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US 2026/0267261 A1Published application
Heater and image heating device mounted with heater
AssigneeCanon Kabushiki Kaisha
InventorYasuhiro Shimura
Life of this patent
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Abstract
A heater of the present invention includes jointed heat generating resistors having a positive temperature characteristic of resistance and provided between a first conductive element and a second conductive element on a substrate in a longitudinal direction of the substrate, and a plurality of heating blocks provided in the longitudinal direction, each of which is a set of the first conductive element, the second conductive element, and the heat generating resistor,, and power supplied to at least one of the plurality of heating blocks can be controlled independent of other heating blocks.
Claims16
An image heating apparatus for heating an image formed on a recording material, the image heating apparatus comprising:
- (i) a cylindrical film;
- (ii) a heater provided in an inner space of the cylindrical film, the heater including:
- (ii-1) a substrate having a short direction that is a conveying direction of the recording material and a longitudinal direction that is a width direction of the recording material orthogonal to the conveying direction of the recording material, the substrate including a longitudinal end area and a longitudinal central area in the longitudinal direction;
- and
- (ii-2) an entire heat generating area including first and second heat generating blocks arranged in the longitudinal central area and the longitudinal end area, respectively, each of the first and second heat generating blocks including first and second conductive elements arranged on the substrate along the longitudinal direction and spaced apart from each other in the short direction, the first heat generating block including a first heat generating resistor portion between the first and second conductive elements of the first heat generating block in the short direction, the second heat generating block including a second heat generating resistor portion between the first and second conductive elements of the second heat generating block in the short direction, a length of a heat generating area of the first heat generating block being greater than a length of a heat generating area of the second heat generating block;
- (iii) a first temperature detecting element;
- (iv) a second temperature detecting element;
- (v) a safety element;
- (vi) a power supply line through which power from an AC power source is supplied to the first and second heat generating blocks, and
- (vii) a roller contacting an outer surface of the cylindrical film and, in cooperation with the heater through the cylindrical film, forming a nip configured to nip and convey the recording material between the cylindrical film and the roller,
- wherein the image heating apparatus heats, by heat of the heater, the image formed on the recording material nipped in the nip,
- wherein the first temperature detecting element is provided at a position on the heater corresponding to a first side area of the first heat generating block with respect to a center of the entire heat generating area in the longitudinal direction,
- wherein the safety element is provided at a position on the heater corresponding to both a second side area of the first heat generating block with respect to the center of the entire heat generating area opposite to the first side area in the longitudinal direction and a sheet-passing area through which a recording material of the smallest size among recording materials to be conveyed in the nip passes,
- wherein the second temperature detecting element is provided at a position on the heater corresponding to the second heat generating block, and
- wherein, in the power supply line, the first heat generating block is electrically connected in parallel with the second heat generating block, and the safety element is connected in series with the first and second heat generating blocks.
12 more elements
An image heating apparatus for heating an image formed on a recording material, the image heating apparatus comprising:
- (i) a cylindrical film;
- (ii) a heater provided in an inner space of the cylindrical film, the heater including:
- (ii-1) a substrate having a short direction that is a conveying direction of the recording material and a longitudinal direction that is a width direction of the recording material orthogonal to the conveying direction of the recording material, the substrate including a longitudinal end area and a longitudinal central area in the longitudinal direction;
- and
- (ii-2) first and second heat generating blocks arranged in the longitudinal central area and the longitudinal end area, respectively, each of the first and second heat generating blocks including first and second conductive elements arranged on the substrate along the longitudinal direction and spaced apart from each other in the short direction, the first heat generating block including a first heat generating resistor portion between the first and second conductive elements of the first heat generating block in the short direction, the second heat generating block including a second heat generating resistor portion between the first and second conductive elements of the second heat generating block in the short direction, a length of a heat generating area of the first heat generating block being greater than a length of a heat generating area of the second heat generating block;
- (iii) a first temperature detecting element;
- (iv) a second temperature detecting element;
- (v) a safety element;
- (vi) a power supply line through which power from an AC power source is supplied to the first and second heat generating blocks;
- and
- (vii) a roller contacting an outer surface of the cylindrical film and, in cooperation with the heater through the cylindrical film, forming a nip configured to nip and convey the recording material between the cylindrical film and the roller,
- wherein the image heating apparatus heats, by heat of the heater, the image formed on the recording material nipped in the nip,
- wherein the first temperature detecting element is provided at a position on the heater corresponding to a first side area of the first heat generating block with respect to a reference position in the longitudinal direction, the reference position being a conveyance reference position of the recording material in the width direction,
- wherein the safety element is provided at a position on the heater corresponding to both a second side area of the first heat generating block with respect to the reference position opposite to the first side area in the longitudinal direction and a sheet-passing area through which a recording material of the smallest size among recording materials to be conveyed in the nip passes,
- wherein the second temperature detecting element is provided at a position on the heater corresponding to the second heat generating block, and
- wherein, in the power supply line, the first heat generating block is electrically connected in parallel with the second heat generating block, and the safety element is connected in series with the first and second heat generating blocks.
13 more elements
Dependencies are inferred from the claim text.