Abstract: A device for fusing and fixing a transferred toner of a predetermined image onto a print paper is provided. In particular, a fusing device which can instantly control induced current provided to a fusing unit in an image printing apparatus which heats the fusing unit using the induced current is provided. The fusing device includes a fusing unit which is resistance heated or induction heated by an induced current, and fuses the toner onto the print paper using the generated heat. A sensing unit senses the temperature of the fusing unit. A reference current generating unit generates a predetermined reference current to heat the fusing unit to reach a predetermined temperature based on the temperature of the sensed fusing unit and the reference temperature. A pulse width modulation signal generating unit generates a pulse width modulation signal for generating the induced current so that the induced current corresponding to the reference current is supplied to the fusing unit.

Abstract: An image forming apparatus includes a fixing roller to fix a toner on a recording medium; a heater to heat the fixing roller; an alternating current (AC) power source to generate an AC electric power such that the heater heats the fixing roller according to the AC electric power; a unit interposed between the heater and the AC power source to selectively supply the AC electric power from the AC power source to the heater so as to control the heater to heat the fixing roller; a relay including a first relay contact point disposed on a first AC power supply line between the AC power source and the unit and a relay coil to open and close the first relay contact point; the relay selectively supplying the AC electric power from AC power source to the heater and the power control switch; a direct current (DC) power supplier to supply a DC power to the relay coil; and a thermoswitch interposed on a DC power supply line between the DC power supplier and the relay coil to control the supply of the AC electric power fr

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 an alternating current (AC) power source to supply an AC electric power to the heater may include a power converting part to convert the AC electric power of the AC power source and to supply the converted power to the heater; a relay including a first relay contact point disposed on a first AC power supply line between the AC power source and the power converting part and a relay coil to open and close the first relay contact point, the relay selectively supplying the AC electric power from the AC power source to the heater and the power converting part; a direct current (DC) power supplier to supply a DC power to the relay coil; and a thermoswitch interposed between the relay coil and the DC power supplier and mounted adjacent to the fixing roller so as to interrupt the DC power from the DC power supplier to the relay coil, when a temperature of the fixi

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 method and an apparatus to control power supplied to a heating roller and a phase control circuit corresponding to the method or the apparatus. The phase control circuit may include an examination unit to compare levels of a sine wave having a predetermined first period and a switching signal to increase and decrease repeatedly according to a predetermined second period, and a phase control signal generation unit to generate a phase control signal having a non-zero in intervals of time sections including a time when levels of the switching signal and the sine wave which is in a decreasing section are equal to each other during a time period when the level of the sine wave is zero, and a time when levels of the switching signal and the sine wave which is in an increasing section are equal to each other during a time period when the level of the sine wave is zero.

Abstract: A method and an apparatus to control power supplied to a heating roller and a phase control circuit corresponding to the method or the apparatus. The phase control circuit may include an examination unit to compare levels of a sine wave having a predetermined first period and a switching signal to increase and decrease repeatedly according to a predetermined second period, and a phase control signal generation unit to generate a phase control signal having a non-zero in intervals of time sections including a time when levels of the switching signal and the sine wave which is in a decreasing section are equal to each other during a time period when the level of the sine wave is zero, and a time when levels of the switching signal and the sine wave which is in an increasing section are equal to each other during a time period when the level of the sine wave is zero.

Abstract: A power control method and apparatus to heat a heating roller. The power control method includes heating a heating roller provided to fix a toner image of print data in an image forming apparatus, the heating roller having a heating resistor to receive roller power, the power control method includes gradually increasing a maximum level of a source power supplied from an external source up to a specific maximum supply level, and supplying the maximum source power to the heating resistor as the roller power while gradually increasing the maximum level of the source power up to a specific maximum supply level, measuring a surface temperature of the heating roller, and further supplying the source power of which maximum level is equal to the maximum supply level to the heating resistor as the roller power until the measured surface temperature reaches a specific fixing target temperature, and fixing the toner image onto a fed printing medium.

Abstract: A power converter controlling apparatus that can prevent burnout caused by overcurrent and/or overvoltage generated by low power index operation or output short circuit in a high frequency power converter employing a digital controlling method, and a method thereof. The power converter controlling apparatus includes a digital controller which outputs a gate signal for controlling intermittent operation of a predetermined switch based on inputted control data, a detector which generates a detection signal in response to generation of overcurrent and/or overvoltage, and a registration maintenance unit for maintaining a state where the output of the gate signal is shut off, when the detection signal is generated.

Abstract: A power control method includes heating a heating roller provided to fix a toner image of print data in an image forming apparatus, the heating roller having a heating resistor to receive roller power. The power control method includes gradually increasing a maximum level of a source power supplied from an external source up to a specific maximum supply level, supplying the maximum source power to the heating resistor as the roller power while gradually increasing the maximum level of the source power up to a specific maximum supply level, measuring a surface temperature of the heating roller, further supplying the source power of which maximum level is equal to the maximum supply level to the heating resistor as the roller power until the measured surface temperature reaches a specific fixing target temperature, and fixing the toner image onto a fed printing medium.

Abstract: A power control method and apparatus to control a heating roller, the power control method including gradually increasing a maximum level of a source power supplied from an external source up to a specific maximum supply level, and supplying the source power to a heating resistor as a roller, power, measuring a surface temperature of the heating roller, and supplying the source power having a maximum level equal to the maximum supply level to the heating resistor as the roller power until the measured surface temperature reaches a specific fixing target temperature, supplying the source power having an upper limit of the maximum level equal to a specific fixing property improving level to the heating resistor as the roller power until a printing medium is first fed, and fixing a toner image of print data onto the fed printing medium by using the heating roller.

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 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 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: A power converter controlling apparatus that can prevent burnout caused by overcurrent and/or overvoltage generated by low power index operation or output short circuit in a high frequency power converter employing a digital controlling method, and a method thereof. The power converter controlling apparatus includes a digital controller which outputs a gate signal for controlling intermittent operation of a predetermined switch based on inputted control data, a detector which generates a detection signal in response to generation of overcurrent and/or overvoltage, and a registration maintenance unit for maintaining a state where the output of the gate signal is shut off, when the detection signal is generated.

Abstract: A power converter controlling apparatus that can prevent burnout caused by overcurrent and/or overvoltage generated by low power index operation or output short circuit in a high frequency power converter employing a digital controlling method, and a method thereof. The power converter controlling apparatus includes a digital controller which outputs a gate signal for controlling intermittent operation of a predetermined switch based on inputted control data, a detector which generates a detection signal in response to generation of overcurrent and/or overvoltage, and a registration maintenance unit for maintaining a state where the output of the gate signal is shut off, when the detection signal is generated.

Abstract: An image forming apparatus includes a fixing roller to fix a toner on a recording medium; a heater to heat the fixing roller; an alternating current (AC) power source to generate an AC electric power such that the heater heats the fixing roller according to the AC electric power; a unit interposed between the heater and the AC power source to selectively supply the AC electric power from the AC power source to the heater so as to control the heater to heat the fixing roller; a relay including a first relay contact point disposed on a first AC power supply line between the AC power source and the unit and a relay coil to open and close the first relay contact point; the relay selectively supplying the AC electric power from AC power source to the heater and the power control switch; a direct current (DC) power supplier to supply a DC power to the relay coil; and a thermoswitch interposed on a DC power supply line between the DC power supplier and the relay coil to control the supply of the AC electric power fr

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 an alternating current (AC) power source to supply an AC electric power to the heater may include a power converting part to convert the AC electric power of the AC power source and to supply the converted power to the heater; a relay including a first relay contact point disposed on a first AC power supply line between the AC power source and the power converting part and a relay coil to open and close the first relay contact point, the relay selectively supplying the AC electric power from the AC power source to the heater and the power converting part; a direct current (DC) power supplier to supply a DC power to the relay coil; and a thermoswitch interposed between the relay coil and the DC power supplier and mounted adjacent to the fixing roller so as to interrupt the DC power from the DC power supplier to the relay coil, when a temperature of the fixi

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: 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.