Konica Corporation

Konica Minolta Business Technologies, Inc.

Toru Komatsu

Kunio Shigeta

Hirotaka Kabashima

Tetsuya Ishikawa

Yotaro Sato

Hiroyuki Nomori

Isao Endo

Masahiro Onodera

Hiroshi Akita

Seiko Itagaki

Seiji Yamaguchi

Kazuhiro Nakazawa

Yasushi Koshimura

Toru Yamaguchi

Koichi Gunji

An image forming apparatus for forming a toner image on an image carrier and transferring the toner image to a recording medium including a developing device, cleaning device, first toner conveyer, second toner conveyer, third toner conveyer, and a controller for controlling whether the toner removed by the cleaning device is to be conveyed by the second toner conveyer on the basis of an amount of new toner conveyed to the developing device by the third toner conveyer.

Image forming apparatus

A developing device has a rotary developer carrier, a rotary developer supply and collection member, a first and second rotary developer stirring members for stirring the developer while conveying and circulating the developer between them in the direction opposite to each other and having the same developer conveyance power, and a third rotary developer stirring member having a zero conveyance power in the rotary axis direction, which are provided in a housing in parallel with each other in this order in the direction to leave a latent image carrier. A toner replenishment inlet is provided at an upper part where the second and third stirring members face each other, and on an upstream side of the second stirring member in the developer conveyance direction, and the second and third stirring members are rotated downwardly at the position where both developer stirring members face each other.

Developing device and image forming apparatus

An image forming method includes the steps of: forming a plurality of electrostatic latent images of a non-solid control patch by converting a reference input density; detecting a patch potential of each of the plurality of electrostatic latent images; calculating a density value of image data corresponding to a desired patch potential from the detected plurality of patch potentials; detecting a density of each of the plurality of non-solid control patches which has been formed by an imagewise exposure according to the image data of the reference input density obtained by the calculating step; forming an image by controlling an image forming condition in accordance with a detected density signal.

Image forming method and image forming apparatus utilizing a control patch

Image forming method and image forming apparatus

An image forming apparatus includes a photoreceptor, an exposure device for exposing the photoreceptor with a laser beam dot by dot so as to form a dotted latent image on the photoreceptor, and a developing device for developing the dotted latent image with developer. The apparatus also includes a dot diameter correcting device for correcting a diameter of the dot formed on the photoreceptor. The dot diameter correcting device includes an image patch producing device for forming an image patch having a specific dot pattern with a laser beam having a predetermined power strength by the exposure device, an image patch detector for detecting a density level of the image patch formed on the photoreceptor, and a memory for storing data of laser power strengths with correlation to the detected density levels. With this structure, a controller controls laser power strength of the exposure device based on the correlated data stored in the memory and the density level detected by the image patch detector.

Image forming apparatus employing dots of a predetermined diameter

A development apparatus for developing a latent image formed on an image forming body with a developer so as to obtain a toner image. A developer conveyance unit conveys the developer, including a toner, to a development zone, between the developer conveyance unit and the image forming body, from an upstream side of the development zone in a conveyance direction to a downstream side thereof. A plate member having an electrode portion is positioned at the upstream side of the development zone, wherein a downstream end portion of the plate member is positioned in contact with the development zone. A power supply unit applies a first voltage, including a DC component and an AC component, to the developer conveyance unit so that an electric field is generated at the development zone. The power supply unit applies a second voltage, including a DC component, to the electrode portion of the plate member, and the plate member controls the electric field with the second voltage. The development apparatus satisfies: V.sub.AC &gt;.vertline.V.sub.DEN .vertline.-.vertline.V.sub.DC .vertline. when an amplitude of the AC component of the first voltage is defined as V.sub.AC (volts), the DC component of the first voltage is defined as V.sub.DC (volts), and the DC component of the second voltage is defined as V.sub.DEN (volts). The development apparatus satisfies: 10.multidot..vertline.Qt.vertline..multidot.d.sub.t .multidot.D.sub.1 &gt;V.sub.AC &gt;5.multidot..vertline.Qt.vertline..multidot.d.sub.t .multidot.D.sub.2 when a closest distance from the developer conveyance unit to the image forming body is defined as D.sub.1 (mm), a closest distance from the developer conveyance unit to the electrode portion is defined as D.sub.2 (mm), an average charge-to-mass of the toner is defined as Qt (.mu.C/g), and an average particle size of the toner is defined as dt (.mu.m).

Multi-color image forming apparatus having high developability without

A non-contact type of developing device for use in an image forming apparatus having an image forming body, includes a developer conveying body facing the image forming body in which a magnet body having a plurality of magnet poles are attached therein, to convey two-component developer in the form of a developer layer onto a developing area and a control electrode provided at the developing area or upstream of the developing area. The control electrode has an electrically insulating member which is in contact with or close to the developing layer, and an electrode to which a voltage is applicable is attached to the insulating member. The following condition is satisfied: ##EQU1## where D.sub.T represents a number of toner layers on the assumption that the toner particles passing through the developing area are filled most densely, D.sub.WS represents a conveying amount (mg/cm.sup.2) of the developer layer at the developing area on the developer conveying body, T.sub.c represents a toner concentration (%) in the developer, dt represents an average sphere equivalent diameter (.mu.m) of toner in the developer, .rho.t represents a toner density (g/cm.sup.3) in the developer, vs represents a circumferential speed (mm/s) of the developer conveying body at the developing area, and vp represents a circumferential speed (mm/s) of the image forming body at the developing area.

Developing device

Growing community of inventors

Hachioji, Japan

Toru Komatsu