Ricoh Company, Ltd.

Yutaka Shio

Nobuo Iwata

Tadashi Shinohara

Tomonori Yabuta

Mitsugu Sugiyama

Eiichi Sasaki

Toshiya Sato

Kouichi Irie

Toshihiro Yamashiro

Takahiro Tamiya

Tsuyoshi Deki

Takeshi Motohashi

Yoshiyuki Ishiyama

Shingo Katou

Yasuhide Konishi

Shingo Katoh

A system, method, computer program and apparatus for providing regulating signals for regulating the position of an objective lens relative to a track on a disk. The regulating signals are obtained in response to an access request specifying an access target region on the disk. The tracks of a disc are divided into a plurality of zones, each zone having associated signal regulation information. In response to an access request, the signal regulation information for the zone containing the access target region is used to regulate the position of the objective lens.

Optical disk system with improved signal regulation capability

An apparatus and method of forming a color image on a recording sheet by transferring respective images onto a single recording sheet conveyed by a conveying belt, where the combination of the respective images form the color image. The respective color images are formed with a plurality of electrophotographic processing sections disposed along the conveying belt such that the respective color images are superimposed on one another to make the color image. The electrophotographic processing sections also form more than two colors, of a same pattern, of image positional deviation detecting marks. The image positional deviation detecting marks include a line in a main scanning direction and another line positioned at an incline with respect to the former line in order on the conveying belt. A detector is included that detects the image positional deviation detecting mark with a single detecting device composed of a light source, a slit, and a light accepting element.

Color image forming apparatus and method of obtaining color images with decreased image positional deviation

A color image forming apparatus capable of superposing toner images of respective colors in accurate register by preventing an exposing position from being displaced in the subscanning direction. The rotation phase of a polygonal mirror is controlled on the basis of the mark detection timing of a mark sensor. Hence, the exposing position in the subscanning direction is prevented from being displaced without regard to irregularities in the circumferential length and feed speed of an intermediate image transfer belt.

Color image forming apparatus with polygonal mirror rotation phase control

Color image forming apparatus and method of obtaining color images with

In a color image forming apparatus, a test pattern is formed by a color toner and provided with multiple tones by a dither method. The toner density of the test pattern is accurately read by a simple structure and faithfully corresponds to the actual toner density.

Color image forming apparatus

An apparatus for a rotational speed detecting includes a rotating disc having plural slits in a circumferential direction. A radiant element radiates light rays through the slits. A photodetector receives the rays radiated by the radiant element. Peak detectors detects peak points of the detected signal and a calculator calculates a rotational speed. The photodetector include two photodetectors separated by a distance .DELTA.L.

Apparatus for detecting rotational speed

A device for adjusting the position of a deflecting mirror included in an image forming apparatus, particularly one including a plurality of photoconductive elements, is disclosed. The device includes eccentric cams rotatable to adjust the position of the deflecting mirror.

Deflecting mirror adjusting device for an image forming apparatus

An image processing apparatus eliminates a detection error in a color offset detecting operation due to a periodic fluctuation in a speed of a conveying belt which conveys a transfer sheet on which color component images are transferred and superimpose to form a multi-color image. A plurality of image forming units are arranged along the conveying belt, each of the image forming units transferring a color component image on the transfer sheet and also transferring a register mark on the conveying belt. A register mark detecting sensor located along the conveying belt detects the register mark on the conveying belt. A distance between the register mark detecting sensor and one of the plurality of image forming units adjacent to the register mark detecting sensor is a multiple of an integer of a circumference of the drive roller. A distance between adjacent ones of the plurality of image forming units is a multiple of an integer of the circumference of the drive roller.

Image forming apparatus eliminating influence of fluctuation in speed of

In an image forming apparatus, a plurality of image forming means devices are sequentially arranged along a conveyor belt and sequentially form register marks on the conveyor belt. A sensor senses the register mark formed by the individual image forming device. A correcting section corrects, based on the output of the sensor, the register position of the individual image forming device with respect to a regular deviation component and an irregular deviation component fluctuating at a particular period. The apparatus is capable of producing high quality color images suffering from a minimum of color misregister.

Apparatus for registration of plural image in an image forming apparatus

A full-color image forming apparatus having a photo-conductive belt on which mono-color toner images are respectively formed, an intermediate transfer belt onto which the mono-color toner images are respectively transferred to form a full-color toner image, and a transfer member for transferring the full-color toner image onto a copy sheet. The intermediate transfer belt includes timing marks printed thereon which are detected by a sensor to generate an image forming start signal for each of the first mono-color toner image forming processes. The start signal is generated by a controller only when cleaning of the intermediate transfer belt has completed and the cleaning blade has left therefrom. A timer may be used to delay the starting of the first mono-color image forming process until the transfer belt returns to a normal operating speed after the cleaning blade is removed from the transfer belt.

Registration control for an image forming apparatus having an

In a color image forming apparatus, a plurality of color images of component colors are combined to form a full color image. These images of the component colors are overlapped on an intermediate recording medium, and are then transferred to a transfer medium. Control circuitry reduces the amount of time required to form the component color images on the intermediate transfer medium, and to prevent an abnormality such as an out-of-phase or pull-out of a closed loop control circuit for controlling such a formation of the component color images. This may be achieved by abruptly changing a phase of a motor synchronizing signal. Further, for a period of time after the motor synchronizing signal is abruptly changed, a gain of an amplifier in the motor control circuit can be reduced, an abnormality detection in the motor control circuit can be reduced, the motor control circuit can be placed in an open loop state, or an addition or subtraction signal can be input to the closed loop motor control circuit. This specified period can also be detected based on a feedback including a rotational phase of a polygon motor formed as part of a unit for writing the individual component color image signals.

An image forming apparatus includes a revolver type developer, and prevents toner stored within the revolver type developer from being adversely influenced by heat from a fixing unit. As one feature, the revolver developing unit is intermittently rotated when the image forming apparatus is in a stand-by state. As a further feature, the revolver developing unit is rotated at a very slow continuous speed when the image forming apparatus is in a stand-by state. As a further feature, the intermittent rotation and the slow continuous rotation of the revolver developing unit can be stopped if the temperature of the fixing unit falls below a predetermined value.

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Yokohama, Japan

Yutaka Shio