Page: 29
[31] The Patent Act promotes adherence to the language of the
claims, which in turn promotes fairness and predictability (Free
World Trust at paras. 31(a), (b) and 41). The words of the claims
must, however, be read in an informed and purposive way (at para.
31(c)), with a mind willing to understand (at para. 44). On a
purposive construction, it will be apparent that some elements of
the claimed invention are essential while others are non-essential
(at para. 31(e)). The interpretative task of the court, in claim
construction, is to separate and distinguish between the essential
and the non-essential elements, and to give the legal protection to
which the holder of a valid patent is entitled only to the essential
elements (at para. 15).
[32] To identify these elements, the claim language must be read
through the eyes of a [skilled person], in light of the latter’s
common general knowledge (Free World Trust at paras. 44-45; see
also Frac Shack at para. 60; Whirlpool at para. 53). As noted in
Free World Trust:
[51] …The words chosen by the inventor will be
read in the sense the inventor is presumed to have
intended, and in a way that is sympathetic to
accomplishment of the inventor’s purpose
expressed or implicit in the text of the claims.
However, if the inventor has misspoken or
otherwise created an unnecessary or troublesome
limitation in the claims, it is a self-inflicted wound.
The public is entitled to rely on the words used
provided the words used are interpreted fairly and
knowledgeably. [Emphasis in the original.]
[33] Claim construction requires that the disclosure and the claims
be looked at as a whole “to ascertain the nature of the invention
and methods of its performance, … being neither benevolent nor
harsh, but rather seeking a construction which is reasonable and
fair to both patentee and public” (Consolboard at p. 520; see also
Teva Canada Ltd. v. Pfizer Canada Inc., 2012 SCC 60, [2012] 3
S.C.R. 625 at para. 50). Consideration can thus be given to the
patent specifications to understand what was meant by the words in
the claims. One must be wary, however, not to use these so as “to
enlarge or contract the scope of the claim as written and …
understood” (Whirlpool at para. 52; see also Free World Trust at
para. 32). The Supreme Court recently emphasized that the focus
of the validity analysis will be on the claims; specifications will be
relevant where there is ambiguity in the claims (AstraZeneca
Canada Inc. v. Apotex Inc., 2017 SCC 36, [2017] 1 S.C.R. 943 at
para. 31; see also Ciba at paras. 74-75).