Patent application number | Description | Published |
20090016179 | NEAR-FIELD OPTICAL DISK APPARATUS AND FOCUS PULL-IN METHOD - A near-field optical disk apparatus, which can perform stable focus pull-in even when overshoot occurs, and a focus pull-in method, of which the method includes: raising an actuator, and monitoring and determining whether light focused on a disk is near-field light; holding or storing a driving voltage of the actuator if the light focused on the disk is the near-field light; raising the actuator, and determining a maximum driving voltage of the actuator; and performing focus pull-in while lowering the actuator in an interval where a driving voltage of the actuator is between the maximum driving voltage and the held or stored driving voltage. | 01-15-2009 |
20090059752 | OPTICAL DISC APPARATUS AND METHOD OF DRIVING THE SAME - An optical disc apparatus, and a method of driving the same, includes a light focusing element disposed to focus light emitted from a light source onto a disc; an actuator to move the light focusing element toward or away from the disc according to a voltage applied to the actuator; a light intensity detection unit to detect the intensity of light reflected from the disc ; a servo unit to generate a gap error signal and a third voltage, the third voltage being the sum of a first voltage and a second voltage, and to apply the generated third voltage to the actuator; and a control unit to control the servo unit to perform a gap pull-in operation when the light focusing element is moved toward the disc according to the gap error signal and the third voltage. | 03-05-2009 |
20090059753 | OPTICAL DISK APPARATUS AND METHOD OF DRIVING THE SAME - An optical disk apparatus includes a light focusing element arranged to face a disk and to focus light emitted from a light source on the disk, an actuator to move the light focusing element towards and away from the disk according to an actuator driving voltage, a light intensity detection unit to detect an intensity of light reflected by the light focusing element and generate a gap error signal based on the detected intensity, a servo unit to generate the actuator driving voltage and a predetermined threshold voltage based on the gap error signal generated by the light intensity detection unit and to provide the actuator driving voltage to the actuator, a distance detection unit to detect a first distance at which the actuator driving voltage is maintained when the threshold voltage is detected using the gap error signal and to detect a second distance at which a gap between the light focusing element and the disk is shorter than the first distance and at which a gap servo operation is started based on the gap error signal; and a control unit to control the servo unit to start the gap servo operation based on the detected first and second distances. | 03-05-2009 |
20090154309 | NEAR-FIELD GAP PULL-IN METHOD AND OPTICAL DISC APPARATUS THEREFOR - A gap pull-in method and an optical disc apparatus. Whether light condensed on a disc as an actuator ascends is near-field light is determined using a gap error signal. The range of an actuator driving voltage value during a section where the decrease rate of the gap error signal is constant is obtained when it is determined that the light condensed on the disc is near-field light. Gap pull-in is performed on the disc during a section where the actuator driving voltage value is within the obtained range. | 06-18-2009 |
20090190453 | SOLID IMMERSION LENS (SIL) NEAR-FIELD SYSTEM AND METHOD OF CONTROLLING TILT - In a near-field optical recording/reproducing system and a method of controlling a tilt, the near-field optical recording/reproducing system includes: a light source; an objective lens to focus light emitted from the light source to transmit near-field light to an information storage medium; a PD (photodetector) to receive a portion of the light that is transmitted from the objective lens to the information storage medium and is reflected from the information storage medium, to detect a GES (gap error signal) used for controlling an air gap formed between the objective lens and the information storage medium; a signal processor/determiner to obtain an edge voltage using the GES detected by the PD and determine a tilt control point using the edge voltage; and an adjuster to control a relative tilt between the objective lens and the information storage medium in the tilt control position. | 07-30-2009 |
20110013918 | Method and apparatus to control electronic power of coil which performs induction heating in imaging apparatus - Provided is a method of controlling electric power of a coil which performs induction heating in an imaging apparatus. The method includes: detecting an input current of the coil; detecting a resonant current of the coil; calculating a difference between the detected resonant current and the detected input current; and controlling electric power supplied to the coil based on the difference. These operations are repeatedly performed whenever the detected input current is changed. | 01-20-2011 |
20110058826 | APPARATUS AND METHOD TO PROTECT HALF OR FULL BRIDGE CIRCUIT INCLUDING FIRST SWITCHING UNIT AND SECOND SWITCHING UNIT IN IMAGE FORMING APPARATUS PERFORMING INDUCTION HEATING - An apparatus to protect a half or full bridge circuit including a first switching unit and a second switching unit in an image forming apparatus performing induction heating, the apparatus including a switching control unit to control operations of the first switching unit and the second switching unit by generating and outputting a first driving signal to turn on or off the first switching unit and a second driving signal to turn on or off the second switching unit; and an arm-short detecting unit to output a disable signal to stop operation of the switching control unit in response to the first driving signal and the second driving signal simultaneously being signals to turn on the first switching unit and the second switching unit. | 03-10-2011 |
20110158672 | FUSING DEVICE, IMAGE FORMING APPARATUS HAVING THE SAME, AND CONTROL METHOD THEREOF - An induction heating type fusing device to reduce the size of an induction coil and an image forming apparatus having the same, and a control method thereof. The image forming apparatus includes a printing device to form an image on a recording medium, and a fusing device to fix the image to the recording medium. The fusing device includes a heating member arranged to transfer heat to the recording medium and having a main heater and a sub heater, and an induction coil having a width equal to or less than a width of the recording medium and arranged in an axial direction of the heating member to generate a magnetic field acting on the main heater. The sub heater is arranged inside the heating member to heat both ends of the main heater. | 06-30-2011 |
20130129367 | SWITCHING-MODE POWER SUPPLY (SMPS) HAVING OVERVOLTAGE CUTOFF FUNCTION, AND METHOD OF CUTTING OFF OVERVOLTAGE AND IMAGE FORMING APPARATUS USING THE SMPS - A switching-mode power supply (SMPS) for an image forming apparatus which may prevent an overvoltage supplied to the SMPS, and damage to circuits in the SMPS in the image forming apparatus. The SMPS includes a rectifying circuit to rectify an alternating-current (AC) voltage input from an external power supply source into a direct-current (DC) voltage, a transformer to transform the rectified DC voltage input to a primary coil and output the transformed DC voltage to a secondary coil, a main switch that is connected to the primary coil and switches an output of the transformer, a first overvoltage detecting unit to determine whether the rectified DC voltage is an overvoltage by comparing the rectified DC voltage with a first reference voltage, and a switching control unit to control a switching operation of the main switch based on a result of the determination. | 05-23-2013 |
20130142535 | IMAGE FORMING APPARATUS AND METHOD OF CONTROLLING FUSING TEMPERATURE OF THE SAME - An image forming apparatus having two or more different rated voltages, the image forming apparatus including a voltage detecting unit, which detects a voltage level of alternating current (AC) power supplied from outside of the image forming apparatus; a control unit, which outputs a control signal according to the detected voltage level; a fusion driving circuit, which controls a number of waveforms and phase of the AC power according to the control signal and outputs the controlled AC power as fusing power; and a fuser including a heat generating body having a negative temperature coefficient (NTC) characteristic, which receives the fusing power and generates resistance heat; and a heating member, which is heated by the heat generated by the resistance heat generating body and fuses an image formed on a printing medium. | 06-06-2013 |
20130155737 | SWITCHING MODE POWER SUPPLY USABLE IN AN IMAGE FORMING APPARATUS, AND IMAGE FORMING APPARATUS AND METHOD OF SUPPLYING POWER BY USING THE SAME - A switching mode power supply and a method of supplying power by using the same. The switching mode power supply includes a converting unit to convert an alternating current (AC) voltage input to the switching mode power supply to at least one direct current (DC) voltage by using at least one transformer, and a voltage controller to control a voltage level of an output voltage to be output to a system controller of the image forming apparatus from among the at least one DC voltage, where the system controller controls operations of the image forming apparatus. The voltage controller includes a switching unit to switch the voltage level of the output voltage from a first voltage level to a second voltage level when the image forming apparatus enters a power saving mode, where the second voltage level is lower than the first voltage level. | 06-20-2013 |
20130308152 | POWER SUPPLY DEVICE AND IMAGE FORMING APPARATUS HAVING THE SAME - Power supply device and an image forming apparatus having the power supply device are provided. The power supply device includes an input unit to input alternating current (AC) power, a converter to convert the input AC power to direct current (DC) power having a preset level and to output the DC power, and a sensor to be connected to the input unit in parallel and to sense whether the AC power has been input. The sensor includes a transformer to receive the AC power and to output a sensing signal having a level reduced more than a level of the AC power, and a resistor unit connected to the transformer in series so that a current of the AC power input into the transformer is lower than or equal to a preset current. | 11-21-2013 |
20140044447 | POWER CONTROL APPARATUS AND IMAGE FORMING APPARATUS - A power control apparatus and an image forming apparatus is provided to prevent a heating element from overheating when DC power is supplied and to perform normal operation regardless of the type of input power. The power control apparatus includes a power supply to supply power to a load, an alternating current (AC) power switch to discontinuously switch on AC power between the power supply and the load, and a direct current (DC) cutoff circuit to block supply of DC power through the AC power switch to prevent supply of the DC power to the load via the AC power switch when the DC power is input through the power supply. | 02-13-2014 |
20140062421 | DISCHARGING CIRCUIT, IMAGE FORMING APPARATUS HAVING THE DISCHARGING CIRCUIT, AND POWER SUPPLY UNIT - A discharge circuit, an image forming apparatus having the discharge circuit, and a power-supply unit are disclosed to minimize a standby power generated in a standby mode and improve a discharging speed of a capacitor charged with electricity by the AC power in a power off mode. The discharge circuit connected between AC power input lines receiving an AC power includes a first resistor and a first switch element connected in series between the AC power lines, and a second resistor and a second switch element which are connected in series between the AC power lines, turn off the first switching element upon receiving an electric current during supply of the AC power, and turn on the first switching element in response to cutoff of the AC power to discharge the first capacitor. | 03-06-2014 |