1. Description requirement
Article 42, paragraph 4 of the Patent Act
stipulates: "claims shall be supported by the detailed description of the
invention and shall define the invention clearly and concisely." Claims must
be supported by the detailed description of the invention. That means that the
scope of each claim must be identical or equivalent to the subject matter
described in the detailed description. Thus, an applicant should draft a
specification to include a wide variety of examples with respect to the claimed
invention.
KIPO maintains a rather strict attitude
towards the support requirement through its narrow interpretation of the scope to
be supported. As a practical strategy, a divisional application rather than an
amendment of claims may be used to secure the broader scope of the protection
and avoid prosecution estoppel. But, because it is required that the scope of a
divisional application be within the scope of the original specification, in
order to secure a broad scope of protection the original specification should
include sufficient examples and the descriptions of its equivalents to support
the claimed subject matter.
2. Claim Interpretation
The scope of a patent is defined by the
elements of a claim. It is well settled that each element in a claim is deemed
material to defining the scope of the patented invention. Therefore, only when
every element defined in a claim is found in an accused product or process, the
accused product or process literally infringes the patent right.
Doctrine of Equivalents
It has been long time for the Patent Court
and the Supreme Court to adopt the doctrine of equivalents as a part of Korean
patent law for interpreting claims.
The rationales of the doctrine of
equivalents in Korea are similar to those of the U.S. Thus, it is true that if
the accused product or process performs substantially the same function in
substantially the same way to obtain the substantially same result of the
patented invention, the accused infringes the patent in Korea.
In particular, the Supreme Court held that
the accused product or process infringes a patent where an element of the
patented invention is substituted with another element and, if (i) the
technical concepts or principle to solve the objective of the patented
invention and the accused invention are the same or common; (ii) the
substituted element in the accused invention performs substantially the same
function in substantially the same way to obtain the substantially same result
of the patented invention; (iii) such substitution is obvious to an ordinarily
skilled person in the art. However, the doctrine of equivalents shall not be
applicable to the circumstances that (iv) the accused substitution was already
known to skilled persons in the art at the time of filing an application and
(v) the accused element was excluded from the claimed invention during
prosecution.
Prosecution History Estoppel
Based on the doctrine of equivalents, a
patentee cannot regain his rights to any elements that were abandoned through
an amendment or a response during prosecution. For example, when an element is
excluded through an amendment in order to secure novelty and non-obviousness in
response to the examiner’s rejection, an invention
with an equivalent element is outside the scope of the patent.
The Supreme Court held that prosecution
history estoppel should be applied in view of specification, opinions of an
examiner from filing of the application to issuance of a patent and the intent
of an applicant as indicated in the amendments and arguments during
prosecution. Furthermore, in a patent containing more than one claim, the
prosecution history of each claim should be independently reviewed to decide
whether certain subject matter was intentionally excluded from the scope of the
claim.
