Hunter Douglas Australia Pty Ltd v Perma Blinds

Hunter Douglas Australia Pty Ltd (Hunter Douglas) appealed to the High Court of Australia against a decision of the Full Court of the Supreme Court of New South Wales, which had affirmed a judgment in favour of Perma Blinds. The dispute concerned the infringement of a patent for a type of blind, specifically the method of operating the blinds. Hunter Douglas, the patentee, alleged that Perma Blinds had infringed its patent by manufacturing and selling blinds that employed the patented mechanism.

The High Court was required to determine whether the blinds manufactured and sold by Perma Blinds infringed the patent held by Hunter Douglas. This involved a close examination of the patent claims and a comparison of the Perma Blinds product against those claims to ascertain whether the essential integers of the patent were present in the alleged infringing product. A key issue was the interpretation of the patent claims and whether Perma Blinds’ construction fell within the scope of those claims, either literally or by equivalence.

The Court, applying the principles of patent law, undertook a detailed analysis of the patent specification and the evidence presented regarding the construction and operation of both the patented blinds and those manufactured by Perma Blinds. The judges considered the doctrine of equivalents, which allows for infringement even if a product does not precisely match the wording of the patent claims, provided it performs substantially the same function in substantially the same way to achieve substantially the same result. After careful consideration of the technical aspects and the legal tests for infringement, the High Court found that Perma Blinds’ product did not infringe the patent. The appeal was therefore allowed, and the judgment of the Supreme Court of New South Wales was set aside.