Treating two terms coextensively in the specification leads to an inference that they are related and largely synonymous. Here, for example, a “positional” relationship as in the prior art was found to be equivalent to the claimed indication of a “distance” because the specification used these terms as effectively synonymous. It may therefore be best to ensure that terminology in the specification is consistent and not intermingled, so as to avoid an inference that two different aspects are coextensive.
Background / Facts: The patents on appeal here from rejection at the PTO during reexamination are directed to vehicular rearview vision systems comprising an image capture device and a display system. The claims recite a display system that enhances images by using a graphic overlay of horizontal lines to indicate distance. The prior art teaches a graphic overlay with regularly spaced horizontal lines that show the driver the relative position of objects behind the vehicle.
Issue(s): Whether the prior art’s use of horizontal lines to indicate a “positional” relationship is equivalent to the claimed invention’s use of horizontal lines to generate a specific “distance” measurement.
Holding(s): Yes. “[The patentee’s] argument emphasizes an alleged distinction between a positional relationship and an indication of a distance. Even assuming arguendo that such a distinction exists, the [] patent essentially treats the two terms coextensively: ‘[h]orizontal grid markings on the display may be provided to indicate distances behind the vehicle at particular markings. Such a grid would allow the driver to judge the relative position of vehicles behind the equipped vehicle.’ [] All that the [] patent requires is a graphic overlay to indicate the distance, i.e., relative position, of objects behind a vehicle. And, as the Board found, that is precisely what [the prior art] teaches.”