Ricoh Company, Ltd.

Hiroyoshi Haga

Junpei Fujita

Kenji Sengoku

Hiromi Ogiyama

Yasunobu Shimizu

Tomokazu Takeuchi

Kazuki Yogosawa

Yuuji Wada

Kenji Sugiura

Naohiro Kumagai

Seiichi Kogure

Tatsuya Ohsugi

Takehide Mizutani

Hirokazu Ishii

Shinya Tanaka

Naoto Kochi

Masayoshi Nakayama

Toshitaka Yamaguchi

Mitsuru Takahashi

Jyunya Sakuraba

Emi Kita

Yoshiaki Nagao

Kazuchika Saeki

Yasuhide Ohkubo

Kuniyori Takano

Yohhei Watanabe

Tsutomu Kato

Tatsuhiko Oikawa

Satoru Uchida

Kenji Sugirua

Yoshimi Saitoh

Kiyoshi Horikawa

A powder container includes a collection port to receive and collect powder from outside; a driven unit that is disposed on one end side in a width direction of the powder container and to which drive is transmitted from outside; a first rotary shaft that rotates by the drive transmitted to the driven unit; a first gear disposed on other end side of the powder container and rotating with the first rotary shaft; a second rotary shaft that is disposed on the other end side, that includes a second gear to which drive is transmitted from the first gear, and that rotates with the second gear; and a driving gear that is disposed on the second rotary shaft in a position between the second gear and a central portion in the width direction of the powder container, and that rotates with the second rotary shaft to transmit drive to outside.

Powder container, process cartridge, and image forming apparatus

An image forming apparatus includes an image bearing member to bear a toner image charged with a predetermined polarity, and a power source to apply a bias to a transfer portion to transfer the toner image from the image bearing member to a recording medium, a polarity of the bias being changed alternately. The toner image formed with toner of a plurality of colors is transferred in a color mode and the toner image formed with toner of a single color is transferred in a monochrome mode. The bias includes a peak voltage with a polarity that returns toner from the recording medium to the image bearing member. An absolute value of the peak voltage in the color mode is equal to or greater than an absolute value of the peak voltage in the monochrome mode.

Image forming apparatus with a controller to set transfer bias

An image forming apparatus includes an image bearer; a toner image forming device; an intermediate transferor; a primary transfer power source; a secondary transfer nip forming device; and a secondary transfer power source to output a secondary transfer bias. One of two peak values of the secondary transfer bias is a transfer peak value to provide a greater transfer-directional force to move toner from the intermediate transferor toward the recording medium in the secondary transfer nip. An absolute value of the transfer peak value is greater than an absolute value of the primary transfer bias.

Image forming apparatus and transfer bias control

An image forming apparatus includes a plurality of image bearers, a transfer bias member, and a power source. When the transfer bias member transfers a color toner image onto a recording sheet, a second peak value of a peak-to-peak of a transfer bias, which is smaller than a first peak value of the peak-to-peak in an electrostatic force to move toner from the image bearers or an intermediate transfer body to the recording sheet, is zero or has a first polarity to generate the electrostatic force in a transfer direction to move toner from the image bearers or the intermediate transfer body to the recording sheet. When the transfer bias member transfers a monochromatic toner image including only black toner onto the recording sheet, the second peak value is zero or has a second polarity to generate an electrostatic force in an opposite direction to the transfer direction.

Image forming apparatus

An endless rotatable belt device including an endless rotatable belt, a scale tape bonded on the belt, at least one optical sensor to detect a scale pattern, and auxiliary tape to cover at least one of the first end and the second end of the scale tape of the belt. The scale tape has a first end and a second end and includes at least one scale pattern. The auxiliary tape has a lower surface friction coefficient than the surface friction coefficient of the scale tape.

Belt device and image forming apparatus including same

An image forming apparatus includes a rotatable image bearer, a toner image forming device, a transfer device, a transfer bias power source, and a cleaner. The toner image forming device is to form a toner image on the image bearer. The transfer device contacts a surface of the image bearer to form a transfer nip between the transfer device and the image bearer. The transfer bias power source is to output a transfer bias to transfer the toner image from the image bearer onto a recording medium in the transfer nip. The cleaner is disposed downstream from the transfer nip in a direction of rotation of the image bearer, to electrostatically attract and remove toner from the surface of the image bearer to a surface of the cleaner. The transfer bias includes an alternating current component.

An image forming apparatus, including an image bearer configured to bear a toner image; a transfer device disposed opposing to the image bearer; and a transfer bias power source. The transfer bias power source is configured to output a transfer bias to transfer the toner image onto a recording medium. The transfer bias is a superimposed bias that cyclically alternates between a transfer-directional bias to transfer the toner image from the image bearer onto the recording medium and an opposite-directional bias in an opposite direction of the transfer direction. A ratio of a time period of application of the opposite-directional bias to a total time period of one cycle of the output transfer bias is greater than 50%. The transfer bias power source changes a value of a direct current voltage in the superimposed bias according to a linear velocity of the image bearer.

An image forming apparatus includes a toner image forming unit, a nip formation member, a transfer power source, an information acquisition device, and a controller. The information acquisition device acquires specific information that specifies whether a recording sheet as a transfer target of a toner image is an uneven surface sheet having an uneven surface. The controller outputs a bias including a superimposed voltage, in which an alternating current (AC) voltage is superimposed on a direct current (DC) voltage, as a transfer bias from the transfer power source when the specific information acquired by the information acquisition device is not information corresponding to the uneven surface sheet and to output a bias including only the DC voltage as the transfer bias from the transfer power source when the specific information is the information corresponding to the uneven surface sheet.

Image forming apparatus that adjusts a transfer bias according to surface properties of a transfer target

An image forming apparatus includes an image bearer, a transfer member, and a power source. The image bearer includes a plurality of layers. The transfer member forms a transfer nip between the image bearer and the transfer member. The power source outputs a transfer bias to transfer a toner image from the image bearer onto a recording sheet in the transfer nip. The transfer bias alternates between a transfer-side bias that causes the toner image to move from the image bearer to the recording sheet, and an opposite-side bias different from the transfer-side bias. A duty ratio of a time period, during which the opposite-side bias is output, relative to one cycle of a waveform, is greater than 50%.

A cleaning device includes an upstream cleaner, an upstream cleaner, and a collection member. The upstream cleaner is configured to remove toner from a surface of a cleaning target. The downstream cleaner is disposed downstream from the upstream cleaner in a direction of movement of the surface of the cleaning target. The downstream cleaner is configured to remove toner from the surface of the cleaning target. The collection member is configured to collect toner from the downstream cleaner.

Cleaning device and image forming apparatus incorporating same

An image forming apparatus includes an image bearer, a transfer device contacting the image bearer to form a transfer portion, a transfer bias power source, and a controller. A ratio of a time period of application of the opposite-directional bias to a total time period of one cycle of the AC component of the superimposed bias is greater than 50%. A ratio of a value of the DC component of the superimposed bias output within a region ranging from a leading end of the recording medium to a predetermined length to a value of the DC component of the superimposed bias output outside the region is greater than a ratio of a value of the AC component of the superimposed bias output within the region to a value of the AC component of the superimposed bias output outside the region.

An image forming apparatus includes an image bearer, a toner image forming device, a nip forming device, a power source, a controller, and a temperature-and-humidity detector. The toner image forming device forms a toner image on the image bearer. The nip forming device contacts the image bearer to form a transfer nip. The power source outputs a transfer bias, in which an alternating current component is superimposed on a direct current component, to transfer the toner image onto a recording medium interposed in the transfer nip. The temperature-and-humidity detector detects a temperature and humidity. The controller controls the power source to output the transfer bias including the direct current component with a smaller absolute value as at least one of the detected temperature and humidity increases.

Image forming apparatus controlling transfer bias based on temperature and humidity

A cleaning device includes a cleaner, a casing, and an exit seal. The cleaner is configured to remove toner from a cleaning target. The casing accommodates the cleaner. The exit seal is attached to the casing and has a free end contacting the cleaning target at a position downward from the cleaner in a direction of movement of the cleaning target and an attached end attached to the casing. A space is disposed between a surface of the cleaning target and an opposite face of the exit seal opposite the cleaning target. The space includes an opening at a lateral end of the exit seal. The exit seal contacts the cleaning target from a trailing direction of the exit seal and seals the opening at at least an attached end side of the exit seal.

An image forming apparatus includes a belt-shaped image bearer; a transfer device disposed opposing to the image bearer; an opposed device disposed opposing to the transfer device; and a transfer bias power source. The image bearer is disposed along an outer circumferential surface of the transfer device at least one of an upstream side and a downstream side of the transfer portion in a direction of conveyance of the recording medium. The transfer bias power source cyclically alternates the transfer bias applied to the transfer portion, between a transfer directional bias in a transfer direction to transfer the toner image from the image bearer onto the recording medium and a reverse directional bias in a reverse direction of the transfer direction. The transfer bias power source applies the reverse directional bias during a time period longer than 50% of one cycle of the applied transfer bias in the one cycle.

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Kanagawa, Japan

Hiroyoshi Haga