Patents by Inventor Stig R. Johansson

Stig R. Johansson 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: 5150114
    Abstract: A transmission system comprising an interrogator (1) and a number of transponders (2). The transponders (2) communicate with the interrogator (1) by means of individual addresses for reading and/or writing of information in the transponders, which admits more than one transponder to be located within the read/write zone of the interrogator. By transmitting the start code from the interrogator and giving the transponders opportunity to answer with an address dependent time delay of the reply code and investigating time differences between transmitted and received reply codes in the interrogator, the address of the transponder is determined. The transmission system is suitable for use in connection with identification, for example, personal identification.
    Type: Grant
    Filed: November 6, 1990
    Date of Patent: September 22, 1992
    Assignee: U.S. Philips Corporation
    Inventor: Stig R. Johansson