Electric and Musical Industries Ltd and Boonton Research Corporation v Lissen Ltd     Patent – Infringement – Order for delivery up – Infringement by particular user only.
The plaintiffs had been successful in an action against the defendants for infringement of
their letters patent, and the registrar had made an order (inter alia) for delivery up as prayed in
the statement of claim—the judgment being silent as to the form of order to be made. The
defendants applied to the court to have the registrar’s order varied so as to exclude delivery
up, on the ground that the infringement proved was by user only:—