Fujitsu Corporation

Tsutomu Nagatomi

Hirofumi Nakayasu

Youji Houki

Takeo Kojima

Morihisa Kawahara

Kouichi Kobayashi

Yoshihiko Taira

Hiroji Uchimura

Tomoyuki Nagamine

Yoshito Fukata

Masakazu Kinoshita

Kazuhiro Tamada

Yukio Saito

Takashi Suzuki

Yoshihiro Tonomoto

Masahiro Wanou

Takao Sugano

Toshimasa Toyama

Masaaki Ohyama

Toshio Hino

Tetsuya Fujimoto

Hiroshi Fujimoto

Hiroaki Naito

Hidenori Fujioka

Tsutomu Kawai

Hiroshi Kishimoto

Tatsuhiro Taniwa

Hiroyuki Kaneda

Jun Shimizu

Osamu Watanabe

Akihisa Sota

Kazuhiko Hamazoe

Hirotoshi Ikuta

Kaneastu Uchiyama

Masakazu Meguro

Takeshi Tanimoto

Yuzuru Sugiura

Shingo Ashida

Hisao Moriwaki

Kouichi Uozumi

Daigo Uchikoshi

Mitsunori Hiraishi

Yasushi Mouri

Masakazu Kanaka

Shinichirou Yamamoto

Masao Konisi

In a recording device, electrostatic recording units of Y, M, C and K are arranged along the direction of the feed of a recording sheet by a belt unit. The device forms latent images corresponding to image data by optical scanning of an exposure device onto a rotating photosensitive drum, develops the latent images with toner components having different colors, and then transfers the developed images onto the recording sheet on the belt unit. A color matching processing unit performs color matching processing including color slippage correction of different color images. An automatic color matching mode processing unit works the color matching processing unit when conditions beforehand decided in the state that an automatic correction mode is set up are realized. A manual color matching mode processing unit controls the color matching processing unit when the manual color matching mode processing unit recognizes operator's manual color matching instructing operation in the state that a non-correction mode is set up.

Electrophotographic recording device

It is an exemplified object of the present invention to provide a manufacturing device and method that can manufacture a high-performance exposure device in a short time. To achieve this object, the manufacturing method of the exposure device is configured to have its part detachable from its main body. This may allow, for instance, a holding member that holds the exposure device after a bonding step of the exposure device is finished while an adhesive is being cured, to be detached from the manufacturing device and to attach another holding member to the manufacturing device to continue the manufacturing process up to a bonding step, thereby reducing or eliminating a downtime of the device.

Manufacturing device and method of the exposure device

An exposure device in which an image forming lens is disposed in such a posture that the center line of an image forming is out of axial alignment with the center of beam intensity distribution of the light emitting diode output (the center of beam intensity distribution) so as to reduce possible incidence of stray light when local part of the light output from the light emitting diode array reflects on said wires. As a result, the stray light does not strikes the circumference surface of the image supporting body and the vivid image can be formed.

Image forming apparatus and exposure device thereof

A plurality of resist marks of K, C, M and Y color toner components are transferred at predetermined pitches onto a belt for conveying record paper, by means of a plurality of electrostatic recording units. The resist marks are optically detected by sensors. A positional offset detection unit detects positions of resist lines from phases &phgr; obtained through Fourier transform of sensor detection signals, and employs as the reference the detected position of the resist mark of K component to thereby detect positional offsets of the detected positions of the resist marks of the other C, M and Y color toner components. A positional offset correction unit corrects the transferred positions of the other C, M and Y color toner components so as to eliminate any positional offsets relative to the K component image.

Printing apparatus

An image forming apparatus includes a frame, a closing cover mounted to said frame so as to be opened and closed, a plurality of printing assemblies each comprising a developing device for developing an image, a fixing device, and a paper conveyer belt for conveying paper through said plurality of printing assemblies. The apparatus further includes an optical sensor having a light-emitting element and a light receiving element to read marks readably formed on the paper conveyer belt. A movable cover is provided which is operatively connected to the closing cover to open an optical passage of the optical sensor when the apparatus is in operation and shut off the optical passage of the optical sensor when the apparatus is not in operation.

Image forming apparatus with belt mark sensor

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

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.

A developing apparatus of an electrophotographic apparatus includes a housing for accommodating a developer, first, second and third developing rollers are rotatably disposed in the housing and arranged opposite to a photoconductor drum for conveying a developer carried on respective surfaces of the developing rollers, and a conveyor roller rotatably disposed in the housing for conveying the developer carried on a surface thereof to one of the developing rollers. First and second screw conveyors are disposed in the housing for conveying the developer in an axial direction opposite to each other. Each of these conveyors has an axial length larger than an axial length of the developing rollers. A partition wall is disposed between the first and second screw conveyors. A toner container for accommodating a toner is mounted on the housing. The toner in the toner container is supplied into the housing and agitators agitate the toner in the housing. A first doctor blade regulates the developer carried on the conveyor roller, a second doctor blade regulates the developer on the first developing roller, and scrapers scrape the developer from the second and third developing rollers.

Electrophotographic image-forming apparatus having developing device

The image forming apparatus includes a frame, a top cover pivotally mounted to the frame, a lock member for locking the top cover onto the frame, a plurality of printing assemblies, a fixing device, and a paper conveyor belt. Each of the printing assemblies having a photosensitive body, a charger, an optical head for forming an electrostatic latent image on the photosensitive body, a developing device, and a transfer element. An optical sensor is used to read marks formed on the paper conveyor belt. The top cover opens an optical passage of the optical sensor when the apparatus is in operation and shuts off the optical passage when the apparatus is not in operation.

Image forming apparatus with cover lifting mechanism

An image forming apparatus which includes a frame, a top cover pivotally mounted to the frame, a lock member for locking the top cover onto the frame, a plurality of printing assemblies, a fixing device, and a paper conveyer belt. Each of the printing assemblies includes a photosensitive body, a charger, an optical head for forming an electrostatic latent image on the photosensitive body, a developing device, and a transfer element. The optical heads are mounted to the top cover. A cover lifting mechanism is provided for lifting the top cover by a predetermined amount relative to the frame when the lock member is released. The lifting mechanism includes a spring loaded rod which is linked to a cover releasing button.

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.

A plurality of resist marks of K, C, M and Y color toner components are transferred at predetermined pitches onto a belt for conveying record paper, by means of a plurality of electrostatic recording units. The resist marks are optically detected by sensors. A positional offset detection unit detects positions of resist lines from phases .phi. obtained through Fourier transform of sensor detection signals, and employs as the reference the detected position of the resist mark of K component to thereby detect positional offsets of the detected positions of the resist marks of the other C, M and Y color toner components. A positional offset correction unit corrects the transferred positions of the other C, M and Y color toner components so as to eliminate any positional offsets relative to the K component image.

Printing apparatus with positional offset detection and correction

An image forming apparatus includes an exposure unit forming a latent image using a light from a light source, a developing unit forming a toner image by visualizing the latent image using a toner, a detector outputting a detection signal by optically detecting an amount of toner of the toner image, a memory storing an optimum value of the detection signal output from the detector with respect to a light emission time of the light source, with respect to a plurality of light emission times of the light source to thereby store a plurality optimum values, and a control unit controlling the light emission time of the light source by calculating a light emission time corresponding to a value of the detection signal output from the detector based on the plurality of light emission times stored in the memory.

Image forming apparatus with image tone adjusting function

A paper delivery system having a printing unit with an upstream tractor and a downstream tractor disposed on an upstream side and a downstream side, respectively, of the paper delivery unit in the direction of paper delivery, a coupler coupling the upstream tractor and the downstream tractor to each other and a support shaft for supporting the coupler so that the coupler is movable in a direction transverse to the paper delivery direction and a resilient member positioned between the coupler and a fixed frame of the printing unit for energizing the coupler in a predetermined direction for constantly holding the coupler at a certain position in relation to the support shaft.

Paper delivery system

Growing community of inventors

Kawasaki, Japan

Tsutomu Nagatomi