Ricoh Company, Ltd.

Kentaro Yamashita

Hiroshi Yoshinaga

Yoshiki Yamaguchi

Takashi Seto

Daisuke Inoue

Takamasa Hase

Ippei Fujimoto

Arinobu Yoshiura

Toshiyuki Kabata

Ryohei Matsuda

Ryohhei Sugiyama

Mototaka Iwama

A fixing device includes a first rotator and a second rotator that form a nip therebetween and fix an image on a recording medium that enters the nip. A heater heats at least one of the first rotator or the second rotator. A controller controls the heater to switch between a first heating and a second heating, to switch from the first heating to the second heating before the recording medium enters the nip, to start the second heating at a time prior to a nip entry time at which the recording medium enters the nip by a delay time period taken for the heater to conduct heat to the nip, and to continue the first heating before the second heating for at least one control cycle at a duty cycle of power supplied to the heater. The duty cycle is not greater than 40%.

Fixing device and image forming apparatus with a controller to switch between a first heating and a second heating

A fixing device includes a fixing rotator, a first heater, a second heater, and circuitry. The first heater heats a region on the fixing rotator to heat a recording medium having a width smaller than a predetermined width. The second heater heats a region on the fixing rotator to heat a maximum recording medium used in the fixing device. The second heater has a heat generation distribution in which a heat generation amount of each of both end portions corresponding to both end portions of the maximum recording medium in a width direction of the recording medium is larger than a heat generation amount of a center portion. The circuitry determines whether to turn on the first heater and turn off the second heater or to turn on both the first heater and the second heater based on a required power to bring the fixing rotator to a fixing temperature.

Fixing device and image forming apparatus incorporating same

A nip formation pad includes a base, a high thermal conduction member, and an attachment. The high thermal conduction member has a thermal conductivity greater than a thermal conductivity of the base. The attachment is attached to the high thermal conduction member by elastic deformation of the attachment on the base held between the high thermal conduction member and the attachment.

Nip formation pad, heating device, fixing device, and image forming apparatus

A nip former that forms a nip between an endless belt and a pressure rotator includes a base that is made of aluminum and has a nip forming face disposed opposite the nip. An anodic oxidation coating is treated with sealing and coats at least the nip forming face. The anodic oxidation coating has a thickness that is not smaller than 22 &#x3bc;m and is not greater than 45 &#x3bc;m and a variation in thickness that is not greater than 20 percent. The base and the anodic oxidation coating define a nip forming portion that is disposed opposite the nip. The nip forming portion has a thickness that is not smaller than 0.40 mm and is not greater than 1.20 mm.

Nip former, fixing device, and image forming apparatus

A fixing device includes a fixing rotator that is endless and rotates in a rotation direction and a pressure rotator that contacts an outer circumferential surface of the fixing rotator to form a nip between the fixing rotator and the pressure rotator. A flange is disposed opposite each lateral end of the fixing rotator in an axial direction of the fixing rotator and contacts an inner circumferential surface of the fixing rotator. The flange includes a first portion disposed farthest from the nip and a second portion disposed in proximity to the nip. The flange is inclined to define a distance from the inner circumferential surface of the fixing rotator to the flange in a separation direction in which the flange separates from the inner circumferential surface of the fixing rotator. The distance increases from the first portion to the second portion.

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Shizuoka, Japan

Kentaro Yamashita