How are drawings in prior art interpreted for patent examination?

How are drawings in prior art interpreted for patent examination?

Drawings in prior art are interpreted as follows for patent examination:

• Proportions of features: The drawings are not assumed to be to scale unless specifically described as such in the reference.
• Disclosed features: Drawings can anticipate claims if they clearly show the structure which is claimed, even if the feature is unexplained in the specification.
• Measurement accuracy: Exact measurements from patent drawings are not reliable unless the drawing is expressly labeled as to scale.

As stated in MPEP 2125: “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.” However, the same section also notes that “the description of the article pictured can be relied on, in combination with the drawings, for what they would reasonably teach one of ordinary skill in the art.”

To learn more:

• prior art drawings
• patent examination
• MPEP 2125
• drawing interpretation