Patents by Inventor Sang T. La

Sang T. La 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).

  • Telephone capable of selectively accepting callers and enabling partial recognition of callers
    Patent number: 5228075
    Abstract: A telephone set capable of selectively accepting callers and enabling partial recognitions of callers is disclosed, and the telephone set includes: tip and ring terminals; a first analogue switch connected to said tip terminal; a first bridge diode connected to the first analogue switch and the ring terminal; a wave rectifying circuit connected to the first bridge diode; a microprocessor connected to the wave rectifying circuit and the first analogue switch; an EEPROM connected to the microprocessor; a hook switch connected to the microprocessor; a selecting switch connected to the microprocessor; a second bridge diode connected to the tip and ring terminals; a hybrid IC circuit connected to the second bridge diode; a DTMF decoder connected to the hybrid IC circuit and the microprocessor; a power supply means for supplying the required power to the internal circuits; and a second analogue switch and a microphone.
    Type: Grant
    Filed: November 27, 1990
    Date of Patent: July 13, 1993
    Assignee: Hyundai Electronics Co., Ltd.
    Inventors: Sang T. La, Dong K. Hahn