Fair Basis

1For the purpose of determining priority of a complete specification based on a provisional specification the issue of whether the complete specification is 'fairly based' on the provisional specification or what is disclosed in the provisional specification affords a 'fair basis' for the complete specification has to be ascertained. The doctrine of fair basis requires that the complete specification should be fairly based on the provisional specification. (Mond Nickel Company Limited's Application (1956) RPC 189.) Under s 15 of the UK Patents Act 1977 the applicant is no longer required to file a provisional specification. Though the UK Act abolishes the filing of provisional specification, the position under the UK Act remains the same as that under the 1949 Act. The date of filing of a patent application, which gives it its priority under s 5(1) of the UK Patents Act, may be a date at which under s 15(1) the specification was incomplete, and did not include an enabling disclosure. Section 15(1) also permits the filing of an application without claims, and without a refined description. (See Asahi Kasei Kogyo KK's Application (1991) RPC 485, pp 515, 518(HL).) The issue of fair basis will depend on the contents and language of the relevant documents. What is required to be fair is not the applicant's claim to priority, but the basis which one document affords for a claim in the other. (Stauffer Chemical Company's Application (1977) RPC 33, p 52.)

2Any claim in the complete specification relating to any such development or addition is entitled to a priority date as of the date of the relevant application for protection in the convention country if the claim is fairly based on the matter disclosed in the application for protection in the convention country. Any claim in the complete specification in respect of any development or addition which is not fairly based on the matter disclosed in the application for protection of the invention in the convention country will be entitled to priority only as of the date of the complete specification. (Ibid, p 46.) As such a patent will be held invalid if the claim in the patent goes beyond the disclosure in the specification. (Therm-A-Stor Ltd v Weatherseal Windows Ltd [1984] FSR 323, p 339 (CA) followed in Du Pont de Nemours (EI) & Co v Enka BV [1988] FSR 69.)

3A narrow claim of a specific nature may be fairly based on a prior disclosure in general terms. (Muto Industrial Company Limited's Application (1978) RPC 70, p 75. See also British Drug Houses Application (1964) RPC 237.) In other words, an invention in the relevant claim in the complete specification will be treated as fairly based if it can be derived from, and is based on the disclosure in the provisional, even if it is not specifically disclosed in such provisional specification. (UCB Societe Anonyme's Application [1973] FSR 433, p 435.) The test is to determine whether the inventions in the respective specifications were in essence the same. (Farbenfabriken Bayer AG (Zirngibl's) Patent (1973) RPC 698.) On the issue of whether developments and new introductions to the complete specification will be fairly based on a general provisional specification, Lloyd-Jacob J remarked as follows:

The interval of time between the filing of the two specifications is intended to provide an opportunity for the development and precise expression of the invention foreshadowed in the provisional and where as here the provisional expresses the invention in terms of general applicability to a specified series of steroids, reference in the complete to new introductions in such steroid series confirms the general applicability, conforms with the expression of the invention in the provisional, and finds the justification for its presence, not in any particular characteristic of its own, but in its membership of the class of substances to which the applicants process was stated to be applicable. (Glaxo Group Limited's Application [1968] FSR 503, p 506.)

4The concept of 'fair basis' was introduced to ensure that the court or the tribunal should hold the balance fairly as between the patentee and the public. (Letraset Ltd v Rexel Ltd [1973] FSR 302, p 315.) The courts have developed three tests in determining fair basis, which are summarised as follows: (Ibid.)

(1) whether the patentee is entitled to a fair and reasonable monopoly having regard to the disclosure made without causing prejudice to the public; (2) whether the result in the complete specification necessarily flows from the constitution of the materials disclosed in the provisional specification thereby justifying the priority date attributed to the provisional specification; (3) whether the feature in question as to which the provisional is silent is one which does not necessarily result from the embodiment of the other features which it does mention.

5The claim should be fairly based on the matter disclosed. Where any claim in the complete specification is not fairly based on the matter disclosed in the specification, the patent stands the risk of being revoked. (Patents Act 1970, s 64(1)(i).) This is based on a fundamental rule that the monopoly claimed must not go beyond the consideration. (See Mullard Radio Valve Co Ltd v Philco Radio and Television Corpn (1936) 53 RPC 323, pp 346-348 (HL).) This requirement ensures that the extent of patent monopoly as described in the claims corresponds to the technical contribution to the art in order for it to be supported or justified. The matter disclosed provides the technical information upon which the invention is based. The claim defines and restricts the scope of the monopoly of the invention. The matter disclosed together with the claim will define the scope of the protection offered to the patentee which, if trespassed, would constitute infringement. Whether the claim is fairly based on the matter disclosed, is entirely a matter of construction for the court. (See Schering Agrochemicals Ltd v ABM Chemicals Ltd (1987) RPC 185, p 187.)

6When the claims are not commensurate with the description disclosed in the specification, a patent may be revoked. Interestingly, in Britain, non-compliance with s 14(5) of the UK Patents Act 1977 which requires that the claims must be supported by the description, is not a ground for revocation of patent under s 72(1) of the said Act. However, in Biogen Inc v Medeva Plc (1997) RPC 1, p 47, Lord Hoffmann stated that s 14(5)(c) is given effect by s 72(1)(c). Lord Hoffmann did not regard this as a gap or illogicality in the scheme of the UK Patents Act. Just as in the case of sufficiency of description, the matter disclosed may disclose one way of performing an invention and claim protection for a broader claim. This is more likely to happen in cases where disclosure of one way of carrying out the invention enables a skilled person to obtain the same effect in a broader area by using suitable variants of the component features. A single embodiment can justify a broader claim if the entire class shares a common principle. (See Mölnlycke AB v Proctor & Gamble [1992] FSR 549, p 600.)

7In determining whether a claim is fairly based on the matter disclosed, the following factors shall be considered, as observed by the Court of Appeal in General Tire and Rubber Co v Firestone Tyre and Rubber Co Ltd: ([1971] FSR 417, p 484, (1972) RPC 457, per Sachs LJ.)

It is clear in our judgment that the question whether the patentee has sufficiently defined the scope of his claims is to be considered in relation to the facts of each case, that allowance is to be made for any difficulties to which the circumstances give rise, and that all that is required of the patentee is to give as clear a definition as the subject matter admits of. It is also clear in our judgment that, while the court is to have regard to all the relevant facts, the issue of definition is to be considered as a practical matter and little weight is to be given to puzzles set out at the edge of the claim which would not as a practical matter cause difficulty to a manufacturer wishing to satisfy himself that he is not infringing the patent. We accept also that definition of the scope of a claim is not necessarily insufficient because cases may arise in which it is difficult to decide whether there has been infringement or not provided the question can be formulated which the court has to answer in deciding the issue of infringement.

8In determining whether the claim is fairly based on the matter disclosed in the complete specification, the same principles employed in determining priority of a complete specification under s 11 will apply. The priority date of the claim in a complete specification shall be the date of filing of the provisional specification, provided the claim is 'fairly based' on the matter disclosed in the provisional specification. A patent shall be held invalid if the claim in the patent goes beyond the disclosure in the specification. (See Therm-A-Stor Ltd v Weatherseal Windows Ltd [1984] FSR 323, p 339 (CA) followed in Du Pont de Nemours (EI) & Co v Enka BV [1988] FSR 69.)