Ricoh Company, Ltd.

Haruki Nagata

Ryo Hasegawa

Atsushi Nagata

Kenji Honjoh

Naoto Kochi

Shinya Tanaka

Hirokazu Ishii

Teppei Kawata

Yuji Kato

Yasufumi Takahashi

Kazuosa Kuma

Nobuo Kuwabara

Takehide Mizutani

Michiharu Suzuki

Naoto Suzuki

Osamu Ichihashi

Yuta Azeyanagi

Takahiro Konishi

Yohhei Watanabe

Tsutomu Kato

A snap ring is set to a set portion of a shaft of a rotator from a direction orthogonal to an axial direction of the shaft. The snap ring includes a first arcuate portion and a second arcuate portion facing each other, being elastically deformable in directions away from each other, holding the set portion by elastic deformation restoring force. One ends of the first and second arcuate portions are away from each other to form an insertion portion to insert the set portion. When the snap ring is not used, the first arcuate portion has a same radius of curvature as the second arcuate portion and the set portion, and a center of curvature closer to the second arcuate portion than the first arcuate portion, and the second arcuate portion has a center of curvature closer to the first arcuate portion than the second arcuate portion.

Snap ring, rotator device, fixing device, and image forming apparatus

A cam drive device includes a cam to rotate; a displacement body to be displaced in response to a change in a rotation position of the cam in contact with the displacement body; a motor to rotate the cam; and a power source to output an electric current to be supplied to the motor. An electric current to cause a stall torque to the motor being a stop state is changed in response to a change in a rotation stop position of the cam.

Cam drive device and image forming apparatus incorporating same

An image forming apparatus includes an apparatus body, a plurality of image bearers, an endless belt, a contact and separation mechanism to generate a first trajectory and a second trajectory of the endless belt, a sensor to detect an object on a surface of the endless belt, and a positioning mechanism to enable the sensor to detect the object in the first trajectory and the second trajectory of the endless belt. The positioning mechanism includes a stay to support the sensor, a first bracket, a second bracket, a first positioning portion attached to the apparatus body to position the sensor in a direction of rotation of the first bracket and the second bracket at a time of the first trajectory, and a second positioning portion attached to the second bracket to position the sensor in the direction of rotation of the first bracket at a time of the second trajectory.

Image forming apparatus

An image forming apparatus includes an image bearer, a nip forming device, a contact-and-separation device, a thickness information retrieving device, and a controller. The contact-and-separation device moves the image bearer and the nip forming device to contact and separate from each other. The controller controls the contact-and-separation device based on information on a thickness of a recording medium obtained by the thickness information retrieving device such that in a case in which a thickness of a preceding recording medium and a thickness of a successive recording medium are different in continuous printing in which a plurality of recording media is printed out continuously, the contact-and-separation device adjusts a space between the image bearer and the nip forming device when the preceding recording medium exits the transfer nip to a preset size corresponding to the thickness of the successive recording medium that enters the transfer nip.

An image forming apparatus includes an image carrier that carries a toner image; a transfer member that forms a transfer nip between the transfer member and the image carrier; and a power supply capable of outputting a superimposed transfer bias in which an alternating current component is superimposed onto a direct current component. The toner image on the image carrier is transferred onto a recording medium in the transfer nip by the superimposed transfer bias or a direct current bias consisting of the direct current component output by the power supply. The apparatus also includes a controller that controls the power supply so that an output target value of the direct current component when the direct current component rises up is larger than an output target value of the direct current component when the toner image is transferred onto the recording medium.

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Kanagawa, Japan

Haruki Nagata