Patents by Inventor In T. Hwang

In T. Hwang 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).

  • Patent number: 5644325
    Abstract: A digital to analog converter is described for a multimedia system in which the magnitude of the analog output is controlled by signals applied to level select inputs of the digital to analog converter. Digital signals to be converted to an analog output are connected to a different set of inputs. This converter is advantageous for use in a display system where the brightness of the display may be independently controlled by the signals applied to the level select inputs. In this way, the digital information signals to be converted to an analog signal need not be modified to increase or decrease the brightness of the display.
    Type: Grant
    Filed: December 12, 1994
    Date of Patent: July 1, 1997
    Assignee: AuraVision Corporation
    Inventors: Sherman T. King, Niantsu Wang, Guorjuh T. Hwang
  • Patent number: 5644333
    Abstract: This method is most advantageous when an analog multiplexer is controlled to pass either analog graphics signals or analog motion video signals to a multimedia display screen. In the preferred embodiment, this method includes the steps of outputting a digital color key from a graphics memory buffer at a designated time and for a designated period and then converting this color key to an analog signal. This analog color key signal is then detected during this designated period and stored to obtain a stored color key value. The graphics memory is then controlled to output the graphics signals to be displayed on a multimedia screen. These graphics signals include a digital color key for controlling a multiplexer to display a motion video window on the multimedia screen in place of the color key. The outputted graphics signals are converted into analog signals, and these analog signals are compared to the stored color key value for detecting whether a color key is being outputted in the graphics data stream.
    Type: Grant
    Filed: December 12, 1994
    Date of Patent: July 1, 1997
    Assignee: AuraVision Corporation
    Inventors: Sherman T. King, Tommy C. Lee, Niantsu Wang, Scott A. Kimura, Guorjuh T. Hwang
  • Patent number: 5506531
    Abstract: A phase locked loop circuit comprising a first counter for dividing a reference frequency at a division ratio predetermined or determined by an input unit, a second counter for dividing a frequency of an output signal from the phase locked loop circuit at a division ratio predetermined or determined by a different input unit, a phase detector for inputting output signals from the first and second counters and generating a voltage based on a phase difference between the inputted signals, a low pass filter for low pass filtering an output signal from the phase detector, and a voltage controlled oscillator for generating a frequency signal proportioned to an output voltage from the low pass filter. The phase locked loop circuit further comprises an unlock detector for generating a control signal for synchronization of one of the first and second counters with an earlier phase in response to an unlocked signal from the phase detector.
    Type: Grant
    Filed: October 6, 1994
    Date of Patent: April 9, 1996
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventors: Hyun S. Jang, Gyu T. Hwang
  • Patent number: 5498013
    Abstract: A bicycle frame includes a front frame having a bottom bracket secured to the bottom portion. A middle frame is pivotally coupled to the bottom bracket and is rotatable relative to the front frame. A chain stay has one end pivotally coupled to the bottom bracket and has the other end coupled to the middle frame by a shock absorbing device. Another shock absorbing device is secured between the front frame and the middle frame so as to allow relative movement-between the middle frame and the front frame and so as to absorb shocks transmitted between the middle frame and the front frame.
    Type: Grant
    Filed: December 12, 1994
    Date of Patent: March 12, 1996
    Inventor: Chiuon T. Hwang
  • Patent number: 5441766
    Abstract: The present invention relates to a method for the production of highly pure copper thin films free from carbonaceous impurities, which comprises depositing a thin copper film using an organic copper compound precursor containing ketoesters alone or in combination with a Lewis base as ligands, by which the ligands are not thermally decomposed during the vapor deposition.
    Type: Grant
    Filed: August 25, 1994
    Date of Patent: August 15, 1995
    Assignee: Korea Institute of Science and Technology
    Inventors: Hyung S. Choi, Young S. Cho, Chong J. Lim, Soon T. Hwang
  • Patent number: 5278134
    Abstract: The present invention relates to new 3-(aminooxoacetyl)-2-(2-imidazolin-2-yl)pyridines and their salts, having herbicidal activity.
    Type: Grant
    Filed: October 27, 1992
    Date of Patent: January 11, 1994
    Assignee: Korea Research Institute of Chemical Technology
    Inventors: Dae W. Kim, Hae S. Chang, Dong J. Jeon, Jae W. Ryu, In T. Hwang
  • Patent number: 5037467
    Abstract: The present invention relates to amidoxime derivatives of the formula (I): ##STR1## wherein R.sub.1 is a C.sub.1-3 alkyl or allyl group, a methyl group substituted by chlorine or fluorine atom or ethoxycarbonyl or diethyldithiophosphate group, a phenoxymethyl group unsubstituted or substituted by chlorine atom, a C.sub.2 alkoxy or phenoxy group unsubstituted or substituted by chlorine atom or ethoxycarbonylethoxy group, a phenyl group unsubstituted or substituted by chlorine or fluorine atom, a benzyl group unsubstituted or substituted by chlorine atom, or a morpholine group; R.sub.2 is a phenoxymethyl or phenoxyethyl group substituted by chlorine atom, a phenyl group substituted by chlorine atom or methoxy group, or an ethoxy group. The compounds of the invention have a extremely high selectivity between paddy rice or crop plants and weeds and a strong activity on weeds. Moreover, the compounds have a very low phytotoxicity to paddy rice and crop plants.
    Type: Grant
    Filed: June 29, 1989
    Date of Patent: August 6, 1991
    Inventors: Kwang Y. Cho, In H. Jeong, Young S. Kim, Beom T. Kim, Yong K. Min, Geun S. Jeon, Jin S. Kim, Kyung S. Hong, In T. Hwang, Suk J. Koo
  • Patent number: 4972247
    Abstract: A circuit configuration which provides protection against damage to semiconductor devices, such as integrated circuits or discrete components caused by high energy events. An additional base region is formed in the epitaxial layer collector of a bipolar transistor. The added base region overlaps an isolation region having an opposite conductivity to the epitaxial layer. During a high energy event, the reverse breakdown of the junction formed between the added base region and the epitaxial layer is in parallel with the reverse breakdown of the junction formed between the epitaxial layer and the substrate. The breakdown voltage of the junction formed at the added base region is less than that of the epitaxial layer/substrate breakdown so that less power is dissipated as heat in the silicon. As a result, the likelihood of thermal damage to PN/junctions near silicon-aluminum contacts is reduced.
    Type: Grant
    Filed: January 11, 1988
    Date of Patent: November 20, 1990
    Assignee: Silicon Systems, Inc.
    Inventors: Joseph M. Patterson, Daniel T. Hwang
  • Patent number: 4785670
    Abstract: A compact pressure gauge includes a cylinder which has a compressed gas inlet, a piston, a U-shaped piston rod, and a compression spring. The compression spring is sleeved on the piston rod in the cylinder for biasing the piston against the compressed gas pressure exerted on the piston. The U-shaped piston rod has parallel first and second arms. The first arm extends into the cylinder. The second arm includes a rack secured thereto. A rotating shaft includes an indicator secured thereto for displaying the rotational degree of the rotating shaft, and a pinion secured to the rotating shaft for meshing with the rack. A channel member is secured to the cylinder and has a guide slot through which the second arm extends. A positioning plate is secured to the channel member so that the rotating shaft is journalled on the cylinder and the positioning plate. When the piston rod is moved, the rotating shaft is rotated due to the fact that the pinion always meshs with the rack.
    Type: Grant
    Filed: March 1, 1988
    Date of Patent: November 22, 1988
    Inventor: Ten T. Hwang
  • Patent number: 4389946
    Abstract: A folding columnar support structure for use as a stool, snack table or other collapsible furniture device is made up of foldable articulated elements positioning a support surface or top relative to a flat base in a locked open position with the top spaced from the base or in a closed position with the support structure and base folded flatly against the top.
    Type: Grant
    Filed: April 2, 1980
    Date of Patent: June 28, 1983
    Inventor: Sung T. Hwang
  • Patent number: 4374783
    Abstract: The new compounds, O,O dialkyl S-(2,3,4 trihalo) butyl phosphorothioates, are prepared by reacting 2,3,4 trihalo-butyl sulfenyl chloride with O,O dialkyl hydrogen phosphites, or other salts. The compounds of this invention have pesticidal activity, especially insecticidal and nematocidal activity.
    Type: Grant
    Filed: May 8, 1981
    Date of Patent: February 22, 1983
    Inventor: Seong T. Hwang
  • Patent number: D325647
    Type: Grant
    Filed: June 1, 1990
    Date of Patent: April 21, 1992
    Inventor: H. T. Hwang
  • Patent number: D328647
    Type: Grant
    Filed: April 16, 1990
    Date of Patent: August 11, 1992
    Assignee: Lewis Woolf Griptight Limited
    Inventor: Bao T. Hwang