Ricoh Company, Ltd.

Yasumori Nagahara

Koichi Suzuki

Shigeru Suzuki

Kyoji Omi

Yoshiyuki Kobayashi

Kazuhiko Kobayashi

Tadashi Shinohara

Tatsuo Tani

Toshiyuki Takahashi

Toshiyuki Andoh

Koji Sakamoto

Katsuo Sakai

Kohji Suzuki

Nobuto Yokokawa

Masato Yokoyama

Setsuo Soga

Mitsuo Hasebe

Akio Katsumata

Jun Hosokawa

Kenichirou Asada

Goro Mori

Yoshiaki Kanmoto

Yuuji Matsuda

Kiyoto Nagasawa

Takanobu Fujioka

Yohhei Miura

Makoto Hashimoto

Haruki Iida

Sakae Ohta

Kiyozo Hashizume

Kyoji Kunitomo

Saburo Honda

Yoshiharu Kagari

A belt driving controller includes a driving roller having a radius ra plurality of driven rollers that is driven by rotation of the driving roller, the driven rollers having a radius ran endless belt that is wound on the driving roller and the driven rollers and an encoder that is attached to one of the driven rollers, and that outputs a signal. The rotation of the driving roller is controlled based on the signal from the encoder, and ()&#xd7;(r/r)&#x2266;1 is satisfied where &#x3b1;is a correction coefficient for a fluctuation in thickness of the endless belt caused by a belt winding angle on the driving roller, and &#x3b1;is a correction coefficient for a fluctuation in the thickness on the driven roller.

Belt driving controller, process cartridge, and image forming apparatus

A color image forming apparatus is provided with a printer controller which is capable of receiving color image data for one page, which is divided into a plurality of data for each of a corresponding plurality of colors, at an irregular interval, and, upon receiving the image data for one color, driving an image forming device to form an image of the color whose data has been received, and after images of all of the plurality of colors are completed, outputting the final image on a recording media. The image forming device may also include, an intermediate image transfer belt for forming thereupon an image of each of the plurality of colors, superposing one on another, and a leading edge detect sensor to detect a leading edge of an image of each of the plurality of colors for registering the leading edges of images of the plurality of colors. The apparatus may further include, in addition to a scanner and a printer, a system controller which issues an image formation command for each of the plurality of colors to the scanner and the printer at a regular interval in a copy mode, and to the printer at an irregular interval in a print mode.

Color image forming apparatus

An image forming apparatus includes a fixing speed setting unit for selectively setting the fixing speed in accordance with a desired mode of operation, a fixing unit for fixing a reproduced image of an original formed on a image forming medium at a variable fixing speed in accordance with the fixing speed setting unit, and a scanning unit provided with opto-electrical elements arranged in one line extended laterally to a predetermined scanning direction for optically receving an image of the original through the opto-electrical elements. The opto-electrical elements are carrying out a scanning operation in the predetermined scanning direction with varied scanning speed by changing a sweep spacing of an image data with averaging every N line of the image data in accordance with the operation mode with using every N-1 lines of the image data to reproduce the image of the original on the image forming medium.

Image reproducing apparatus

A multiple mode copying apparatus including a drive for moving a lens in the direction of a principal light beam, a conversion cam for converting the distance covered by the movement of a lens into a rotational angle, and a mirror moving device for moving mirrors in accordance with the rotational angle. The conversion cam is formed with a first cam surface for deciding the distance to be covered by the movement of the mirrors and a second cam surface for following up the distance covered by the movement of the lens. The second cam surface is profiled such that it is in the form of an arc such that when a cam follower moves past a point of contact of the cam follower for effecting copying without magnification and reduction, the direction movement of the cam member is reversed by starting at the point of contact thereof. By selecting a suitable profile for the second cam surface, it is possible to have the first cam surface profiled to be in the form of a straight line.

Multiple mode copying apparatus

Either a single copy or a plurality of copies of an original document may be made. Making a single copy or the last copy of a plurality of copies comprises, during a first revolution of a photoconductive drum, electrostatically charging the drum, radiating a light image of the document onto the drum to form an electrostatic image, developing the electrostatic image using a magnetic brush to form a toner image, transferring the toner image to a copy sheet, electrostatically discharging the drum and uniformly radiating the drum with light to further discharge the same. During a second revolution of the drum the drum is cleaned with the same magnetic brush to remove residual toner, and again electrostatically discharged and uniformly radiated. During a third revolution of the drum the magnetic brush is again used for cleaning. For making all but the last of a plurality of copies, the drum is charged, imaged, transferred and electrostatically discharged during a first revolution thereof and cleaned with the magnetic bruch during a second revolution. Whether the process is used to make one or more copies, the same portion of the drum is always used. Subsequently, the drum rotation is indexed so that the next process will use a different portion of the drum.

Electrophotographic process

In a variable magnification copying machines capable of performing slit exposure of the image of original document to the surface of a photoconductor with a desired magnification by moving a contact glass on which the original document is placed or an optical system in synchronization with the photoconductor which is moved at a predetermined constant speed, a scanning method and apparatus in which the moving speed of the optical system or of the contact glass at the exposure step and the moving speed of the same at the returning step to the original position thereof are made variable depending upon a selected magnification of the copy of the original document, and the moving speed of the optical system or of the contact glass is set in such a manner that the sum of the time required for the optical system or the contact glass to move for exposure scanning and the time required for the optical system or the contact glass to return to the home position thereof is constant regardless of the selected magnification of the copy of the original document.

Scanning method and apparatus applicable to variable magnification

The powder material transportation apparatus for transporting powder materials such as developer powder, by a rotating member such as a coil is provided with an agitator for destroying a bridge of powder material which is apt to be formed in an upper portion of the rotating member. The diameter or pitch of a rotating coil member is designed to be greater in a transportation termination portion than in a transportation initiation portion, whereby the powder material transportation force is increased in the transportation termination portion and formation of the bridge of powder material is prevented.

Powder material transportation apparatus

An oil supply apparatus for use with copying machines comprises a tank for holding an offset preventing oil therein, a pump for sucking the oil from the tank, a container for holding the sucked oil therein, an oil application device for applying the oil taken from the container to an image fixing roller and an oil recovery means device for recovering an excessive amount of the oil which was taken from the container and returning it to the tank. The oil is always circulated in the oil supply apparatus and the container can be detached from the tank. When the container is detached from the tank, a stopper is engaged in a drain hole formed in the container concurrently with the detachment action so as to prevent the oil from being spilled.

Oil supply apparatus

A photosensitive member for use in an electrophotographic apparatus in which a bias potential is applied to the member during development. The member comprises a conductive support having at least one support edge and a photosensitive layer formed on the surface of the support and extending up to a point substantially coincident with the support edge. A tapered surface is formed at the extremity of the photosensitive layer adjacent to each support edge which extends from the top of the photosensitive layer to the support edge. The maximum angle between a tangent of the tapered surface and the surface of the conductive support is less then 45.degree. thereby preventing an edge effect by which a background smearing in the form of a black band may appear on copied paper obtained. Such a tapered surface can be easily formed through a vaporizing technique with a special masking in accordance with the present invention.

Photosensitive member for use in electrophotographic apparatus and

The apparatus is for heat-fixing a toner image onto a support sheet in which the fixing of toner image is effected through both infrared radiation and direct contact with a heated surface of fixing roller in succession. An endless belt, having a transparency for infrared and trained over a pair of rollers, is disposed within a heat insulating casing, an upper run of the belt defining a path of movement of a toner image bearing support sheet to be fixed. An infrared radiator is disposed beneath the upper run of belt while a reflecting plate is disposed at the opposite side of the belt from the radiator with respect to the path. A fixing roller is disposed downstream of the radiator along the path for completing the fixing.

Apparatus for heat-fixing a toner image

An apparatus for color electrophotography including optical scanning means which moves intermediate a stationary original document and a copy sheet for scanning the colored image on the document onto, and a drum-shaped photoreceptor which is rotated in synchronism with the scanning movement of said scanning means. Successive images are scanned through different color filters to form successive electrostatic latent images thereon which are successively transferred from the rotating photoreceptor onto a stationary copy sheet. Each electrostatic image is successively developed using developer of a color corresponding to that of the filter used during the preceding scan before the following scan.

Apparatus for color electrophotography

An electrically insulated minor portion is provided on the periphery of a photosensitive drum comprising a cylindrical supporter, a photoconductive strip wound in roll form on a supply reel disposed in the interior of the cylindrical supporter and paid out thereof to apply a portion thereof to a major portion of the outer periphery of the cylindrical supporter so that the portion may serve as a photoreceptor on which an electrostatic latent image of an original to be copied is formed. The strip portion on the outer periphery is withdrawn and wound on a take-up reel that is also disposed in the interior of the cylindrical supporter. The minor portion of the outer periphery of the cylindrical supporter has on its surface an electrically insulating layer with electrical resistance in the range of 1 to 5 .times. 10.sup.9 .OMEGA.cm, the layer consisting of a material which is not charged by frictional contact with either the magnetic developing brush or the cleaning brush.

Growing community of inventors

Yokosuka, Japan

Yasumori Nagahara