Patents by Inventor Hee-Chan Doh

Hee-Chan Doh 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: 20210157303
    Abstract: A smart factory control system using a smart plug for a plant, includes: multiple smart plugs each configured to electrically connect, to a socket, each of multiple load devices disposed in at least one plant within a specific manufacturing environment; a management server configured to receive the information from the multiple smart plugs, store the received information in an internal separate storage space, generate control information, and transmit the control information to the smart plug; and at least one gateway positioned for each at least one plant and configured to relay information transmitted from the multiple smart plugs within a specific plant to the management server and information transmitted from the management server to the multiple smart plugs within the specific plant.
    Type: Application
    Filed: July 22, 2020
    Publication date: May 27, 2021
    Applicant: OS LAB Co., Ltd.
    Inventors: Hee Chan Doh, In Seong LEE, Jae Mun Park
  • Patent number: 7330670
    Abstract: A bottom level detection device is disclosed for a burst mode optical receiver. The receiver includes a converter for converting a burst mode signal into a voltage signal and an automatic gain controller for automatically controlling a gain of the converter. The bottom level detection device detects a bottom level of an output signal from the converter and controls the automatic gain controller on the basis of the detected bottom level. The bottom level detection device includes an amplification circuit for receiving the output signal from the converter at its first input terminal and a fed-back output signal from the device at its second input terminal, respectively, and amplifying a difference between the received signals, a detector for detecting a bottom level of an output signal from the amplification circuit, and an output buffer.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: February 12, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hee-Chan Doh, Hyeon-Cheol Ki, Yun-Je Oh, Gil-Yong Park, Tae-Sung Park, Shin-Hee Won
  • Patent number: 7266312
    Abstract: A burst mode optical receiver is disclosed and includes a converter for converting a burst mode signal into a voltage signal, a bottom level detector for detecting a bottom level of an output signal from the converter, an automatic gain controller for automatically controlling the gain of the converter on the basis of the bottom level detected by the bottom level detector in order to maintain an amplitude of the output signal from the converter and generating a reset signal when the bottom level is lower than a predetermined reference value, and a power level detector for detecting a power level of the output signal from the converter and generating the reset signal and an LOS signal indicative of the presence of no input signal when the detected power level is lower than a predetermined reference value.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: September 4, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hee-Chan Doh, Gil-Yong Park, Shin-Hee Won, Byung-Chang Kang, Tae-Sung Park, Hyeon-Cheol Ki
  • Patent number: 7218865
    Abstract: A burst-mode optical receiver of a differential-output structure is disclosed.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: May 15, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hee-Chan Doh, Hyeon-Cheol Ki, Yun-Je Oh, Gil-Yong Park, Tae-Sung Park, Shin-Hee Won
  • Patent number: 7206521
    Abstract: In an optical receiver having a pre-amplifier for converting a current signal outputted from an optical detector to a voltage signal, a signal level detecting device is provided to provide an LOS (loss of signal) signal and a reset signal from the output of the pre-amplifier. The signal level detecting device comprising: a capacitor for receiving the output from the pre-amplifier; first and second transistors each consisting of an emitter and a collector connected to the output of the pre-amplifier and a base connected to the collector; a third transistor having a collector connected to the collector of the first transistor and an emitter connected to the collector of the second transistor; and, a common emitter circuit with a pair of resistors connected, respectively, to the emitter and collector of the third transistor and capable of detecting the level of a signal inputted from the collector of the third transistor.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: April 17, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hee-Chan Doh, Gil-Yong Park, Shin-Hee Won, Yun-Je Oh, Tae-Sung Park, Hyeon-Cheol Ki
  • Patent number: 6911644
    Abstract: An automatic-gain-control device in an optical receiver is provided and includes a pre-amplifier for converting a current signal outputted from an optical detector to a voltage signal and a bottom level detector for detecting the bottom level from the output of the pre-amplifier, the automatic-gain-control device comprising a bottom signal-level-determining section for analyzing the bottom level from the bottom level detector and outputting a signal denoting the presence of a signal and a reset signal for initialization at intervals between packets; and an automatic-gain-control signal generating section for providing an automatic-gain-control signal by showing the presence of a signal, the automatic-gain-control-signal-generating section including a first transistor which turns on according to a signal from the bottom signal-level-determining section and a second transistor which is connected to a capacitor for charging or discharging a voltage applied by the first transistor, and the drain voltage of which
    Type: Grant
    Filed: March 14, 2003
    Date of Patent: June 28, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hee-Chan Doh, Gil-Yong Park, Shin-Hee Won, Yun-Je Oh, Tae-Sung Park, Hyeon-Cheol Ki
  • Patent number: 6909082
    Abstract: An automatic threshold control device for a burst mode optical receiver is disclosed. The receiver includes a converter that converts a burst mode signal into a voltage signal and an automatic gain controller for automatically controlling a gain of the converter, independently generating a reset signal and applying it to the automatic threshold control device. The automatic threshold control device is adapted to detect a voltage level of an output signal from the converter.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: June 21, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hee-Chan Doh, Hyeon-Cheol Ki, Yun-Je Oh, Gil-Yong Park, Tae-Sung Park, Shin-Hee Won
  • Patent number: 6684033
    Abstract: A receiver in an optical network with a bit rate detection circuit for automatically detecting input signal data bit rates to automatically adjust the frequency of a voltage controlled oscillator in the receiver is disclosed. The receiver has a data rate detection and frequency adjustment circuit which automatically detects the data rate of an input signal and automatically adjusts the frequency of the VCO in the receiver in accordance with the data rate of the input signal. The data rate detection and frequency adjustment circuit detects the data rate of the input signal by converting the input signal into a DC voltage value that varies with respect to the data rate of the input signal.
    Type: Grant
    Filed: October 30, 2000
    Date of Patent: January 27, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hee-Chan Doh, Yun-Je Oh, Tae-Sung Park, Chan-Youl Kim, Gil-Young Park
  • Publication number: 20030206744
    Abstract: A bottom level detection device is disclosed for a burst mode optical receiver. The receiver includes a converter for converting a burst mode signal into a voltage signal and an automatic gain controller for automatically controlling a gain of the converter. The bottom level detection device detects a bottom level of an output signal from the converter and controls the automatic gain controller on the basis of the detected bottom level. The bottom level detection device includes an amplification circuit for receiving the output signal from the converter at its first input terminal and a fed-back output signal from the device at its second input terminal, respectively, and amplifying a difference between the received signals, a detector for detecting a bottom level of an output signal from the amplification circuit, and an output buffer.
    Type: Application
    Filed: March 19, 2003
    Publication date: November 6, 2003
    Inventors: Hee-Chan Doh, Hyeon-Cheol Ki, Yun-Je Oh, Gil-Yong Park, Tae-Sung Park, Shin-Hee Won
  • Publication number: 20030201382
    Abstract: An automatic-gain-control device in an optical receiver is provided and includes a pre-amplifier for converting a current signal outputted from an optical detector to a voltage signal and a bottom level detector for detecting the bottom level from the output of the pre-amplifier, the automatic-gain-control device comprising a bottom signal-level-determining section for analyzing the bottom level from the bottom level detector and outputting a signal denoting the presence of a signal and a reset signal for initialization at intervals between packets; and an automatic-gain-control signal generating section for providing an automatic-gain-control signal by showing the presence of a signal, the automatic-gain-control-signal-generating section including a first transistor which turns on according to a signal from the bottom signal-level-determining section and a second transistor which is connected to a capacitor for charging or discharging a voltage applied by the first transistor, and the drain voltage of which
    Type: Application
    Filed: March 14, 2003
    Publication date: October 30, 2003
    Inventors: Hee-Chan Doh, Gil-Yong Park, Shin-Hee Won, Yun-Je Oh, Tae-Sung Park, Hyeon-Cheol Ki
  • Publication number: 20030202803
    Abstract: In an optical receiver having a pre-amplifier for converting a current signal outputted from an optical detector to a voltage signal, a signal level detecting device is provided to provide an LOS (loss of signal) signal and a reset signal from the output of the pre-amplifier. The signal level detecting device comprising: a capacitor for receiving the output from the pre-amplifier; first and second transistors each consisting of an emitter and a collector connected to the output of the pre-amplifier and a base connected to the collector; a third transistor having a collector connected to the collector of the first transistor and an emitter connected to the collector of the second transistor; and, a common emitter circuit with a pair of resistors connected, respectively, to the emitter and collector of the third transistor and capable of detecting the level of a signal inputted from the collector of the third transistor.
    Type: Application
    Filed: April 3, 2003
    Publication date: October 30, 2003
    Inventors: Hee-Chan Doh, Gil-Yong Park, Shin-Hee Won, Yun-Je Oh, Tae-Sung Park, Hyeon-Cheol Ki
  • Publication number: 20030202802
    Abstract: An automatic threshold control device for a burst mode optical receiver is disclosed. The receiver includes a converter that converts a burst mode signal into a voltage signal and an automatic gain controller for automatically controlling a gain of the converter, independently generating a reset signal and applying it to the automatic threshold control device. The automatic threshold control device is adapted to detect a voltage level of an output signal from the converter.
    Type: Application
    Filed: March 25, 2003
    Publication date: October 30, 2003
    Inventors: Hee-Chan Doh, Hyeon-Cheol Ki, Yun-Je Oh, Gil-Yong Park, Tae-Sung Park, Shin-Hee Won
  • Publication number: 20030194243
    Abstract: A burst mode optical receiver is disclosed and includes a converter for converting a burst mode signal into a voltage signal, a bottom level detector for detecting a bottom level of an output signal from the converter, an automatic gain controller for automatically controlling the gain of the converter on the basis of the bottom level detected by the bottom level detector in order to maintain an amplitude of the output signal from the converter and generating a reset signal when the bottom level is lower than a predetermined reference value, and a power level detector for detecting a power level of the output signal from the converter and generating the reset signal and an LOS signal indicative of the presence of no input signal when the detected power level is lower than a predetermined reference value.
    Type: Application
    Filed: March 19, 2003
    Publication date: October 16, 2003
    Inventors: Hee-Chan Doh, Gil-Yong Park, Shin-Hee Won, Byung-Chang Kang, Tae-Sung Park, Hyeon-Cheol Ki
  • Publication number: 20030194244
    Abstract: A burst-mode optical receiver of a differential-output structure is disclosed.
    Type: Application
    Filed: April 15, 2003
    Publication date: October 16, 2003
    Inventors: Hee-Chan Doh, Hyeon-Cheol Ki, Yun-Je Oh, Gil-Yong Park, Tae-Sung Park, Shin-Hee Won
  • Patent number: 6580263
    Abstract: Disclosed is a bit rate discrimination device that accurately discriminates a bit rate regardless of variations in the operating temperature. A photoelectric converter converts an input optical signal into an electric signal, and a bit rate detector detects a bit rate of the optical signal from the electric signal and outputs a discrimination signal indicating the bit rate. A DC amplifier outputs a bit rate detection signal by amplifying the discrimination signal, and a temperature detector detects the operating temperature of the DC amplifier and outputs a temperature signal indicating the detected operating temperature. A variation amplifier outputs a temperature compensation signal by amplifying the voltage level difference between the temperature signal and a predetermined reference signal, so as to cancel variations in an output voltage of the DC amplifier according to the operating temperature.
    Type: Grant
    Filed: August 15, 2001
    Date of Patent: June 17, 2003
    Assignee: Samsung Electronics Co., LTD
    Inventors: Jeong-Seok Choi, Tae-Sung Park, Hee-Chan Doh, Gil-Yong Park, Yun-Je Oh
  • Publication number: 20020065623
    Abstract: Disclosed is a bit rate discrimination device that accurately discriminates a bit rate regardless of variations in the operating temperature. A photoelectric converter converts an input optical signal into an electric signal, and a bit rate detector detects a bit rate of the optical signal from the electric signal and outputs a discrimination signal indicating the bit rate. A DC amplifier outputs a bit rate detection signal by amplifying the discrimination signal, and a temperature detector detects the operating temperature of the DC amplifier and outputs a temperature signal indicating the detected operating temperature. A variation amplifier outputs a temperature compensation signal by amplifying the voltage level difference between the temperature signal and a predetermined reference signal, so as to cancel variations in an output voltage of the DC amplifier according to the operating temperature.
    Type: Application
    Filed: August 15, 2001
    Publication date: May 30, 2002
    Inventors: Jeong-Seok Choi, Tae-Sung Park, Hee-Chan Doh, Gil-Yong Park, Yun-Je Oh