Kyocera Document Solutions Inc.

Kyocera Documents Solutions Inc.

Yukari Ota

Takahisa Nakaue

Masahito Ishino

Yasuhiro Tauchi

Kotatsu Kawaguchi

Yoshimi Shimizu

Tomohiro Tamaki

Takashi Somete

Shinji Otani

Minoru Wada

Ikuo Makie

Yu Sasaki

Yuji Kamiyama

Ryo Yamada

An image forming apparatus includes an image carrier, a charger, an exposure device, a development device and a pressing mechanism. The developer carrier is pressed on the image carrier with a predetermined pressing force to form a nip area between the roller part and the image carrier. A roller part of the developer carrier has an Asker C hardness of 65&#xb0; or more and 73&#xb0; or less. When the pressing force is set to X (N) and a width of the nip area in a circumferential direction of the image carrier is set to Y (&#x3bc;m), 3.0&#x2264;X&#x2264;8.0 and 550&#x2264;Y&#x2264;700, and the following expressions (1) and (2) are satisfied, 

Image forming apparatus

An image forming apparatus includes an image carrier, a charger, an exposure device, a development device and a pressing mechanism. When a developer carrier and the image carrier are rotated in a state where a film is held in a development nip area and then a pulling force of the film is measured, a maximum value MAX, a minimum value MIN, and an average value X of the pulling force satisfy the expressions (1) and (2). When a development voltage applied to the developer carrier is set to Vdc, the surface potential of the image carrier is set to V0, and the surface potential of the image carrier after exposure is set to VL, the expressions (3) and (4) are satisfied.&#x2264;MAX&#x2264;1.5&#x2003;&#x2003;(1),0.5&#x2264;MIN&#x2264;&#x2003;&#x2003;(2),0&#x2212;&#x2265;2()&#x2003;&#x2003;(3) and&#x2265;100&#x2003;&#x2003;(4).

Image forming apparatus capable of suppressing a white void in an image and a cleaning failure in a non-magnetic one component development device

A development device includes a development housing, a development roller, a supply roller and a layer thickness regulating member. The development housing stores a nonmagnetic one-component toner. The development roller is formed by a cylindrical elastic body, and moves in a same direction as a rotational direction of a rotatable photosensitive drum at a development nip area while coming into contact with the photosensitive drum. The supply roller is formed by a cylindrical elastic body, and supplies the toner to the development roller and collects the toner from the development roller. The development roller has a surface free energy within a range of 5 mJ/mor more and 27 mJ/mor less.

Development device and image forming apparatus including the development device

A developing device includes a developing container, a first stirring member and a second stirring member, and a developing roller. The developing container includes a first stirring chamber, a second stirring chamber, and a communication portion. The first stirring member includes a reverse spiral vane that conveys a developer in a direction reverse to a circulation direction. An air discharge duct is formed on a wall portion of the first stirring chamber opposed to the reverse spiral vane and in an area excluding the communication portion and discharges air from the first stirring chamber to an outside of the developing container via an air discharge port at a distal end of the air discharge duct. A filtration portion is disposed in the air discharge duct adjacently to the air discharge port and restricts leakage of the developer through the air discharge port.

Developing device having air discharge duct and image forming apparatus including the developing device

A developing device of the present disclosure includes a developing container, a first stirring-conveyance member, a second stirring-conveyance member, and a developer carrier. The developing container includes a first conveyance chamber, and a second conveyance chamber arranged above the first conveyance chamber. The first stirring-conveyance member conveys a developer in the first conveyance chamber in a first direction, while stirring the developer. The second stirring-conveyance member conveys the developer in the second conveyance chamber in a second direction, while stirring the developer. The first stirring-conveyance member includes a plurality of spiral blades formed on an outer peripheral surface of a rotary shaft, and a reverse spiral blade which is arranged downstream of the spiral blades in the first direction and opposite in winding direction to the spiral blades. Downstream ends of the spiral blades in the first direction are located substantially equally distant from the reverse spiral blade.

Developing device and image forming apparatus including same

An image forming apparatus includes a photoreceptor, an exposure unit, a developing unit, and a control unit. The control unit sets the toner-layer-forming electric potential difference lower than an electric potential when forming the image on the print medium, forms a combined patch for calibration by the set toner-layer-forming electric potential difference for calibration, so as to adjust the developing-bias potential by measuring a print density of the formed combined patch. The combined patch includes a first patch and a plurality of second patches. The plurality of second patches have a width within a range of 0.2 mm to the predetermined value in the peripheral-velocity direction of the photoreceptor, extend with a length equal to or more than the predetermined value in the rotation-shaft direction of the photoreceptor, and are arranged at a predetermined interval in the peripheral-velocity direction of the photoreceptor.

Image forming apparatus and image forming method that ensure improved measurement sensitivity of patch density with optical sensor, and recording medium therefor

A developing device includes a developing roller, a toner supplying roller, a regulation blade, a casing, a toner receiver support member, a toner receiver member, and a vibration generator. The toner receiver member is disposed along a longitudinal direction of the toner receiver support member facing the developing roller, and has a toner receiving surface inclined downward from the image-carrier side toward the toner-supplying-roller side. The toner receiving surface is disposed to be inclined so as to rise from the toner-supplying-roller side toward the image-carrier side. The toner receiving surface has a plurality of grooves formed therein to be inclined to approach a center part of the toner receiving surface from each end side of the toner receiving surface in its longitudinal direction, from an edge of the toner receiving surface on the image-carrier side toward an edge of the toner receiving surface on the toner-supplying-roller side.

A developing device of the present disclosure includes a developing roller, a toner supplying roller, a regulation blade, a casing, a toner receiver support member, a toner receiver member, and a vibration generator. The toner receiver support member is disposed inside the casing so as to face the developing roller or the toner supplying roller between the regulation blade and an image carrier. The toner receiver member is disposed along a longitudinal direction of the toner receiver support member, and has a toner receiving surface that receives toner falling from the developing roller. The vibration generator vibrates the toner receiver member. At each end part of the toner receiving surface in its longitudinal direction, there is formed a thin-walled portion that is thinner in thickness than other parts of the toner receiving surface.

A developing device includes a toner carrying member, a developer carrying member, a layer thickness restricting portion, a rotation control portion, and a developer carrying member difference voltage control portion. The rotation control portion, when developing is not performed, causes the developer carrying member to rotate forwardly and then to rotate reversely. The developer carrying member difference voltage control portion, in the non-developing forward rotation state, sets a voltage of the developer carrying member that is based on a potential of the toner carrying member, to a voltage that is smaller than a first reference voltage that is set when the developing is performed. The non-developing forward rotation state is a state in which the developer carrying member rotates forwardly when the developing is not performed.

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Osaka, Japan

Yukari Ota