Abstract: The present invention is related to a fixing device for fusing and fixing an unfixed toner image on a recording sheet. In the fixing device, a heating member such as rollers and endless belts and the like, is heated to a fixing temperature. An endless belt is provided opposite the heating member and is pressed against the heating member by a pressure member provided inside the endless belt. The heating member is driven in rotation in a transport direction of the recording sheet and the endless belt is driven in conjunction with the rotation of the heating member. The recording sheet bearing a toner image passes between the heating member and the endless belt while in this state, and the toner image is heated by the heating member so as to be fused onto the recording sheet under the pressure produced between the heating member and endless belt while the recording sheet is transported therebetween.

Abstract: An induction heating type fixing apparatus comprises a fixing sleeve formed of a flexible thin electrically conductive magnetic material, a coil for producing an induced eddy current in the fixing sleeve to generate heat therein, a holder adapted to retain the coil and disposed stationarily in the fixing sleeve, and a pressing roller pressed against the holder through the fixing sleeve. A sheet carrying thereon an unfixed toner is conveyed as nipped between the fixing sleeve and the pressing roller. The toner on the sheet is melted by the heat of the sleeve itself and exposed to the pressure exerted between the holder and the pressing roller and fixed on the sheet. The holder is provided with a separating member adapted to effect the curvature separation of the sheet from the fixing sleeve. The holder is further provided with a heat-diffusing member made of a material with good thermal conductivity characteristics and non-magnetic properties.

Abstract: An induction heating device for printers, copiers and the like includes a magnetic coil assembly and a heated metal body that form a closed magnetic circuit. To compensate for the effects of heat radiation at the ends of the heated metal body, a greater amount of heat is generated at the ends of the body than at the center thereof. In one approach, the amount of heat is varied by changing physical parameters of the magnetic circuit, such as the spacing of the coil assemblies from the heated body, the relative sizes of the cores, and/or the relative magnetic permeability of the cores. In another approach, the electrical connection of the coils of multiple assemblies are arranged such that the coils in the center of the heated body are in parallel, and the coils at the ends of the body are in series with the parallel central coils.

Abstract: The present invention relates to an induction type heat fixing device. In the induction type fixing device, a high frequency current is supplied to a coil by switching an electric current supply to coil between a supply state and an interrupted state so that an induction current is generated in a fixing roller (heat-receiving member). The high frequency current is controlled in accordance with at least one of the voltage fluctuation of the electric power source, the amount of coil current and the coil voltage.

Abstract: A toner image formed on a recording member is fixed onto the recording member by a fixing device having a heatable member, a heater for heating the heatable member positioned on one side of the heatable member, the recording member being positioned on an opposite side of the heatable member and spaced from the heatable member to heat the recording member by radiation from the heatable member, and a fixing structure for fixing the toner image on the heated recording member. The heatable member can be a fixing belt arranged in a loop while the heater is an electromagnetic induction coil positioned substantially within the loop. The electromagnetic induction coil generates a magnetic flux perpendicular to the transport direction of the fixing belt to produce an eddy-like induction current in a conductive member of the fixing belt to heat the fixing belt. The fixing belt, in turn, heats the recording member on the exterior side of the belt to soften the toner image thereon. The fixing structure, e.g.

Abstract: The induction-heating apparatus of this invention contains a conductive member, a power source, and a first and a second induction coil connected to the power source and adapted for causing the conductive member to generate an induced current, the first and the second induction coil being parallelly connected. The induction coil is formed by winding a copper wire round a core in such a manner that the numbers of turns of the copper wire gradually decrease from the lowermost layer approximating most closely to the core to the upper layers. This heating apparatus has the thickness of the induction coil in the range of 0.2-0.8 mm. The gap between the induction coil and the conductive member is in the range of 0.5-4.0 mm. This heating apparatus has the induction coil thrust out of the conductive member. The induction coil is formed of a Litz wire.

Abstract: A fixing device for heating and fixing an unfixed image to a record member bearing the unfixed image, including a heating roller, a backup member, and a current transmitting units. The heating roller includes a core roller, and a resistance heating member which is formed on the core roller and generates heat when a current is transmitted thereto through the current transmitting units, and is rotatably carried at opposite ends of the core roller by bearing units. The current transmitting units are arranged at positions opposed to the bearing units. The current transmitting unit includes a current receiver member and a current supply member. At mutual contact surfaces of them, the current receiver member has a concave section, and the current supply member has a convex section. The outer periphery circle of at least one side surface of said current receiver member has a radial difference of 6 mm or more with respect to an outer periphery circle of the heating roller at a sheet passing region.

Abstract: In the printing apparatus wherein the laser diode is used as light source for writing images on an image carrier, a control transistor is serially connected to the laser diode. The magnitude of the drive current for driving the laser diode is adjusted in accordance with the magnitude of the base current of the control transistor. The base current of the control transistor is turned on when the main power supply is implemented. That is, the control transistor is pre-heated up to print command. Consequently, the drive current is stable from the initial image formation after the main power supply is turned on.

Abstract: An induction heating fixing device comprises a heat roller in which coil assemblies are disposed. The coil assemblies are aligned axially of the roller to produce magnetic flux in a direction orthogonal to the axis of the heat roller.

Abstract: A laser drive apparatus capable of modulating the intensity of a laser output in conformity with a variation in the intensity of laser output. In this apparatus, the interval of laser emission intensity between 40% and 100% is equally divided by the number of intensity levels, the magnitude of the laser drive current (digital data) corresponding to the intensity levels is determined by computation, the results of this computation are memorized by the lookup table RAM (LUTRUM) 14, and the control of intensity levels is effected by the digital data in the LUTRAM 14.