Konica Minolta Business Technologies, Inc.

Konica Minolta, Inc.

Tomohiro Kato

Junji Murauchi

Megumi Minami

Masato Kimura

Naotoshi Kawai

Hiroaki Takada

Yuusuke Okuno

Hisashi Murata

Tomoyuki Imura

Kazuki Kobori

Tomo Kitada

Hirohisa Shirai

Eri Kusano

Kazuhiro Saito

Narutaka Yoshida

Toru Hayase

Tetsuya Kagawa

Tomohisa Yoshida

Dai Suwama

Kohei Hayashi

Wataru Onoda

An image forming apparatus includes: an image carrier that carries a toner image; a cleaning unit that collects a toner on the image carrier; and a hardware processor that controls the cleaning unit, wherein the cleaning unit includes a first cleaner brush and a second cleaner brush that remove the toner from the image carrier, and the hardware processor applies bias voltages having opposite polarities to the first cleaner brush and the second cleaner brush, and determines whether life is ended with respect to each of the first cleaner brush and the second cleaner brush.

Image forming apparatus and control method of adjusting cleaner brush polarities of cleaning unit of image forming apparatus

An image forming apparatus has: an image supporting member, a charger, a power source unit, an amperometric detector, and a processor. The power source unit applies a plurality of charging voltages, which includes alternating voltages respectively, to the charger sequentially while no print medium is fed. The alternating voltages have different peak-to-peak voltages for a forward discharge range and different peak-to-peak voltages for a reverse discharge range, respectively. The amperometric detector detects values of alternating current flowing in the charger during application of the charging voltages. The processor derives characteristic lines of alternating current value with respect to alternating voltage for the forward discharge range and for the reverse discharge range, respectively, from the values detected by the amperometric detector. The processor derives a peak-to-peak voltage to be used in a process in a different way depending on a difference in slope between the characteristic lines.

Image forming apparatus with a proximity charger

An image forming apparatus has: an image supporting member; a charger in proximity to the image supporting member; a power source unit configured to apply charging voltages to the charger sequentially, the charging voltages including alternating voltages having different peak-to-peak voltages, respectively; an amperometric detector configured to detect values of alternating currents flowing in the charger during application of the charging voltages; and a processor configured to carry out a first charging voltage determination process or a second charging voltage determination process requiring a shorter time than the first charging voltage determination process selectively based on a detection result of the amperometric detector. The processor carries out the first charging voltage determination process or the second charging voltage determination process selectively in accordance with a difference between an ambient temperature at a previous time of carrying out the first charging voltage determination process and a current ambient temperature.

Image forming apparatus

An image forming apparatus includes an image forming unit, a sheet conveying unit, a TOD (Top of Data) control module for instructing the image forming unit to start generation of a toner image, a timing roller driving module for instructing the sheet conveying unit to start driving of the timing roller, an image synchronization module designed depending on the sheet conveying unit and the image forming unit, and a sheet information module for generating an image synchronization identifier for designating a pattern of image synchronization control related to printing of the toner image on the sheet, depending on a type of the sheet designated. The image synchronization module is activated when the formation of the toner image on the sheet has become possible, and activate each of the TOD control module and the timing roller driving module, with a relative time lag based on the image synchronization identifier.

A developing device having: a guide member creating a guide channel for guiding the developer being fed thereto while being supported on the developer support; and a regulating member regulating the amount of the developer that has passed through the guide channel, the guide member further creates a reflux channel in a gap from an inner surface of the housing, the reflux channel is connected to the guide channel via a communication channel such that the developer regulated by the regulating member returns toward an upstream end of the guide member, the upstream end of the guide member is disposed in a position opposed to the position where the magnetic flux density of the catch pole peaks, and the magnet assembly further includes a feeding pole that is disposed downstream of the catch pole and upstream of the developing pole, so as to be opposed to the guide channel.

Developing device and image forming apparatus including same

A development device having: a main unit having formed therein a first space and a second space extending in a first direction perpendicular to a vertical direction, a first communicating portion and a second communicating portion that allow the first space and the second space to communicate with each other at both ends in the first direction; a first stirring member that extends in the first direction within the first space; a second stirring member that is positioned within the first space between the first stirring member and the second space and extends in the first direction; a conveyance member that extends in the first direction within the second space; and a developer support member that extends in the first direction within the second space.

Development device

An image forming apparatus selects a screen from a plurality of screens corresponding respectively to a plurality of gradation values and each including a pattern in which a first region to which toner is to adhere and a second region to which toner is not to adhere are defined, and forms a toner image on media. The apparatus includes a storage device for storing a minimum formable distance between first regions or second regions adjacent to each other, and a controller calculating a distance between the first regions or second regions adjacent to each other in the screen and, when the distance of the region of a screen that corresponds to a gradation value of an input image and has a first pattern is smaller than the minimum formable distance, selecting a screen corresponding to the gradation value of the input image and having a second pattern.

Electrophotographic image forming apparatus that selects a screen from a plurality of screens based on distance between toner adhesion or non-adhesion regions

A first screen group and a second screen group are stored in an image forming apparatus. In the first screen group, the first region expands with increasing gradation value based on a first rule. In the second screen group, the first region expands with increasing gradation value based on an independent second rule different from the first rule. A screen selector relocates a first portion and a second portion such that the first portion and the second portion are joined by a second region that is not a toner adhesion control target, when the first portion and the second portion are adjacent as a result of the selection of the screen in each unit region of the input image. The first portion includes the screen included in the first screen group, and the second portion includes the screen included in the second screen group.

Image forming apparatus in which intermediate gradation reproducibility is enhanced

The present invention provides a developing apparatus capable of predicting how much carrier is accumulated inside a developer tank beyond the discharge level of a trickle discharging mechanism in the case that images having high coverage ratios are printed out continuously in a trickle developing apparatus that uses a two-component developer. The developing apparatus, having stirring members for conveying and stirring a developer-tank-contained developer and a developer holder, comprises a developer replenishing tank; a discharging mechanism for discharging an excessive amount of the developer-tank-contained developer outside the developer tank when the amount of the developer-tank-contained developer inside the developer tank has exceeded a predetermined amount; and calculating device for calculating the amount of the carrier existing inside the developer tank, and judges using the calculating device that the integrated value of carrier obtained by integrating the amount of the carrier existing inside the developer tank is likely to exceed a predetermined excessive accommodation amount of carrier.

Developing apparatus and image forming machine

The present invention provides a developing device and an image forming apparatus capable of preventing a developer from being discharged excessively using simple configurations in the case that a trickle developing device that uses a two-component developer is in a tilted state. The developing device having stirring members for conveying and stirring a developer and a developer holder, comprises a developer replenishing tank for replenishing the developer to a developer tank and a trickle discharging mechanism, wherein the conveying passages thereof include an upper conveying passage, a lower conveying passage, a first communicating passage for connecting the downstream side of the upper conveying passage to the upstream side of the lower conveying passage, and a second communicating passage for connecting the downstream side of the lower conveying passage to the upstream side of the upper conveying passage, and also include a circulation passage through which the developer circulates using the upper conveying passage, the first communicating passage, the lower conveying passage and the second communicating passage; the discharging mechanism is disposed in the downstream end section of the upper conveying passage; the bottom face on the downstream side of the upper conveying passage is positioned above the bottom face on the upstream side of the lower conveying passage; and the first communicating passage is disposed obliquely downward with respect to the horizontal plane.

Developing device and image forming apparatus

The development apparatus that develops an electrostatic latent image formed on an image carrier comprises: a developer roller operable to carry toner on a circumferential surface thereof and develop the electrostatic latent image using the toner; a supply roller operable to perform toner supply to the developer roller; a voltage applier operable to apply a bias voltage Vto the developer roller and apply a bias voltage Vto the supply roller; and a controller operable to control the voltage applier in a toner compulsive consumption mode so that a value obtained by subtracting an average Sof the bias voltage Vper unit time from an average Sof the bias voltage Vper unit time indicates the same polarity as a normal charging polarity of the toner. Here, the toner compulsive consumption mode performs development to compulsively consume the toner carried on the circumferential surface of the developer roller.

Development apparatus, image forming apparatus and image forming method for consuming degraded toner

In a trickle developing device that uses a two-component developer, a simple configuration is adopted to prevent carrier from being discharged without being used. The developing device having stirring members for conveying and stirring developer and a developer holder, comprises a developer replenishing tank for replenishing developer to a developer tank and a trickle discharging mechanism, wherein the initial filling amount of the developer-tank-contained developer to be filled initially into the developer tank is less than a full filling amount.

Developing device, image forming apparatus and method for filling developer

A developing device has a bearing member that can bear a toner, a storing chamber for storing the toner, a waiting chamber disposed below the storing chamber for receiving the bearing member that can be filled with the toner and a buffer chamber positioned between the storing chamber and the waiting chamber for storing the developer material. A first horizontal connecting path connects upper portions of the storing and buffer chambers, and two second connecting paths connect lower portions of the buffer chamber and the waiting chamber. A feed member feeds toner from the storing chamber through the first connecting path into the buffer chamber. A first conveying member in the buffer chamber conveys the toner from one of the connecting paths to the other of the connecting paths, and a second conveying member in the waiting chamber conveys the toner within the waiting chamber in the opposite direction.

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Okazaki, Japan

Tomohiro Kato