Minolta Camera Kabushiki Kaisha

Konica Minolta, Inc.

Minolta Company, Ltd.

Kouichi Etou

Hiroshi Mizuno

Akihito Ikegawa

Hiroshi Murasaki

Naoyoshi Kinoshita

Shuichi Nakagawa

Junji Kanda

Kazuyoshi Ota

Wanli Zhang

Masahiro Anno

Tateki Oka

Junji Machida

Kazuyuki Fukui

Eiichi Sano

Ichiro Demizu

Naoki Toyoshi

Tomoaki Yokoyama

Yoshinobu Hada

Masaki Tanaka

Masashi Yamamoto

Hideo Kitakubo

An image forming apparatus including an image forming unit and a controller configured to control an operation of the image forming unit is provided. The image forming unit includes a conductive member to which a bias voltage is supplied in image formation. The controller is configured to calculate an operating ratio indicating a percentage of a time period during which the conductive member is used, and calculate a value indicating a consumption degree of the conductive member based on the calculated operating ratio and a magnitude of an electrical resistance of the conductive member.

Image forming apparatus and image forming system

Conductive particlehas conductive carbon black particle (CB)and cover layer. The amount of an insulating resin in conductive particleis from 10 to 50% by mass. The number-average primary particle diameter of CBis from 20 to 60 nm; DBP absorption amount is from 100 to 200 mL/100 g. Cover layeris formed by a phase-inversion emulsification method that contains an insulating resin having an amino group and CBin an oil phase. Conductive particleis used suitably for a conductive agent of an intermediate transfer belt of an image forming apparatus.

Conductive member, image forming apparatus, conductive particle and method for manufacturing the same

An intermediate transfer belt used for an image forming apparatus of an electrophotographic system includes: an elastic layer; and a surface layer formed on the elastic layer, wherein stress relief time &#x3c4; [ms] of a material used for the elastic layer and hardness H [MPa] of the surface layer satisfy a first condition that 0.48&#x3c;&#x3c4;&#x3c;0.75 and 50&#x3c;H&#x3c;6275&#x3c4;&#x2212;13820&#x3c4;+10140&#x3c4;&#x2212;2330 or a second condition that 0.75&#x2266;&#x3c4; and 50&#x3c;H&#x3c;150.

Intermediate transfer belt and image forming apparatus

In a digital image forming apparatus, the intensity or the pulse width of laser beam exposure is modulated according to image signals of a document detected by a sensor. A peak waveform having a peak is generated in each light-emitting period of laser beam. For example, and a signal having a peak is synthesized with the image signals to generate the peak waveform. Thus, the laser is driven according to the peak waveforms so that the exposed portions on a photoconductor in correspondence to the peaks are exposed with a larger quantity of light at low densities. Then, the amount of the gamma correction can be decreased and the gradation characteristic can be stabilized.

Image forming apparatus for synthesizing a differential peak signal and

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

The present invention discloses a monocomponent developing device including a developing sleeve for developing an electrostatic latent image formed on the surface of a photoreceptor by supplying a toner to the electrostatic latent image. The developing sleeve contains a whisker with 0.1 .mu.m to 1 .mu.m outside diameter at least in a surface layer thereof.

Developing device for producing a developed image

A developing apparatus is accommodated in an image forming apparatus to develop an electrostatic laten image formed on an electrostatic latent image support member, using two-component developer of toner and magnetic carrier. The developing apparatus is provided with a developing sleeve opposed to the electrostatic latent image support member, a magnetic roller disposed inside the developing sleeve to hold the carrier on a peripheral surface of the developing sleeve, a toner hopper accommodating the toner and having an opening at its one end, a toner supply roller rotatably disposed in the opening of the toner hopper and opposed to the developing sleeve, a bristle height adjusting member opposed to the developing sleeve on the downstream side of a developing region and on the upstream side of a toner supply region in a direction of movement of the carrier held on the peripheral surface of the developing sleeve. The developing sleeve confronts the electrostatic latent image support member in the developing region and the toner supply roller in the toner supply region.

Electrostatic latent image developing apparatus with bristle height

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.

Apparatus for measuring developer density

A developing apparatus includes a photosensitive drum positioned in confronting relation to a developing sleeve. A toner accommodating tank is provided for supplying toner to the developing sleeve. The toner accommodating tank is divided into a small chamber and a supplementary chamber which are separated from one another by a partition which permits toner to be supplied from the supplementary chamber to the small chamber but which prevents the return of toner from the small chamber to the supplementary. A movable shutter selectively permits and prevents toner from being supplied from the supplementary chamber to the small chamber in accordance with operation of the apparatus.

Developing apparatus including a partitioning arrangement for

An electrostatic latent image developing apparatus includes an agitating member accommodated in a casing, a roller member accommodated in a front of the casing, and a blade contacting under pressure with an outer circumferential portion of the roller member, which is arranged in the casing. Toner held on the outer circumferential portion of said roller member being supplied to develop an electrostatic latent image on the basis of rotation of the roller member while being regulated by the blade. The apparatus includes a partition member arranged between the roller member and the agitating member at an upper stream side of said blade corresponding to a rotary direction of the roller member. The casing has a space defined among the partition member, the blade, and the outer circumferential portion of the roller member.

Developing apparatus provided with a chamber for controlling toner grain

This invention relates to a developer for developing electrostatic latent images formed on an electrostatic latent image carrier, which comprises a toner including;

Developer for electrostatic latent image containing fine particle

An electrophotographic copying apparatus includes a main body, a developing system, removably mounted on the main body, provided with a developing device having the developing sleeve holding a carrier on the outer surface, and a toner cartridge having a toner supply roller which confronts the developing sleeve. A voltage-adjusting device adjusts the bias voltage to be supplied respectively to the developing sleeve and the toner supply roller depending on a toner color so as to generate a predetermined electric potential between the developing sleeve and the toner supply roller. The voltage adjusting device adjusts the bias voltage difference between the developing sleeve and the toner supply roller according to a saturation charge amount which is different depending on the toner color.

Developing apparatus with color dependent toner supply voltage

A developing apparatus is disposed adjacent to an electrostatic latent image support member in an image forming apparatus, and includes a rotatable developing sleeve confronting the electrostatic latent image support member, a magnetic roller disposed inside the developing sleeve for holding magnetic carrier on a peripheral surface of the developing sleeve, and a plurality of toner supply units confronting the developing sleeve for supplying toner to the developing sleeve. The magnetic roller accommodates a plurality of magnetic poles extending in a direction of its axis. Each toner supply unit is provided with a toner supply roller rotatable in contact with a magnetic brush held on the developing sleeve and a toner storing portion for storing the toner. A control device and an operation panel is also provided for selectively rotating either of the toner supply rollers by means of a driving source, for selecting the toner stored in any of the toner supply units, and for controlling the movement of the toner supply roller.

Developing apparatus

A developing device includes a developing sleeve provided rotatably at a side of an electrostatic latent image support member, a supply member for supplying developer to the developing sleeve, a bristle height regulating member which confronts an upper portion of the developing sleeve so as to adjust an amount of the developer transported to a developing region and a plurality of magnets provided in the developing sleeve. The magnetic poles of the magnets not only extend in an axial direction of the developing sleeve but are arranged in a circumferential direction of the developing sleeve. The magnetic poles include a weak magnetic pole disposed adjacent to the upper portion of the developing sleeve and two strong magnetic poles between which the weak magnetic pole is interposed. The strong magnetic poles have a polarity different from that of the weak magnetic pole.

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Toyokawa, Japan

Kouichi Etou