Abstract: A fixing apparatus according to one aspect of the present invention comprises a first non-contact temperature detecting section which detects a surface temperature of a heat roller in the vicinity of a heating apparatus, a second non-contact temperature detecting section which is provided in non-contact with a surface of each of a heat roller and a pressure roller, and which detects a surface temperature of at least one of the heat roller and the pressure roller, and a control section which compares a difference between a first temperature detected by the first non-contact temperature detecting section and a second temperature detected by the second non-contact temperature detecting section with a predetermined specified temperature difference, and when the difference between the first temperature and the second temperature is greater than the specified temperature difference for a predetermined period or longer, stops heating of the heat roller by the heating apparatus.

Abstract: A fixing apparatus of an image forming apparatus of the present invention strikes a support plate having an infrared temperature sensor against a roller shaft of a heat roller, thereby, regardless of the part accuracy, keeps a gap between the heat roller and the infrared temperature sensor constant. By improvement of the temperature detection accuracy of the infrared temperature sensor, the temperature control of the heat roller is improved and toner images can be fixed always at a fixed temperature. The fixing property is improved and fixed images of high image quality free of ripple marks are obtained.

Abstract: A fixing apparatus according to one aspect of the present invention comprises a non-contact temperature detecting element 81 allocated in non-contact with a heat roller, the sensing element detecting a temperature of the heat roller. The non-contact temperature sensing section 81 comprises a thermopile P which detects a target temperature Pt of a heat roller 2, a temperature element CPU 100 which estimates an ambient temperature at the periphery of the thermopile P and computes an estimated ambient temperature SQt, and a thermister Q which detects an ambient temperature Qt at the periphery of the thermopile and outputs the ambient temperature Qt at an output voltage of a predetermined rate with respect to a total output voltage value corresponding to the estimated ambient temperature SQt.

Abstract: A fixing device of an image forming apparatus of the present invention enables induction heating coils for a 100 V power source to set a ratio of inductance L to load resistance R of a heat roller to L/R <35×10?6 (H/?) and coil impedance Z (?) to Z<10 (?) and supplies a drive current at a high frequency of 40 to 70 kHz. By doing this, an eddy current generated in the heat roller is concentrated upon a metallic conductive layer by the skin effect and the heat generation efficiency of the heat roller is improved.

Abstract: A fixing apparatus according to the invention is provided with a heating roller 2 including an elastic member 2b and a metal conductive layer 2c. The elastic member has a greater outer diameter at its end portions than at its central portion. At least one air hole 100 is formed through the metal conductive layer 2c at a predetermined position opposing the small-diameter central portion of the elastic member. The air hole connects the outside to a clearance formed between the elastic member 2b and the metal conductive layer 2c.

Abstract: A fixing apparatus according to the invention is provided with a heating roller 1. The heating roller 1 includes an elastic layer 1b formed around a shaft member 1a, a conductive layer 1e formed outside the elastic layer 1b, and at least one impedance-adjusting layer 1d interposed between the elastic layer 1b and the conductive layer 1e. The conductive layer 1e includes conductive paste containing metal particles.

Abstract: An image forming system has: a manuscript image reading device to scan a manuscript and obtain shade information on the manuscript; an exposure/development device to record a charged latent image in a photosensitive body based on the shade information obtained by said manuscript image reading device, to apply toners to the photosensitive body to transfer the toners to a recording medium; and a fixing device to fix the toners transferred to the recording medium by thermal pressing; said fixing device having a rotational heating member; a pressing roller for pressing from a bottom of the rotational heating member; and a non-contact temperature detector provided above a horizontal surface passing a rotation axis of the rotational heating member, which detects a temperature of said rotational heating member; wherein heating of the rotational heating member is controlled by a value detected by said non-contact temperature detector.

Abstract: A fixing apparatus of one embodiment of the present invention has a heating member which is heated by induction heating, a pressing member which supplies a predetermined pressure to the heating member, and induction heating mechanisms which supply a predetermined magnetic field to the heating member. The induction heating mechanisms have a plurality of coils. By arranging the adjacent coils and adjacent coils to overlap, the temperature distribution in the length direction of the heating member can be made uniform.

Abstract: An excitation coil and/or a core member, which has a characteristic frequency other than frequencies used, is employed. Thereby, resonance is prevented between adjacent coils or between a coil and an adjacent component such as a core member.

Abstract: In an image forming apparatus according to the present invention, a shield plate 202 which is made of a specific material and has a specific thickness is provided between an exciting coil and at least one of a first and a second magnetic field intensity measuring point P1, P2, which prevents a magnetic field of a specific magnetic field intensity or higher from leaking to the outside of the image forming apparatus or alleviates the effect of the magnetic field on the circuits in the apparatus or optionally installed devices.

Abstract: A CPU detects a temperature of a central part of a heating roller. If the detected temperature does not exceed 180° C., the CPU drives a central coil or a side-end coil for 0.4 second in accordance with a temperature difference between the central part of the heating roller and a side-end part of the heating roller. Then, the CPU drives the side-end coil or central coil for 0.2 second. Thereafter, the CPU detects the temperature of the central part and repeats the driving control until the detected temperature reaches 180° C.

Abstract: According to one aspect of the present invention, there is provided a fixing apparatus having a non-contact temperature detecting unit which detects temperature by sensing infrared rays emitted from the a heating roller. A difference between a real temperature and the temperature detected by the non-contact temperature detecting unit, which is produced by time-lag until reaching the infrared rays emitted from the heating roller, is corrected.

Abstract: According to a mode of the present invention, there is disclosed a fixing apparatus comprising a non-contact temperature detection section which detects a temperature by infrared rays radiated from a heating member, to made uniform a surface temperature of the heating member in an axial direction and a rotation direction based on first temperature information for detecting a temperature difference of the axial direction of the heating member and second temperature information for detecting the temperature difference of the rotation direction of the heating member.

Abstract: A fixing apparatus of one embodiment of the present invention has a heating member which is heated by induction heating, a pressing member which supplies a predetermined pressure to the heating member, and induction heating mechanisms which supply a predetermined magnetic field to the heating member. The induction heating mechanisms have a plurality of coils. By arranging the adjacent coils and adjacent coils to overlap, the temperature distribution in the length direction of the heating member can be made uniform.

Abstract: An electrophotographic fixing device allowing a flow of an AC current through an electromagnetic induction coil arranged close to a heating roller having a metal layer formed of a conductor and allowing the heat generation of the heating roller to heat a to-be-fixed member, in which the fixing device comprises a circuit board for outputting the AC current from an output terminal and passing the current through the electromagnetic induction coil, a conductive plate metal having one end side fixed by a fastening screw to the output terminal of the circuit board, a male-side connection terminal provided on the other end of the plate metal, and a female-side connection terminal provided at an end of a leader line of the electromagnetic induction coil and detachably connected to a male-side connection terminal.

Abstract: A heating apparatus includes first and second coil members, a heat roller and an input control mechanism. The first and second coil members respectively are part of first and second excitation circuits. The heat roller generates an eddy current inside by a magnetic field generated by the first and second coil members. The input control mechanism drives the first and second excitation circuits. The input control mechanism starts driving only the first excitation circuit from a state where operations of the first and second excitation circuits are stopped. When the temperature detection mechanism detects a predetermined temperature, the input control mechanism stops supplying power to the first excitation circuit and supplies power only to the second excitation circuit, and the heat roller initiates rotating.

Abstract: A DC circuit 110 is provided to convert the voltage of a commercial AC power supply 100 into a DC voltage having a fixed level and output the DC voltage irrespective of the level of the voltage. The rectifier circuit 110 includes contacts 117, 118 and 119 and functions as one of a full-wave doubler voltage rectifier circuit and a full-wave rectifier circuit according to the opening and closing of each of the contacts.

Abstract: The present invention relates to a device including a body to be heated to which a magnetic field is supplied to generate heat and which heats a developer on a material to be recorded, a plurality of coil bodies which generate an induced heat in the body to be heated from the outside of the body to be heated and which include litz wires having cross sections formed in rectangular shapes and which are disposed in a longitudinal direction of the body to be heated, and a pressure applying member which contacts the body to be heated in a predetermined position and which fixes the developer on the material to be recorded passing between the pressure applying member and the body to be heated.

Abstract: A heat roller is configured to have a heat insulating member 4 and a metal member formed on the heat insulating member. Coils 21, 22 and 23 are provided outside the heating roller 2 to induction-heat the heating roller 2.

Abstract: A fixing apparatus according to an embodiment of the present invention has a plurality of coils which are independently controlled by an inverter circuit. These coils have shapes to make the difference between the frequencies of the flowing high-frequency current out of an audible frequency range, preventing interference noise.