Fixing device and heater used in fixing device

Patent metadata

Field	Value
Publication number	US-9494899-B2
Application number	US-201514749454-A
Country	US
Kind code	B2
Filing date	Jun 24, 2015
Priority date	Dec 17, 2012
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A heater used for a fixing device includes a substrate, first and second conductor patterns formed at either end of the substrate in the short direction of the substrate, a third conductor pattern formed between the first and second conductor patterns and separated from the two conductor patterns, a first heating member disposed between the first and third conductor patterns and electrically connected to the two conductor patterns, and a second heating member disposed between the second and third conductor patterns and electrically connected to the conductor patterns. The heater has both end regions in which the widths of the third conductor pattern in the short direction is smaller than that of a middle portion of the third conductor pattern. The widths of the first and second heating members in the end regions are smaller than the widths of the first and second heating members in the other region, respectively.

First claim

What is claimed is:

1. A heater for use in a fixing device that fixes a toner image onto a recording medium, the heater comprising:
an elongated planar substrate;
a first conductor pattern provided on the substrate along a longitudinal direction of the substrate, the first conductor pattern has an annular shape that includes first and second conductor portions provided along the longitudinal direction;
a second conductor pattern provided on the substrate along the longitudinal direction, the second conductor pattern has an annular shape that includes first and second conductor portions provided along the longitudinal direction;
a first heat generating resistor electrically connected to the first conductor portion of the first conductor pattern and the first conductor portion of the second conductor pattern, the first heat generating resistor being disposed between the first conductor portion of the first conductor pattern and the first conductor portion of the second conductor pattern;
a second heat generating resistor electrically connected to the second conductor portion of the first conductor pattern and the second conductor portion of the second conductor pattern, the second heat generating resistor being disposed between the second conductor portion of the first conductor pattern and the second conductor portion of the second conductor pattern;
a first electrical contact portion disposed at one end portion of the first conductor pattern in the longitudinal direction;
a second electrical contact portion disposed at the opposite end portion of the first conductor pattern in the longitudinal direction where the first electrical contact portion is disposed;
a third electrical contact portion disposed at one end portion of the second conductor pattern in the longitudinal direction; and
a fourth electrical contact portion disposed at the opposite end portion of the second conductor pattern in the longitudinal direction where the third electrical contact portion is disposed,
wherein the first and second heat generating resistors generates heat by electrical power supplied through the first, second, third, and fourth electrical contact portions.

2. The heater according to claim 1 , wherein the width of the first conductor portion of the first conductor pattern in the direction perpendicularly to the longitudinal direction is larger than the width of the first conductor portion of the second conductor pattern in the direction perpendicularly to the longitudinal direction.

3. The fixing device according to claim 2 , wherein the width of the first conductor portion of the first conductor pattern in the direction perpendicularly to the longitudinal direction is larger than the width of the first conductor portion of the second conductor pattern in the direction perpendicularly to the longitudinal direction.

4. A fixing device for fixing a toner image onto a recording medium while conveying the recording medium at a nip portion, the device comprising:
a cylindrical film;
a heater in contact with an inner surface of the film; and
a pressing member configured to form the nip portion with the heater via the film,
wherein the heater includes:
an elongated planar substrate;
a first conductor pattern provided on the substrate along a longitudinal direction of the substrate, the first conductor pattern has an annular shape that includes first and second conductor portions provided along the longitudinal direction;
a second conductor pattern provided on the substrate along the longitudinal, the second conductor pattern has an annular shape that includes first and second conductor portions provided along the longitudinal direction;
a first heat generating resistor electrically connected to the first conductor portion of the first conductor pattern and the first conductor portion of the second conductor pattern, the first heat generating resistor being disposed between the first conductor portion of the first conductor pattern and the first conductor portion of the second conductor pattern;
a second heat generating resistor electrically connected to the second conductor portion of the first conductor pattern and the second conductor portion of the second conductor pattern, the second heat generating resistor being disposed between the second conductor portion of the first conductor pattern and the second conductor portion of the second conductor pattern;
a first electrical contact portion disposed at one end portion of the first conductor pattern in the longitudinal direction;
a second electrical contact portion disposed at the opposite end portion of the first conductor pattern in the longitudinal direction where the first electrical contact portion is disposed;
a third electrical contact portion disposed at one end portion of the second conductor pattern in the longitudinal direction; and
a fourth electrical contact portion disposed at the opposite end portion of the second conductor pattern in the longitudinal direction where the third electrical contact portion is disposed,
wherein the first and second heat generating resistors generates heat by electrical power supplied through the first, second, third, and fourth electrical contact portions.

5. A heater for use in a fixing device that fixes a toner image onto a recording medium, comprising:
an elongated planar substrate;
a first conductor pattern provided on the substrate along a longitudinal direction of the substrate;
a second conductor pattern provided on the substrate along the longitudinal direction, the second conductor pattern has an annular shape that includes first and second conductor portions provided along the longitudinal direction;
a first heat generating resistor electrically connected to the first conductor pattern and the first conductor portion of the second conductor pattern, the first heat generating resistor being disposed between the first conductor pattern and the first conductor portion of the second conductor pattern;
a second heat generating resistor electrically connected to the first conductor pattern and the second conductor portion of the second conductor pattern, the second heat generating resistor being disposed between the first conductor pattern and the second conductor portion of the second conductor pattern;
a first electrical contact portion disposed at one end portion of the first conductor pattern in the longitudinal direction;
a second electrical contact portion disposed at the opposite end portion of the first conductor pattern in the longitudinal direction where the first electrical contact portion is disposed;
a third electrical contact portion disposed at one end portion of the second conductor pattern in the longitudinal direction; and
a fourth electrical contact portion disposed at the opposite end portion of the second conductor pattern in the longitudinal direction where the third electrical contact portion is disposed,
wherein the first and second heat generating resistors generates heat by electrical power supplied through the first, second, third, and fourth electrical contact portions.

6. The heater according to claim 5 , wherein the width of the first conductor pattern in the direction perpendicularly to the longitudinal direction is larger than the width of the first conductor portion of the second conductor pattern in the direction perpendicularly to the longitudinal direction.

7. A fixing device for fixing a toner image onto a recording medium while conveying the recording medium at a nip portion, the device comprising:
a cylindrical film;
a heater in contact with an inner surface of the film; and
a pressing member configured to form the nip portion with the heater via the film,
wherein the heater includes:
an elongated planar substrate;
a

Assignees

• Canon Kk

Inventors

• Nakahara Hisashi
• Yonekubo Hideaki
• Taniguchi Satoru
• Sakakibara Hiroyuki
• Nihonyanagi Koji
• Shimura Yasuhiro
• Nakajima Nozomu
• Fujiwara Yuji
• Iwasawa Yusaku

Classifications

• H05B2203/016

  Heaters using particular connecting means · CPC title

• H05B2203/007

  using multiple electrically connected resistive elements or resistive zones · CPC title

• H05B3/26

  heating conductor mounted on insulating base {(for transparent areas H05B3/84, H05B3/86)} · CPC title

• G03G15/2042

  specially for the axial heat partition · CPC title

• H05B3/03

  Electrodes · CPC title