Ricoh Company, Ltd.

Masaaki Kogure

Yoshihiro Mitekura

Takayuki Maruta

Mitsuo Hasebe

Itaru Matsuda

Hiroshi Hosaka

Akio Katsumata

Yoshio Kaneko

Takashi Mama

Kenichirou Asada

Satoshi Shinguryo

Takanobu Fujioka

Katsuhisa Tsuji

Kotaro Yonenaga

Naoki Matsuyama

In processing a colored image in multilevel gradations, a color which does not affect the gradation of the image is processed in fewer multilevels and colors which affect the gradation are processed in an ordinary number of multilevels.

Method of processing colored image in multilevel gradations

An image forming apparatus of the type producing a single composite color image on a paper which is transported by a belt by transferring image components of different colors to the paper in register with each other. The apparatus reduces with a simple construction the positional deviation of the image components which occurs in an intended direction of paper transport. Recording devices individually adapted for black, cyan, magenta and yellow are arranged side by side. Pattern images for measurement each being associated with a respective one of those colors are formed on the belt. A timing at which each of the pattern images arrives is sensed and counted. The count is compared with a reference value to calculate an amount of deviation. Write start timing signals each being associated with a particular color are generated which are individually variable on the basis of the deviation calculated. The pattern images of the respective colors are each generated by using a write start timing associated with the color as a reference, and the pattern to be provided by any of the recording devices is outputted on a downstream side of the belt relative to the pattern to be provided by another recording device which is located downstream of the first-mentioned recording device.

Color image forming apparatus

An electrophotographic copier, facsimile machine, laser printer or similar image forming apparatus for reproducing an image on a paper sheet by transforming an image signal representative of the image into an image forming signal by pulse width modulation, causing a spot beam in the form of a laser beam which is modulated by the image forming signal to scan a photoconductive element to form an electrostatic latent image thereon, developing the latent image to render it visible, and transferring the visible image to a paper sheet. The laser beam output, the set pulse widths of the image forming signal (beam turn-on times) and the bias voltage for development are changed in association with the deterioration of the laser beam power and the sensitivity of the photoconductive element.

Image forming apparatus

An image display device in which image data produced by an image scanner separate from the display may be written and erased. The display consists of a movable endless belt. Four embodiments are shown with the belt being made of an electrochromic material which electrochemically shows oxidation-reduction reactions; an optically reversible photochromic material; a thermoplastic sheet produced by applying a photoconductor and a thermoplastic resin to a transparent conductive film; and a color photochromic sheet made up of a photochromic film whose absorption changes when illuminated by light of predetermined wavelengths and a repetitive sequence of color filters of red, green and blue each being formed in a stripe configuration, respectively. Visible images are displayed on the display member based on the image data.

Wide screen display device using an endless belt

An image reading device applies to a photoelectric transducer optical image data which are produced by scanning a document and samples the image data on a pixel basis to read images on the document. The device includes a fiber optic bundle comprising a plurality of optical fibers which are bound together such that their light inlet ends and light outlet ends are configured differently from each other. Optical image data from the document are propagated through the fiber optic bundle to the photoelectric transducer.

Image reading device using fiber optic bundles configured differently at

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Tokyo, Japan

Masaaki Kogure