Patent Law FAQ

Can patent drawings be used to determine specific dimensions or proportions?

Generally, patent drawings cannot be relied upon to determine specific dimensions or proportions unless explicitly stated to be to scale. According to 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, there are exceptions:

• If the drawing is expressly labeled as being to scale, measurements can be relied upon.
• The overall proportions and relative sizes of elements may be considered if they would be apparent to a person of ordinary skill in the art.
• Specific features clearly shown in the drawings can be used as prior art, even if dimensions are not given.

It’s important to note that while exact measurements are typically not reliable, the drawings can still be used in combination with the written description to determine what would be reasonably taught to one skilled in the art.

To learn more:

• patent drawings
• dimensions
• proportions
• MPEP 2125
• drawing interpretation