Abstract: An apparatus to generate a high voltage includes an outputting part having a power transforming part formed with a primary and a secondary coil, a switching part to control an output voltage induced in the secondary coil of the power transforming part, by interrupting a current in the primary coil of the power transforming part, a digital controlling part to control an interruption operation of the switching part according to a time constant determining a wave form of the output voltage of the power transforming part and a control reference value determining a level of the output voltage, and a digital interfacing part to convert input control data having first and second forms into the time constant and the control reference value, respectively, and to provide the time constant and the control reference value to the digital controlling part.

Abstract: An apparatus to generate a high voltage includes a switching part to control a voltage induced in a secondary coil of a power transforming part, by interrupting a current in a primary coil of the power transforming part, a digital controlling part to control the interruption operation of the switching part according to supplied control data. The switching part, the digital interfacing part and the digital controlling part may be embodied in an ASIC chip (application-specific integrated circuit). An optimum control according to an output state of the apparatus is easily achieved, manufacturing time for tuning each parameter is reduced and heat generation in the apparatus is reduced.

Abstract: A fixing device usable with an image forming apparatus having a fixing roller to fix a toner on a recording medium, a heater to heat the fixing roller, and a power supplier to supply an electric power to the heater includes a relay interposed between the power supplier and the heater to supply and interrupt the electric power to the heater, an auxiliary power supplier to supply a driving power to the relay, and a thermoswitch interposed between the relay and the auxiliary power supplier and mounted adjacent to the fixing roller -to be electrically opened when the fixing roller reaches a predetermined overheating temperature. The fixing device is used in an image forming apparatus to reduce manufacturing costs and improve credibility and stability on an overheating prevention operation.

Abstract: An analog control application specific integrated circuit (ASIC) apparatus for a high voltage power supply (HVPS) in an image for apparatus, and a method for controlling the HVPS are provided. The HVPS includes a transformer transforming an AC signal to a high voltage signal and a voltage doubler outputting a DC high voltage for the HVPS. The ASIC includes an analog control circuit configured as a one-chip ASIC that converts a predetermined DC level signal to a high frequency switching signal using a switching component and outputs the converted high frequency switching signal to a primary winding of the transformer. If the high voltage output signal output from the voltage doubler is not feedbacked, the switching component high frequency switches a received driving signal of a gate driver, and outputs the high frequency switched signal to the transformer.

Abstract: An image printer uses a common filter to remove harmonic waves generated at a common operating frequency band of a fixing module to fix toner onto a print medium using high frequency power generated from a high frequency generator and a switch mode power supply module to supply operating power to the high frequency generator. The image printer includes a fixing module to fix toner to a print medium using high frequency power generated from a high frequency generator, a switch mode power supply module to supply operating power to the high frequency generator, and a band pass filter to filter harmonic waves of a common operating frequency band of the fixing module and the switch mode power supply module. The fixing module rectifies an input AC current supplied through the band pass filter to generate a high frequency current and fixes the toner to the print medium by generating heat using the generated high frequency current.

Abstract: A fusing apparatus in an image forming apparatus that heats a fusing unit by applying an induced current is provided. The flicker characteristics of the fusing apparatus are improved by gradually increasing the amount of induced current applied to the fusing unit for a predetermined amount of time so that the amount of induced current applied to the fusing unit is prevented from severely varying. The fusing apparatus comprises a fusing unit which is resistance-heated or induction-heated by applying an induced current and fuses toner onto paper using the heat. The fusing apparatus further comprises a pulse width modulation (PWM) signal generation unit which generates a PWM signal in response to the ON signal so that the amount of induced current input to the fusing unit gradually increases to a reference current.

Abstract: A fusing roller and a fusing apparatus using the same are provided. The fusing roller includes a coil unit resistance heated by a predetermined alternating current, and generating an alternating magnetic flux by the alternating current. A heating roller unit is heated by an induced current generated by the alternating magnetic flux. An adhering unit is formed of a non-magnetic material and is installed to contact the inside of the coil unit to elastically bias the coil unit toward the heating roller unit to adhere the coil unit onto the heating roller unit.

Abstract: A fusing roller and a fusing apparatus using the same are provided. The fusing roller includes a coil unit resistance heated by a predetermined alternating current, and an alternating magnetic flux is generated by the alternating current. A heating roller unit is heated by an induced current generated by the alternating magnetic flux. End caps are installed on both ends of the heating roller unit and have electrodes for receiving power from an external power source. Reduction units are formed on both ends of the coil unit to reduce contact resistance generated when the coil unit contacts the electrodes.

Abstract: A fixing device of an image forming apparatus includes a fixing roller rotatably mounted on a moving path of a printing medium having a toner image transferred thereon to fuse the toner image on the printing medium, a heater mounted in the fixing roller to generate a magnetic field by applied voltage, thus heating the fixing roller, and at least one magnetic core disposed around the fixing roller to concentrate, onto the fixing roller, the magnetic field generated by driving the heater. Accordingly, a density difference of the magnetic field generated by the heater is minimized by disposing the at least one magnetic core around the fixing rollers, thus enabling a uniform fixing temperature.

Abstract: A fusing device for fusing a predetermined toner image on paper, and which controls the heating range of a fusing unit by inputting an eddy current generated by a transformer to a terminal corresponding to the size of paper selected from a plurality of terminals of the fusing unit. The fusing device includes a power supply unit to which a predetermined alternating current is input and which generates an induced current in response to the input alternating current, a fusing unit being resistance-heated and induction-heated by the induced current and fusing the toner image on the paper using the generated heat, and a controller for controlling the induced current supplied to the fusing unit according to the size of the paper.

Abstract: A fusing roller and a fusing apparatus having the same are provided.

Abstract: A fusing roller and a fusing apparatus having the fusing roller are provided, wherein the fusing roller includes a coil unit, which generates resistive heat and an alternating magnetic flux in response to an alternating current input thereto, a heating roller unit, which generates an eddy current in response to the alternating magnetic flux and generates induced heat in response to the eddy current, and a contact unit, which is formed of a non-magnetic material in the fusing roller and which firmly contacts the coil unit with the heating roller unit.

Abstract: A fusing roller and a fusing apparatus having the fusing roller are provided. The fusing roller includes a roller unit and an induced heat generation unit that is installed on an outer circumferential surface of the roller unit. Eddy currents are generated in the roller unit in response to an alternating current input thereto. An insulation unit insulates the induced heat generation unit from the roller unit.

Abstract: Provided is a device for fusing a predetermined toner image on paper, and more particularly, to a device for heating a toner fusing unit by using resistance heating and induction heating simultaneously and fusing a toner image on paper using the heated toner fusing unit. The fusing device comprises an alternating current generator for generating a predetermined alternating current; a coil portion that is resistance-heated by the alternating current and generates an alternating magnetic flux by the alternating current; and a toner fusing unit for generating an eddy current by the alternating magnetic flux and that is induction-heated by the generated eddy current.

Abstract: A device for fusing a predetermined toner image on a paper and which electrically insulates a heating body of a fusing unit from a power supply unit by heating the heating body using an induced current generated by a transformer. The fusing device includes an insulation unit for generating an induced current in response to an alternating current, a heating body heated by the generated induced current, a toner fusing unit which fuses the toner image on the paper using the heat received from the heating body, and a tube-expansion adhesion portion closely adhering the heating body to the toner fusing unit using a predetermined tube-expansion pressure.

Abstract: A fuser-controlling apparatus for generating a power synchronization signal and detecting a power voltage. The fuser-controlling apparatus comprises a power synchronization signal generation circuit for outputting a power synchronization signal for synchronizing fuser operations with a power voltage, a power voltage detection circuit for detecting a level of the power voltage and for outputting a level of the power voltage, and a control unit for controlling a voltage to the fuser in a phase control manner based on the power synchronization signal and the detected level of the power voltage. The fuser-controlling apparatus can produce a power synchronization signal at the zero-crossing points of the power voltage regardless of the levels and frequencies of the power voltage. Accordingly, the fuser-controlling apparatus can instantaneously perform phase and power controls based on such a power synchronization signal, resulting in improvements to the power factor and flicker characteristics of the system.

Abstract: A high voltage power supply (HVPS) including an oscillation circuit for generating and outputting an alternating current (AC) voltage using an oscillation of a transformer, and a voltage multiplying circuit for increasing the AC voltage from the oscillation circuit using a plurality of voltage doublers, and outputting the increased AC voltage. The power supply further includes a controller for controlling the oscillation circuit, such that a high voltage output can be obtained without requiring expensive, high voltage rated elements, and as a result, reducing the price of the HVPS circuit and allowing production of economical ultra-high HVPS systems.

Abstract: An apparatus and method of controlling a fixer in an image forming apparatus includes an AC power source inputting unit to receive an external power source voltage signal, a synchronization signal generating device to generate a pulse signal synchronized with a peak of the power source voltage signal received from the AC power source inputting unit, and a controlling unit to control the pulse signal generated by the synchronization signal generating device so that a power source is supplied to the fixer.

Abstract: A high voltage power supply apparatus and a method of correcting current output from the high voltage power supply apparatus. The high voltage power supply apparatus includes a switching unit; a transformer; a pulse width modulation signal processing unit, which receives a pulse width modulation signal changed for environmental conditions, converts the received pulse width modulation signal into a direct current (DC) voltage, and outputs the converted signal as a reference signal; a drive control signal generating unit, which compares an output current signal output from the transformer with the reference signal, and outputs a drive control signal to drive the switching unit; and an output current detecting unit, which detects the output current signal. Accordingly, the magnitude of current output from the high voltage power supply apparatus can vary according to environmental conditions and the current can be uniformly output without an output error.