Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Naoyoshi Kinoshita

Keiji Kusumoto

Masaki Tanaka

Kouichi Etou

Yukihiko Okuno

Atsushi Kawai

Takeru Kinoshita

Hiroyuki Ideyama

Suguru Hamamichi

Yoshihiko Hatta

Hideo Kitakubo

Masazumi Ito

Takanobu Yamada

Kenji Matsuhara

Makoto Fujii

Tetsuya Sakai

Katsuhiko Takeda

Yoshikazu Watanabe

Shizuo Yuge

Kaoru Hashimoto

Naotoshi Kawai

Hideaki Kodama

Teruhiko Fujikura

Hirohisa Miyamoto

Munehiro Natsume

Toshifumi Watanabe

Yasuyuki Matsuuchi

Takeshi Satake

Naoki Ohashi

Toshikazu Higashi

Takahisa Nakanishi

Yoshihito Aoki

An image forming apparatus includes a communications line for connecting the image forming apparatus to other image forming apparatuses to create a system of a plurality of image forming apparatuses; a device for setting a connected printing mode to allocate and print jobs to be printed by the plurality of image forming apparatuses; a device for executing printing in the connected printing mode by the plurality of image forming apparatuses; and a device for releasing the use of the image forming apparatus under the connected printing mode when the image forming apparatus receives a print command while a printing operation is being executed by the plurality of image forming apparatuses under the connected printing mode.

Image forming system including means for inhibiting or releasing one of

An image forming apparatus is provided with a printer section for printing an image on a sheet and a sorter having a plurality of bin trays. Printed sheets discharged from the above printer section are discharged onto the designated bin tray corresponding to the destination of the print job among the plurality of bin trays. There are provided a page number counting section for counting the number of pages of the print job and a capacity changing section for increasing the capacity of the designated bin tray when the number of pages of the print job is greater than a specified number. This image forming apparatus can improve the ease of use in a mail bin mode.

Image forming apparatus capable of improving ease of use in mail bin mode

In an electrophotographic image forming apparatus, a correction coefficient corresponding to each density level of toner consumption of a developing device is determined in accordance with a selected tone correction method, and/or the ratio of the emission period to the non-emission period of a light source. A toner consumption calculator multiplies the correction coefficients by the number of pixels of each density level of document image data, and determines the amount of toner consumed by the developing device from the sum total value of the multiplication results determined for each density level. A toner replenishment device resupplies toner to the developing device based on the determined amount of consumed toner. As a result, a constant toner concentration Tc normally can be maintained because toner is resupplied based on the calculated amount of toner consumption.

Image forming apparatus which calculates toner consumption in accordance

An image formation apparatus for forming a full color image in the four colors of cyan, magenta, yellow and black has a optical ATDC sensor attached in a cyan developing device to control the toner density under optical ATDC. A black developing device has the toner density controlled by AIDC. A standard develop efficiency .eta.STD of the cyan developing device obtained as a result of the AIDC is compared with a develop efficiency .eta. of black toner. The toner supply amount of the black developing device is determined according to the comparison result to supply the toner. Thus, an image formation apparatus is provided that can detect at favorable accuracy the toner density of a developing device incorporating a developer of which the toner density cannot be detected using optical ATDC to supply a required amount of toner.

Image formation apparatus that can maintain appropriately toner density

In an electrophotographic image forming apparatus including a photoconductive drum, the photoconductive drum is electrically charged by a corona charger, and light corresponding to an image is projected onto the photoconductive drum by an exposure optical system, thereby forming an electrostatic latent image thereon. Thereafter, the formed electrostatic latent image is developed with toner by a developing unit to form a toner image thereon, and then the toner image is transferred onto a sheet of paper. There is further provided a voltage sensor for detecting a surface voltage at at least one position of the photoconductive drum. An operation value of at least one of the corona charger, the exposure optical system and the developing unit is adjusted by an adjustment controller based on the surface voltage detected by the voltage sensor at a timing between respective image forming processes when an image forming process is continuously repeated a plurality of times. Further, the operation value of at least one of the corona charger, the exposure optical system and the developing unit is further adjusted with a preciseness higher than that of the adjusting controller, based on the surface voltage detected by the voltage sensor, prior to a process of continuously repeating an image forming process a plurality of times.

Electrophotographic image forming apparatus adjusting image forming

An image forming apparatus for forming images by an electrophotographic process. The image forming apparatus includes a humidity sensor for detecting the humidity in the area around the image forming members provided therein, a density sensor for detecting the density of images formed on a photoreceptor, and a humidity controller having a dehumidifying unit and a humidifying unit for adjusting the humidity in the area around image forming members. The humidity controller is operated according to humidity historical data generated based on the humidity data outputed from the humidity sensor, a detected photoreceptor potential, a detected amount of developer scattered from the developing unit or the detection result from the density sensor.

Image forming apparatus with humidity controlling device

Developer density measuring apparatus comprising a transparent detection window confronting the interior of a developing device, illumination means for illuminating developer comprising a toner and a carrier accommodated in said developing device, and density determining means for determining developer density by the amount of light reflected from said developer measured through said transparent detection window, and wherein the surface of the transparent detection window on the side confronting the interior of the developing device is roughened.

Apparatus for measuring developer density

An image forming apparatus having a developing device which accommodates a developer for developing an electrostatic latent image formed on the surface of a latent image carrier, a developing member provided in said developing device for supplying the developer to the electrostatic latent image formed on the surface of the latent image carrier and a mixing member provided in the developing device for mixing the developer accommodated within the developing device. In the above image forming apparatus, the operating time of the mixing member is determined prior to the start of operation of the developing member based on at least one value of a toner density at the end of developing, the developer standing idle time, and the total number of developing cycles with the same developer.

Electrophotographic image forming apparatus with controlled mixing of

Apparatus for measuring developer density comprising, a developer agitator section agitating a developer, a rotational conveying member conveying the developer in the developer agitator section with its rotation, a transparent detection window facing the developer agitator section, a plurality of magnets being fixed on the rotational conveying member, and retaining the developer, and causing the developer to be brought into contact with the transparent detection window with a rotation of the rotational conveying member, a density detection section measuring the developer density on the basis of reflected light by illuminating the developer retained on the magnets, and caused to be brought into contact with the detection window, and the magnets including at least one cleaning magnet, and the density detection section is situated in a passage of the developer which is conveyed so as to be circulated through first agitator passage adjacent to a development section and second agitator passage behind the first agitator passage, and between a passage for conveying the developer from the first agitator passage to the second agitator passage and a replenishment opening for replenishing the toner to the second agitator passage.

Apparatus for measuring developer density by reflected light from the

An apparatus for optically measuring toner density, having a rotary member which rotates and retains a developer constituted by a toner and a carrier by magnetic force, a transparent detection window which is disposed at a position where the developer retained on the rotary member rubs said detection window through rotation of said rotary member, a detection device which illuminates the developer through the detection window and detects the amount of reflected light from the developer and the magnitude of variations of the amount in response to rotation of the rotary member, and a warning device which issues an abnormal warning when the magnitude is smaller than a predetermined reference value, and a method for optically measuring toner density by using the apparatus.

Method and apparatus for optically measuring toner density

A copying machine capable of color copying includes a filter apparatus for color-separating scanning light for scanning original images, and the original images are copied by electrophotographic process. The filter apparatus includes mirror filters having color separation filters of blue, green and red, respectively deposited on mirror surfaces and a half mirror, and these mirrors are arranged apart from each other at an angle of 90.degree., so that the apparatus as a whole has a cylindrical shape. The light scanned the original images is reflected by the filter mirrors, and latent electrostatic images corresponding to respective colors are formed on a photoreceptor drum.

Method of forming a reference pattern for adjusting image density in

A detecting device for detecting the position of a rotatable image bearing member which is provided in an image forming apparatus. The detecting device has a reference member provided in the image bearing member and a sensor for detecting the reference member. The position of the rotating image bearing member is detected by this detecting device. Further, by this detecting device, the image forming apparatus is able to detect that the image bearing member is slipped in a direction perpendicularly to the image bearing member rotation direction.

Belt position detecting device using timing measurement

An image forming method and an image forming apparatus in which a plurality of kinds of toner images are supported on an image support member, the method comprising the steps of: forming, on the basis of first image data, a first toner image on the image support member with first toner; detecting the first toner image so as to output a detection signal; forming, on the basis of second image data, a second toner image on the image support member with second toner which is different from the first toner; and executing, by an output of the detection signal, a program for setting conditions for forming the second toner image.

Multi-color image forming apparatus and method of setting image data for

An electrophotographic image forming apparatus for forming a color toner image by a developing device and fixing the toner image by a fixing device including top and bottom rollers. When OHP mode for forming images on transparency sheets is selected, the time required for fixing the toner image is prolonged so as to assure the transparency of the image fixed to a recording member. That is, if the size of the transparency sheet is larger than a predetermined value, the transparency sheet is sent to a returning path which returns the recording member discharged from the fixing device to the fixing device again, and if the size of the transparency sheet is smaller than the predetermined value, the fixing device is operated more slowly than a case of forming images on non-transparency sheets. Further, when the OHP mode is selected, heating power is supplied to both top and bottom fixing rollers, and when the OHP mode is not selected, the heating power is supplied to the top fixing roller only.

Image forming apparatus with a fixing device capable of fixing a

Apparatus for measuring developer density comprising, a container containing a developer constituted by a toner and a carrier, a rotary member agitating the developer in the container with its rotation, a transparent detection window facing the container, and having an electrically conductive film on its surface facing the developer, a measuring section measuring developer density in container on the basis of reflected light from developer illuminated through the detection window, an electrode which is supported by the rotary member, and is rotated together with the rotary member such that a gap between the electrode and the detection window is maintained at a predetermined value, the electrode being made, at least at one portion facing the detection window, of electrically conductive material, at least one magnet which is supported by the electrode, retains the developer, so that the magnet makes the developer to be brought into contact with the detection window with rotation of the rotary member, and a bias application member for applying bias between the detection window and the electrode so as to make the detection window and the toner electrically repulsive to each other.

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Aichi-Ken, Japan

Naoyoshi Kinoshita