Abstract: A test apparatus for a power supply unit is provided, which includes a body unit configured to define a space to receive a light emitting diode (LED) and to provide a test environment to test a supply state of power applied to the LED; and a test unit mounted in the body unit to face the LED and configured to detect flicker of the LED occurring when a power supply is abnormal. According to the foregoing structure, power supply with respect to the LED may be regularly detected and analyzed, thereby increasing quality of power supply with respect to the LED.

Abstract: Provided is an image forming apparatus and a method of controlling the same. When an external power is supplied to a heating resistance member of a fusing unit in the image forming apparatus that is in a standby mode, a power supply unit supplies an internal power to a different load (for example, an exposure unit, a developing unit, or a transfer unit) in one or more time sections so as to supply the internal power to the load at a continuously changing operating frequency.

Abstract: A high voltage power supply apparatus comprising a first circuit disposed on a prepared substrate, and for receiving a first voltage and generating a second voltage that is previously set according to the first voltage, and a second circuit for amplifying and rectifying the second voltage to generate a plurality of high voltage signals, wherein the first circuit and the second circuit are embodied as a single module, wherein at least a portion of the single module is surrounded by an insulator.

Abstract: Provided is an image forming apparatus and a method of controlling the same. When an external power is supplied to a heating resistance member of a fusing unit in the image forming apparatus that is in a standby mode, a power supply unit supplies an internal power to a different load (for example, an exposure unit, a developing unit, or a transfer unit) in one or more time sections so as to supply the internal power to the load at a continuously changing operating frequency.

Abstract: In a provided power supply unit, a plurality of circuit elements are integrated into a chip, wherein the circuit elements generate one or more output voltages by using an input voltage. Thus, although the number of voltages, which can be generated by the power supply apparatus, is remarkably large, the power supply apparatus can be miniaturized. In addition, an apparatus, in which the power supply apparatus is installed, can be miniaturized.

Abstract: A power supply with surge voltage control functions. The power supply has a rectifying unit rectifying a voltage of an AC power source externally applied; a fuse resistor inputting and applying the AC power source to the rectifying unit, and cutting off the voltage of the AC power source exceeding a predetermined value; a pulse generation unit driven by an output voltage of the rectifying unit, and generating a pulse having a predetermined period; a transformer driven by the pulse, and inducing a predetermined ac voltage; and a surge voltage control unit turning on by an ac voltage induced by the transformer to form a current path between the AC power source and the rectification unit, wherein the current path is formed between the AC power source and the rectifying unit via the fuse resistor when the output voltage of the rectifying unit exceeds a predetermined value.

Abstract: A scanning apparatus having a cold cathode fluorescent lamp includes a central processing unit (CPU) controlling a scan unit to be in one of the stand-by mode, a scan mode and a sleep mode and outputting a PWM signal having a variable duty ratio based on an operation mode of the scan unit; a filter unit receiving the PWM signal from the CPU, filtering the PWM signal, and outputting the filtered signal; a feedback unit detecting the voltage applied to the fluorescent lamp and outputting a feedback signal; a controlling unit controlling the illumination of the fluorescent lamp based on the voltage input from the feedback unit, the controlling unit outputting a control signal variably controlling the voltage applied to the fluorescent lamp depending on the filtered signal; and a lamp drive unit applying variable AC voltage to the fluorescent lamp based on the control signal, thereby driving the fluorescent lamp.

Abstract: An apparatus for and a method of controlling a power supply for a printer. A power on signal is automatically provided to turn on the printer power supply in accordance with a predetermined printing command, and a power off signal to turn off the printer power supply is automatically provided when the printer has not performed a printing operation for a predetermined time period. A low voltage and current switch is provided for manual on/off control of the printer power supply in accordance with an operation of a user. If the printer power supply in off, operation of the switch generates the power on signal. If the printer power supply is on, operation of the switch causes the controller to generate the power off signal to turn off the printer power supply.

Abstract: An apparatus and method of controlling the driving of a heat source using an AC voltage. If the temperature of the heat source is lower than a reference temperature and the level of the AC voltage is greater than a reference level, the level of a sensing signal is changed. Then, it is determined whether a predetermined period of time has lapsed from the moment when the level of the sensing signal has been changed. Thereafter, if it is determined that the predetermined period of time has lapsed from the moment when the level of the sensing signal has been changed, the heat source is driven when the level of the AC voltage is a zero level.

Abstract: An apparatus and method of controlling the driving of a heat source using an AC voltage. If the temperature of the heat source is lower than a reference temperature and the level of the AC voltage is greater than a reference level, the level of a sensing signal is changed. Then, it is determined whether a predetermined period of time has lapsed from the moment when the level of the sensing signal has been changed. Thereafter, if it is determined that the predetermined period of time has lapsed from the moment when the level of the sensing signal has been changed, the heat source is driven when the level of the AC voltage is a zero level.

Abstract: A scanning apparatus having a cold cathode fluorescent lamp includes a central processing unit (CPU) controlling a scan unit to be in one of the stand-by mode, a scan mode and a sleep mode and outputting a PWM signal having a variable duty ratio based on an operation mode of the scan unit; a filter unit receiving the PWM signal from the CPU, filtering the PWM signal, and outputting the filtered signal; a feedback unit detecting the voltage applied to the fluorescent lamp and outputting a feedback signal; a controlling unit controlling the illumination of the fluorescent lamp based on the voltage input from the feedback unit, the controlling unit outputting a control signal variably controlling the voltage applied to the fluorescent lamp depending on the filtered signal; and a lamp drive unit applying variable AC voltage to the fluorescent lamp based on the control signal, thereby driving the fluorescent lamp.

Abstract: A power supply with surge voltage control functions. The power supply has a rectifying unit rectifying a voltage of an AC power source externally applied; a fuse resistor inputting and applying the AC power source to the rectifying unit, and cutting off the voltage of the AC power source exceeding a predetermined value; a pulse generation unit driven by an output voltage of the rectifying unit, and generating a pulse having a predetermined period; a transformer driven by the pulse, and inducing a predetermined ac voltage; and a surge voltage control unit turning on by an ac voltage induced by the transformer to form a current path between the AC power source and the rectification unit, wherein the current path is formed between the AC power source and the rectifying unit via the fuse resistor when the output voltage of the rectifying unit exceeds a predetermined value.

Abstract: An apparatus for and a method of controlling a power supply for a printer. A power on signal is automatically provided to turn on the printer power supply in accordance with a predetermined printing command, and a power off signal to turn off the printer power supply is automatically provided when the printer has not performed a printing operation for a predetermined time period. A low voltage and current switch is provided for manual on/off control of the printer power supply in accordance with an operation of a user. If the printer power supply in off, operation of the switch generates the power on signal. If the printer power supply is on, operation of the switch causes the controller to generate the power off signal to turn off the printer power supply.

Abstract: An apparatus controlling a cold cathode fluorescent lamp and a scanning apparatus having the same are disclosed.

Abstract: An apparatus for controlling power and reducing power consumption in a system including a switching mode power supply. (SMPS), and a method thereof. The apparatus includes a switch that is set to an ON state when a user contacts the switch, a detection portion connected in parallel with the switch and detecting whether a signal for requiring a predetermined operation is applied to the system from outside, and a power supply portion supplying the power to each part in a system when the switch is set to the ON state or the signal is input from the detection portion. The power supply portion terminates the power to each part in the system including the system controller when a power off signal is applied from the system controller when the switch is set to an OFF state and when signal is not input from the detection portion.

Abstract: An apparatus for controlling power so that] and reducing power consumption in a system including a switching mode power supply (SMPS), and a method thereof . The apparatus includes a switch that is set to an ON state when a user contacts the switch, a detection portion connected in parallel with the switch and detecting whether a signal for requiring a predetermined operation is applied to the system from outside, and a power supply portion supplying the power to each part in a system when the switch is set to the ON state or the signal is input from the detection portion. The power supply portion terminates the power to each part in the system including the system controller when a power off signal is applied from the system controller when the switch is set to an OFF state and when signal is not input from the detection portion. the system to which power is supplied using the SMPS can be reduced.

Abstract: A method and apparatus for removing a jammed paper from an ink jet printer is aimed at an efficient removal of the jammed paper. When an operator pulls jammed paper to remove it the feed roller rotates in response to such a motion, and a sensing unit senses a rotational movement of the feed roller and activates a line feed motor, whereby the jammed paper is ejected. The operator has only to pull the jammed paper just a little so as to remove it from the ink jet printer, thereby permitting an efficient removal of the jammed paper and decreasing the chance of tearing of the jammed paper by pulling it too hard which may be a more serious problem than the paper jam itself.

Abstract: A home position sensor system and method capable of shortening the amount of time consumed for sensing a home position. The home position sensor system including a carriage wherein a recording head is mounted and being movable in a horizontal direction, two sensing ribs separated by a constant interval from each other along the moving direction of the carriage and protrudedly formed in the carriage, a home sensor provided at one side cad of a moving path of the carriage to thereby correspond to the sensing ribs, a carriage driver for moving the carriage, and a controller for moving the carriage in a horizontal direction through the carriage driver in accordance with sensing states of the home sensor to the two sensing ribs to thereby sense a home position.