Fujitsu Corporation

Youji Houki

Hirofumi Nakayasu

Tsutomu Nagatomi

Yoshihiko Taira

Kouichi Kobayashi

Takeo Kojima

Morihisa Kawahara

Hiroji Uchimura

Tomoyuki Nagamine

Masakazu Kinoshita

Yukio Saito

Shinya Hasegawa

Satoshi Maeda

Fumio Yamagishi

Shigeo Kayashima

Masahiro Wanou

Takao Sugano

Shinichi Watarai

Shigetake Iwata

Hidenori Fujioka

Tsutomu Kawai

Tomohiro Nonomura

Kazuhiro Tamada

Hiroyuki Kaneda

Kazuhiko Hamazoe

Keiji Ohyabu

Akihisa Sota

Kaneastu Uchiyama

Takeshi Tanimoto

Masao Konisi

Masakazu Kanaka

Shinichirou Yamamoto

There is provided a new image formation apparatus which does not generate a positional gap or discrepancy of a transferred image even when a final product is dependent upon a manufacturing accuracy in the exposure portion, particularly at the time of formation of the color image. Further, the present invention provides a new image exposure apparatus such as an LED head, an EL head, an LD scan unit, etc. which are used for the image formation apparatus. The image formation apparatus comprises an image storage device for storing image information, a read-out device for assigning an image information read-out position of an image storage device to read out the image information, an image transfer unit for transferring an image onto a paper in accordance with the image information read out by the read-out device from the image storage device, and an accuracy information storage device for storing position accuracy information in a scanning direction of the image transfer unit. The read-out device has a device for reading out the position accuracy information from the accuracy information storage device and correcting the image information read-out position by the position accuracy information.

Image formation apparatus and image exposure apparatus

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

The present invention aims at providing an exposure device, image-forming device, and manufacturing method of the exposure device that can reduce a color deviation and form a high-quality multicolor image. An interval of dots in an LED array that is most likely to undergo a thermal influence by radiant and conductive heat from a fixer is made smaller beforehand, whereby the color deviation that would otherwise be produced by the image-forming device is reduced.

Thermal correction for image-forming exposure device and method of manufacturing the 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

An electrophotography apparatus is provided with one or a plurality of recording units which optically form a latent image on a body. Each of the recording units includes a plurality of light emitting elements having a shape which satisfies a relationship t/y<T/Y<1, where t indicates a width of a pixel of the latent image in a sub scanning direction, y indicates a length of the pixel in a main scanning direction, T indicates a width of a light emitting element in the sub scanning direction, and Y indicates a length of the light emitting element in the main scanning direction.

Electrophotography apparatus and exposure apparatus using particularly shaped light emitting elements

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

Electrostatic developing units are arranged in the record paper conveyance direction, form dot latent images in conformity with image dot data through the issue of scanning light on photosensitive drums in rotation, and after developing by toner components, transfer dots onto record paper for development. For each lighting noticeable dot amount image dot data, a quantity-of-light control unit provides control and output of optical energy of the noticeable dot on the basis of peripheral dots which may have influence on the size of the noticeable dot on the record paper, for example, in response to the distance from the peripheral dots.

Electrophotographic apparatus with quantity-of-light control

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.

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.

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Kawasaki, Japan

Youji Houki