Patents by Inventor Chern-Jsair Chung

Chern-Jsair Chung 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: 5034977
    Abstract: A method and apparatus for generating dual tone multiple frequency signals employing a low frequency quartz oscillator, wherein a phase accumulation dual tone multiple frequency generator is comprised of a low frequency quartz oscillator. Two phase selectors are connected to produce digital phase signals in response to a signal input. Two phase accumulators, each composed of an adder and a register, are connected to accumulate the phase signals. Two ROM based sine wave tables are addressed by the outputs of the accumulators. An adder adds the outputs of the ROMs, and a D/A converter produces an analog output from the output of the adder.
    Type: Grant
    Filed: April 4, 1989
    Date of Patent: July 23, 1991
    Assignee: Industrial Technology Research Institute
    Inventors: Yarn-Chern Chen, Chern-Jsair Chung