Patents by Inventor Chung-wook Roh

Chung-wook Roh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20100014321
    Abstract: There is provided a variable switching frequency type power supply that can achieve high efficiency by fixing a switching duty cycle to 50% and varying switching frequency. A variable switching frequency type power supply according to an aspect of the invention may include: a switching unit switching input power; a transformation unit converting a voltage level of the power switched by the switching unit into a predetermined voltage level; a rectification unit rectifying the power converted by the transformation unit; and a control unit fixing a switching duty cycle of the switching unit to a predetermined switching duty cycle, and varying switching frequency of the switching unit according to a voltage level of output power.
    Type: Application
    Filed: December 10, 2008
    Publication date: January 21, 2010
    Applicant: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Jae Sun WON, Sung Soo Hong, Chung Wook Roh, Sang Kyoo Han, Jong Sun Kim, Dong Seong Oh, Tae Won Heo, Dong Joong Kim, Don Sik Kim, Hak Ryong Kim
  • Publication number: 20090316452
    Abstract: The present invention relates to power supplies, and more particularly, to a power supply having a maximum power point tracking function that controls power switching so that a detected power value is within a reference range having a maximum power point in a predetermined current-voltage curve. A power supply having a maximum power point tracking function according to an aspect of the invention includes: a converter section switching input power and converting the switched input power into predetermined DC power; and a maximum power point tracking section detecting a power value determined according to a switching operation of the converter section among power values included in a predetermined power-voltage curve, and controlling the switching operation of the converter section so that the detected power value is located within a predetermined reference range having a maximum power value among the power values included in the power-voltage curve.
    Type: Application
    Filed: October 31, 2008
    Publication date: December 24, 2009
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Jin Wook KIM, Sung Soo HONG, Chung Wook ROH, Sang Kyoo HAN, Jong Sun KIM, Jae Sun WON, Dong Seong OH, Dea Min JANG, Jong Hae KIM
  • Publication number: 20090316447
    Abstract: The present invention relates to power supplies, and more particularly, to a power supply having a maximum power point tracking function that can reduce manufacturing costs and circuit size by using a maximum power point tracking section with a simplified circuit in a solar photovoltaic power generator supplying power using sunlight instead of using a micro controller, the maximum power point tracking section that controls power switching according to a result of integration of a value obtained by dividing a power variation by a voltage variation to track a maximum power value.
    Type: Application
    Filed: October 31, 2008
    Publication date: December 24, 2009
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Jin Wook KIM, Sung Soo HONG, Sang Kyoo HAN, Chung Wook ROH, Jong Sun KIM, Sang Hun LEE, Jae Sun WON, Dong Seong OH, Jong Hae KIM
  • Patent number: 7616086
    Abstract: There is provided an integrated type transformer that reduces the volume by integrating a plurality of transformers transmitting power for driving a plurality of lamps in an inverter circuit for an LCD into one transformer structure. An integrated type transformer according to an aspect of the invention includes a bobbin unit including a bobbin body having a predetermined length and a through hole therein in a longitudinal direction of the bobbin unit, and a core unit including an inner core inserted into the through hole of the bobbin unit, and an outer core formed along one surface in the longitudinal direction among outer circumferential surfaces of the bobbin unit and electromagnetically coupled to the inner core to form one magnetic path.
    Type: Grant
    Filed: December 26, 2007
    Date of Patent: November 10, 2009
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Gie Hyoun Kweon, Sug Chin Sakong, Chung Wook Roh, Sang Kyoo Han, Sung Soo Hong, Jong Rak Kim
  • Patent number: 7612738
    Abstract: A plasma display device includes first to fourth transistors and a plurality of first electrodes. A first terminal of a first capacitor is connected to a power supply supplying a voltage. A second terminal of a second capacitor connected to a second terminal of the first capacitor is connected to a ground terminal. A first diode is connected to the first electrodes through a first inductor and a fifth transistor, which forms a voltage rising path. A second diode is connected to the first electrodes through a second inductor and a sixth transistor, which forms a voltage falling path. A third diode is connected to the third transistor and the second diode, which forms a voltage sustaining path during a voltage rising period. A fourth diode is connected to the second transistor and the first diode, which forms a voltage sustaining path of a voltage falling period.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: November 3, 2009
    Assignee: Samsung SDI Co., Ltd.
    Inventors: Hak-Cheol Yang, Joon-Yeon Kim, Jong-Ki Choi, Hyun-Gu Heo, Yong-Jin Jeong, Suk-Chin Sakong, Sung-Soo Hong, Chung-Wook Roh, Sang-Kyoo Han, Won-Seok Nam, Yon-Goo Park
  • Publication number: 20090251120
    Abstract: There is provided a high voltage power supply capable of reducing voltage stress of a voltage multiplying device. The high voltage power supply includes: a power converter switching on/off and converting an input direct current power into a direct current power having a preset voltage level; and a voltage multiplier including a first multiplying cell multiplying the voltage level of the direct current power from the power converter, wherein the first multiplying cell includes: first and second capacitors charging the direct current power from the power converter, respectively; a first diode providing a path for transferring the direct current power when the power converter is switched off; and a second diode providing a path for transferring the direct current power when the power converter is switched on.
    Type: Application
    Filed: October 27, 2008
    Publication date: October 8, 2009
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Jin Wook KIM, Sug Chin SAKONG, Sung Soo HONG, Sang Kyoo HAN, Chung Wook ROH, Jong Sun KIM, Dong Seong OH, Jae Sun WON, Jong Hae KIM
  • Publication number: 20090243388
    Abstract: Disclosed is a multi-output DC/DC converter controlling power-conversion switching in synchronization with a frequency of one output voltage among multiple output voltages in an LLC resonant DC/DC converter. The multi-output DC/DC converter includes a power conversion circuit performing alternate switching on an input DC voltage to output multiple DC voltages including a first DC voltage and a second DC voltage each having a preset voltage level, and a control circuit controlling the alternate switching of the power conversion circuit in synchronization with a preset resonant frequency.
    Type: Application
    Filed: October 1, 2008
    Publication date: October 1, 2009
    Applicant: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Jong Hae KIM, Sug Chin Sakong, Sung So Hong, Chung Wook Roh, Sang Kyoo Han, Jong Sun Kim, Dong Seong Oh
  • Patent number: 7504779
    Abstract: A plasma display panel sustain driver that has a decreased flywheel current.
    Type: Grant
    Filed: July 12, 2004
    Date of Patent: March 17, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chung-wook Roh, Sang-hoon Lee
  • Patent number: 7505289
    Abstract: Provided is a flyback DC/DC converter for a power supply. In the flyback DC/DC converter, a flyback driver unit provides a primary current. A transformer includes a plurality of secondary coils for inducing energy from the primary coil receiving the primary current. A rectifier unit includes a plurality of rectifier diodes for rectifying secondary currents of the corresponding secondary coils of the transformer. A plurality of clamp diodes are connected in series to the corresponding rectifier diodes of the rectifier unit in a forward direction to clamp ringing voltage across the corresponding rectifier diodes when the power switch is turned off. Accordingly, the voltage across the rectifier diode on the secondary side can be reduced such that it is lower than the output voltage. Also, it is possible to remove the ringing voltage of the rectifier diode and to enhance the efficiency of the flyback DC/DC converter.
    Type: Grant
    Filed: November 30, 2006
    Date of Patent: March 17, 2009
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Don Sik Kim, Sug Chin Sakong, Sung Soo Hong, Chung Wook Roh, Sang Kyoo Han, Young Seung Roh, Kwang Seung Cho
  • Publication number: 20090021179
    Abstract: There is provided a backlight driving system for a liquid crystal display that can reduce size and weight of a product because a DC-DC converter is not used when commercial AC power is converted into lamp driving power. A backlight driving system for a liquid crystal display according to an aspect of the invention includes a power supply unit converting commercial alternating current (AC) power into direct current (DC) power having a voltage level set beforehand, an inverter unit converting the DC power from the power supply unit into AC power at a one-to-one conversion ratio set beforehand, a boosting unit boosting the AC power from the inverter unit into lamp lighting power set beforehand; and a lamp group receiving the lamp lighting power from the boosting unit to emit light.
    Type: Application
    Filed: March 7, 2008
    Publication date: January 22, 2009
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Jin Wook KIM, Dong Seong Oh, Jong Duck Kim, Sug Chin Sakong, Sung Soo Hong, Sang Kyoo Han, Chung Wook Roh, Dea Min Jang, Sung Ho Kim, Jin Woo Cho, Kwang Seung Cho
  • Publication number: 20080231404
    Abstract: There is provided an integrated type transformer that reduces the volume by integrating a plurality of transformers transmitting power for driving a plurality of lamps in an inverter circuit for an LCD into one transformer structure. An integrated type transformer according to an aspect of the invention includes a bobbin unit including a bobbin body having a predetermined length and a through hole therein in a longitudinal direction of the bobbin unit, and a core unit including an inner core inserted into the through hole of the bobbin unit, and an outer core formed along one surface in the longitudinal direction among outer circumferential surfaces of the bobbin unit and electromagnetically coupled to the inner core to form one magnetic path.
    Type: Application
    Filed: December 26, 2007
    Publication date: September 25, 2008
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Gie Hyoun KWEON, Sug Chin Sakong, Chung Wook Roh, Sang Kyoo Han, Sung Soo Hong, Jong Rak Kim
  • Publication number: 20080136355
    Abstract: Provided is a backlight driving apparatus for a non-emissive display device which comprises an inverter (or lamp driver) (110) that converts a DC voltage to a preset voltage, a lamp (120) that emits light in response to the input of the converted voltage from the inverter (or lamp driver) (110), a detector (130) that detects electric current or brightness at the lamp, a controller (140) that controls the pulse width of a digital dimming signal in order to provide an adequate control of the electric current or brightness according to a lamp brightness command, a signal generator (150) that generates a signal with fixed frequency and fixed duty ratio for optimizing the operation of the inverter (or lamp driver) (110) and a digital dimmer (160) that generates an inverter driving signal from the logical intersection of the digital dimming signal generated by the controller (140) and the signal generated by the signal generator (150).
    Type: Application
    Filed: March 19, 2007
    Publication date: June 12, 2008
    Inventors: Sang-Kyoo Han, Chung-Wook Roh, Sung-Soo Hong, Sung-Chin Sakong
  • Publication number: 20080088531
    Abstract: A plasma display device includes first to fourth transistors and a plurality of first electrodes. A first terminal of a first capacitor is connected to a power supply supplying a voltage. A second terminal of a second capacitor connected to a second terminal of the first capacitor is connected to a ground terminal. A first diode is connected to the first electrodes through a first inductor and a fifth transistor, which forms a voltage rising path. A second diode is connected to the first electrodes through a second inductor and a sixth transistor, which forms a voltage falling path. A third diode is connected to the third transistor and the second diode, which forms a voltage sustaining path during a voltage rising period. A fourth diode is connected to the second transistor and the first diode, which forms a voltage sustaining path of a voltage falling period.
    Type: Application
    Filed: March 28, 2007
    Publication date: April 17, 2008
    Inventors: Hak-Cheol Yang, Joon-Yeon Kim, Jong-Ki Choi, Hyun-Gu Heo, Yong-Jin Jeong, Suk-Chin Sakong, Sung-Soo Hong, Chung-Wook Roh, Sang-Kyoo Han, Won-Seok Nam, Yon-Goo Park
  • Patent number: 7327331
    Abstract: A ramp reset waveform generating apparatus in a display panel driving apparatus for a display panel includes a current source which is connected to a first electrode sustain circuit of the display panel through a first terminal of the current source, and generates a current corresponding to a predetermined reference current; a first switching unit which switches current flow between a second terminal of the current source and a first electrode terminal of the display panel; and a second switching unit which switches current flow between the second terminal of the current source and a second electrode terminal of the display panel, wherein, in a reset period, a ramp reset waveform is generated in the first electrode terminal and the second electrode terminal by the charge or discharge process of the display panel by the current generated in the current source according to a predetermined switching sequence.
    Type: Grant
    Filed: December 6, 2004
    Date of Patent: February 5, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jeong-il Kang, Young-sun Kim, Chung-wook Roh
  • Publication number: 20070183172
    Abstract: Provided is a flyback DC/DC converter for a power supply. In the flyback DC/DC converter, a flyback driver unit provides a primary current. A transformer includes a plurality of secondary coils for inducing energy from the primary coil receiving the primary current. A rectifier unit includes a plurality of rectifier diodes for rectifying secondary currents of the corresponding secondary coils of the transformer. A plurality of clamp diodes are connected in series to the corresponding rectifier diodes of the rectifier unit in a forward direction to clamp ringing voltage across the corresponding rectifier diodes when the power switch is turned off. Accordingly, the voltage across the rectifier diode on the secondary side can be reduced such that it is lower than the output voltage. Also, it is possible to remove the ringing voltage of the rectifier diode and to enhance the efficiency of the flyback DC/DC converter.
    Type: Application
    Filed: November 30, 2006
    Publication date: August 9, 2007
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Don Sik KIM, Sug Chin Sakong, Sung Soo Hong, Chung Wook Roh, Sang Kyoo Han, Young Seung Roh, Kwang Seung Cho
  • Patent number: 7209099
    Abstract: Provided are an apparatus and a method of driving a high-efficiency plasma display panel for quickly eliminating a free-wheeling current, generated due to the parasitic effect in an energy recovery circuit, thereby improving energy recovery efficiency.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: April 24, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chung-wook Roh, Sang-hoon Lee, Hye-jeong Kim
  • Publication number: 20070052629
    Abstract: A plasma display apparatus comprises a plasma display panel that comprises an electrode; a sustain driver that supplies a sustain signal to the electrode and that comprises a first and second switching elements for supplying the sustain signal; and a first and second gate drivers that drives each of the first and second switching elements, wherein the first gate driver receives a driving voltage for driving the first switching element from a driving voltage source of the first gate driver, the second gate driver comprises a driving voltage source that supplies a driving voltage for driving the second switching element, and an auxiliary voltage for assisting the driving voltage is supplied from the outside of the second gate driver so that the second switching element is driven by the driving voltage.
    Type: Application
    Filed: September 7, 2006
    Publication date: March 8, 2007
    Inventors: Seonghak Moon, Sung Hong, Taehyung Kim, Chung-Wook Roh, Byung Kong, Byeong Ahn
  • Patent number: 7158193
    Abstract: Disclosed is an image misconvergence correction apparatus having a correction value generation unit for calculating a convergence correction value to correct misconvergence occurring when a video signal is scanned on a display device; an amplification unit for performing D-class amplification with respect to the convergence correction value; a convergence yoke mounted in the display device to control a path of electron beams corresponding to the video signal based on the convergence correction value amplified in the amplification unit; and a feedback sensing unit for differentially amplifying a voltage value for electric current passing through the convergence yoke, and feeding back the differentially amplified voltage value to the correction value generation unit.
    Type: Grant
    Filed: July 7, 2003
    Date of Patent: January 2, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kyoung-geun Lee, Chung-wook Roh, Joon-hwan Lee
  • Publication number: 20060290610
    Abstract: A plasma display apparatus and a method of driving the plasma display apparatus are disclosed. The plasma display apparatus includes a plasma display panel including a scan electrode, a sustain voltage source, an inductor, an energy supply/recovery capacitor, and a maintenance capacitor. The inductor and the energy supply/recovery capacitor form a current path for supplying/recovering a sustain voltage to/from the plasma display panel, and for forming a current path for supplying/recovering one half of the sustain voltage to/from the plasma display panel. The maintenance capacitor forms a current path for maintaining a voltage of the plasma display panel at one half of the sustain voltage.
    Type: Application
    Filed: June 27, 2006
    Publication date: December 28, 2006
    Inventors: Seonghak Moon, Taehyung Kim, Byung Kong, Chung-Wook Roh, Byeong Ahn
  • Publication number: 20050162087
    Abstract: A plasma display panel is provided, including lower and upper substrates separated from each other to form a discharge space therebetween. A plurality of partitions are provided between the lower and upper substrates to partition the discharge space to define the discharge cells, and a plurality of first and second discharge electrodes generate a discharge within the discharge cells. A plurality of fluorescent layers are provided to inner surfaces of the discharge cells, each of the fluorescent layers being exited by the discharge to generate visible rays of light, and a plurality of light shielding elements are provided to the upper substrate to prevent external rays of light from entering the discharge cells, wherein a plurality of light focusing elements provided to the upper substrate focus the visible rays of light generated in the discharge cells and emit the visible light.
    Type: Application
    Filed: October 15, 2004
    Publication date: July 28, 2005
    Inventors: Young-sun Kim, Chang-wan Hong, Young-soo Han, Chung-wook Roh, Hye-jeong Kim