Patents by Inventor Franz J. Porscht

Franz J. Porscht 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: 4261648
    Abstract: An objective of the pancratic type includes a varifocal front lens group and a fixed-focus rear lens group, the latter consisting of five air-spaced singlets. The front lens group is constituted by a positive first component consisting of three singlets, an axially shiftable negative second component consisting of a singlet and a doublet, and an axially shiftable positive third component in the form of a nearly planoconvex singlet of low power.
    Type: Grant
    Filed: June 1, 1978
    Date of Patent: April 14, 1981
    Assignees: Karl Vockenhuber, Raimund Hauser
    Inventors: Irmgard Gobl, Trude Muszumanski, Franz J. Porscht