Patents by Inventor Per Wistrand

Per Wistrand 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: 6061639
    Abstract: The present invention provides a fast, simple and accurate method for determining remaining battery capacity by taking into account the measured discharge parameters, such as voltage and current, which determine the shape of discharge curves for several different discharge currents. By normalizing the measured values, a normalized table is created that is used as a starting point for retrieving the remaining capacity in a battery at an arbitrary discharge current.
    Type: Grant
    Filed: December 29, 1997
    Date of Patent: May 9, 2000
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Per Wistrand
  • Patent number: 4812666
    Abstract: The invention is directed to a method and apparatus for providing an auxiliary feedback of the position of a pick and place spindle during multi-image repositioning of the spindle at the inspection station, wherein the auxiliary feedback is sufficiently precise to meet lead inspection requirements which are not met by the existing encoder. The auxiliary feedback is achieved by attaching a mapping plate with very accurately spaced reference marks onto the pick and place head and by mounting a second sufficiently precise camera adjacent the inspection station so that at least one reference mark or fiducial of the mapping plate is always in the field of view of the second camera while the component is at the inspection station.
    Type: Grant
    Filed: September 17, 1987
    Date of Patent: March 14, 1989
    Assignee: Universal Instruments Corporation
    Inventor: Per Wistrand