US-12625444-B2 - Heating device including a plurality of conductor supports for supporting a conductor, fixing device including the same, and image forming apparatus including the same

US12625444B2US 12625444 B2US12625444 B2US 12625444B2US-12625444-B2

Abstract

A heating device includes a pair of rotators in contact with each other to form a nip through which a sheet passes, a heater heating at least one of the pair of rotators, a temperature sensor detecting detects a temperature of the heater, a conductor, a plurality of conductor supports supporting the conductor, and a component supporting the plurality of conductor supports. The conductor has flexibility and is coupled to the temperature sensor. The conductor supports extend in a direction away from the heater and include first conductor supports and second conductor supports. The first conductor supports face an outside of a predetermined region of the heater in a width direction of the sheet and are arranged at first intervals in the width direction. The second conductor supports face the predetermined region of the heater and are arranged at second intervals larger than the first intervals in the width direction.

Inventors

Yuusuke Furuichi
Shigeo Nanno
Yukimichi Someya

Assignees

Yuusuke Furuichi
Shigeo Nanno
Yukimichi Someya

Dates

Publication Date: 20260512
Application Date: 20230414
Priority Date: 20220511

Claims (20)

1 . A heating device comprising: a pair of rotators in contact with each other, the pair of rotators configured to form a nip through which a sheet passes; a heater configured to heat at least one of the pair of rotators; a temperature sensor configured to detect a temperature of the heater; a conductor having flexibility and being coupled to the temperature sensor; a plurality of conductor supports configured to support the conductor, the plurality of conductor supports extending in a direction away from the heater, the plurality of conductor supports including, a plurality of first conductor supports facing an outside of a desired region of the heater in a width direction of the sheet, the plurality of first conductor supports arranged at first intervals in the width direction, and a plurality of second conductor supports facing the desired region of the heater, the plurality of second conductor supports arranged at second intervals larger than the first intervals in the width direction; a component configured to support the plurality of conductor supports, the component having a first side facing the heater and a second side opposite the first side; and a heater holder configured to hold the heater, wherein the component is between the heater holder and the conductor, and the component is a sensor holder configured to hold the temperature sensor.
2 . A heating device comprising: a pair of rotators in contact with each other, the pair of rotators configured to form a nip through which a sheet passes; a heater configured to heat at least one of the pair of rotators; a temperature sensor configured to detect a temperature of the heater; a conductor having flexibility and being coupled to the temperature sensor; a plurality of conductor supports configured to support the conductor, the plurality of conductor supports extending in a direction away from the heater, the plurality of conductor supports including, a plurality of first conductor supports facing an outside of a desired region of the heater in a width direction of the sheet, the plurality of first conductor supports arranged at first intervals in the width direction, and a plurality of second conductor supports facing the desired region of the heater, the plurality of second conductor supports arranged at second intervals larger than the first intervals in the width direction; and a component configured to support the plurality of conductor supports, the component having a first side facing the heater and a second side opposite the first side, wherein the component is a heater holder configured to hold the heater.
3 . The heating device according to claim 2 , wherein the heater holder and the plurality of conductor supports are formed as one component.
4 . A heating device comprising: a pair of rotators in contact with each other, the pair of rotators configured to form a nip through which a sheet passes; a heater configured to heat at least one of the pair of rotators; a temperature sensor configured to detect a temperature of the heater; a conductor having flexibility and being coupled to the temperature sensor; a plurality of conductor supports configured to support the conductor, the plurality of conductor supports extending in a direction away from the heater, the plurality of conductor supports including, a plurality of first conductor supports facing an outside of a desired region of the heater in a width direction of the sheet, the plurality of first conductor supports arranged at first intervals in the width direction, and a plurality of second conductor supports facing the desired region of the heater, the plurality of second conductor supports arranged at second intervals larger than the first intervals in the width direction; and a component configured to support the plurality of conductor supports, the component having a first side facing the heater and a second side opposite the first side, wherein the heater includes a plurality of heat generators arranged at intervals in the width direction, and at least one of the plurality of conductor supports overlaps a region between the plurality of heat generators in the width direction.
5 . The heating device according to claim 1 , wherein the heater includes a heat generator at a center of the heater in a sheet conveyance direction; at least one of the plurality of conductor supports projects from the second side of the component in the direction away from the heater and is configured to support the conductor at a position shifted from the center of the heater in the sheet conveyance direction; and a distance from the second side of the component to a center position of the at least one of the plurality of conductor supports in the sheet conveyance direction is higher than a distance from the second side of the component to a tip of each of both sides of the at least one of the plurality of conductor supports in the sheet conveyance direction.
6 . The heating device according to claim 1 , further comprising: a stay configured to support the heater holder; and a low thermal conductor between the stay and the conductor, the low thermal conductor having a thermal conductivity lower than a thermal conductivity of the stay.
7 . A fixing device comprising: the heating device according to claim 1 , the heating device configured to fix an unfixed image onto a sheet.
8 . An image forming apparatus comprising: the heating device according to claim 1 .
9 . A fixing device comprising: the heating device according to claim 2 , the heating device configured to fix an unfixed image onto a sheet.
10 . A fixing device comprising: the heating device according to claim 4 , the heating device configured to fix an unfixed image onto a sheet.
11 . An image forming apparatus comprising: the heating device according to claim 2 .
12 . An image forming apparatus comprising: the heating device according to claim 4 .
13 . The heating device according to claim 1 , wherein the heater holder is made of a heat-resistant resin.
14 . The heating device according to claim 6 , wherein the stay is made of a metal.
15 . The heating device according to claim 6 , wherein the temperature sensor is in contact with a stay side face of the heater.
16 . The heating device according to claim 1 , further comprising: a connector configured to hold the heater and the heater holder together.
17 . The heating device according to claim 2 , wherein the heater holder is made of a heat-resistant resin.
18 . The heating device according to claim 2 , further comprising: a stay configured to support the heater holder, the stay being made of a metal.
19 . The heating device according to claim 18 , wherein the temperature sensor is in contact with a stay side face of the heater.
20 . The heating device according to claim 2 , further comprising: a connector configured to hold the heater and the heater holder together.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/IB2023/053814 which has an International filing date of Apr. 14, 2023, which claims priority to Japanese Application Nos. 2022-078180, filed May 11, 2022 and 2022-086031, filed May 26, 2022, the entire contents of each of which are hereby incorporated by reference. TECHNICAL FIELD Embodiments of the present disclosure generally relate to a heating device, a fixing device, and an image forming apparatus. BACKGROUND ART An image forming apparatus such as a copier or a printer includes a fixing device as an example of a heating device. The fixing device heats a sheet bearing an unfixed image to fix the unfixed image onto the sheet. One type of fixing devices includes a temperature sensor such as a thermistor or a thermostat disposed on a heater holder holding a heater. The temperature sensor is coupled to a controller via a conductor such as a lead wire. The controller controls heat generated by the heater based on temperatures detected by the temperature sensor to maintain the temperature of the heater to an appropriate temperature. Since the conductor coupled to the temperature sensor is disposed in the vicinity of the heater that becomes high temperature, the conductor is preferably made of a material having heat resistance or is protected by a covering material having the heat resistance. However, selecting the material having the heat resistance has a disadvantage such as increasing a manufacturing cost. To solve the disadvantage, Japanese Unexamined Patent Application Publication No. 2011-118246 discloses a configuration including a plurality of projections disposed on a back side of a heater holder to support the conductor. The back side is opposite to a side holding the heater. Japanese Unexamined Patent Application Publication No. 2011-118246 argues that the above-described configuration decreases a contact area of the conductor with respect to the heater, which reduces an amount of heat transmitted from the heater holder to the conductor and reduces the temperature rise of the conductor. CITATION LIST Patent Literature Japanese Unexamined Patent Application Publication No. 2011-118246 SUMMARY OF INVENTION Technical Problem The temperature distribution of the heater is not always uniform as a whole. For example, an uneven temperature distribution occurs in the heater when sheets continuously pass through the fixing device. When sheets each having a width smaller than that of a heat generation area of the heater pass through the fixing device, the sheets do not absorb the heat of the heater in a region facing a non-sheet passing region of the fixing device through which the sheets do not pass. As a result, the heat is accumulated in the region facing the non-sheet passing region, and the temperature of the region becomes higher than a temperature in a region facing a sheet passing region of the fixing device through which the sheets pass. For this reason, a temperature difference in the heater occurs between the region facing the sheet passing region and the region facing the non-sheet passing region. The above-described Japanese Unexamined Patent Application Publication No. 2011-118246 discloses the plurality of projections preventing the heat from transmitting to the conductor, but no consideration is given to the influence of heat from the region of the heater that is likely to have a higher temperature than another region of the heater to the conductor. It is necessary to reduce a temperature rise of the conductor in a region in which the temperature is likely to be higher than the temperature in another region. Solution to Problem According to an embodiment of the present disclosure, a heating device includes a pair of rotators, a heater, a temperature sensor, a conductor, a plurality of conductor supports, and a component supporting the plurality of conductor supports. The pair of rotators is in contact with each other to form a nip through which a sheet passes. The heater heats at least one of the pair of rotators. The temperature sensor detects a temperature of the heater. The conductor has flexibility and is coupled to the temperature sensor. The plurality of conductor supports supports the conductor and extends in a direction away from the heater. The plurality of conductor supports includes first conductor supports and second conductor supports. The first conductor supports face an outside of a predetermined region of the heater in a width direction of the sheet and are arranged at first intervals in the width direction. The second conductor supports face the predetermined region of the heater and are arranged at second intervals larger than the first intervals in the width direction. The component has a first side facing the heater and a second side opposite the first side. Advantageous Effects of Invention The heating device according to the present di