145results about "Roller heating devices" patented technology

The image heating apparatus includes a heater that achieves even heat-generation distribution and suppression of a non-sheet feeding portion temperature increase when an image is printed on a sheet whose size is smaller than a maximum size for the apparatus, and an endless belt, wherein plural heat-generation resistive members having positive temperature coefficients are connected in parallel are provided between first and second conductive members provided along a longitudinal direction of a substrate; plural heat-generation blocks including the plural heat-generation resistive members connected in parallel, are arranged in series along the longitudinal direction; and in the plural heat-generation resistive members included in one of the heat-generation blocks, a heat-generation resistive member arranged at an end portion in the longitudinal direction has a resistivity value higher than that of a heat generation resistive member arranged at a center in the longitudinal direction, or an interval between heat generation resistive members is larger in the end portion.

The heater is capable of improving heat generation uniformity in a sheet feeding area while suppressing the temperature rise of a non-sheet feeding portion. Each of heat generation lines includes a plurality of heat blocks in which a plurality of heat generating resistors are electrically connected in parallel between two conductive members. The heat generation lines are arranged in a lateral direction of the substrate, and the heat blocks are arranged so that the end of the heat block in the heat generation line of a first row does not overlap with the end of the heat block in the heat generation line of a second row in a longitudinal direction of a heater.

A heating device suitable for use as a fixing means for fixing a toner image onto a recording medium in, e.g., an electrophotographic image forming apparatus is provided so as to provide images free from image blurring or fixing failure while improving the anti-offset performance. The heating device includes a heating member, and a heat-resistant film having a first surface to be moved relative to and in contact with the heating member and a second surface to be in contact with a member to be heated, so that the member to be heated and the heat-resistant film are moved together over the heating member to heat the member to be heated. The heat-resistant film comprises at least a base layer and an elastic layer, wherein the elastic layer contains a filler exhibiting a thermal conductivity of at least 0.04 cal/cm.sec. °C.

The image heating apparatus for heating an image formed on a recording material has a heater, a film moving in contact with the heater, and a back-up roller for defining a nip with the heater via the film. In the image heating apparatus, the heater includes a metallic substrate, and the metallic substrate has a convex surface on a side of the nip and a concave surface on an opposite surface.

A heater is provided having at least one thermally sprayed resistive heating layer, the resistive heating layer comprising a first metallic component that is electrically conductive and capable of reacting with a gas to form one or more carbide, oxide, nitride, and boride derivative; one or more oxide, nitride, carbide, and boride derivative of the first metallic component that is electrically insulating; and a third component capable of stabilizing the resistivity of the resistive heating layer. In some embodiments, the third component is capable of pinning the grain boundaries of the first metallic component deposited in the resistive heating layer and/or altering the structure of aluminum oxide grains deposited in the resistive heating layer.

The invention is to provide an image heating apparatus capable of preventing an excessive temperature increase in a sheet non-passing area and a heater for use in such apparatus, and the heater for use in the image heating apparatus of the invention is constructed by including: a substrate; a heat generating resistor formed on the substrate; and first and second electrodes for supplying an electric power to the heat generating resistor; wherein each of the first and second electrodes has a first area to be contacted with a power supplying connector and a second area provided at an end portion electrically opposite to the first area, the second areas are provided along a longitudinal direction of the substrate, and the heat generating resistor is so provided as to electrically connect the second area of the first electrode and the second area of the second electrode; wherein, within the second area of the first electrode, a portion electrically closest to the first area of the first electrode is provided in the vicinity of an end portion of the substrate in the longitudinal direction thereof, and within the second area of the second electrode, a portion electrically closest to the first area of the second electrode is provided in the vicinity of the other end portion of the substrate in the longitudinal direction thereof; and wherein, when the heater is at a set temperature for an image heating operation in the image heating apparatus, a resistance value Rc of the second area of either of the first and second electrodes and a resistance value Rt between a portion within the second area of the first electrode electrically closest to the first area of the first electrode and a portion within the second area of the second electrode electrically closest to the first area of the second electrode satisfy a relation:

The image heating apparatus includes first and second lines having a first and second heat generation blocks, the first and second lines being disposed at different positions in a transverse direction, wherein the first and second lines are arranged so that a whole of first heat generation block in the first line and a whole of second heat generation block in the second line overlap with each other in the longitudinal direction, and a whole of second heat generation block in the first line and a whole of first heat generation block in the second line overlap with each other in the longitudinal direction. By the virtue of the present invention, it achieves to be capable of suppressing a temperature rise in a non-sheet feeding area in a case of printing a sheet smaller in size than a maximum size supported by the image heating apparatus.

An electric power supply is controlled below a maximum suppliable current value by detecting the applied current of a heater. The image forming apparatus includes a heater which includes heating elements that generate heat when electric power is supplied, a current detector for detecting a current value supplied to the heater, a temperature detector for detecting the temperature of the fixing device, and an electric power controller for supplying electric power to the heater with a current application duty based on the temperature detected by the temperature detector within a range below a maximum current application duty. The maximum current application duty can be reset based on a current application duty to the heater and based on a current value detected by the current detector.

A heating member includes a resistive heating layer disposed on an outermost layer of the heating member, where the resistive heating layer comprises a conductive filler distributed in a base material and where the resistive heating layer emits heat when supplied with an electric current from an electrode, and a contacting unit which exposes the conductive filler of the resistive heating layer and contacts the electrode..

The heating apparatus comprises a substrate extending in one direction and a plurality of heat generating members provided on one surface of the substrate along a longitudinal direction thereof and wherein at least one of the plural heat generating members has heat generating regions having different heat generation amount per unit length in the longitudinal direction, substrate reinforcing members are provided on the other surface of the substrate in correspondence to the high heat generating regions provided on one surface of the substrate. By the virtue of the invention, cost can be reduced, emergency safety upon occurrence of overrun of a CPU can be achieved, and increase in temperature of a sheet non-passing portion can be suppressed.

A heater including a substrate, a first heat generating line provided on the substrate and in a longitudinal direction of the substrate, the first heat generating line being divided into a plurality of heat generating blocks in the longitudinal direction, the plurality of heat generating blocks being controllable independently, and a second heat generating line provided on the substrate and in the longitudinal direction of the substrate, the second heat generating line being divided into a plurality of heat generating blocks in the longitudinal direction, the plurality of heat generating blocks being controllable independently. In the heater, divided positions of the first heat generating line and divided positions of the second heat generating line are different.

An upper heat roller with an external heat source and a lower heat roller with an internal heat source are arranged with a paper transport path therebetween, in such a manner as to be pressed against each other. The lower heat roller is heated sufficiently, thereby supplying a paper sheet with sufficient heat when the paper sheet is transported through a contact region between the upper and lower heat rollers to be heated.

Provided is a heating resistor element including: an insulating substrate including a glass material; a heat accumulating layer bonded to the insulating substrate through heating to temperature ranging from an annealing point to a softening point in a state of being adhered to a surface of the insulating substrate, and including the same material as the glass material of the insulating substrate; and a heating resistor provided on the heat accumulating layer, in which, on at least one of bonded surfaces between the insulating substrate and the heat accumulating layer, at least one of the insulating substrate and the heat accumulating layer is provided with a concave portion in a region opposed to the heating resistor to form a hollow portion. Accordingly, deformation caused by a difference in coefficient of thermal expansion is suppressed to improve printing quality.

An apparatus includes a first and second driving circuits that energize a first and third heat generating blocks; a first and second temperature detection members that detect each temperature of the first and third heat generating blocks; a control portion that controls the first and second driving circuits according to at least one of the temperatures detected by the first and second temperature detection members; and a connection switching portion that selectively connects any one of the first and second driving circuits to a second heat generating block according to a switching instruction from the control portion. The control portion controls energization of the second heat generating block together with a heat generating block which is energized by the driving circuit connected to the second heat generating block.

In a fixing device for causing a pressurizing roller to come in pressure contact with a heating roller including a central region heating heater for heating a central region and a side end region heating heater for heating a side end region on an outside of the central region, thereby fixing an unfixed toner, or an image forming apparatus comprising the fixing device, an outside of an image region of the heating roller is caused to have a peak of heat distribution of the central region heating heater and heat radiated from both side ends of the heating roller is compensated to flatten the temperature distribution of the image region, thereby preventing a deterioration in an image.