Abstract: A method for preparing a zinc ferrite-based catalyst according to an embodiment of the present application comprises the steps of: contacting a metal precursor solution including a zinc precursor, a ferrite precursor, an acid solution and water with a basic aqueous solution to obtain a precipitate; and filtering and thereafter drying and calcining the precipitate, wherein the acid solution includes one or more of nitric acid (HNO3) and hydrocarbon acid.

Abstract: A power control method and apparatus to heat a heating roller 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 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 printing medium.

Abstract: A power control apparatus and an image forming apparatus include a non-heating control unit to control non-heating control components according to a power-on signal, and a heating control unit to increase a level of a source power supplied as roller power and to supply the increased level of the roller power to a heating roller according to phases of current of the source power such that heating the roller reaches a temperature before a power-on process of the non-heating control unit is completed.

Abstract: A power supply, which outputs a plurality of voltages in order to improve the cross regulation between output voltages and at the same time reduce the amount of electric power consumed, and an image forming device having the same are disclosed. The power supply includes a power converter, which generates a first output power source and a second output power source in response to an external power supply and a power control signal, respectively; a power output part, which includes output parts to rectify and smooth each of the first and second output power sources; a first output controller, which receives the first output power source feedback from the power output part to generate the power control signal; and a second output controller, which receives the second output power source feedback from the power output part to control to operate the power output part in stable mode.

Abstract: An apparatus and method for detecting program plagiarism through memory access log analysis is provided. A data extractor extracts an access log of an original program and an access log of a target program to be compared with the original program from a memory accessed by the programs. A common string detector enumerates values, which are obtained from the access logs extracted from the original program and the target program, into strings and detects a common string that commonly exists in the strings. A discontinuity calculator calculates a discontinuity value that indicates a distance between the strings by using an array of the detected common strings. A plagiarism determining unit determines that the target program is plagiarized if the calculated discontinuity value is less than a predetermined reference value.

Abstract: A power control method and apparatus to heat a heating roller 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 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 printing medium.

Abstract: An image forming apparatus includes a power supply unit that controls a level of electrical power supplied to the heating lamp during a warm-up of the heating unit that involves at least a first warm-up stage. During the first warm-up stage, when power begins to be supplied to the heating lamp, the power supply unit gradually increases a level of power supplied to the heating lamp from zero to a defined supply level according to a phase control of an alternating current (AC) of the source power. If a second warm-up stage is included, during the second warm-up stage, the power supply unit may maintain the level of power supplied to the heating lamp at the defined supply level until the measured surface temperature of the heating unit has reached a defined target temperature.

Abstract: An image fixing control system and method are provided comprising a power supply, a power switching unit, a heating roller, in which a temperature detector detects a temperature of the heating roller, and a controller detects a temperature variation slope of the heating roller using the temperature detected by the temperature detector and controls an on and off switching operation of the power switching unit according to the detected temperature variation slope. Accordingly, by varying a duty ratio of power through a phase control using a temperature variation slope of a heating roller, a fine control of a fixing system can be performed. In addition, since a temperature variation, that is, overshoot or undershoot, of the heating roller is reduced, a fixing efficiency can be increased.

Abstract: A power control apparatus includes 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. A maximum level of a source power supplied from an external source is gradually increased up to a specific maximum supply level and the maximum source power to the heating resistor is supplied as the roller power while gradually increasing the maximum level of the source power up to a specific maximum supply level. A surface temperature of the heating roller is measured, and the source power of which maximum level is equal to the maximum supply level is supplied to the heating resistor as the roller power until the measured surface temperature reaches a specific fixing target temperature, and the toner image is fixed onto a fed printing medium.

Abstract: A power control method and apparatus to heat a heating roller 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 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 printing medium.

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 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 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 power supply, which outputs a plurality of voltages in order to improve the cross regulation between output voltages and at the same time reduce the amount of electric power consumed, and an image forming device having the same are disclosed. The power supply includes a power converter, which generates a first output power source and a second output power source in response to an external power supply and a power control signal, respectively; a power output part, which includes output parts to rectify and smooth each of the first and second output power sources; a first output controller, which receives the first output power source feedback from the power output part to generate the power control signal; and a second output controller, which receives the second output power source feedback from the power output part to control to operate the power output part in stable mode.

Abstract: A power supply, which outputs a plurality of voltages in order to improve the cross regulation between output voltages and at the same time reduce the amount of electric power consumed, and an image forming device having the same are disclosed. The power supply includes a power converter, which generates a first output power source and a second output power source in response to an external power supply and a power control signal, respectively; a power output part, which includes output parts to rectify and smooth each of the first and second output power sources; a first output controller, which receives the first output power source feedback from the power output part to generate the power control signal; and a second output controller, which receives the second output power source feedback from the power output part to control to operate the power output part in stable mode.

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 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: An apparatus and method for detecting program plagiarism through memory access log analysis is provided. A data extractor extracts an access log of an original program and an access log of a target program to be compared with the original program from a memory accessed by the programs. A common string detector enumerates values, which are obtained from the access logs extracted from the original program and the target program, into strings and detects a common string that commonly exists in the strings. A discontinuity calculator calculates a discontinuity value that indicates a distance between the strings by using an array of the detected common strings. A plagiarism determining unit determines that the target program is plagiarized if the calculated discontinuity value is less than a predetermined reference value.