Konica Minolta, Inc.

Yuusuke Mandai

Yasuyuki Inada

Kanji Nakayama

Yu Mukobayashi

Masato Kimura

Junji Kanda

Shinichi Yoshimoto

Shinji Ogawa

Kazuya Kitamura

An image forming apparatus includes a density detector that detects a density of a fog image formed on an image bearing member, a temporary determiner that determines a temporary fog margin which is a fog margin representing a difference between a developing bias to be applied to a toner bearing member and a charging bias to be applied to a charging device for charging the image bearing member based on a density detected by the density detector, and a corrector that corrects the temporary fog margin based on a change rate of a density detected by the density detector with respect to a change of a fog margin.

Image forming apparatus, fog margin determination method and non- transitory computer-readable recording medium encoded with fog margin determination program

An image formation apparatus includes a first electrode portion including a contact electrode and a counter electrode, a second electrode portion arranged as not being in contact with a recording medium, a first sensing unit configured to sense a first current which flows to the first electrode portion as a result of application of a voltage across the contact electrode and the counter electrode while the recording medium lies between the contact electrode and the counter electrode, a second sensing unit configured to sense a second current which flows from the charged recording medium to the second electrode portion, and a control unit. The control unit sets a transfer condition for transferring a toner image to the recording medium based on the first current sensed by the first sensing unit and the second current sensed by the second sensing unit.

Image formation apparatus

An image forming apparatus includes: a photoreceptor including a surface layer; a storage that stores a target value of a variation of a film thickness of the surface layer; and a hardware processor that acquires a variation of the film thickness in a first period within which the photoreceptor rotates a predetermined number of times, and sets a margin that is an amount of a portion for allowance with respect to a proper value of a parameter related to control of the photoreceptor, the margin being to be employed after the first period.

Image forming apparatus and method for controlling image forming apparatus

A developing device is equipped with a developing roller rotationally driven for developing an electrostatic latent image formed on a surface of an image supporting body with toner, a screw rotationally driven of which a ratio of number of rotations to number of rotations of the developing roller being rotationally driven is constant, and a processor. The processor is configured to detect toner density in developer by using a sensor installed facing the screw, during rotationally drive of the screw, and detect information indicating a rotational position of the developing roller, based on ripples which occur in the toner density detected.

Developing device which can detect rotational position of developing roller

A developing device includes a developer carrying member and first and second conveyance members. The first conveyance member conveys a developer in a first direction through a first conveyance path to the developer carrying member. The second conveyance member conveys the developer in a second direction through a second conveyance path included in a circulation path along with the first conveyance path. The second conveyance member has a helical second screw around a second shaft. The second conveyance path includes a developer replenishing port and a developer discharge port. The second screw is approximately constant in diameter in a second section being a portion extending a predetermined distance from an end of the discharge port in the second direction when viewed in a top view. The second screw conveys the developer at a lower speed in the second section than on an upstream side with respect to the second section.

Developing device and image forming apparatus

An image forming device includes: a charging unit configured to apply charging bias voltage to a charging member and charge a surface of an image carrying body; an exposure unit configured to expose the surface of the image carrying body, and form an electrostatic latent image; a developing unit configured to apply developing bias voltage to a developer carrying body, and develop the electrostatic latent image; and a control unit configured to control timing to start applying the developing bias voltage relative to timing to start applying the charging bias voltage, wherein the control unit performs control such that the larger an absolute value of the charging bias voltage is, the shorter an interval from timing to start applying the charging bias voltage to timing to start applying the developing bias voltage becomes, and such that the smaller the absolute value is, the longer the interval becomes.

Image forming device, control method for image forming device, and control program for image forming device

There are provided a developing device including a developing roller to develop an image carrier by use of a two-component developer and a developing bias power source, and an image forming apparatus using the developing device. The developing device further includes a variable resistance unit provided on a bias apply path to apply a bias from the developing power source to the developing roller, and a resistance controller to control a resistance value of the variable resistance unit based on a charge amount signal indicating a toner's charge amount in a developer layer on the developing roller. The resistance controller provides a low mode to lower the resistance of the variable resistance unit and a high mode to enhance the resistance. The low mode is set if the toner charge amount is low, and the high mode is set if the toner charge amount is high.

A damage amount determination device, which is used for an image forming device that forms an image on paper, includes an information acquisition unit that acquires information related to whiteness of the paper used for printing and a damage amount determination unit that determines an amount of damage, which is caused by the paper to a predetermined component of the image forming device when the paper passes through the predetermined component, based on the information related to the whiteness.

Damage amount determination device, image forming device, computer-readable recording medium storing damage amount determination program, and damage amount determination method

A developing apparatus that develops an electrostatic latent image on an image supporting body using developer including toner and carrier includes a circulation path where the developer circulates, a discharge path connected to the circulation path through which some of the developer passes, and a first recycle path connected to the discharge path and allowing some of the developer flowing into the discharge path to return to the circulation path. The discharge path includes a discharge opening for discharging the developer flowing into the discharge path, and a first return opening for connecting to the first recycle path. The first return opening is located on an upper side in a vertical direction with respect to the discharge opening and located on an upstream side in a pass-through direction of the developer flowing into the discharge path.

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Kyoto, Japan

Yuusuke Mandai