Standard For Determining Design Patent Infringement

DEREK FAHEY, ESQ.

Design patent infringement is evaluated under the ordinary-observer test. The central question is whether an ordinary observer, familiar with the prior art, would view the accused design as substantially the same as the patented design.

The Role of Prior Art

Prior art provides context for determining which visual features are significant. When a patented design is close to existing designs, relatively small differences may be important. When the patented design departs sharply from the prior art, copying those distinctive features may weigh more heavily toward infringement.

Egyptian Goddess

The Federal Circuit’s decision in Egyptian Goddess, Inc. v. Swisa, Inc. established the ordinary-observer framework as the sole test for design patent infringement. The analysis compares the overall visual impression of the patented and accused designs rather than dissecting isolated details.

In that case, the court considered competing nail-buffer designs in light of earlier three-sided and four-sided buffers. The prior art helped the court determine that the accused design’s overall appearance was not substantially the same as the patented design.

Practical Evaluation

A proper infringement analysis should compare the claimed ornamental design, the accused product, and the closest prior art from the viewpoint of an informed ordinary observer. Product photographs, patent figures, prosecution history, and prior-art references all may affect the assessment.