Whether enforcing a patent or prosecuting a patent application,
obviousness is often the key issue. The Patent Examiner (in the
case of a patent application) or the Court (in the case of an
issued patent) must determine if a claimed invention is obvious in
view of the prior art and the knowledge and skill or persons of
ordinary skill in that art. In Mintz v. Dietz & Watson
the United States Court of Appeals for the Federal Circuit (the
Federal Circuit) held that bald conclusory statements that a
claimed invention is obvious in view of "common general
knowledge", are unacceptable unless supported by objective
An argument that a claimed invention is obvious is necessarily a
fictional exercise based on hindsight. Obviousness is an issue
neither of what was done, nor of what could have been done
(all inventions could have been made before – but were
not). Rather it is what that person skilled in the art
would have done. In both Canada and the U.S., an
obviousness analysis requires determination of:
the level of skill and knowledge of a person of ordinary skill
in the art.
the scope and content of the prior art.
the differences between the claimed invention and the prior
whether the differences over the prior art are
In the end, step (iv) is still a subjective determination of
whether a person of ordinary skill, would, in the light of the
state of the art and of common general knowledge, have come
directly and without difficulty to the claimed
It is easy, once the teaching of a claimed invention is known,
to say, "I could have done that." Before the assertion
can be given any weight, one must have a satisfactory answer to the
question, "Why didn't you?"3 In both the
U.S. and Canada the courts guard against impermissible hindsight
analyses by requiring that prior art be considered as if by a
person not having knowledge of the claimed invention, without using
the claimed invention as a road-map. An important part of that
safeguard against impermissible hindsight analyses is the
requirement that an Examiner or a judge provide a clearly
articulated reason as to why it would be obvious to combine or
modify the prior art to arrive at the claimed invention.
Applicants commonly face rejections that rely on conclusory
assertions that "it would have been obvious to a person of
ordinary skill in the art to ..." These assertions, generally
symptomatic of impermissible hindsight analyses, are typically not
supported by any evidence, and are often found in the context of a
rejection made that the claimed feature missing from the art is
"common general knowledge", or is a matter of
"design choice." The lack of evidence is usually quite
telling: if something is genuinely "common general
knowledge" then there should be an abundance of sources for
the Examiner to cite. The habit of relying upon unsupported
conclusory statements has been harshly criticised by the Federal
Circuit on previous occasions – see, for example, In
Re Lee4 or In re Kahn5.
Mintz v. Dietz & Watson is a reaffirmation that
bald conclusory statements cannot be the basis of a rejection for
obviousness. The Mintz claims pertained to a sausage
encasement that included an interlocking netting arrangement
producing a checkerboard pattern on the surface of the meat. The
trial judge relied on a "commons sense view" or
"common sense approach" to hold that it was obvious to
try a locking engagement.
On appeal, the Federal Circuit held mere recitation of the words
"common sense", without any support to be a clear
error6. The Court stated:
Common sense is a shorthand label for knowledge so basic that it
certainly lies within the skill set of an ordinary artisan. With
little more than an invocation of the words common sense (without
any record support showing that this knowledge would reside in the
ordinarily skilled artisan), the district court over-reached in its
determination of obviousness7.
The Court concluded that the trail judge erred by failing
properly to consider the objective evidence of the patentee, and
instead basing the decision on an unsupported conclusory
In requiring that alleged "common sense" must be
supported by an objective basis in evidence, the Mintz
decision is a welcome relief.
1 Graham v. John Deere Co. 383 US 1 (1966),
sometimes referred to as the "Graham
2 Beloit Canada v. Valmet Oy, (1986) 8 CPR (3d)
289 (FCA per Hugesson) at 294.
3 Beloit Canada v. Valmet Oy, supra, at
4 In re Lee, 277 F.3d 1338 (Fed. Cir.
5 In re Kahn, 441 F.3d 977 (Fed. Cir.
6 Mintz, page 8, lines 26 - 29
7 Mintz page 8, line 29 – page 9, line
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A recent Saskatchewan Court of Queen's Bench decision allowed a court-appointed receiver to sell and transfer intellectual property rights free and clear of encumbrances, finding that a license to use improvements of an invention was a contractual interest and not a property interest.
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