Patents Act, 1970
11. Priority dates of claims of a complete specification
(1) There shall be a priority date for each claim of a complete
specification.
(2) Where a complete specification is filed in pursuance of a
single application accompanied by-
(a) a provisional specification; or
(b) a specification which is treated by virtue
of a direction under sub-section (3) of section 9 as a provisional
specification, and the claim is fairly based on the matter disclosed in the
specification referred to in clause (a) or clause (b), the priority date of
that claim shall be the date of the filing of the relevant specification.
(3) Where the complete specification is filed or proceeded with
in pursuance of two or more applications accompanied by such specifications as
are mentioned in sub-section (2) and the claim is fairly based on the matter
disclosed-
(a) in one of those specifications, the
priority date of that claim shall be the date of filing of the application
accompanied by that specification;
(b) partly in one and partly in another, the
priority date of that claim shall be the date of the filing of the application
accompanied by the specification of the later date.
(4) Where the complete specification has been filed in pursuance
of a further application made by virtue of sub-section (1) of section 16 and
the claim is fairly based on the matter disclosed in any of the earlier
specifications, provisional or complete, as the case may be, the priority date
of that claim shall be the date of the filing of that specification in which
the matter was first disclosed.
(5) Where, under the foregoing provisions of this section, any
claim of a complete specification would, but for the provisions of that
sub-section, have two or more priority dates, the priority date of that claim
shall be the earlier or earliest of those dates.
(6) In any case to which sub-sections (2), (3), (4) and (5) do
not apply, the priority date of a claim shall, subject to the provisions of
section 137, be the date of filing of the complete specification.
(7) The reference to the date of the filing of the application
or of the complete specification in this section shall, in cases where there
has been a post-dating under section 9 or section 17 or, as the case may be, an
ante-dating under section 16, be a reference to the date as so post-dated or
ante-dated.
(8) A claim in a complete specification of a patent shall not be
invalid by reason only of-
(a) the publication or use of the invention so
far as claimed in that claim on or after the priority date of such claim; or
(b) the grant of another patent which claims
the invention, so far as claimed in the first mentioned claim, in a claim of
the same or a later priority date.