Samsung Electronics Co., Ltd.

Hp Printing Korea Co., Ltd.

Young-min Chae

Sang-yong Han

Joong-Gi Kwon

Hwan-guem Kim

Durk-hyun Cho

Jin-ha Kim

Jun-seok Cho

Jong-hwa Cho

Se-Joong Kim

Chul-woo Oh

Tae-kwon Na

Su-kyoung Chae

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 from the AC power source to the heater and the unit according to an temperature of the fixing roller.

Fixing device usable with an image forming apparatus

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.

Power control method and apparatus to heat a heating roller

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.

Apparatus and method of controlling power supply to heating roller and phase control circuit corresponding to the apparatus and method

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.

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.

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.

Device for fusing toner on print medium

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.

Fusing device heated by induced current for instantly controlling power

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 fixing roller exceeds a threshold temperature, causing the relay coil to open the first relay contact point.

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.

Apparatus to generate high voltage by digital control and method thereof

Printing apparatus and a method of controlling a power supply to a heating roller and to a phase control circuit

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.

Apparatus and method for controlling power converter

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.

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Suwon-si, South Korea

Young-min Chae