Fixing device

Patent metadata

Field	Value
Publication number	US-11829090-B2
Application number	US-202217807036-A
Country	US
Kind code	B2
Filing date	Jun 15, 2022
Priority date	Jun 16, 2021
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A fixing device includes a heater, an endless belt, a holder, a temperature detector, and a partition sheet. The heater includes a substrate, and a resistance heating element provided on the substrate, and has a frontside surface and a backside surface opposite to the frontside surface. The endless belt is configured to rotate around the heater and has an inner peripheral surface in contact with the frontside surface of the heater. The holder holds the heater. The temperature detector is configured to detect a temperature of the heater and has a detection surface that detects a temperature. The partition sheet is located between the backside surface of the heater and the holder, and is in contact with the detection surface. A length of the partition sheet in a direction of conveyance of a recording material is longer than a length of the heater in the direction of conveyance.

First claim

What is claimed is:

1. A fixing device comprising:
a heater comprising a substrate, and a resistance heating element provided on the substrate, the heater having a frontside surface and a backside surface opposite to the frontside surface;
an endless belt configured to rotate around the heater, the endless belt having an inner peripheral surface in contact with the frontside surface of the heater, with lubricant being provided between the endless belt and the frontside surface;
a holder that holds the heater;
a temperature detector configured to detect a temperature of the heater, the temperature detector having a detection surface that detects a temperature; and
a partition sheet located between the backside surface of the heater and the holder, the partition sheet being in contact with the detection surface;
wherein a length of the partition sheet in a direction of conveyance of a recording material is longer than a length of the heater in the direction of conveyance,
wherein the partition sheet includes an extension that extends from at least one end that is at least one of two ends upstream and downstream in the direction of conveyance, the extension extending away from the frontside surface in an opposed direction in which the backside surface of the heater and a surface of the partition sheet are opposed to each other, and
wherein the holder includes a groove in which the extension is inserted.

2. The fixing device according to claim 1 , wherein the at least one end is a downstream end of the partition sheet in the direction of conveyance.

3. The fixing device according to claim 1 , wherein the groove has a bottom.

4. The fixing device according to claim 1 , wherein the extension extends in the opposed direction, to a position farther, than the detection surface, from the frontside surface.

5. The fixing device according to claim 1 , wherein the partition sheet has a thermal conductivity lower than a thermal conductivity of the substrate.

6. The fixing device according to claim 5 , further comprising a thermally-conductive member located between the backside surface of the heater and the partition sheet, the thermally-conductive member having a higher thermal conductivity than the thermal conductivity of the substrate,
wherein the length of the partition sheet in the direction of conveyance is longer than a length of the thermally-conductive member in the direction of conveyance.

7. The fixing device according to claim 6 , wherein an area of contact between the partition sheet and the thermally-conductive member is equal to or larger than an area of contact between the heater and the thermally-conductive member.

8. The fixing device according to claim 6 , wherein the holder has:
a first surface that supports the partition sheet and the thermally-conductive member; and
a second surface that supports the backside surface of the heater, the second surface being located in a position outside the first surface in a direction perpendicular to the direction of conveyance, and closer, than the first surface, to the heater.

9. The fixing device according to claim 8 , wherein a distance between neighboring edges of the first surface and the second surface is equal to or smaller than a sum of a thickness of the partition sheet and a thickness of the thermally-conductive member.

10. The fixing device according to claim 1 , further comprising a pressure roller that forms a nip in combination with the heater, the belt being held in the nip between the pressure roller and the heater, and
wherein a length of the partition sheet in a direction perpendicular to the direction of conveyance is longer than the length of the nip in the direction perpendicular to the direction of conveyance.

11. The fixing device according to claim 1 , comprising at least one other temperature detector that detects a temperature of the heater, the at least one other temperature detector being positioned on a side of the partition sheet opposite to a side of the partition sheet on which the heater is positioned,
wherein the temperature detector and the at least one other temperature detector are placed inside a contour of the partition sheet as viewed in an opposed direction in which the backside surface of the heater and a surface of the partition sheet are opposed to each other.

12. The fixing device according to claim 1 , wherein the partition sheet includes polyimide.

13. A fixing device comprising:
a heater comprising a substrate, and a resistance heating element provided on the substrate, the heater having a frontside surface and a backside surface opposite to the frontside surface;
an endless belt configured to rotate around the heater, the endless belt having an inner peripheral surface in contact with the frontside surface of the heater, with lubricant being provided between the endless belt and the frontside surface;
a holder that holds the heater;
a temperature detector configured to detect a temperature of the heater, the temperature detector having a detection surface that detects a temperature;
a thermally-conductive member located between the backside surface of the heater and the holder, the thermally-conductive member having a higher thermal conductivity than a thermal conductivity of the substrate and being in contact with the detection surface; and
a partition sheet in contact with the backside surface of the heater and the thermally-conductive member, the partition sheet having a thermal conductivity lower than the thermal conductivity of the substrate,
wherein a length of the partition sheet in a direction of conveyance of a recording material is longer than a length of the heater in the direction of conveyance.

14. The fixing device according to claim 13 , wherein the heater is not in contact with the thermally-conductive member.

15. A fixing device comprising:
a heater comprising a substrate, and a resistance heating element provided on the substrate, the heater having a frontside surface and a backside surface opposite to the frontside surface;
an endless belt configured to rotate around the heater, the endless belt having an inner peripheral surface in contact with the frontside surface of the heater, with lubricant being provided between the endless belt and the frontside surface;
a holder that holds the heater;
a temperature detector configured to detect a temperature of the heater, the temperature detector having a detection surface that detects a temperature;
a thermally-conductive member located between the backside surface of the heater and the holder, the thermally-conductive member having a higher thermal conductivity than a thermal conductivity of the substrate and having a through hole or a notch; and
a partition sheet in contact with the backside surface of the heater and the thermally-conductive member, the partition sheet having a thermal conductivity lower than the thermal conductivity of the substrate,
wherein the detection surface is in contact with the partition sheet through the through hole or the notch, and
wherein a length of the partition sheet in a direction of conveyance of a recording material is longer than a length of the heater in the direction of conveyance.

Assignees

• Brother Ind Ltd

Inventors

• Maruyama Yasuhiro
• Souda Makoto

Classifications

• G03G15/2039 Primary

  with means for controlling the fixing temperature · CPC title

• G03G15/2028 Primary

  with means for handling the copy material in the fixing nip, e.g. introduction guides, stripping means · CPC title