Kyocera Document Solutions Inc.

Einosuke Kikuchi

Kuniaki Nakano

Akira Matayoshi

Sueaki Okamoto

An image forming apparatus includes a plurality of image carrying members, a charging device, an exposure device, a developing device, an intermediate transfer belt, and a plurality of transfer rollers. On the image carrying member disposed most downstream in the traveling direction of the intermediate transfer belt, a black tonner image is developed. The rotation shaft of at least one transfer roller located upstream of the transfer roller disposed most downstream in the traveling direction of the intermediate transfer belt is offset upstream from directly above the rotation shaft of the corresponding image carrying member.

Image forming apparatus for preventing transfer defects due to electrical discharge and suppressing degradation of secondary transferability

A fixing device includes a fixing member, a pressurizing member, a charging portion, and a control portion. The fixing member rotates while being heated. The pressurizing member forms a nip portion between itself and a surface of the fixing member in such a way as to hold a sheet therebetween and conveys the sheet by rotating together with the fixing member, wherein an image of toner has been formed on the sheet. The charging portion electrically charges the surface of the fixing member to a polarity that is same as a charging polarity of the toner by supplying a charging current to a pair of electrodes that is disposed to face the surface of the fixing member. The control portion derives an index value of a charge amount of the toner on the sheet, and adjusts the charging current based on the index value.

Fixing device, image forming apparatus, fixing control method

A fixing device includes a fixing member, a pressurizing member, a charging portion, and a control portion. The fixing member rotates while being heated. The pressurizing member forms a nip portion between itself and a surface of the fixing member in such a way as to hold a sheet therebetween and conveys the sheet by rotating together with the fixing member, wherein an image of toner has been formed on the sheet. The charging portion electrically charges the surface of the fixing member to a polarity that is same as a charging polarity of the toner by supplying a charging current to a pair of electrodes that is disposed to face the surface of the fixing member. The control portion increases the charging current as time passes during a control time period that corresponds to a time period for which the sheet passes through the nip portion.

Image forming apparatus, fixing control method

A fixing device includes a fixing member, a pressurizing member, a charging portion, and a control portion. The fixing member rotates while being heated. The pressurizing member forms a nip portion between itself and a surface of the fixing member in such a way as to hold a sheet therebetween and conveys the sheet by rotating together with the fixing member, wherein an image of toner has been formed on the sheet. The charging portion electrically charges the surface of the fixing member to a polarity that is same as a charging polarity of the toner by supplying a charging current to a pair of electrodes that is disposed to face the surface of the fixing member. The control portion acquires sheet information that includes one or more of length information, width information, and thickness information of the sheet and adjusts the charging current based on the sheet information.

A fixing device includes a heating body, a pressuring body, a charging part and a collecting part. The heating body contacts with a medium having a toner image while rotating to heat the medium. The pressuring body forms a nip with the heating roller while rotating to pressure the medium passing through the nip with the heating body. The charging part is positioned to face to the heating body and electrically discharges to electrically charge the heating body with the same polarity as polarity of toner. The collecting part is positioned to face to a position at an upstream side with respect to a facing position on the heating body to the charging part and at a downstream side with respect to a forming position of the nip in a rotating direction of the heating body, and collects impurities caused by the medium passing the nip by absorbing or removing.

Fixing device including collecting part collecting impurities of medium and image forming apparatus including this fixing device

A cleaning device includes a cleaning member, a collecting roller and a cleaning blade. The cleaning member is disposed to be rotatable while being in contact with a surface of an image carrier configured to carry a toner image to the surface. The collecting roller is disposed to be rotatable while being in contact with the cleaning member at a downstream side from the image carrier in a rotation direction of the cleaning member. The cleaning blade is disposed while being in contact with the collecting roller in a counter direction with respect to rotation of the collecting roller at a downstream side from the cleaning member in a rotation direction of the collecting roller. The collecting roller is formed so as to have larger surface roughness at an end than that at a central part in an axial direction.

Cleaning device and image forming apparatus

An image forming apparatus includes a toner containing portion, a first conveying member, an image conveying portion, and an image forming portion. The first conveying member is configured to convey the toner in a conveyance direction within the toner containing portion. The image conveying portion includes a surface layer portion having a first end portion located at an upstream side in the conveyance direction and a second end portion located at a downstream side in the conveyance direction. The first end portion has a larger layer thickness than second end portion. The image conveying portion is configured to convey a toner image formed on a surface of the surface layer portion at a predetermined image forming position, to a transfer position for transfer to a transfer target medium. The image forming portion is configured to form the toner image on the surface layer portion by using the toner being conveyed.

Image forming apparatus forming toner image on surface layer portion of image conveying portion

An image forming apparatus includes: a photosensitive body including a photosensitive layer having a first end and a second end, the first end having a larger thickness than the second end; a charging portion charges the photosensitive layer; a light irradiation portion applies light to the photosensitive layer; a developing device develops by toner charged with the same polarity as charge polarity of the photosensitive layer; an intermediate transfer medium including a surface layer having a third end and a fourth end, the third end having a larger thickness than the fourth end, the third end being opposed to the second end, the fourth end being opposed to the first end; and a transfer portion transfers a toner image developed on the photosensitive layer, onto the surface layer when a voltage having polarity opposite to the charge polarity is applied to the transfer portion.

Image forming apparatus transferring toner image onto surface layer portion of intermediate transfer medium

An image forming apparatus includes a development device, an electrostatic transfer device, a stopping period measuring part, a driving period measuring part, a toner consumption amount measuring part, an environment measuring part and a transferring bias adjusting part. The driving period measuring part measures a driving period in which the development device is driven in order to form the toner image. The transferring bias adjusting part adjusts the transferring bias on the basis of the stopping period measured by the stopping period measuring part, the driving period measured by the driving period measuring part, the toner consumption amount measured by the toner consumption amount measuring part and the condition of the surrounding environment measured by the environment measuring part.

Image forming apparatus having a transferring bias adusting part adjusting a transferring bias according to a surrounding environment

An image forming apparatus includes an apparatus main body, a power supply switch, a photoreceptor drum, a charging device, an exposure device, a developing device, a transfer roller, a cleaning device, and a toner-layer formation unit. The transfer roller contacts the circumferential surface of the photoreceptor drum at a downstream side with respect to the developing device in the rotation direction and is configured to transfer the toner image to a sheet. The cleaning device is cleaning device arranged opposed to the photoreceptor drum, downstream. The cleaning device is configured to clean the photoreceptor drum. The toner-layer formation unit is configured to form a toner layer on a surface of the transfer roller in an initial operation started after the apparatus main body is installed in a predetermined installation location and the power supply switch is switched on.

Image forming apparatus ensuring reduced initial bleeding phenomenon

An image forming apparatus includes an image bearing member and a transfer member, which form a transfer nip portion, and a guide member for guiding a sheet to the transfer nip portion. The guide member includes a rigid restricting member including a guide surface, a cut portion formed at a leading edge part of the guide surface, and a sheet-like elastic restricting member to cover the cut portion. The elastic restricting member includes an end edge portion extending straight in the sheet width direction on a downstream side in the sheet conveying direction. A ridge defining the leading edge part of the guide surface is a ridge extending straight in the sheet width direction, and the end edge portion of the elastic restricting member is arranged at a position shifted toward an upstream side in the sheet conveying direction from the ridge of the guide surface.

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Osaka, Japan

Einosuke Kikuchi