| 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 |
