How is the scope of protection of patent claims construed?
Patent claims are construed through the eyes of the skilled person in the art. Experts can give evidence on the meaning of technical or scientific terms and unusual or specific meanings of words.
A patent specification is given a purposive, not a purely literal, construction, in the light of the common general knowledge and the art before the priority date. The claims are to be construed in the context of the specification as a whole. There is no recognised doctrine of equivalents in Australian law, rather it is a question of whether the claims can be read sufficiently broadly on the basis of the above principles.
The doctrine of prosecution history (or file wrapper) estoppel is not applied in Australia, although in at least one case it has been suggested that this is an open question.
The scope of protection is determined from the perspective of an expert skilled in the art based on the patent claims. However, the description and the drawings shall be used for the interpretation of the patent claims (Sec 22a para 1 PA).
The claims, therefore, have priority over the content of the description and the drawing, which merely have an auxiliary function. Subject matter which is only mentioned in the description and the drawing but is not reflected in the wording of the claims is, therefore, irrelevant.
At the same time, the claims always have to be interpreted using the description and the drawing and not just when the meaning of the wording of the claims would otherwise be unclear.
Of secondary importance is information outside the patent, as the general language usage of the relevant experts or technical dictionaries.
Furthermore, the Protocol on the Interpretation of Art 69 of the European Patent Convention (EPC) is to be used in interpretation (Sec 22a para 1 PA).
According to the doctrine of equivalents, the scope of protection also extends to objects which fulfil all features of the patent equivalently.
Equivalent infringement is established by the following three-pronged test set out in the Austrian Supreme Court decision of Bicalutamid II (Austrian Supreme Court 20.05.2008, 17 Ob 6/08v; based on the German Schneidemesser decision) and recently confirmed by the Austrian Pemetrexed decision (Higher Reginal Court Vienna 12.04.2018, 133 R 15/18f):
a) The modified embodiment must solve the problem using modified, but objectively equivalent means (equivalent effect);
b) the person skilled in the art is able to infer the alternative means, based on his expert knowledge, as having an equivalent effect with regard to the solution of the problem (obviousness);
c) the considerations of the person skilled in the art are oriented towards the meaning of the technical teaching protected by the patent in such a way as to ensure that the person skilled in the art will take the alternative embodiment into consideration as an equivalent solution to the patented embodiment (‘equivalence’ or ‘parity’).
So far case law has confirmed that prosecution history and the Patent Office files are not to be considered for patent interpretation in infringement proceedings. However, Austrian law also contains the possibility of filing a declaratory action asking the court to rule if a certain object infringes the patent (Sec 163 PA; see Question 27.). In this quite rare proceeding, the court has to take the Patent Office files into account, which can potentially lead to a different outcome than an interpretation during infringement proceedings. However, also in these proceedings there is no strict prosecution history estoppel. Rather the Patent Office files are merely an additional basis for interpretation.
Under the art. 41 of the Statute #9,279/96, the extension of the protection conferred by a patent will be determined by the content of the claims, interpreted in the light of the specification and drawings.
The Patent Statute (art. 186) also provides the possibility of a doctrine of equivalents. However, there is no criteria for applying this doctrine and there is no precedent establishing a standard for applying it.
The scope of protection afforded to a granted patent is defined by the claims as purposively construed by the courts. The aim is to identify the words or phrases in the claims which describe the essential elements of the invention. The patent will be construed from the perspective of a person skilled in the art based on a reading of the patent specification as a whole, including the claims description and drawings, as of the date of publication.
In order to find infringement, the defendant’s apparatus, method or process must contain all essential claim elements of the subject claim(s) of the patent. Infringement can still be found where non-essential claims are missing or have been substituted.
Until recently, there was no prosecution or “file-wrapper” estoppel in Canada. However, as a result of recent legislative amendments, written communications between the applicant/patentee and the Commissioner, an officer or employee of the Patent Office or member of a re-examination board can now be introduced as evidence to rebut a patentee’s representations on claim construction.
Basically, the scope of protection of patent rights for an invention or a utility model shall be based on the contents of the letter of claim, and the manual and attached pictures may be used to explain the contents of the letter of claim, further provides that
According to Article 11 of the China Patent Law and Article 17 of Several Provisions of Supreme People’s Court on Issues Relating to Laws Applicable for Trial of Patent Dispute Cases, the scope of protection of patent right shall not only be based on the scope determined by the all the technical features set out in the patent claim, but also shall include the scope determined by features equivalent to the said technical features. Equivalent features shall mean features which use basically identical means to achieve basically identical functions and attain basically identical effects as the technical features set out, and which can be associated, at the time of occurrence of the infringement act, by ordinary technical personnel in the same field without making creative efforts.
In addition, Article 6 of Interpretations of the Supreme People’s Court Concerning Certain Issues on Application of Law for Trial of Cases on Disputes over Patent Infringement and Article 13 of Interpretation of Patent Law (II) further provide that where the right holder includes the technical solutions in the protection scope of patent rights that have been waived by the patent applicant or the patentee in the procedure for patent licensing or invalidation announcement through the amendment to or statement of the claim or descriptions, the People's Court shall not uphold such inclusion, unless the abandonment of the technical scheme has been explicitly rejected by the CNIPA.
The claim is to be constructed according to its literal meaning with regard to the description and drawings. The ‘skilled person’s’ view is determinative.
However, where a feature of the patent claim is missing in the product or process it is necessary to examine whether an equivalent feature is present. Even if no equivalent feature exists the patent owner can claim that the missing feature is in fact not an essential feature of the claim.
Patent prosecution history is not usually considered, but there is no categorical prohibition on doing so.
Article L. 613-2 of the IPC, equivalent to Article 69 of the European Patent Convention, defines the scope of protection of the patent.
French courts do not construe the claims literally, but in light of the description and the drawings, and where the language of the description is ambiguous it is impossible to add, by way of interpreting, any element or feature which was not originally in the description or the claims.
Drawings are used to complete the description, but cannot replace it, unless the shape or the layout of the invention cannot be described in words and the description expressly states that such shape or layout is represented by a drawing.
Where the literal infringement is not constituted, the doctrine of equivalents might apply. This doctrine is based on the principle that a 'means' whose structure does not literally reproduce the claims of the patent is equivalent when it has the same function as the patented means and achieves similar results. The “means” are considered in:
- their form or structure;
- their technical function; and
- the technical result they achieve.
The doctrine of equivalents is only available when the patented means cover a novel function. If the claimed means differ from the prior art only by their structure, the doctrine of equivalents cannot apply and the scope of the claim is limited to the claimed structure. On the contrary, if the claimed means differ from the prior art not only by their structure but also by their function, the scope of the claim extends to any equivalent means.
The claim wording as such is the starting point for claim interpretation. First, the meaning of the words used in the claim has to be understood. In a second step, the functional interpretation of the claim has to be established, while considering the description and drawings of the patent. Contradictions between description and claims are to be avoided. As a general rule, the claims have to be interpreted in a way that the claims cover all embodiments in the description and the drawings.
Clear definitions in the description are binding even if they are unconventional. The patent provides its own dictionary in this respect. Where no definition or information on the understanding of the terms used in the claim is provided, the claim features have to be understood in such that the relevant addressee, namely the person skilled in the art, would do while also considering any prior art.
The prosecution history of the patent is generally irrelevant for strict claim interpretation but can be considered for showing the understanding of a person skilled in the art (exemplified by the patent examiner).
The Greek law generally accepts the doctrine of equivalence, according to which, due account must be taken of any element which is equivalent to an element specified in the claims. It must be note though, that there is no particularly sophisticated case law in this respect.
Yes, Doctrine of Equivalents has been recognized in India.
The leading authority in Ireland on construction of claims remains the decision in Ranbaxy Laboratories v Warner Lambert  4 IR 584 where Clarke J in the Irish High Court approved at paragraph 31 the then leading case in the UK of Kirin Amgen v Hoechst  RPC 9. The central question of patent construction is;-
“What would a person skilled in the art have understood the patentee to have used the language of the claim to mean.”
The applicable law and principles are comprehensively addressed by Clarke J in his judgment. The starting point is Article 69 (1) of the European Patent Convention (“EPC”) which states that the extent of the protection conferred by a European patent “shall be determined by the claims” and that the “description and drawing shall be used to interpret the claims”.
The Protocol on the interpretation of Article 69 of the EPC provides that Article 69 is not to be interpreted as confining the scope of protection to the literal meaning of the words used in the claims, but nor are the claims a mere guideline. Instead, the interpretation adopted has to combine fair protection for the patent proprietor with a reasonable degree of legal certainty for third parties. Article 69 and the Protocol are given effect to by Section 45 of the Patents Act and the Second Schedule the Act.
In the Ranbaxy judgment Clarke J noted that the claims of the patent were to be construed purposively the inventors purpose being ascertained from the description and the drawings, and at paragraph 30 of his judgment he noted the statement in Catnic v Hill  RPC 183 by Diplock that:-
“a patent specification should be given a purposive construction rather than a purely literal one. The question in each case is: Whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive work and phrase appearing in the claim was intended by the patentee to be an essential requirement of the intervention so that any variant would fall outside the monopoly claimed, even though it could have no material effect upon the way the invention worked.”
Clarke J approved the statement in the UK case law that:
"......it follows that if the patentee has included what is obviously a deliberate limitation in his claims, it must have a meaning. One cannot disregard obviously intentional elements… the well-known principle that patent claims are given a purposive construction does not mean that an integer can be treated as struck out if it does not appear to make any difference to the invented concept. It may have some other purpose buried in a prior art and even if this is not discernible, the patentee may have had some reason of his own for introducing it."
Clarke J therefore approved the statement that followed that there was no general "doctrine of equivalents". However:
"On the other hand purposive construction can lead to the conclusion that a technically trivial or minor difference between an element of a claim and the corresponding element of the alleged infringement nonetheless falls within the meaning of the element when read purposively. This is not because there is a doctrine of equivalents: it is because that is a fair way to read the claim in context."
Clarke J then set out his own views upon patent construction in the light of these principles and summarised his approach as follows at paragraph 3.32;-
"a Court [will] lean against a construction for which there is no rational basis from the perspective of the patentee. That is not to say that the Court will enter into a detailed analysis of the sort of consideration that might have entered the patentee's mind. The issue of construction is to be addressed from the perspective of a skilled addressee. That skilled addressee must be taken to know what the purpose of the patent is and the basic principles of patent law which would inform any person as to the general way in which a patent application would be formulated. If, from that perspective, a particular construction would immediately seem to the skilled addressee to be irrational, then there seems to me to be no reason in principle why the Court should not take that fact into significant account in the construction exercise. I propose approaching the question of construction on that basis."
Whilst the Irish Courts have adopted the purposive construction taken by the UK Courts in Kirin-Amgen v. Hoechst, rather than a purely literal construction, it remains to be seen whether the Irish Courts will reconsider the position in light of decision in Eli Lilly v Actavis  UKSC 48, where the UK Supreme Court introduced a new two-stage test that introduces an explicit doctrine of equivalents.
The scope of the claims is determined in light of the specification as a whole. The terms used by the patentee are interpreted with reference to the specification and the drawings, so as to provide to them the meaning that the patentee intended. The Supreme Court adopted the well-known statement of Lord Diplock in Catnic Components Ltd v. Hill & Smith Ltd  R.P.C. 183, that a "patent specification is a unilateral statement by the patentee, in words of his own choosing, addressed to those likely to have a practical interest in the subject matter of the invention (i.e., ‘skilled in the art’), by which he informs them what he claims to be the essential features of the new product or process". In line with the UK Catnic judgment, the Supreme Court further held that the patent specification should be given a purposive construction rather than a purely literal one and that meticulous verbal analysis is inappropriate in the construction of the specification.
The scope of protection afforded to the patentee is ‘flexible’ in the sense that it will increase in accordance with the contribution of the invention to the relevant professional field.
It is yet to be decided whether prosecution history can be used as an aid to claim construction and, if so, to which extent. The Supreme Court has noted that the application of the US doctrine of prosecution history estoppel to Israeli law may not be straightforward due to differences between US and Israeli prosecution practices. The Supreme Court further noted that caution must be exercised when reviewing prosecution statements so as not to accord them excessive weight. It therefore seems that only prosecution statements amounting to clear and unmistakable surrender of subject matter are to be considered as binding.
Israeli law provides protection against both literal infringement and infringement of the essence (‘pith and marrow’) of the invention. As was held by the Supreme Court in a series of judgments, taking the essence of the invention is possible by numerous ways. The law should be flexible and address the particular facts and circumstances of each matter. Among others, in order to address nonliteral infringement, the Supreme Court adopted the UK doctrine of variations as developed in Rodi & Wienenberger v. Showell  R.P.C. 367, 381 and in Catnic Components v. Hill & Smith Ltd.,  FSR 60, 66 and the US doctrine of equivalents as developed in Graver Tank & Mfg. Co. v. Linde Air Product Co., 339 U.S. 605 (1950). Furthermore, the omission of some elements of the invention or the addition of other elements does not necessarily avoid an infringement. The doctrines of equivalents and ‘pith and marrow’ have been reiterated and emphasized in numerous cases and were applied with regard to a wide range of technologies including pharmaceutical inventions.
Art. 52(1) of the Italian IP Code provides that the scope of protection is determined by the patent claims, interpreted in light of the description and the drawings. As provided in subsequent paragraph 52(2), patent claims need to be interpreted so as ensure both the patentee’s right to a fair protection and, on the other hand, legal certainty for third parties.
Our statutory provisions are therefore perfectly aligned with the principles condensed in Article 69 of the European Patent Convention (EPC) and the related Protocol of Interpretation.
The material application of the above statutory provisions has resulted into our courts introducing a ‘doctrine of equivalents’, which was itself made the object of a statutory provision in 2010, namely Art. 52(3) which states that in determining the scope of protection, account must be taken of features that might be equivalent to the claimed features.
Our doctrine of equivalents has witnessed the adoption of several tests. The test most likely to be applied by Italian courts today is the renowned “triple test”, according to which an element is equivalent to the claimed features if it performs the same function, in the same way so as to obtain the same result. That being stated, the assessment of whether a patent is or is not infringed by equivalents is fact-sensitive and to a large extent affected by the specificities of the case.
Italy does not have a prosecution history estoppel, although discussions over statements rendered to the EPO examiner during prosecution often arise in patent litigation. Italian courts have a trend of considering the patentee’s statements during prosecution irrelevant for purposes of determining the scope of protection, the main argument being that those statements are released in an administrative (not jurisdictional) venue and for purposes of curing a potential grant impediment/invalidity, which is a matter separate from infringement. Nevertheless, the issue is still fairly controversial.
The scope of a patented invention is defined by the claims, and the meanings of the terms are interpreted in consideration of the specification and the drawings (Article 70(1) and (2) of the Patent Act). Further, the theory of file wrapper estoppel exists, under which a patentee is not permitted to make arguments contrary to the arguments made by itself in the prosecution history, and, from such perspective, the arguments made by the applicant in the prosecution history may be taken into consideration when the claims are interpreted. Further, the interpretation of the claims may be made in consideration of the dictionary meanings of the terms and the common technical knowledge as of the filing of the application. In terms of the precedents, infringement under the doctrine of equivalents has been accepted in which, even if the accused product/process does not have configurations in line with the claims, the establishment of patent infringement is still admitted as long as such accused product/process satisfies the requirements under which the accused product/process is substantially equivalent to the patented invention.
Pursuant to section 39 of the Patents Act, the scope of the patent is determined by the patent claims. The description may serve as a guide to the understanding and interpretation of the patent claims.
Norwegian Law provides for protection by equivalence.
Following the Supreme Court's decision in the so-called Donepezil Decision from 2009, the conditions for protection by equivalence under Norwegian law, may be summarized as follows:
First, the alleged infringing product or process must solve the same problem as the patented invention, second, those modifications that are made must have been obvious to the skilled man and third, the alleged infringing product or process must not belong to prior art. Whether the alleged product or process is infringing the patent on the basis of the doctrine of equivalence, will in any event depend on a discretionary assessment by the Court, and the court will likely consider whether the product or process is a close modification of the patent.
Although there is no absolute prosecution history estoppel under Norwegian Law, it will generally be very difficult for a patentee to argue that the scope of protection shall be broaden beyond the wording of the claims by invoking the doctrine of equivalence if this would imply that the patent would be extended to cover subject matter that was ceded by the amendments (narrowing) of the claims that were done during the prosecution.
The extent of protection conferred by a national patent is determined by the terms of the claims. Polish courts tend to apply a strict meaning to the patent claims. One of the major differences between the EPC and Polish law is that the latter does not require to use the description and drawings in claim construction as they may be used to interpret the claims when necessary. Thus, based on the clara non sunt interpretanda principle, Polish courts, especially in the preliminary injunction proceedings, often do not refer to the description or the drawings if the claims are prima facie clear and unambiguous.
In the main action, claims are almost always construed with the assistance of a court-appointed expert.
The prosecution files are not used for construing the claims although there is no such explicit prohibition.
There is very little case law pertaining to infringement under the doctrine of equivalents in Poland. Polish courts accept that in certain instances patent protection may extend beyond the literal meaning of the claims. Furthermore, in a most recent judgment in that respect, the Supreme Court (case V CSK 149/15) confirmed that the patent infringement needs to be evaluated also in the context of the doctrine of equivalents involving particular consideration as to whether the gist of invention have been used in the contested solution.
The relevant IPC provision that determines a patent scope of protection is tailored on Article 69 of the European Patent Convention – “EPC”), so patent claims are generally interpreted under this legal criterion.
There is no provision of the Portuguese law that foresees ‘equivalents’ for determining the extent of protection by a patent. However, such doctrine is invoked in patent litigation cases and is also considered and applied by the courts and arbitral tribunals, although not in a harmonized way.
The prosecution history may also play an important role in determining the scope of patent protection, notably whenever the doctrine of equivalents is argued, but also in invalidity matters. The briefs and documents filed with the Patent Office also play a role in determining the scope of a patent
The scope of patent protection is defined by the patent claims (Art. 1354 of the Civil Code). To interpret the claims of an invention a specification and drawings may be used. The application doctrine of equivalence is directly specified by part 3 of Article 1358 of the RUCC, while the definition of equivalent feature is not defined in the law. The equivalency as a matter of fact is established based on explanations of an expert, if such features are 1) known in the art 2) known to be interchangeable 2) provide the same technical effect. There is no indication of the prosecution history estoppel for patent infringement cases in the written law or in case law. Meanwhile the Supreme Court of Russia has indicated in its several recent decisions on other subjects, that a party in court litigation proceedings should not go against facts established by this party. The other option to refer in court proceedings to the prosecution history estoppel is a defense of abuse of right which is a valid defense.
Under section 113(1) of the PA, the scope of protection conferred by a patent is determined by the claims of the specification of the patent. Ascertaining the meaning of the claims is an exercise in claim construction, which is undertaken with a purposive approach.
The key principles to claim construction are as follows:
(a) in ascertaining the true construction of a patent specification, the claims themselves are the principal determinant. What is not claimed is deemed to be disclaimed;
(b) the description and other parts of the patent specification form the context for and may assist in claim construction;
(c) the claims are to be construed purposively and not literally. Since this is aimed at giving the patentee the full extent, but not more, of the monopoly which a person skilled in the art and reading the claims in context would think the patentee was intending to claim, the threshold question is to ask what the notional skilled person would have understood the patentee to mean by the use of the language in the claims;
(d) generally, the notional skilled person should be taken to be a skilled technician aware of all relevant prior art but incapable of a scintilla of invention or to engage in lateral thinking;
(e) a Court is not entitled to disregard clear and unambiguous words in a patent claim, or to rewrite or amend the claim; and
(f) an article infringes a patent if it falls within the words of one of the claims of a patent and usurps each and every one of the essential elements of that relevant claim.
Under the doctrine of equivalents, a device which is functionally equivalent to the patented invention will be held to infringe it, notwithstanding that certain essential features of the patented invention are absent from the device. This doctrine has not been accepted in Singapore on the basis that a wholly functional approach to claim construction objectionably disregards the clear and unambiguous words stated in the patent claims when such words must be given their natural and ordinary meaning.
It is a central principle that the scope of a patent right is determined by the limitations recited in each patent claim. However, the Korean Supreme Court has held that the claim language should be interpreted in an objective and reasonable manner based on its common meaning. It has also held that in a case where the technical meaning of the patented invention cannot be specifically understood from the languages of the claims alone, the detailed description of the invention and drawings shall be taken into consideration.
The Korean Supreme Court also adopts the doctrine of equivalents. The Korean courts would find a product infringes under the doctrine of equivalents (DOE) if:
(1) The technical idea or principle to solve a problem is identical between the patented invention and the accused product;
(2) The accused product with the modified element accomplishes substantially the same function and exhibits substantially the same effect; and
(3) The modification of an element in the patented invention to the corresponding element in the accused product is obvious to a person skilled in the art.
Equivalents cannot be found if (a) the accused product was already known or could have been easily conceived from the prior art; or (b) the prosecution history of the patented invention indicates that the accused product was deliberately excluded from the claims of the patented invention.
The scope of protection is defined by the claims. Terms in patents are construed in accordance with their ordinary meaning in the art, unless the patent defines the term in a different manner and the description may be taken into consideration. Construction is done in light of the patent’s contribution to the state of the art.
All elements of a patent claim must be satisfied for infringement but in narrowly defined circumstances a claim can extend to equivalents.
Statements from the prosecution history may be relied on in the construction where the claims or description is unclear, but only to limit the scope of protection.
The scope of protection conferred by the patent is determined by the claims of the patent. The claims are construed as they would be understood by a person skilled in the art. The description and the drawings must be taken into account in claims construction.
Patent infringement covers both literal infringement as well as infringement by equivalent means. There is infringement by equivalent means if: (i) the substituted features objectively fulfil the same technical functions (same effect); (ii) the substituted features and their objectively identical function are obvious and implied to a person skilled in the art by the doctrine of the patent (accessibility); and (iii) on the basis of a patent claim, a person skilled in the art would consider the substituted features to be an equivalent solution (equal value). In principle, prosecution history is not relevant for claims construction.
The scope of protection of patent claims includes the literal scope and the scope expanded under the doctrine of equivalents. The literal scope of a patent is determined based on the claims set forth in the specification. When interpreting the scope of the claims, the description and drawings of the patent may be used as references. Evidence used to interpret the scope of the claims includes both intrinsic and extrinsic evidence. Intrinsic evidence include the claims, the description of the invention, the drawings and the file of prosecution history. Extrinsic evidence refers to the technique information previously disclosed, such as patents, books, magazines, reports, or products. The scope expanded under the doctrine of equivalents is provided to protect the interests of patentees. The scope will be expanded to cover substantially the same functions, means, and results. This expansion can prevent others from derogating a patent without changing or replacing substantial technical features set forth in the specifications.
Prosecution history estoppel will also be considered when construing the scope of patent claims. When the supplement, amendment, correction, response, and reply related to patentability narrow the scope of the claims during the process of examination of a patent application and / or maintenance, the patent owner is no longer allowed to claim the limited or excluded parts in subsequent patent infringement litigation.
The scope of a patent will be determined by its claims, pursuant to the Patent Act, Section 36 bis, first paragraph, which states that “the right of the patentee to the patented invention under Section 36 shall be delimited by the claims. In deciding what the delimitations of the claims are, the characteristics of the invention as set forth in the specification and drawings shall be considered.”
In addition, Thai law recognizes the doctrine of equivalents under the second paragraph of Section 36 bis.
The scope of protection of patent is determined by its claims. The description and drawings are also taken into account when interpreting the claims. The claims are not interpreted word by word, but also the scope of protection cannot be extended to the features that are obvious to an expert yet not clearly written in the claims.
When determining the scope of protection, all elements equivalent to those defined in a claim are considered. If an element performs the same function and provides the same result as the one specified in a claim, that element is accepted as equivalent.
Moreover, to determine the scope of the patent, the statements of the patent owner made during the prosecution history and the validity term of the patent, are also considered.
Section 130(7) Patents Act provides that certain provisions of the Patents Act, including Section 60 which defines infringement, are framed so as to have, as nearly as practicable, the same effects in the United Kingdom as the corresponding provisions of the European Patent Convention (“EPC”), the Community Patent Convention (“CPC”) and the Patent Co-operation Treaty (“PCT”) have in the territories to which those Conventions apply.
Article 69(1) of the European Patent Convention (as amended in 2000) (“EPC 2000”) relevantly states:
The extent of the protection conferred by a European patent or a European patent application shall be determined by the claims. Nevertheless, the description and drawings shall be used to interpret the claims.
Article 1 of the Protocol on the Interpretation of Article 69 EPC 2000 (“the Protocol”) in essence provides that this Article should not be interpreted to mean that the extent of protection conferred by a European patent is defined by the strict, “literal” meaning of the wording used in the claims, description and drawing, nor should it be taken to mean that the claim serves only as a guideline and that the actual protection conferred extends to that contemplated by the patentee. Rather, the extent of protection is to be found in a position between these extremes which combines a fair protection for the patentee with a reasonable degree of legal certainty for third parties.
Article 2 of the Protocol states that for the purpose of determining the extent of protection conferred by a European patent, due account shall be taken of any element which is equivalent to an element specified in the claims.
Pursuant to Article 69 EPC 2000, in the UK the scope of protection of a patent is to be determined purposively by reference to its claims. This involves the identification of what a person skilled in the art as at the priority date would have understood the patentee to be using the language of the claim to mean, interpreted in the context of the specification as a whole. Whether an act infringes a given claim will depend on whether that act falls within the scope of the claim as a matter of normal interpretation.
Infringement by equivalence
Beyond the question of “literal” infringement of the claims, it is necessary to consider the extent to which the scope of protection afforded by a claim extends beyond its “literal” meaning (i.e. according to the normal purposive approach to interpretation, discussed above) and encompasses equivalent products or processes.
Following the UK Supreme Court decision in Actavis v Eli Lilly  UKSC 48, a doctrine of equivalents now applies in the UK. In that decision, the court propounded the following test for infringement by equivalence, whereby an act infringes the claim of a patent even in the absence of “literal” infringement:
i) Notwithstanding that it is not within the literal meaning of the relevant claim(s) of the patent, does the variant achieve substantially the same result in substantially the same way as the invention, ie the inventive concept revealed by the patent?
ii) Would it be obvious to the person skilled in the art, reading the patent at the priority date, but knowing that the variant achieves substantially the same result as the invention, that it does so in substantially the same way as the invention?
iii) Would such a reader of the patent have concluded that the patentee nonetheless intended that strict compliance with the literal meaning of the relevant claim(s) of the patent was an essential requirement of the invention?
In order to establish infringement under the doctrine of equivalents where there is no “literal” infringement, a patentee must establish that the answer to the first two questions is “yes” and that the answer to the third question is “no”.
Literal infringement occurs when the accused product or process falls within the scope of a properly construed claim. Claim construction is determined by the court, usually through a specific hearing and briefing schedule before trial.
Where there is no literal infringement, infringement can still be found under the doctrine of equivalents. According to this doctrine, infringement occurs if a product or process does not fall within the literal scope of the properly construed claim but is the substantial equivalent of the patented invention. To determine equivalence, a judge or jury analyzes whether the differences between the two are insubstantial to one of ordinary skill in the art.
Vietnam applies the doctrines of equivalent and literal infringement. Therefore, patent infringement can take any of the following forms:
- A product or part (component) of a product that is identical or equivalent to a product or part (component) of a product within the scope of protection of an invention patent.
- A process that is identical or equivalent to a process that is protected as an invention.
- A product or part (component) of a product that is manufactured by a process that is identical or equivalent to a process protected as an invention.
In practice, most patent infringement cases in Vietnam involve literal infringement. Therefore, the courts in Vietnam have not had much practice applying the law on equivalent infringement.