Patents by Inventor Johannes Dornaus

Johannes Dornaus 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).

  • Telecommunication system with automatically switched modems
    Patent number: 4013956
    Abstract: A telecommunication system in which two terminal stations are coupled to one another via a telephone exchange and the transmission paths between the exchange and the terminal stations are provided with pairs of modems for transmitting, via the transmission paths, information signals of modulation types which are different in the terminal stations and in the transmission paths, the modems nearer to the exchange being switched off by means of an auxiliary signal the frequency of which corresponds to a component of the frequency spectrum of the modulation type employed in the transmission path. Thus information transmission in the telephone exchange is obtained in the same modulation type as employed in the transmission paths so that unnecessary conversion from one type of modulation to the other is avoided.
    Type: Grant
    Filed: May 5, 1975
    Date of Patent: March 22, 1977
    Assignee: U.S. Philips Corporation
    Inventors: Johannes Dornaus, Jurgen Lahmer, Bernd Refflinghaus