Abstract: A fixing apparatus of the present invention includes a heating roller 2 that is a cylindrical member having a center axis, a pressurizing roller 3 that exerts pressure on the heating roller 2, and a temperature detecting element 6 that detects the temperature of the heating roller 2. The outer peripheral surface of the heating roller 2 is induction heated on the basis of the temperature information detected by the temperature detecting element 6. The fixing apparatus thus utilizes induction heating. The present invention is characterized in that the temperature detecting element 6 is placed in an area located vertically below the center axis of the heating member 2 and vertically below the outer peripheral surface of the heating member. The temperature detecting element 6 is thus provided at a position where it is unlikely to suffer thermal convection from the heating roller 2.

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 comprises an elastic member, a heating roller including a conductive metal layer on the outside of the elastic member, a pressurizing roller for supplying a predetermined pressure to the heating roller, and a driving mechanism for rotating the heating roller through the conductive metal layer, wherein a member for connecting the driving mechanism and conductive metal layer is made of material that is not twisted and deformed by the rotation of the heating roller.

Abstract: In a fixing device for an image forming apparatus of the invention, circumferences of both side parts of an elastic layer are made larger than a circumference of a central part, and the expansion of a foamed rubber layer is absorbed by space between the elastic layer and a metal conductive layer. Thereby, the hardness of a heat roller at the time of fixing is made nearly uniform across the entire length in the shaft direction. The contact area of a core member and the elastic layer in the both side parts of the heat roller is made larger, and the stress per unit area generated in the elastic layer due to contact with the pressure roller is reduced.

Abstract: A fixing device for an image forming apparatus according to the present invention is configured in such a manner that both end portions of a form rubber layer are formed so as to be thicker than a center portion thereof for absorbing expansion of the foam rubber layer by a space between the foam rubber layer and a metal conductive layer. Accordingly, the hardness of a heat roller at the time of fixation becomes substantially uniform over the entire length thereof in the longitudinal direction. A pressure roller is out of contact with the heat roller until warming up is completed, and the pressure roller is brought into pressure contact with the heat roller after the heat roller has reached a warming up complete temperature, so that a load applied to both end portions of the heat roller is alleviated.

Abstract: The fixing device of the image forming apparatus of the present invention has a cleaning pad arranged on the upper frame which supports a heat roller. An infrared temperature sensor is supported by a supporting mechanism that is capable of supporting the infrared temperature sensor at the temperature detecting position and the evacuating position. When the right and left frames are attached/removed to/from the main body of the apparatus at the time of maintenance, the infrared temperature sensor is moved to the evacuating position and pressed against the cleaning pad and then, the right and left frames are moved by sliding to the main body of the apparatus. The cleaning pad is also slid and moved jointly with the slide moving of the right and left frames, and the infrared temperature sensor contacts the cleaning pad and dirt on the infrared temperature sensor is removed.

Abstract: The fixing device of the image forming apparatus of the present invention is provided with a heat transfer probe which contacts the heat roller and a surface temperature of the heat roller is transferred thereto. The erroneous detection of the surface temperature of the heat roller caused from materials adhered to the heat roller is prevented, induction heating coils is regulated at a high level of accuracy using the highly precious detection result obtained from the heat transfer probe, the temperature control of the heat roller is promoted and a fixed image of high quality is obtained.

Abstract: In an aspect of this invention, a fixing device includes a heating member including a first area and a second area formed of conductive members (e.g., aluminum and iron) having different magnetic permeability ratios, and an induction heating unit which generates a magnetic field from a coil to induction-heat this heating member, and the fixing device changes a frequency of a high-frequency current to be supplied to the coil to thereby control a heating area of the heating member.

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: A fixing apparatus according to the present invention ensures a nip width larger than a certain value by a heating roller which has a thin film metal conductive layer, and a foamed rubber layer which is bonded to the end part of the metal conductive layer, formed with a gap in a center part, and not bonded to the metal conductive layer.

Abstract: A fixing apparatus according to one aspect of the present invention includes 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 includes 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 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: The present invention relates to a heat generator including a central shaft, an elastic body formed to be a predetermined thickness at a circumference of the central shaft, a conductor layer formed to be a predetermined thickness at a circumference of the elastic body, and a second elastic body formed to be a predetermined thickness at a circumference of the conductor layer, and an apparatus including a magnetic field generator which provides a magnetic field such that the conductor layer of the heat generator can generate heat, and a pressure member which is provided along the central shaft of the heat generator, and applies pressure that deforms the elastic body layer by a predetermined amount to a predetermined position of the central shaft or the heating generator.

Abstract: The present invention relates to a temperature detection apparatus having a radiant temperature detection section including at least a ray emission portion which radiates at least rays and a ray detection portion which detects the rays, and capable of detecting temperature without contacting a detection object, a first atmospheric temperature detection section which outputs temperature information having a high temperature follow-up property in a case where the atmospheric temperature of the radiant temperature detection section is not more than predetermined temperature, and a second atmospheric temperature detection section which outputs temperature information having a high temperature follow-up property in a case where the atmospheric temperature of the radiant temperature detection section exceeds the predetermined temperature.

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: According to one aspect of the present invention, there is disclosed a fixing apparatus including a mold (holding member) formed by injection molding to hold a coil so that the coil maintains a predetermined positional relation with respect to a heating roller, and capable of holding a temperature sensor which detects a temperature of the heating roller and a thermostat which detects an abnormal temperature of the heating roller in predetermined positions facing the heating roller.

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: 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 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.

Abstract: The present invention relates to a temperature detection apparatus having a radiant temperature detection section including at least a ray emission portion which radiates at least rays and a ray detection portion which detects the rays, and capable of detecting temperature without contacting a detection object, a first atmospheric temperature detection section which outputs temperature information having a high temperature follow-up property in a case where the atmospheric temperature of the radiant temperature detection section is not more than predetermined temperature, and a second atmospheric temperature detection section which outputs temperature information having a high temperature follow-up property in a case where the atmospheric temperature of the radiant temperature detection section exceeds the predetermined temperature.