Minolta Camera Kabushiki Kaisha

Hiroshi Murasaki

Hiroshi Mizuno

Masaya Ogawa

Akihito Ikegawa

Yuji Enoguchi

Kouichi Etou

Kenichi Wada

Takao Fujiwara

Hidetoshi Kawabata

Susumu Tanaka

Takaji Kurita

Tamotsu Shimizu

Masahiko Matsuura

Takashi Sugiyama

Shuichi Nakagawa

Susumu Mikawa

Toshiya Natsuhara

Tateki Oka

Junji Machida

Naoki Toyoshi

Tomoaki Yokoyama

Junji Ohtani

Noboru Ito

Fumio Masuda

Masanori Fujiwara

Yoshihisa Terasaka

Mikio Masui

Masasi Yamamoto

Hirokazu Yoshida

An image forming apparatus has a toner recycling mechanism for effecting toner recycling. The image forming apparatus includes a developing unit accommodating developer for developing an electrostatic latent image formed on the surface of a photosensitive member, a cleaning unit for recovering developer remaining on the surface of the photosensitive member after development, and a toner recycling assembly. The toner recycling assembly includes a developer conveyor pipe through which the developer recovered by the cleaning unit is conveyed to the developing unit for recycling of toner contained in the developer, and also includes a developer supply or transport pipe for supplying the developer accommodated in the developing unit to either the developer conveyor pipe or the cleaning unit.

Image forming apparatus having a toner recycling mechanism

This invention relates to a method of developing electrostatic latent images which comprises the steps of;

Method of developing electrostatic latent image

In an image forming apparatus accommodating a developing device, a developing roller 1 includes a magnet member 3 non-rotatably fixed and a sleeve 2 rotatably moved around the outer surface of the magnet member 3, powdery developers D held on the outer periphery of the sleeve 2 are brought into contact with a photosensitive member 10 to visualize an electrostatic latent image, and the magnet member 3 is provided with a magnetic pole portion N.sub.0 having first and second magnetic poles N.sub.1 and N.sub.2. The first and second magnetic poles N.sub.1 and N.sub.2 have the same polarities and are adjacent to each other and confront the photosensitive member 10. The powdery developers D include three developer parts, an upper developer D.sub.1, a middle developer D.sub.12 and a lower developer D.sub.2, which are successively retained on the outer surface of the sleeve 2 by the first and second magnetic poles N.sub.1 and N.sub.2. The upper developer D.sub.1 retained by the first magnetic pole N.sub.1 and the middle developer D.sub.12 retained by the middle portion between the first and second magnetic poles N.sub.1 and N.sub.2 are brought into contact with the photosensitive member, while the lower developer D.sub.2 retained by the second magnetic pole N.sub.2 is held out of contact with the photosensitive member.

Developing device for use in an image forming apparatus

A toner supplying device for supplying toner to a developing device in an electrophotographic image forming apparatus comprises a toner hopper for containing and feeding new toner, a recycle device for introducing toner from a cleaner which collects residual toner on an electrostatic latent image carrying member to an outlet of the hopper or the vicinity thereof, a toner agitating chamber opposed to the outlet of the hopper and an outlet of the recycle device, a toner agitating member disposed in the toner agitating chamber, and a toner feeder for feeding the toner from the toner agitating chamber to the developing device.

Toner supplying device

A developing device comprises a rotatable developing sleeve, a magnet member stationarily disposed inside the developing sleeve and a developer restricting member which restricts an amount of developer transported on a peripheral surface of the developing sleeve toward a developing region in accordance with rotation of the developing sleeve. The magnet member has a developing magnetic pole confronting the developing region, an identical polarity magnetic part which is provided between the developer restricting member and the developing magnetic pole and is formed of a plurality of adjacent magnetic poles of an identical polarity, and a magnetic pole which is provided between the identical polarity magnetic part and the developing magnetic pole for transporting the developer.

Developing roller with an identical polarity magnetic part

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

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

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 including a toner support member for supporting toner on its surface, which is so provided as to confront an electrostatic latent image support member and a regulation member for forming a thin layer of the toner on the toner support member, which includes a curved member for pressing the toner support member and a support member for supporting the curved member such that an area S of a space satifies an equation: 0&lt;S.ltoreq.0.15 mm.sup.2 wherein the space is defined in a radial plane of the toner support member and the curved member and is bounded by the toner support member, the curve member and a line drawn in parallel with a normal extending through a point of contact between the toner support member and the curved member and spaced a radius of curvature of the curved member from the normal at an upstream side of the normal in a direction of rotation of the toner support member.

Electrostatic latent image developing device

A developing device including first and second developing sleeves rotatable in the same direction and being disposed adjacent to each other and magnets unrotatable and fixedly mounted in the respective developing sleeves. The first magnet mounted within the first developing sleeve has a first magnetic pole slightly downstream of the position at which the first developing sleeve and the second developing sleeve are closest to each other with respect to the rotational direction of the first developing sleeve. The second magnet mounted within the second developing sleeve has a second magnetic pole slightly upstream of the above-described closest position with respect to the rotational direction of the second developing sleeve. A developer being transported by the first developing sleeve on the peripheral surface thereof is attracted by the second magnetic pole of the second developing sleeve in the region in which the first and second developing sleeves confront each other, thus being transferred easily from the peripheral surface of the first sleeve to that of the second sleeve. A developer being transported by the second developing sleeve on the peripheral surface thereof is attracted by the first magnetic pole of the first developing sleeve in the region in which both developing sleeves confront each other, thus being transferred easily from the peripheral surface of the second sleeve to that of the first sleeve. A repellent magnetic field is generated by the first and second magnetic poles between the region in which both developing sleeves confront each other.

Developing device capable of preventing a developer from passing through

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.

Developing device with developer sleeve facilitating developer supply

A developing apparatus includes a developing roller confronting an image support member for generating an electrostatic latent image on its surface, an accommodating tank for accommodating developing material therein, and a supply roller disposed to confront the developing roller so as to supply the developing material accommodated within the accommodating tank onto the developing roller, and is characterized in that a developing material supply width of the supply roller is smaller than the effective developing width of the developing sleeve.

A developing device includes a developing sleeve which is provided with a plurality of magnets so as to transport a two-component developer composed of toner and carrier to a developing region where the developing sleeve and a member bearing an electrostatic latent image confront each other, a toner reservoir, a toner supply roller for supplying the toner to the developing sleeve, which is disposed at an end portion of the toner reservoir so as to be brought into contact with the toner in the toner reservoir, a rotary member which is rotatably provided in the toner reservoir so as to be rotated in contact with the toner supply roller and a charge erasing member for erasing electric charge of electrically charged toner transported to the toner reservoir by the toner supply roller.

Growing community of inventors

Osaka, Japan

Hiroshi Murasaki