IMAGE HEATING APPARATUS AND HEATER USED FOR THE IMAGE HEATING APPARATUS

• US 20090230114A1
• Filed: 03/12/2009
• Published: 09/17/2009
• Est. Priority Date: 03/14/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Taniguchi, Satoru, Hasegawa, Hiroto
• Granted Patent: US 8,471,178 B2
• Time in Patent Office: Days
• US Class Current: 219/216
• CPC Class Codes: G03G 15/2042 specially for the axial heat partition

Abstract

The image heating apparatus includes a heater has a first and heat-generation segment having a plurality of heat generating parts therein in the longitudinal direction respectively, and the heat generating parts each having a first electro-conductive pattern provided along the longitudinal direction on a substrate, and a second electro-conductive pattern provided along the longitudinal direction on said substrate and has a region that overlaps with said first electro-conductive pattern in the longitudinal direction, and a heat generating resistor which electrically connects the respective overlapping regions of said first electro-conductive pattern and said second electro-conductive pattern with each other and generates heat by a supplied electric power. It simultaneously prevents the temperature in a non-sheet feeding portion from rising and secures fixing properties in a gap between the divided heat generating resistors, and a heater used in this image heating apparatus.

Claims

1. An image heating apparatus for heating an image formed on a recording medium, comprising:

an endless film,

a heater which contacts with the inner face of said endless film, said heater being arranged in a direction whose longitudinal direction is parallel to a generatrix of said endless film;

a back-up member that forms a nipping portion which pinches a recording medium together with said heater through said endless film, and conveys the recording medium;

wherein said heater has a first heat-generation segment provided in an upstream side, and a second heat-generation segment which is provided in a downstream side and is electrically connected to said first heat-generation segment in series, in a transport direction of the recording medium;

wherein said first heat-generation segment and said second heat-generation segment have a plurality of heat generating parts therein in the longitudinal direction respectively, and the heat generating parts are electrically connected to each other in series;

wherein each of the plurality of said heat generating parts has a first electro-conductive pattern which is provided along the longitudinal direction on a substrate, a second electro-conductive pattern which is provided along the longitudinal direction on said substrate and has a region that overlaps with said first electro-conductive pattern in the longitudinal direction, and a heat generating resistor which electrically connects the respective overlapping regions of said first electro-conductive pattern and said second electro-conductive pattern with each other and generates heat by a supplied electric power;

wherein a position of a gap between said adjacent heat generating parts in said first heat-generation segment is different from a position of a gap between said adjacent heat generating parts in said second heat-generation segment, in the longitudinal direction.

2. An image heating apparatus according to claim 1, wherein resistance-temperature characteristics of said heat generating resistor includes negative resistance-temperature characteristics.

3. A heater for an image heating apparatus, including an endless film therein and heating an image formed on a recording medium, comprising:

a first heat-generation segment provided on one end side of said heater in a transverse direction;

a second heat-generation segment provided on the other end side of said heater in the transverse direction and is electrically connected to said first heat-generation segment in series;

wherein said first heat-generation segment and said second heat-generation segment have a plurality of heat generating parts in the longitudinal direction of said heater respectively, and the heat generating parts are electrically connected to each other in series;

wherein each of the plurality of said heat generating parts has a first electro-conductive pattern which is provided along the longitudinal direction on a substrate, a second electro-conductive pattern which is provided along the longitudinal direction on said substrate and has a region that overlaps with said first electro-conductive pattern in the longitudinal direction, and a heat generating resistor which electrically connects the overlapping regions of said first electro-conductive pattern and said second electro-conductive pattern with each other and generates heat by a supplied electric power;

wherein the position of a gap between said adjacent heat generating parts in said first heat-generation segment is different from the position of a gap between said adjacent heat generating parts in said second heat-generation segment, in the longitudinal direction.

4. A heater according to claim 3, wherein resistance-temperature characteristics of said heat generating resistor includes negative resistance-temperature characteristics.