Claim Overbreadth

The word overbreadth does not appear in the Patent Act. However, subsection 27(3) requires that the specification fully describe the invention. If a claim asserts an exclusive privilege or property in more than is described, that claim is considered to be overbroad. In addition, subsection 27(4) requires that a patent end with claims that distinctly and in explicit terms define the subject-matter of the invention. If a claim asserts an exclusive privilege or property in more than the invention, that claim is considered to be overbroad.

Specification

(3) The specification of an invention must

1. correctly and fully describe the invention and its operation or use as contemplated by the inventor;
2. set out clearly the various steps in a process, or the method of constructing, making, compounding or using a machine, manufacture or composition of matter, in such full, clear, concise and exact terms as to enable any person skilled in the art or science to which it pertains, or with which it is most closely connected, to make, construct, compound or use it;
3. in the case of a machine, explain the principle of the machine and the best mode in which the inventor has contemplated the application of that principle; and
4. in the case of a process, explain the necessary sequence, if any, of the various steps, so as to distinguish the invention from other inventions.

Claims

(4) The specification must end with a claim or claims defining distinctly and in explicit terms the subject-matter of the invention for which an exclusive privilege or property is claimed.

The express language of section 60 of the Patent Rules requires that the description support the claims. A claim that is not supported by the description is considered to be overbroad.

60 The claims must be clear and concise and must be fully supported by the description independently of any document referred to in the description.

Justice Thurlow referred to the Patent Act in the process of reasoning that a claim which claims more than the inventor has invented is not granted under the authority of the statute and is therefore not lawfully obtained. In particular, Justice Thurlow cited section 35 and subsections 36(1) and (2) of the Patent Act (now subsections 27(2), (3) and (4) of the Patent Act, respectively).

[65] To resolve this question, it seems to me to be necessary to start with s. 28(1) of the Patent Act. This subsection provides that subject to certain limitations set out in the section, any inventor of an invention may on presentation to the Commissioner of a petition setting forth the facts and on compliance with all other requirements of the Act obtain a patent granting to him an exclusive property in such invention. The right given by this subsection is given only to one who has in fact made an invention and the patent which he may lawfully obtain pursuant to the enactment is limited to one granting him an exclusive property in the invention which he has made. A patent granted for something which is not an invention at all is thus not obtained pursuant to the authority of the statute and is invalid. Similarly, where the inventor has made an invention, a patent purporting to give an exclusive property in more than the inventor has invented is also contrary to what the statute authorizes and subject to the saving effect of s. 60 may also be invalid. These are fundamental statutory limits on the validity of patents which may lawfully be obtained. But in addition to these limitations, the statute also imposes certain requirements on one who seeks to obtain a patent for an invention which he has made, and by the terms of s. 28(1) he is entitled to obtain a patent giving him an exclusive property in such invention only on compliance with these requirements. Requirements of this nature are found in ss. 35, 36(1), 36(2) and 41(1).

…

[67] It follows from the foregoing that a patent which includes in its specification a claim which claims more than the inventor has invented purports to grant an exclusive property in more than the inventor has invented and at least in so far as that claim is concerned the patent, in my opinion, is not granted under the authority of the statute and is therefore not lawfully obtained.

The doctrine of overbreadth has statutory footing that stems from the scheme of the Patent Act and, in particular, subsection 27(4).

[169] It is not accurate to say that the doctrine of overbreadth lacks statutory footing. It stems, by implication, from the scheme of the Patent Act, and in particular section 27(4), which requires a claim or claims defining distinctly and in explicit terms the subject-matter of the invention for which an exclusive privilege or property is claimed. If the subject-matter of the invention must be defined, it must be defined accurately and not in an overly broad manner. Thus, the doctrine of overbreadth flows by necessary implication from the provisions of the Patent Act, very much like anticipation and obviousness before they were codified in sections 28.2 and 28.3 of the Patent Act in 1993. Recognizing overbreadth as a ground of invalidity is not tantamount to adding a new substantive condition of validity of patents. Overbreadth is an issue that arises in the process by which the invention is made public and the monopoly is asserted.

The Federal Court of Appeal stated that the concept of claim invalidity for overbreadth arises from subsections 27(3) and (4) of the Patent Act.

[129] The concept of claim invalidity for overbreadth (or overclaiming) arises from the combination of the requirements that a patent specification (i) correctly and fully describe the invention (see subsection 27(3) of the Patent Act), and (ii) include claims defining distinctly and in explicit terms the subject-matter of the invention for which an exclusive privilege or property is claimed (see subsection 27(4)). One may also consider overclaiming as a natural consequence of the bargain theory of patent law as described in Free World Trust at para. 13: [i]n return for disclosure of the invention to the public, the inventor acquires for a limited time the exclusive right to exploit it. If a patent claims more than it describes, or more than the inventor has made, it gives the patentee more than the bargain entitles them to. Such a claim violates the bargain and is therefore invalid.

The Supreme Court of Canada endorsed the statements of Lord MacMillan in Mullard. A patentee is granted a monopoly in order to protect the invention that has been communicated to the public. He is not entitled to claim a monopoly more extensive than is necessary to protect that which he has himself said is his invention.

And in the Mullard Radio Valve Co. Ld. v. Philco Radio and Television Corporation of Great Britain, Ld. and Others [(1936) 53 RPC 323], in the House of Lords, Lord MacMillan said at p. 345:

A patentee may make a most meritorious discovery and may give an entirely adequate description of his inventive idea and of the manner of putting it into practice, but when he comes to formulate the claim to his invention he may claim a monopoly wider in extent than is warranted by what he has invented. …

And at p. 346:

A patentee is granted his monopoly in order to protect the invention which in his specification he has communicated to the public. He is not entitled to claim a monopoly more extensive than is necessary to protect that which he has himself said is his invention. …

And at p. 347:

If an inventor claims an article as his invention but the article will only achieve his avowed object in a particular juxtaposition and his inventive idea consists in the discovery that in that particular juxtaposition it will give new and useful results, I do not think that he is entitled to claim the article at large apart from the juxtaposition which is essential to the achievement of those results.

And further, on p. 347:

It is undoubtedly the case that a claim may be too wide, in the sense that it claims protection for that for which the patentee is not entitled to protection, or that it gives him a wider protection than his discovery entitles him to receive. …

[pp. 236-237]

President Thorson described the function of patent claims in terms of fences:

By his claims the inventor puts fences around the fields of his monopoly and warns the public against trespassing on his property. His fences must be clearly placed in order to give the necessary warning and must not fence in any property that is not his own. The terms of a claim must be free from avoidable ambiguity or obscurity and must not be flexible; they must be clear and precise so that the public will be able to know not only where it must not trespass but also where it may safely go. If a claim does not satisfy these requirements it cannot stand. [p. 352]

He explained that an inventor must not claim what he has not invented, for doing so would fence off property that does not belong to him.

… The inventor may make his claims as narrow as he pleases within the limits of his invention but he must not make them too broad. He must not claim what he has not invented for thereby he would be fencing off property which does not belong to him. It follows that a claim must fail if, in addition to claiming what is new and useful, it also claims something that is old or something that is useless. [p. 352]

The statements of Lord MacMillan in Mullard were also endorsed by the Federal Court of Appeal. A claim may be for an invention that is new, useful, and adequately described in the patent, yet it may be too wide a claim because it extends beyond the subject-matter of the invention. The consideration given by the patentee for a patent entitles him to protection for an article embodying his inventive idea, but not for an article covering things which do not embody it.

The patent in issue in [Mullard] related to a radio valve or tube and the juxtaposition of certain grids within it to achieve a desirable result. It was found that one of the claims claimed more than the inventor, in his disclosure, stated might have been expected from using the invention. At p. 347 of the report Lord MacMillan had this to say:

It was argued for the Appellants that if an article is new, is useful and has subject-matter, then it is necessarily patentable and entitled to protection. But a claim may be for an article which is new, which is useful and which has subject-matter, yet it may be too wide a claim because it extends beyond the subject-matter of the invention. The consideration which the patentee gives to the public disclosing his inventive idea entitles him in return to protection for an article which embodies his inventive idea but not for an article which, while capable of being used to carry his inventive idea into effect, is described in terms which cover things quite unrelated to his inventive idea, and which do not embody it at all.

…

It is undoubtedly the case that a claim may be too wide, in the sense that it claims protection for that for which the patentee is not entitled to protection, or that it gives him a wider protection than his discovery entitles him to receive.

Notwithstanding the vast differences in the inventions in that case and this, the words of Lord MacMillan are particularly appropriate to the circumstances here as I see them.

[p. 202]

The Federal Court of Appeal observed that overbroad claims make the bargain unfair.

[6] At its essence, the patent system is a bargain between the public and inventors: Free World Trust v. Électro Santé Inc., [2000] 2 S.C.R. 1024, 2000 SCC 66 at paragraph 13. The Act and the common law define that bargain in detail.

[7] The generalities of the bargain can be described in the following way. An inventor can obtain a patent for any new and useful art, process, machine, manufacture or composition of matter: section 2 of the Act (definition of invention). The patent gives its holder, the patentee, a time-limited exclusive right to make, construct, use and sell the invention: section 42 of the Act. There is a quid pro quo. The inventor must disclose the details of the invention in enough detail so that a person skilled in the art — i.e. an uninventive person knowledgeable in the field of the invention — can recreate it. Others, armed with the information previously disclosed, may make, use and sell the invention when the patent expires. The information disclosed may also give rise to inventions by others. This bargain is socially useful because it encourages research and development and broader economic activity: Free World Trust, supra at paragraph 42.

[8] The scope of the subject-matter protected by the patent matters. It can affect this bargain drastically. If the scope is too wide, the inventor will get too much protection.

…

[16] However, an inventor can only claim that which he invented. If an inventor claims more than was invented, the subject-matter of the patent will be too broad. This makes the bargain unfair — the inventor ends up with the exclusive right to exploit subject-matters not invented and not disclosed to the public. Simply put, patents cannot be overbroad.

In Farbwerke Hoechst, Justice Thurlow described two fundamental limitations on the breadth of claims; namely, that a claim must not be broader than:

1. the invention which the inventor made; or
2. the invention which the inventor described in the specification.

There are two fundamental limitations on the extent of the monopoly which an inventor may validly claim. One is that it must not exceed the invention which he has made, the other is that it must not exceed the invention which he has described in his specification. [Ex CR p. 106, para. 20] [CPR p. 238]

In Leithiser, Justice Thurlow restated the Farbwerke Hoechst limitations in the form of two questions:

1. whether the claims of the inventor’s patent claim more than he or she invented; or
2. whether the claims are broader than the invention which is described in the specification.

On this basis two questions arise.

The first is whether the claims of the appellant’s patent claim more than he invented. The second is whether the claims are broader than the invention which is described in the specification. If the answer to either question is in the affirmative, as I understand the law, the claims are invalid. [p. 118]

The Federal Court of Appeal reiterated that it is settled law that a patent which claims more than what was invented or disclosed is overbroad. The Court made it clear that a claim will be considered overbroad if it asserts an exclusive property or privilege in something that the inventor did not:

1. actually invent; or
2. fully disclose in the patent.

[115] It is now settled law that a patent which claims more than what was invented or disclosed can be found invalid for being overly broad. As explained in Lovell Manufacturing Co. and Maxwell Ltd. v. Beatty Brothers Ltd. (1962), 41 C.P.R. 18 (Ex. Ct.) at p. 66:

The other attack was that the claims were too wide and that they claimed more than had been invented. This repeats the central them to which I have referred, namely, the contention that all that had been invented were the specific wringer constructions described in the specification and that unless the claims were limited in their application to inventions of the said specific constructions they were too wide and, therefore, invalid. There is a simple answer to the contention[.] If the claims read fairly on what has been disclosed and illustrated in the specification and drawings, as they do, they are not wider than the invention. The specific wringer constructions described in the specification are simply embodiments or illustrations of the invention. The claims embrace them and might well embrace similar other embodiments or illustrations. There is nothing in any of the specifications that would limit the claims to one of the specific wringer constructions or to all of them.

[116] The test referred to by the Trial Judge, i.e. that … a claim will be considered overly broad and accordingly, invalid, if it asserts an exclusive property or privilege in something the inventor did not actually invent; or something that the inventor did not fully disclose in the patent (paragraph 99 of the Reasons), is, in my view, the correct one.

[Emphasis added in Pfizer 2007 FCA.]

Justice Hughes distinguished the Farbwerke Hoechst limitations. The first limitation is a question of fact and the second is a question of construction.

[46] The first limitation is a question of fact, what is the invention that the inventor(s) have made. The second is a question of construction of the disclosure of the patent to determine what it says. In both cases a comparison must then be made of the claims at issue to determine if the breadth of the claim exceeds either what the inventor(s) actually did or what the disclosure actually says. In the event that evidence from the inventor(s) is not available and secondary evidence such as notebooks, memoranda and evidence of colleagues is unavailable or unsatisfactory, it is reasonable to assume that the disclosure of the patent coincides with that which the inventor(s) invented.

The Federal Court of Appeal in Nova Chemicals reaffirmed the Farbwerke Hoechst limitations.

[45] Nova submits that the Judge erred in finding that the claims of the patent are not broader than the invention made or than the invention disclosed in the specification. These are two well established limitations on the extent of the monopoly which an inventor may validly claim (see Farbwerke Hoechst A.G. vormals Meister Lucius & Bruning v. Canada (Commissioner of Patents), [1966] Ex. C.R. 91 at para. 20, 31 Fox Pat. C. 64 (Ex. Ct.), aff’d [1966] S.C.R. 604, 50 C.P.R. 220 (S.C.C.)). The first limitation is a question of fact, whereas the second is a question of construction.

An overbroad claim may be declared invalid; however, the remaining valid claims can be given effect.

[46] The scheme of the Act treats the mischief of overpromising in multiple ways. There are consequences for failing to properly disclose an invention by claiming, for instance, that you have invented more than you have. A disclosure which is not correct and full, or states an unsubstantiated use or operation of the invention, may be found to fail to fulfill the requirements of s. 27(3). An overly broad claim may be declared invalid; however, under the operation of s. 58 of the Patent Act, remaining valid claims can be given effect. As well, this mischief may result in a patent being void under s. 53 of the Act, where overpromising in a specification amounts to an omission or addition that is wilfully made for the purpose of misleading.