Ricoh Company, Ltd.

Takashi Mama

Takanobu Fujioka

Kan Tomita

Shinji Kobayashi

Takeshi Yamakawa

Yoshio Kaneko

Nobuo Sakuma

Noboru Sawayama

Yoshiki Yoshida

Yuji Yasuda

Kenichirou Asada

Fumihiro Miyagawa

Hidetoshi Kanai

Nobuyuki Sato

Kenichi Ono

Shuichi Yamazaki

Norio Michiie

Koji Oshikiri

Masaaki Kogure

Kenichiro Asada

In an image forming apparatus, a device for removing an image forming substance from a paper or similar image holding medium senses the orientation of fibers constituting the paper. While a light beam is emitted obliquely toward the paper, the diffused distribution distribution of the resulting reflection is measured in order to determine the orientation of the fibers. A preselected relation is set up between the fibers and the direction of paper transport on the basis of the determined orientation. Further, a condition for applying an unstabilizing liquid to the paper and a condition for drying the paper are varied on the basis of the determined orientation.

Method and device for determining fiber orientation of paper, and

Servicing of an image forming device, such as a digital photocopier, is made convenient by providing an access opening exposing each of a number of prescribed serviceable components enclosed in a sealed casing. These serviceable components may include a light source scanner, lens group and beam detector. The casing bears removable cover units on the access openings. The serviceable components are located under the access openings, fixed in place by the cover units or elements attached to the cover units. Electrical switches coupled to the cover units may deactivate the components when the cover units are removed.

Image forming device having convenient access to serviceable components

In an image forming apparatus, a method of correcting a position for writing an image on a photoconductive element on the basis of a signal representative of a pattern formed on the element and detected, and a device therefor. A single photoconductive element is used to form a plurality of different colored images using a single rotating polygonal mirror and a plurality of light sources. The toner images can be sensed either while they are on the single photoconductive element or by sensing them through a transport belt.

Method and device for correcting a position for writing an image on a

Method and device for correcting a position for writing an image

A scanning time after a detection signal from a first laser beam detection sensor is inputted until a detection sensor from a second laser beam detection sensor is inputted by a counter, flip-flops, a corrected write frequency f1 is computed by a control circuit from a value T1 corresponding to the measured scanning time and a function F (T1) for computing a correction factor using the basic write frequency f0 and the value T1 above and through the equation of 'f1=f0.times.F (T1)', and the write clock frequency is corrected by a clock generation circuit, thus the write clock frequency being controlled according to a change in the scanning speed.

Image forming apparatus with frequency corrector

A data transfer device for transferring data in a color digital copier, color printer or similar image forming apparatus of the type using a plurality of different kinds of data. A sending unit assigns other data to a predetermined number of bits of multilevel data to thereby send a plurality of kinds of data over common data lines. A receiving unit receives and separates the plurality of kinds of data. The device reduces the number of signal lines required for data transfer when a plurality of different kinds of data are not transferred at the same time.

Data transfer device for an image forming apparatus

An image forming apparatus having deflection scanning type and line type exposing devices and first and second developing devices arranged around a photoconductive element, so that parts around the photoconductive element are arranged with ease to promote the miniaturization of the apparatus. The exposing devices are selected based on the principle that the image quality is enhanced for an image of particular color and is lowered for an image of another color expected to be printed less frequently. Specifically, the deflection scanning type exposing device forms the image of the particular color, and the line type exposing device which has an inherently long optical path and simple structure forms the image of another color. Fans are provided to produce cooling air flow to the line type exposing device and to draw out toner dirt and ozone produced by the charger associated therewith. The line type exposing device and the associated charger are electrically insulated from each other and mounted in a common casing. Cleaning elements are provided to clean the charger and the line type exposing device during withdrawal of these elements from the photoconductive element.

Compact BI-color electrophotographic image forming apparatus

A bicolor image forming apparatus having first and second exposing means and first and second developing means arranged around a photoconductive element. The first and second developing means are implemented as a deflection scanning type and a line type, respectively. Parts around a photoconductive element are arranged with ease to promote the miniaturization of the apparatus. This stems from the principle that the image quality may be enhanced for an image of particular color and lowered for an image of another color expected to be printed less frequently. Specifically, the apparatus has deflection scanning type exposing means for forming the image of particular color, and line type exposing means which has an inherently long optical path and simple structure for forming the image of another color.

Bicolor image forming apparatus for forming a bicolor image on a

A light beam scanning apparatus includes a laser light source emitting a laser beam, an optical system focusing the laser beam emitted from the laser light source onto a rotating photosensitive drum, a beam scan mechanism moving the point of focus of laser beam on the photosensitive drum, in a direction perpendicular to the direction of main scan, a scan line correction mechanism correcting a scan line to a straight line when the scan line is curved.

Light beam scanning apparatus

A multi-beam detecting apparatus adapted to an optical system in which a recording medium is scanned by a plurality of light beams emitted from respective light sources, includes a photodetector, a light interrupting member, and a control circuit. The photodetector produces detection signals when the corresponding light beams come to a predetermined position. The light interrupting member is interposed between the light sources and the light detecting member, and has transparent portions related to the respective light beams. A controlling circuit controls ON/OFF states of the light source in accordance with the respective detection signals related to the corresponding light beams passing through the respective transparent portions in the light interrupting member.

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 imaging system includes a plurality of semiconductor lasers for emitting a plurality of laser beams for use in forming an image on a photosensitive member. A laser driver circuit is provided for each of the plurality of lasers, and a plurality of photodectors are also provided, each detecting the light intensity of the corresponding one of the laser beams emitted from the lasers. A light intensity stabilizing control circuit is provided to stabilize the light intensity of each of the plurality of laser beams using one of the detected light intensities as a reference and adjusting the light intensity of each of the other beams such that a difference between the reference and the light intensity of each of the other beams is within a predetermined range.

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Yokohama, Japan

Takashi Mama