Fixing device and image forming apparatus

Patent metadata

Field	Value
Publication number	US-2016238975-A1
Application number	US-201615011982-A
Country	US
Kind code	A1
Filing date	Feb 1, 2016
Priority date	Feb 12, 2015
Publication date	Aug 18, 2016
Grant date	—

Abstract

A fixing device includes a first heater and a second heater disposed inside a fixing rotator to heat the fixing rotator. The first heater generates an increased amount of heat and includes a first heat generator having a first heating span in a longitudinal direction of the first heater. The second heater generates a decreased amount of heat and includes a second heat generator having a second heating span in a longitudinal direction of the second heater. A partition is interposed between the first heater and the second heater to define a first compartment having an increased size and accommodating the first heater and a second compartment having a decreased size and accommodating the second heater.

First claim

What is claimed is:

1 . A fixing device comprising:
a fixing rotator rotatable in a predetermined direction of rotation; a pressure rotator disposed opposite the fixing rotator to form a fixing nip therebetween, through which a recording medium bearing a toner image is conveyed; a first heater disposed inside the fixing rotator to generate an increased amount of heat to heat the fixing rotator, the first heater including a first heat generator having a first heating span in a longitudinal direction of the first heater; a second heater disposed inside the fixing rotator to generate a decreased amount of heat to heat the fixing rotator, the second heater including a second heat generator having a second heating span in a longitudinal direction of the second heater; and a partition interposed between the first heater and the second heater to define a first compartment having an increased size and accommodating the first heater and a second compartment having a decreased size and accommodating the second heater.

2 . The fixing device according to claim 1 , wherein the first compartment includes:
a first increased size section accommodating the first heat generator of the first heater; and a first decreased size section disposed outboard from the first increased size section in the longitudinal direction of the first heater and smaller in size than the first increased size section.

3 . The fixing device according to claim 2 , wherein the second compartment includes:
a second increased size section accommodating the second heat generator of the second heater; and a second decreased size section disposed inboard from the second increased size section in the longitudinal direction of the second heater and smaller in size than the second increased size section.

4 . The fixing device according to claim 1 , wherein the first decreased size section of the first compartment is substantially equivalent in size to the second increased size section of the second compartment.

5 . The fixing device according to claim 1 ,
wherein the first heater further includes a first non-heat generator disposed outboard from the first heat generator in the longitudinal direction of the first heater, and wherein the second heater further includes a second non-heat generator disposed inboard from the second heat generator in the longitudinal direction of the second heater.

6 . The fixing device according to claim 5 , wherein the partition includes:
a first partition portion disposed opposite the first heat generator of the first heater with an increased interval therebetween; and a second partition portion disposed opposite the first non-heat generator of the first heater with a decreased interval therebetween.

7 . The fixing device according to claim 1 , wherein the partition extends linearly in the longitudinal direction of the first heater and the second heater.

8 . The fixing device according to claim 1 , further comprising a reflector interposed between the partition and each of the first heat generator of the first heater and the second heat generator of the second heater, the reflector to reflect light radiated from the first heater and the second heater toward the fixing rotator.

9 . The fixing device according to claim 1 ,
wherein the first heater and the second heater generate an identical amount of heat per unit length in the longitudinal direction of the first heater and the second heater, and wherein the first heat generator of the first heater is greater than the second heat generator of the second heater in the longitudinal direction of the first heater and the second heater.

10 . The fixing device according to claim 1 ,
wherein light being radiated from the first heat generator of the first heater and irradiating the fixing rotator directly defines a first irradiation angle in a cross-section perpendicular to the longitudinal direction of the first heater and the second heater, wherein light being radiated from the second heat generator of the second heater and irradiating the fixing rotator directly defines a second irradiation angle in the cross-section perpendicular to the longitudinal direction of the first heater and the second heater, and wherein the first irradiation angle is greater than the second irradiation angle.

11 . The fixing device according to claim 1 ,
wherein the first heat generator of the first heater is disposed opposite a center span of the fixing rotator in an axial direction thereof, and wherein the second heat generator of the second heater is disposed opposite each lateral end span of the fixing rotator in the axial direction thereof.

12 . The fixing device according to claim 1 , wherein the fixing rotator includes an endless belt.

13 . The fixing device according to claim 12 , further comprising a nip formation pad to press against the pressure rotator via the endless belt to form the fixing nip.

14 . The fixing device according to claim 13 , wherein the partition includes a support to support the nip formation pad.

15 . The fixing device according to claim 14 , wherein the support includes a stay.

16 . The fixing device according to claim 15 , wherein the stay is substantially T-shaped in a cross-section perpendicular to the longitudinal direction of the first heater and the second heater.

17 . The fixing device according to claim 1 , wherein the second heat generator of the second heater is disposed outboard from the first heat generator of the first heater in the longitudinal direction of the first heater.

18 . The fixing device according to claim 1 , wherein the first heat generator of the first heater overlaps the second heat generator of the second heater in the longitudinal direction of the first heater.

19 . The fixing device according to claim 1 , wherein the pressure rotator includes a pressure roller.

20 . An image forming apparatus comprising:
an image bearer to bear a toner image; and a fixing device disposed downstream from the image bearer in a recording medium conveyance direction to fix the toner image on a recording medium, the fixing device including:
a fixing rotator rotatable in a predetermined direction of rotation;
a pressure rotator disposed opposite the fixing rotator to form a fixing nip therebetween, through which the recording medium bearing the toner image is conveyed;
a first heater disposed inside the fixing rotator to generate an increased amount of heat to heat the fixing rotator, the first heater including a first heat generator having a first heating span in a longitudinal direction of the first heater;
a second heater disposed inside the fixing rotator to generate a decreased amount of heat to heat the fixing rotator, the second heater including a second heat generator having a second heating span in a longitudinal direction of the second heater; and
a partition interposed between the first heater and the second heater to define a first compartment having an increased size and accommodating the first heater and a second compartment having a decreased size and accommodating the second heater.

Assignees

• Seki Takayuki
• Matsusaka Susumu
• Ogino Yasuhiko
• Kobashigawa Shohta
• Ishll Kenji
• Kishi Kazuhito
• Seto Takashi
• Fujimoto Lppei
• Sawada Kazunari
• Yoshinaga Hiroshi

Inventors

• Seki Takayuki
• Matsusaka Susumu
• Ogino Yasuhiko
• Kobashigawa Shohta
• Ishll Kenji
• Kishi Kazuhito
• Seto Takashi
• Fujimoto Lppei
• Sawada Kazunari
• Yoshinaga Hiroshi

Classifications

• G03G15/2053 Primary

  Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating · CPC title

• G03G15/2064

  combined with pressure · CPC title