Recent Decision By Supreme Court Secures The Rights Of Patent Owners

A March decision by the United States Supreme Court represents a significant victory for patent owners. The court upheld the doctrine that the rights of a patent owner are not always limited to what is literally described in the patent. Instead, if a competitor is using the "equivalent" of the patented invention, the patent is infringed. The Supreme Court's decision is particularly important in areas of rapidly developing technology, where a patent applicant may not be able to foresee technological advances that might provide an equivalent way of using the patented invention. As a result, the inventor may not always be able to draft a patent to cover the unforeseen advances. But in light of the Supreme Court's decision, substituting an equivalent feature in place of a feature literally described in the patent will not avoid infringement. The case, Warner-Jenkinson v. Hilton Davis, involved a patented process for removing impurities from dyes. Hilton Davis Co., a Cincinnati-based food dye manufacturer, had patented a process for passing dye through a porous membrane at pH levels ranging from 6.0 to 9.0. Warner-Jenkinson Co., a St. Louis-based dye manufacturer, practiced the process at a pH of 5.0. The issue was whether the Hilton Davis patent was limited to the pH range of 6.0 to 9.0 stated in the patent, or whether the scope of the patent could be expanded beyond the literal language of the patent to cover a pH of 5.0. According to the Supreme Court's decision, the scope of Hilton Davis's patent could be expanded to cover the Warner- Jenkinson process if a pH of 5.0 is the "equivalent" of the range recited in the patent. The Supreme Court's decision was the result of an appeal of a 1995 decision of the Federal Circuit Court of Appeals. The Federal Circuit's decision set forth a test that took into account the intent of the accused infringer when determining whether the scope of the patent could be expanded beyond its literal language. For example, if a competitor made efforts to design around the patent, these efforts were evidence that the differences between the patented invention and the accused product were substantial, and the patent could not be expanded beyond its literal scope to cover the competitor's product. Conversely, if a competitor simply copied the patented invention, the copying was evidence that the differences were "insubstantial," permitting the patent to be expanded beyond its literal scope to cover the competitor's product. The Supreme Court reversed the Federal Circuit's decision, stating that the intent of the accused infringer is not a factor to be considered in determining whether the patent can be expanded beyond its literal scope. Disregarding the intent of the infringer seems to be much more of a "common- sense" approach to determining infringement. For example, suppose two infringers were marketing identical products, neither of which is covered by the literal language of the patent, but both of which are the "equivalent" of the patented invention. Further suppose that one infringer had copied the patented invention but had substituted an equivalent component for one part of the product because it was less expensive to manufacture. The other infringer had studied the patent and attempted to design around it. Under the Federal Circuit test, the competitor who had copied the patented invention would be liable for infringement, while the other competitor who had attempted to design around the patent would not be liable- even though the products of the two competitors were identical. Under the Supreme Court test, however, the intent of the infringers is not a consideration, and both would be liable for infringement. Warner-Jenkinson had urged the Supreme Court to throw out the so-called doctrine of equivalents entirely or, alternatively, to limit the "equivalents" covered by the patent to those components that are expressly described in the patent. Had the Supreme Court adopted either of these positions, it could have had a detrimental effect on the rights of patent owners. A competitor could have avoided patent infringement by making insubstantial changes to the invention that take it outside the literal language of the patent or by substituting an equivalent component that did not exist at the time the patent application was filed. Despite the Supreme Court's decision, it is still preferable for the patent applicant to define his or her invention in terms that literally cover the broadest scope to which the applicant is entitled and not to rely on expanding the patent to include equivalents. In the Hilton Davis case, for example, the patent examiner had initially rejected the application over a prior art publication that described a process using a pH of 10.0 or greater. There was no need for the applicant to place a lower limit on the pH range to distinguish his invention over the prior art-the invention could simply have been recited as having a pH of "less than or equal to 9.0." Had the Hilton Davis patent not gratuitously included a lower limit, the Warner-Jenkinson process using a pH of 5.0 would have fallen within the literal language of the patent, and the issue of equivalence could have been avoided entirely. The Supreme Court left a number of questions unanswered. The court expressly did not adopt a specific test for determining whether a component of a competing product is the "equivalent" of the patented component. Instead, the Supreme Court left it to the Federal Circuit to refine the test for equivalence as it decides future cases. The decision also left unanswered the issue of whether a jury or the judge is to decide what constitutes an "equivalent." However, one thing is certain: Patent owners have won a significant victory. Larry A. Roberts is managing partner at the Atlanta patent law firm of Jones and Askew.

Recent Decision By Supreme Court Secures The Rights Of Patent Owners

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