How does a prior art reference disclosing a range overlap with a claimed range affect patentability?

When a prior art reference discloses a range that overlaps with a claimed range, it can affect patentability in the following ways:

• If the prior art range overlaps or lies inside the claimed range, it may establish a prima facie case of obviousness.
• The overlapping ranges create an expectation that the claimed range will have similar properties to the prior art range.
• To overcome this rejection, the applicant must demonstrate that the claimed range is critical or produces unexpected results.

As stated in MPEP 2144.05(I): “In the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.”

To learn more:

• prior art
• range overlap
• obviousness
• patentability