Patents by Inventor Bo-hwan Choi

Bo-hwan Choi 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: 20160249825
    Abstract: Embodiments of the present disclosure provide a magnetic-field focusing apparatus including a magnetic-field generating unit including a plurality of transmit coils and configured to receive a transmit pulse to be applied to each of the transmit coils and to generate a magnetic field, and a pulse generating unit configured to calculate a magnitude of a current to be applied to each of the transmit coils by using structure information based on a positional relationship between a focusing point for focusing a magnetic flux and the transmit coils and to generate the transmit pulse to be applied to each of the transmit coils based on the magnitude of the current. A magnetic-field receiving apparatus is also provided for the magnetic-field focusing apparatus.
    Type: Application
    Filed: October 21, 2014
    Publication date: September 1, 2016
    Applicant: KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY
    Inventors: Chun-taek RIM, Eun-Soo LEE, Junpil CHEON, Bo-hwan CHOI
  • Patent number: 9167640
    Abstract: The present disclosure provides an AC-direct-type LED-lighting device including compensation circuit for AC input compensation, including a compensation inductor and first compensation capacitor parallelly connected to one terminal of AC input and a second compensation capacitor connected in series; rectifying unit for rectifying output from second compensation capacitor terminals to obtain direct current; and LED array driven by the rectifying unit output, wherein capacities of the first and second compensation capacitors and the compensation inductor and LED array output voltage are determined to cause 0.9 or larger cosine value of a phase, with respect to the AC input voltage, of resulting current obtained by dividing AC input voltage by sum of (i) parallel value of an equivalent impedance Re of the rectifying unit and LED array and an impedance of the second compensation capacitor and (ii) parallel value of impedances of the compensation inductor and first compensation capacitor.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: October 20, 2015
    Assignees: Korea Advanced Institute Of Science and Technology, OPTOMIND INC.
    Inventors: Chun-taek Rim, Eun-Soo Lee, Bo-hwan Choi, Bong-cheol Kim
  • Publication number: 20150223298
    Abstract: The present disclosure provides an AC-direct-type LED-lighting device including compensation circuit for AC input compensation, including a compensation inductor and first compensation capacitor parallelly connected to one terminal of AC input and a second compensation capacitor connected in series; rectifying unit for rectifying output from second compensation capacitor terminals to obtain direct current; and LED array driven by the rectifying unit output, wherein capacities of the first and second compensation capacitors and the compensation inductor and LED array output voltage are determined to cause 0.9 or larger cosine value of a phase, with respect to the AC input voltage, of resulting current obtained by dividing AC input voltage by sum of (i) parallel value of an equivalent impedance Re of the rectifying unit and LED array and an impedance of the second compensation capacitor and (ii) parallel value of impedances of the compensation inductor and first compensation capacitor.
    Type: Application
    Filed: August 29, 2013
    Publication date: August 6, 2015
    Applicants: Optomind Inc., Korea Advanced Institute of Science and Technology
    Inventors: Chun-taek Rim, Eun-Soo Lee, Bo-hwan Choi, Bong-cheol Kim