink chamber having an orifice through which ink drops are ejected, each ink drop having a variable amount of ink and being ejected at a timing corresponding to the amount of ink; and a controller for causing said ink chamber to eject ink drops therefrom in accordance with print data. The ink drop has an amount of ink in accordance with the level of gradation of the print data and is ejected at a timing in accordance with the amount of ink. The ink chamber may includes a plurality of ink chambers, i.e., black, yellow, magenta, and cyan. A black ink chamber is located at a first distance away from the print medium and ejects black ink drops along line k1. Color ink chambers of yellow, magenta, and cyan are aligned in a plane parallel to the surface of the print medium and oriented so that the color ink drops are ejected toward the print medium along lines k1, k3, and k4, respectively. The color ink chambers eject ink aiming at a point at which the ink drops are merged before they reach the print medium. The point is located at a second distance, which is shorter than the first distance away from the color ink chambers.

Ink jet recording apparatus

Growing community of inventors

Tokyo, Japan

Nobutoshi Chigira