Konica Minolta Business Technologies, Inc.

Konica Minolta, Inc.

Hidetoshi Noguchi

Satoru Shibuya

Kazuyoshi Hara

Takahiro Kuroda

Yasunori Nakayama

Hiroaki Umemoto

Hisashi Murata

Masanori Kawada

Kazuyoshi Ota

Shinya Tokutake

Hideo Yamaki

Yasuo Tanaka

Tomohide Mori

Futoshi Okazaki

Hideji Higashimura

Toshiaki Shima

Kazutoshi Kobayashi

Yohei Ito

Tomohisa Yoshida

Kazuya Kitamura

Ryohei Matsuo

Shinichi Yoshimoto

Kazuki Shimizu

Takahiro Kudora

An image forming apparatus includes a developer that forms a toner image on an endless belt that is suspended over outer portions of a plurality of rollers, a driver that rotates at least one driving roller out of the plurality of rollers, a position adjustment mechanism that corrects relative positions of the plurality of rollers relative to one another, and a hardware processor, wherein the hardware processor controls the position adjustment mechanism to correct a relative position between the belt and the driving roller with tension applied to the belt being a second tension smaller than a first tension that is applied in a developing state in which a toner image is formed on the belt by the developer.

Image forming apparatus, belt adjustment method and non-transitory computer-readable recording medium encoded with belt adjustment program

An image formation apparatus includes: an image carrier having a surface on which a toner image is formed; a transfer roller cooperating with a surface of the image carrier to form a nip at a first position in a direction in which the image carrier rotates; a discharging member provided at a second position downstream of the nip in a direction in which the transfer roller rotates; a first power supply that applies a first voltage opposite in polarity to toner to the transfer roller to transfer the toner image to a recording medium when the recording medium is inserted in the nip; and a second power supply that applies a second voltage identical in polarity to the toner to the discharging member to cause an electric discharge to electrically charge the toner on the surface of the transfer roller to electrically attract the toner to the transfer roller.

Image forming apparatus including a second power supply that applies a voltage with a same polarity as a toner to a discharging member to charge toner on a secondary transfer roller

A magnet roller includes a magnet portion for generating magnetic force such that a plurality of peaks are formed in a magnetic force distribution. The magnet portion includes a plurality of magnetic poles. A cross section of the magnet portion includes a portion in which a distance from an axial center of the magnet portion to an outer edge of the magnet portion continuously changes in the circumferential direction. The magnetic force on a surface of a developing sleeve at a position corresponding to each of the plurality of magnetic poles is determined by (i) a distance from each of the plurality of magnetic poles to the developing sleeve in a radial direction of the developing sleeve and (ii) a magnitude of magnetic force in each of the plurality of magnetic poles. The distances from the plurality of magnetic poles to the developing sleeve in the radial direction are different.

Magnet roller, developing roller, developing device, and image forming apparatus

An image forming apparatus includes: an image carrier that rotates while carrying a toner image; an image former that forms the toner image; a transfer roller that transfers the toner image to a recording medium; and a bias voltage applier that applies a voltage to the transfer roller, wherein the image former forms transfer images and forms a patch image with toner between a first transfer image and a second transfer image, and the bias voltage applier applies a first voltage having a polarity opposite to a charge polarity of the toner to the transfer roller, applies a second voltage having the polarity opposite to the charge polarity of the toner and larger than the first voltage to the transfer roller, and applies a third voltage having the polarity opposite to the charge polarity of the toner and smaller than the second voltage to the transfer roller.

Image forming apparatus

An image forming apparatus includes an image former which forms an image on an image carrying member with toner stored in a storage, a toner supplier which supplies toner to the storage by driving a conveyance member, a density measurer which causes the image former to form an image having a predetermined density at a predetermined timing and measures density of the formed image, a corrector which corrects a driving amount of the conveyance member based on the density measured by the density measurer, and a changer which changes a timing when the density measurer measures the density in response to an event that a predetermined condition is satisfied.

Image forming apparatus which determines a toner supplying amount based on predicted toner consumption and predicted density of stored toner, toner supply method, and non-transitory computer-readable recording medium encoded with toner supply program

An image forming apparatus has an image carrier that carries a toner image; a transfer member that is opposed to the image carrier, a transfer voltage being applied to the transfer member so that the toner image is transferred from the image carrier to a print medium passing between the transfer member and the image carrier; a first voltage application device that applies the transfer voltage to the transfer member; a separation member to which a separation voltage is applied so that the print medium is separated from the image carrier; a second voltage application device that applies the separation voltage to the separation member; a sensing device that senses an image density of the toner image; and a control section that controls a magnitude of the separation voltage based upon the image density of the toner image.

Image forming apparatus with controlled separation voltage and transfer voltage

An image forming apparatus having: an image supporting member; an electrostatic latent image forming section; and a developing device. In the developing device, a supply member receives toner, polish and antifriction at a supply part. The supply member supplies the toner, the polish and the antifriction to a developing roller while conveying the toner, the polish and the antifriction in a predetermined direction along a rotation axis of the image supporting member. A developing roller develops an electrostatic latent image by supplying the toner, the polish and the antifriction to the image supporting member. A toner patch is formed on the image supporting member, in a facing area capable of facing the developing roller, such that the amount of toner adhering to the image supporting member decreases with increasing distance in the predetermined direction from the supply part. A cleaner removes the toner patch from the image supporting member.

Image forming apparatus with a controller for forming a toner patch

An image forming apparatus includes an image carrier configured to carry a toner image. A transfer unit is configured to transfer the toner image on the image carrier onto a recording sheet. A fixing unit is configured to fix the toner image transferred at the transfer unit onto the recording sheet. Through a conveyance path, the recording sheet is conveyed from the transfer unit to the fixing unit. A conveyance guide member is disposed in the conveyance path on an image formation surface side of the recording sheet. A fan is configured to send air from the transfer unit to the conveyance path toward a gap defined between the conveyance guide member and the transfer unit so as to form a flow of air in the conveyance path from an upstream side to a downstream side in a conveyance direction of the recording sheet.

Image forming apparatus including fan to generate air flow in conveyance path in sheet conveyance direction

An image forming apparatus having: an image support that supports a toner image; a transfer member adapted to sandwich with the transfer member and the image support; a voltage application unit that applies a transfer bias voltage to the transfer member; a current detecting unit that detects transfer current flowing from the voltage application unit to the transfer material after transfer processing on the transfer material starts; and a control unit that sets an upper limit of transfer current on the basis of a value of the transfer current detected by the current detecting unit, and thereafter further acquires a transfer current value from the current detecting unit to control a transfer bias voltage generated by the voltage application unit, such that the transfer current value during transfer does not exceed the upper limit.

Image forming apparatus having transfer bias control

An image forming apparatus having: a toner image carrier; a transfer member; a transfer voltage applying device which applies a bias voltage to the transfer member; a voltage controller which performs constant voltage control on the transfer voltage applying device; a transfer contribution current detecting device; an antistatic member for removing static electricity from the record medium after transfer of a toner image; and an antistatic voltage applying device which applies an AC voltage to the antistatic member. The transfer contribution current detecting device measures current values during a current detection time, which corresponds to an integral multiple of a period of the AC voltage applied to the antistatic member, and detects a transfer contribution current value from the measured values, and the voltage controller controls the bias voltage applied to the transfer member based on the transfer contribution current value.

Brush rollers rotate in a direction indicated by an arrow while being in contact with an image formation surface to remove toner remaining on the image formation surface from an intermediate transfer belt. The brush rollers each mainly include a rotational shaft and a brush. The brush rollers face the intermediate transfer belt with brush winding directions being opposite from one another. The brush rollers rotate in the direction indicated by the arrow. Thus, seams of the brush rollers can be prevented from being in contact with the same portion on the image formation surface of the intermediate transfer belt.

An image forming apparatus includes an image carrier to carry a toner image; a driving unit to drive the image carrier to rotate; a transfer unit to transfer the toner image at a transfer position; a cleaner at a cleaning position to remove toner remaining on the image carrier after transfer; an obtaining unit to obtain information indicating a likelihood of the remaining toner adhering to the image carrier; a judging unit to judge whether or not the likelihood is equal to or lower than a predetermined value; and a controller to control the driving unit (i) to stop driving the image carrier before a rear end of an area of the image carrier on which the toner remains reaches the cleaning position, when the judging unit judges affirmatively, and, (ii) to stop driving the image carrier after the cleaner removes the remaining toner, when the judging unit judges negatively.

Image forming apparatus and method for stopping driving image carrier

An image forming apparatus having an image carrier that carries a toner image; an opposed member that is provided so as to be opposed to the image carrier; an application device that applies a bias to the opposed member; and a control device that controls the application device to apply a first bias and thereafter a second bias to the opposed member so as to remove toner from the opposed member. The first bias has an absolute value that is large enough to cause discharge from the opposed member into air. The second bias has an absolute value that is too small to cause discharge from the opposed member into the air, and has a reverse polarity to the first bias.

An image forming apparatus is for transferring a toner image on an image carrier onto a transfer medium, and thermally fixing the toner image by a fixing device, and comprises a cleaner removing residual toner on the image carrier. The apparatus: acquires information relating to a distribution of a density of the residual toner at each position within a section on the image carrier at an end of an image forming job, the section extending from the transfer position to immediately before a cleaning position; determines, based on the information, whether or not the density of the residual toner at the transfer position exceeds a corresponding threshold density pertaining to occurrence of fusion of the residual toner; and causes, if determining negatively, the drive unit to stop when the image forming job is completed and the residual toner at the transfer position reaches a predetermined position within the section.

An image forming apparatus comprises: a rotatable image carrier operable to carry a toner image on a surface thereof; a transfer part operable to electrostatically transfer the toner image carried on the surface of the image carrier, onto a transfer material; a cleaning member that is in contact with the surface of the image carrier and that is operable to clean toner remaining on the surface of the image carrier after transfer by the transfer part; and a voltage supplier operable to apply, to the cleaning member, a bias voltage that is for cleaning the surface of the image carrier and that has a polarity opposite to a normal charging polarity of the toner. Here, application of the bias voltage by the voltage supplier starts before rotation of the image carrier starts, and when Vr&#x3e;0, 0&#x3c;Vc&#x3c;Vr, and when Vr&#x3c;0, Vr&#x3c;Vc&#x3c;0, where Vc is a value of the bias voltage from a start of the application until a start of the rotation, and Vr is a reference value which is a value of the bias voltage from the start of the rotation onward.

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Tahara, Japan

Hidetoshi Noguchi