Konica Minolta Business Technologies, Inc.

Konica Minolta, Inc.

Konica Corporation

Konami Corporation

Nobuyasu Tamura

Hiroshi Morimoto

Yutaka Miyasaka

Kazutoshi Kobayashi

Mineyuki Sako

Kimio Nishizawa

Hayato Mizue

Masatoshi Satoh

Masanori Suganuma

Misao Yamanaka

Kosaku Noda

Satoshi Motegi

Shigetaka Kurosu

Eiji Nomura

Hideo Yamaki

Yusuke Nishisaka

Hajime Kawakami

Keiki Katsumata

A fixing device includes: a fixer that includes a heater controlled and lighted on the basis of a detection result of a temperature sensor, and melts and fixes an unfixed toner on a recording medium, using heat of when the heater is lighted; a lighting rate acquirer that acquires a first lighting rate of the heater after jam recovery and a second lighting rate of the heater before jam occurrence in a case where a jam of the recording medium occurs at a fixing nip position of the fixer; and a determiner that compares the first lighting rate with the second lighting rate, and determines whether the recording medium remains between the temperature sensor and the heater according to a result of the comparison.

Fixing device and image forming apparatus

An image forming apparatus includes a fixing member, a blowing section, and a hard ware processor. The blowing section generates airflow toward the fixing nip, and the airflow is used for separating a sheet from the fixing member. The hardware processor performs a control of the blowing section so that airflow amounts of the blowing section toward the fixing nip are different in an axial direction of the fixing member and part of the airflow flowing from the blowing section toward a non-sheet-passing region of the fixing nip is directed in the moving direction of the fixing member.

Image forming apparatus containing fixing member, blowing section, and hardware processor

An image forming apparatus includes a fixing member, a pressing member, a heating unit and a controller. The fixing member heats a toner image formed on a sheet. The pressing member presses the sheet onto the fixing member. The heating unit heats the fixing member. The controller controls the heating unit. The sheet is located at the fixing member in a first period and the sheet is not located at the fixing member and the fixing member is located between sheets in a second period. The controller controls the heating unit such that the heating unit heats the fixing member in a first heating pattern in which a heating period does not include the second period or in a second heating pattern in which a heating period includes the second period.

Image forming apparatus and computer readable medium storing program

An image forming device includes: an image forming unit configured to form an image on paper fed from a paper housing unit; a heater lighting control unit configured to determine, based on a temperature detected by a temperature detecting unit in a fixing unit at least including a fixing roller that holds and carries the paper on which the image is formed, a pressure roller arranged in pressure-contact with the fixing roller, a heater that heats the fixing roller, and the temperature detecting unit arranged in a vicinity of the heater, a lighting rate of the heater; and a paper determination unit configured to determine information related to the paper based on lighting rates of the heater in standby and in printing which rates are determined by the heater lighting control unit.

Image forming device and paper determining method

An image forming apparatus including a heating rotating body (first body) and a pressurizing rotating body (second body) disposed in a pressure contact state, and commencing image forming when a temperature of the first body reaches a predetermined temperature lower than a fixing temperature. The apparatus acquires a value indicating a temperature of the second body upon commencement of warm-up, and when the value is below a threshold value, heats the first body until the temperature thereof reaches the fixing temperature while rotating the two bodies at a first speed, and when the value equals or exceeds the threshold value, heats the first body until the temperature thereof reaches the predetermined temperature while rotating the two bodies at a second speed slower than the first speed and further heats the first body until the temperature thereof reaches the fixing temperature while rotating the two bodies at the first speed.

Image forming apparatus

A cleaning device for cleaning a belt member, includes a cleaning blade; a removing member coming in contact with the surface of the belt member so as to remove foreign matter adhering on the surface of the belt member; and a contact pressure changing section to change a contact pressure between the removing member to the belt member, wherein, when the contact pressure between the removing member and a region of the belt member corresponding in position to a toner image to be not transferred to a paper sheet is made P, and the contact pressure between the removing member and a region of the belt member corresponding in position to a toner image to be transferred to a paper sheet is made P, the contact pressure changing section changes the contact pressure to satisfy the conditional formula: (PP).

Cleaning apparatus and image forming apparatus

An image forming apparatus includes an image carrier, a developer carrier arranged to face the image carrier to form a developing nip portion, which carries developer containing toner for developing a latent image formed on the image carrier, a developing unit having a developer regulating member that regulates a thickness of a layer of the carried developer, an air sending duct having an air sending path provided on the developing unit, which sends air to the developer carrier and a suction duct having a suction path provided on the developing unit, which sucks air from the developer carrier. The developer regulating member is arranged on an air sending duct side, and the air sending and suction paths are arranged to be connected by forming a space surrounded by a surface of the developer carrier, the developer regulating member and a wall forming the suction path.

An image forming apparatus having an image carrier for forming an electrostatic latent image and a developing unit for developing the electrostatic latent image with a two-component developing agent, the developing unit includes: a developing agent carrier for developing the electrostatic latent image to form a visible image, having inside thereof a development main magnetic pole for forming a bristle of a magnetic brush; and a plurality of magnetic poles for conveying the developing agent, wherein the developing unit performs a counter type contact developing method, and wherein, a development area is formed so that, a contact width of the bristle of the magnetic brush is 70% or less with respect to a development width, and a center position of the contact width is positioned on an upstream side with respect to a center position of the development width in a rotation direction of the image carrier.

Image forming apparatus with developing unit having a magnetic brush

An image forming apparatus includes a fog controller to control a fogging level of a toner image carrier by adjusting a fog control parameter on the basis of the fogging level detected by a fogging level detection section and the target fogging level stored in a memory section. While varying a value of the fog control parameter, the fog controller makes a detection pattern forming section to form a series of detection patterns between toner images for each page on the toner image carrier, makes the fogging level detection section to detect each of fogging levels of the series of detection patterns, determines a target fog control parameter value on the basis of each fogging level of the series of detection patterns detected and the target fogging level stored, and adjusts the fog control parameter on the basis of the target fog control parameter value.

Image forming apparatus and fog control method

High quality images are provided by controlling development conditions based on the proportion of the toner layer potential difference, which a difference between the toner layer potential and electrostatic latent image potential, to the development contrast potential difference, which is a difference between the development bias potential and electrostatic latent image potential. The control section for controlling a development power supply controls the voltage supplied by the development power supply, based on the toner layer potential difference and development contrast potential difference in the development section. This arrangement ensures formation of high-quality images free from concentration of toner.

Image forming apparatus with control section to control development bias potential

There is described an image forming apparatus, which makes it possible to suppress quality degradation of an image on the basis of a developing electric current profile without optically detecting density of a patch image. The image forming apparatus includes: a developing current detecting sensor to detect a developing current; and a control section that conducts consecutive operations of: creating a detecting-use image pattern for detecting a developing characteristic, by aligning a plurality of image patterns, which are different from each other in density; forming a latent image of the detecting-use image pattern onto the photoreceptor element; finding a developing electric current profile, which represents a transition of the developing electric current flowing during an operation of developing the detecting-use image pattern, from an outputted signal of the developing current; and changing an image forming condition, based on the developing electric current profile found by the finding operation.

An image forming apparatus includes: a toner image carrier which carries a toner image thereon; a recording medium selection information input section to which recording medium selection information is inputted to select a recording medium to which the toner image carried on the toner image carrier is transferred; a fog controller which sets a fog control parameter value to control a fogging level of the toner image carrier; and an image forming section which forms the toner image to be carried on the toner image carrier based on the fog control parameter set by the fog controller. The fog controller sets the fog control parameter value so that the fogging level of the toner image carrier when the recording medium selection information inputted corresponds to a coated sheet, is lower than that when the recording medium selection information inputted corresponds to a normal sheet.

Image forming apparatus with a fog controller

An image forming apparatus includes: a moving speed ratio change section which changes a circumferential speed ratio between a surface of a developer bearing member and a surface of an image carrier; and a memory section which stores a target value of fog toner. After the circumferential speed ratio has been changed by the moving speed ratio change section, a controller determines a fog control parameter based on comparing the value detected by the fog toner detection section with the target value stored in the memory section. After then, and the controller controls the moving speed ratio change section to return the circumferential speed ratio to the circumferential speed ratio prior to the change.

Image forming apparatus with moving speed ratio change section and image forming method including changing circumferential speed ratio

An image forming apparatus incorporating: an image forming body; and a developing unit having a developer carrier, a magnetic field generator, a developer restriction member, a first conveyer, and a second conveyer, wherein the magnetic field generator has: a main magnetic pole; pickup magnetic pole; and a strip-off magnetic pole, wherein the developing unit satisfies following conditions: (a) the second conveyer is a screw conveyer having an outer diameter within 24 mm-30 mm, rotating speed of 300-500 rpm, (b) the pickup magnetic pole is arranged at an angle of 25&#xb0;-60&#xb0; downstream with a line connecting a rotation centers of the developer carrier and the second conveyer, (c) the strip-off magnetic pole is arranged at 60&#xb0;-80&#xb0; upward with the line,(d) a transporting capability of the first conveyer is larger than that of the second conveyer.

This invention relates to an image forming apparatus including a developing unit which develops an electrostatic latent image formed on an image carrier by using a two-component developing agent containing polymerized toner. The developing unit includes a supply/convey member which conveys the two-component developing agent in the axial direction while agitating it and a toner density sensor which detects the toner density of the two-component developing agent. The toner density sensor is placed to be in a non-contact state with respect to the supply/convey member and oppose it with a gap of 0.8 mm or less. The diameter of the supply/convey member is set to 23 mm or more.

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Hachioji, Japan

Nobuyasu Tamura