Fujitsu Corporation

Morihisa Kawahara

Hirofumi Nakayasu

Youji Houki

Tsutomu Nagatomi

Takeo Kojima

Kouichi Kobayashi

Tetsuya Takei

Hiroyuki Kawai

Michio Shimura

Hiroji Uchimura

Kiyoshi Taninaka

Nobuo Kuwabara

Junji Wakihara

Minoru Takano

Yoshiki Nagasaki

Kunihiro Kitsu

Yutaka Sato

Kazuhiro Kakuguchi

Masahiro Wanou

Masakazu Kinoshita

Takao Sugano

Yoshihiko Taira

Hidenori Fujioka

Tsutomu Kawai

Hisashi Hanzawa

Kazuhiro Tamada

Hiroyuki Kaneda

Satoshi Seino

Akihisa Sota

Kazuhiko Hamazoe

Kaneastu Uchiyama

Masakazu Kanaka

Shinichirou Yamamoto

Masao Konisi

It is an exemplified object of the present invention to provide an image-forming device that can form a high-quality multicolor image at relatively low cost. To achieve the above object, the inventive image-forming device includes an endless belt that conveys a recordable medium; plural image-forming units that form a toner layer on the recordable medium via the endless belt; and a fixer that fixes the toner layer on the recordable medium, and a first pressing force applicable to the recordable medium by a last image-forming unit at a downstream side along a direction in which the recordable medium is conveyed among the plural image-forming units is greater than a second pressing force applicable to the recordable medium by another image-forming unit adjacent to the last image-forming unit at the downstream side among the plural image-forming units.

Image-forming device having a plurality of image-forming units respectively apply the difference force to the recordable medium

An image forming apparatus includes a transport mechanism transporting a recording medium on a belt which is transported at a constant speed in a transport direction, a plurality of electrostatic recording units arranged in the transport direction of the recording medium and transferring toner images of different colors, a positional error detecting part using the toner image of a reference color transferred by one of the electrostatic recording units as a reference image, and relatively detecting positional error information related to positional errors of the toner images of remaining colors transferred by the remaining electrostatic recording units with respect to the reference image, and a positional error correcting part relatively correcting the positional errors of the toner images transferred by the remaining electrostatic recording units based on the positional error information. The positional error detecting part includes a part for controlling the electrostatic recording units to transfer at least two resist marks on the belt at a scan starting end and a scan terminating end of the belt in a main scan direction which is perpendicular to the transport direction of the recording medium, with respect to each of the colors, and a second part, including a sensor detecting the resist marks, for detecting positional error quantities of the resist marks of each of the remaining colors with respect to the resist marks of the reference color based on detection times of the resist marks of reference color and the remaining colors.

Positional error correction for color image forming apparatus

An electrophotographic image forming apparatus includes an electrostatic latent image carrying body, an electric charger for uniformly electrifying the carrying body, an optical exposure unit to form an electrostatic latent image on the carrying body, a developer for developing the electrostatic latent image to form a toner image on the carrying body, a transfer unit for transferring the toner image from the carrying body onto a printing sheet, a fixing unit for fixing the toner image to the printing sheet, a cleaner for cleaning to remove residual toner from the carrying body and a toner returning mechanism for returning the residual toner removed by the cleaner to the developer. The developer includes a housing in which a toner chamber is defined, a developing roller rotatably mounted in the housing, an agitator rotatably mounted in the housing so as to be positioned in the toner chamber, a partitioning member provided in the housing for defining a carrier chamber adjacent to the developing roller. The toner returning mechanism includes a toner recirculator for recirculating the residual toner removed from the carrying body to the toner chamber.

Image forming apparatus having a toner cartridge

A drum phase correction unit for detecting rotational positions of a plurality of photosensitive drums by means of a plurality of drum position sensors and corrects to set rotational phases of the drums to predetermined phases in such a manner that transfer positions on drum circumferential surfaces relative to a belt when employing the thus detected rotational positions as their respective references have a specific relationship including coincidence. A positional offset detection unit detects positional offsets of transfer image on recording paper attributable to the wow and flutter in a drive system including the belt and the photosensitive drums. On the basis of the thus detected positional offsets, a wow and flutter correction unit corrects the positional offsets of the transfer images on the recording paper attributable to the wow and flutter.

Printing apparatus

A toner developing quantity detection unit operates a plurality of electrostatic recording units to transfer Y, M, C and K color component toner marks onto a belt. A toner developing quantity correction unit detects toner developing quantities per unit area of color toners on the basis of detection signals of the color component toner marks on the belt optically detected by a sensor. The toner developing quantity correction unit corrects the toner developing quantities so as to allow the toner consuming quantities of the plurality of electrostatic recording units to be substantially the same level, on the basis of the thus detected toner developing quantities.

Electrophotographic image-forming apparatus

Image-forming apparatus comprising a process unit

A mounting mechanism for a ribbon cassette for mounting the ribbon cassette on a carrier of a printer having a pair of resiliently deformable arms which are formed in such a manner as to extend forwardly along the opposite side walls from a rear end of the ribbon cassette, and a pin is formed in an integrated relationship on each of the arms. A pair of holes for receiving the pins are formed on the carrier side of the printer, and the ribbon cassette is mounted onto the carrier by resiliently deforming the arms to fit the pins into the holes of the carrier.

Mounting mechanism for ribbon cassette

A ribbon cartridge with an ink ribbon for use in a printer. The printer includes a print head and a carrier, the carrier carrying the print head and ribbon cartridge along a printing position. The carrier has a mounting member for rotatably mounting a first end of the ribbon cartridge and a guide member for positioning a second end of the ribbon cartridge such that the ink ribbon is disposed between the print head and printing position. The second end of the ribbon cartridge has an opening for exposing a part of the ink ribbon loaded in the body of the cartridge. The ribbon cartridge includes a biasing member for producing a force to bias the ribbon cartridge against the guide member by elastic deformation of the biasing member in contact with a part of the carrier. The biasing member is integrally formed as part of the ribbon cartridge, thus eliminating additional and separate components and reducing part and assembling costs. Limitation members are also integrally formed as part of the ribbon cartridge to restrict maximum pivotal movement of the second end of the ribbon cartridge when mounted to the carrier, thus ensuring that the biasing member of the cartridge is not deformed beyond its normal elasticity.

Ribbon cartridge having biasing member for positioning ink ribbon to

Growing community of inventors

Kawasaki, Japan

Morihisa Kawahara