Can the proportions of features in patent drawings be used as evidence?
Generally, the proportions of features in patent drawings cannot be relied upon as evidence unless the drawings are explicitly stated to be to scale. The MPEP 2125 states:
“When the reference does not disclose that the drawings are to scale and is silent as to dimensions, arguments based on measurement of the drawing features are of little value.”
This principle was reinforced in the case of Hockerson-Halberstadt, Inc. v. Avia Group Int’l, where the court held that “patent drawings do not define the precise proportions of the elements and may not be relied on to show particular sizes if the specification is completely silent on the issue.”
However, the MPEP does note that the description of the article pictured, in combination with the drawings, can be relied on for what they would reasonably teach one of ordinary skill in the art.
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