Kyocera Document Solutions Inc.

Minolta Company, Ltd.

Eiji Gyotoku

Akihiro Watanabe

Tamotsu Shimizu

Masahito Ishino

Jun Nakai

Minoru Wada

Akifumi Yamaguchi

Yu Sasaki

Ryo Taniguchi

Akihiro Kawasaki

Tetsumaru Fujita

Koji Kuramashi

Ichiro Demizu

Yasuhiro Tauchi

Hiroshi Goto

Yoshihiro Fukuhata

Koji Uno

Norio Kubo

Masaru Hatano

Takahiro Okubo

Yoichi Fujieda

Yasushi Imanishi

Hiroaki Umemoto

A development device includes a development container, a first conveying member, a second conveying member, a toner concentration sensor, and a developer carrier. The toner concentration sensor is arranged at a wall portion of the first conveying chamber in which the first conveying member is arranged. The first and second conveying members are equal to each other in outer diameter and shaft diameter, the outer diameter being 2.3 times the shaft diameter or more but 3.0 times the shaft diameter or less. Where D represents the shaft diameter of the first conveying member, L represents an axial length of the first conveying member, and K represents a distance of a center position of a sensing surface of the toner concentration sensor from a downstream end of the first conveying chamber in the first direction, formula (1) is satisfied: 500<(L×K)/D<2500 (1).

Developing device and image forming apparatus including developer conveying member and toner concentration sensor

A development device includes a development container, a first conveying member, a second conveying member, a toner concentration sensor, and a developer carrier. The first and second conveying members are equal to each other in outer diameter and shaft diameter, the outer diameter being 1.3 times the shaft diameter or more but 1.6 times the shaft diameter or less. Where L represents an axial length of the first conveying member, K represents a distance of a center position of the sensing surface of the toner concentration sensor from a downstream end of a first conveying chamber of the development container in the first direction, P represents a pitch of the conveying blade of the first conveying member, and R represents a rotational speed of the first conveying member, formula (1) is satisfied: 30000<(P×R×L)/K<45000 (1).

Image forming apparatus including developer conveying member and toner concentration sensor

A toner conveyance device includes a vertical conveyance portion, a horizontal conveyance portion, a conveyance member, and a loosening member. The vertical conveyance portion conveys a toner or developer conveyed therein through an entry port connected to a main-body-side conveyance path by causing the toner or developer to fall vertically. The horizontal conveyance portion is connected to a lower end of the vertical conveyance portion and conveys the toner or developer in a horizontal direction by using the conveyance member. the loosening member is arranged at a first position below a connection portion between the main-body-side conveyance path and the entry port and at a second position protruding upward beyond the connection portion. A toner loosening mode is executable in which the toner or developer is fed into the vertical conveyance portion so as to cause the loosening member to reciprocate at the second position.

Toner conveyance device that can execute toner loosening mode, and developing device and image forming apparatus including the same

A toner conveyance device includes a vertical conveyance portion, a horizontal conveyance portion, a conveyance member, and a loosening member. The vertical conveyance portion conveys a toner or a developer containing the toner conveyed therein through an entry port connected to a main-body-side conveyance path by causing the toner or the developer to fall vertically. The horizontal conveyance portion is connected to a lower end of the vertical conveyance portion and conveys the toner or the developer in a horizontal direction by using the conveyance member arranged in the horizontal conveyance portion. The loosening member is arranged so as to be movable between a first position below a connection portion between the main-body-side conveyance path and the entry port and a second position protruding upward beyond the connection portion and reciprocates in a vertical direction at each of the first position and the second position.

Toner conveyance device, and developing device and image forming apparatus including the same

An image forming apparatus includes a developer information acquisition unit. The developer information acquisition unit performs a developer deterioration information acquisition operation. In the developer deterioration information acquisition operation, the developer information acquisition unit acquires a tilt of a measurement straight line representing the relationship between the change amount of the frequency in a first measurement toner image forming operation and the density change amount of the measurement toner image based on the change amount of the frequency in the first measurement toner image forming operation and a result of detecting density of the measurement toner image in a density detecting unit, and acquires a toner charging amount based on the acquired tilt of the measurement straight line and the reference information in the storage unit so as to acquire information relating to deterioration of developer based on the acquired toner charging amount.

Image forming apparatus with developer information acquisition unit that acquires information relating to deterioration of developer based on an acquired toner charging amount

A developing device includes a developing roller, a conveyor roller, a developer stirring unit and a development bias applying unit. The developing roller is arranged to face a photoconductive drum at a predetermined developing position and supplies the toner. The conveyor roller is arranged to face the developing roller at a predetermined facing position and supplies the developer to the developing roller. The development bias applying unit applies development biases to the first sleeve of the developing roller and the second sleeve of the conveyor roller during a developing operation of developing the electrostatic latent image on the photoconductive drum with the toner. The development bias applying unit applies the development biases such that a shifting electric field to move the toner on the first sleeve of the developing roller toward the second sleeve of the conveyor roller is formed at the facing position during the developing operation.

Developing device and image forming apparatus provided with same

A developing device includes a housing, a developer carrier, a conveying member and a surface layer. The conveying member conveys the developer in the first conveying direction and supplies the developer to the developer carrier. The surface layer is arranged on the circumferential surface of the developer carrier and formed on a surface of a predetermined cylindrical base member. The surface layer is formed by an immersion method of immersing the base member in an immersion tank so that an axial direction of the base member extends along a vertical direction. A lower end side of the base member at the time of the immersion is arranged in a downstream side of the housing in the first conveying direction and an upper end side of the base member at the time of the immersion is arranged in an upstream side of the housing in the first conveying direction.

A developing device includes first and second stirring/transporting members, a developer feeding member, and a developer container that accommodates those components. The first and second stirring/transporting members stir and transport developer. The developer feeding member feeds developer to the first stirring/transporting member. In the developer container, a feeding port through which developer is fed from the developer feeding member to the first stirring/transporting member is formed. The developer feeding member includes a rotary shaft, a first transport blade which stirs and transports developer, a blocking portion which protrudes substantially perpendicularly to the rotary shaft and blocks the developer transported by the first transport blade in a first direction, and a paddle which feeds the developer from a developer supply passage to a first transport chamber.

Developing device including a developer feeding member having a rotary shaft, a first transport blade for stirring and transporting developer, a blocking portion for blocking the developer, a paddle extending parallel to the rotary shaft, and a second transport blade for transporting the developer in the opposite direction to the first transport blade, and image forming apparatus therewith

An image forming apparatus includes a heating element, an interior temperature/humidity detection section, and a controller. The heating element is conducted during connection of the image forming apparatus to an external power source to heat an image bearing member. The interior temperature/humidity detection section detects temperature and humidity in the interior of the image forming apparatus. The controller performs a refresh operation when a relative humidity calculated on the basis of the temperature and humidity detected by the interior temperature/humidity detection section immediately after the image forming apparatus is connected to the external power source is higher than the preset value. The refresh operation is an operation for supply of developer from a development device to the image bearing member and for polish of the surface of the image bearing member with the use of a polishing member.

Image forming apparatus and image deletion reducing method

A developing device includes a developing container, a first agitating feeding member, a second agitating feeding member, a first developer delivery portion, a second developer delivery portion, and a toner sensor. The developing container includes a first transport path and a second transport path. The first agitating feeding member and the second agitating feeding member agitate and feed developer. The first developer delivery portion delivers the developer from the first transport path to the second transport path. The second developer delivery portion delivers the developer from the second transport path to the first transport path. The toner sensor is disposed at a part of the first transport path near the first developer delivery portion. A ceiling height of a part of the first transport path facing the first developer delivery portion is larger than a ceiling height of other part of the first transport path.

Developing device and an image forming apparatus including the same

An image forming apparatus includes an image bearing member, a developing unit, a cleaning unit, and a heating element. The heating element for heating the image bearing member includes: a substrate having a length corresponding to an entire region of the image bearing member in a longitudinal direction of the image bearing member; and a plurality of resistor chips mounted on the substrate. At least either resistance values or spacing intervals of the resistor chips vary in a longitudinal direction of the substrate to ensure that the surface temperature distribution of the image bearing member heated by the heating element is uniform.

Image forming apparatus

An image forming apparatus includes an image bearing member, a charging unit, a laser scanning unit, a developing unit, a transfer member, a recording medium conveyance path, a cleaning unit, and a heating element. The recording medium conveyance path includes a resin member that forms a conveyance surface. The resin member has a concave portion at a location closer to the transfer member than to the image bearing member. The heating element for heating the image bearing member is accommodated in the concave portion. The heating element is disposed downstream from the contact point between the image bearing member and the transfer member in the conveyance direction in which a recording medium is conveyed through the recording medium conveyance path. The developing unit is located upstream from the contact point between the image bearing member and the transfer member in the conveyance direction of the recording medium.

Image forming apparatus having a drum heater

A developing device of the present disclosure has a developer bearing member, a toner bearing member, a bias controller. With respect to a duty ratio of the alternating current bias of a polarity with which the toner is moved from the developer bearing member to the toner bearing member, a second duty ratio that is a duty ratio of the collection bias is set to be smaller than a first duty ratio that is a duty ratio of the development bias. When a transition is made from the development operation to the collection operation, in a state where the developer bearing member and the toner bearing member are being driven to rotate, the bias controller performs control so that the bias applier applies the alternating current bias having a third duty ratio that is smaller than the first duty ratio and larger than the second duty ratio.

Developing device and image forming apparatus including same

The present invention relates to a developing device for developing images formed on an image carrier. The device is capable of regulating toner amount such that the amount of toner conveyed by the toner control to the developing area is reduced, as well a appropriately changing the carrier.

Developing device comprising a regulation member having at least one bent part

A developing apparatus with a developing roller for conveying toners held on its surface to a developing area opposite to an image carrying member, the surface of the developing roller being moved upward from below in the developing area; a regulating member for regulating an amount of the toners to be conveyed to the developing area by the developing roller; a plate-shaped charging member for charging the toners; and a voltage applying device for applying a voltage to the charging member.

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Osaka, Japan

Eiji Gyotoku