Additional Subject Matter
This article appeared at  EIPR 594-600.
- The Legislative Framework
- Interpreting the Provisions
- European Novelty Analysis
- Disclosure in Claims
- The First "Novelty Test"
- The Amended "Novelty Test"
- The "Essentials" Test
- The "Consistency" Test
- The British Case Law
Casting a long shadow over European patent practice is the ever-present requirement that amendments to a patent or patent application should not add subject matter which extends beyond the content of the application as filed. Contravening this requirement is not only a ground of rejection of an application before the European Patent Office (EPO), and those national patent offices in Europe which examine applications, but also generates a ground of revocation of a granted patent. The European Patent Office, and the United Kingdom High Court, have held that matter can be added by implication, by broadening amendments to the claims made in prosecution. Thus, any such amendment (even if approved by the patent office) creates a potential weakness in the granted patent which may be exploited when the patent is enforced. Reported decisions of the Courts and Patent Offices have in the past swung between leniency and rigour, but there are signs that a consistent line of authority may at last be emerging.
Article 123(2) of the European Patent Convention (EPC) provides that
"A European patent application or a European patent may not be amended in such a way that it contains subject-matter which extends beyond the content of the application as filed."
And after grant, it is a ground of opposition (under Article 100(c)) or revocation (under Article 138(c)) of a granted European patent if
"the subject-matter of the European patent extends beyond the content of the application as filed"
Provisions which are intended to have the same effect exist in the current draft of the Community Patent Convention (CPC), and in the national laws of EPC and CPC signatory states (for example, at sections 76(1) and 72(1)(d) of the United Kingdom Patents Act 1977). Similar, but not identical, provisions are present in Articles 19(2), 34(2)(b) and 41, and Rule 66.2(a)(iv), of the Patent Cooperation Treaty (PCT). However, interpreting these provisions has given rise to difficulties; the UK Court of Appeal, has referred to the corresponding UK provision as "obscure or recondite" (1).
What is the intention behind these highly penal provisions? The patent systems of Europe make no provision for re-dating patent applications in the event of amendment. Likewise, there are no provisions for "continuation-in-part" applications. Claims in a European patent are, for validity purposes, judged against the state of the art prior to the date of filing of the application (EPC Article 54(2)) or, where Paris Convention priority is validly claimed, prior to the priority date (EPC Article 89). Even where a major amendment has been made, there is no post-dating of the relevant portions of the application. Likewise, whilst divisional applications are possible, a divisional application must take either the date of filing or priority of the parent (EPC Article 76) or its own date of filing; there is no provision for according different dates to different parts of the application.
Accordingly, there is (at least in principle) the possibility that, as a result of an amendment, a European patent could contain claims and supporting description which effectively monopolise a new invention which was not present in the application as filed, but reaps the benefits of its filing date.
It would appear that the "added subject-matter" provisions were intended to act as a deterrent to applicants attempting to pursue such a course of action (although in retrospect, given the severity with which the EPO examines amendments, one can question the need for additional post-grant sanctions). This is presumably what an EPO Technical Board of Appeal meant, in Decision T 201/83 (2) when they held that
"The well-understood purpose of Article 123(2) is to avoid amendments which would enable the applicant to claim subject-matter that is not supported by the application as filed."
Unfortunately, it is all too often the case that, after filing a patent application, a patentee develops or encounters further embodiments of his invention which fall outside his original claims, because of a limitation which (with hindsight) is unnecessary. As there is no well-developed doctrine of equivalents across Europe, he will accordingly wish to broaden his claims. And it is here that the fault line between broadening the protection of an originally disclosed invention (which is possible in principle - see EPC Article 69(2) last sentence) and claiming a previously undisclosed invention (which is prohibited) has developed.
The phrase "subject-matter" does not have any particularly well-defined meaning in English. Indeed, the equivalent provisions of the UK Patent Act merely refer to "matter", and the PCT refers to "the amendment". The French and German EPC texts, which are equally authoritative, use respectively the phrases "son objet" and "ihr Gegenstand", which are also used in EPC Article 84 in the equivalents of the English requirement that "The claims shall define the matter for which protection is sought". "Subject matter" appears therefore to concern the disclosed invention, which is the subject of the claims. At any rate, an EPO Technical Board of Appeal have pointed out (in Decision T 11/82 (3)) that "subject matter" means more than just "matter"; it must at least mean matter related in some way to the invention which is the subject of the application (rather than, for example, matter describing the prior art, as in T 11/82).
The phrase "extends beyond" gives rise to even greater difficulty. In a first sense, it suggests broadening the scope of protection so that the claims "extend" to cover embodiments which were not described on filing. The normal way of extending the scope of protection in non-chemical cases is, of course, to delete a limitation, and so reduce the number of integers or features present in combination in the claim.
In a second sense, the phrase suggests extending the disclosure, or technical content, of the application, to include additional matter not present on filing. In the context of the claims, adding new technical features in a conjunctive combination actually restricts the scope of protection.
The first reading might seem more natural, but would simply amount to a ban on claim broadening, which is implicitly permitted before grant (by Article 69(2) EPC) and explicitly forbidden after grant (by the separate provisions of Article 123(3) and 138(1)(d) EPC). It seems inconceivable that Articles 123(2) and 138(1)(c) should have been intended to duplicate Articles 123(3) and 138(1)(d).
In fact, the practice of the EPO has been based on the second reading. An authoritative statement of the EPO practice is given in the Guidelines for Examination in the EPO (the "Guidelines") at C-VI para 5.3;
"An amendment should be regarded as introducing subject matter which extends beyond the content of the application as filed, and therefore unallowable, if the overall change in the content of the application (whether by way of addition, alteration or excision) results in the skilled person being presented with information which is not directly and unambiguously derivable from that previously presented in the application, even when account is taken of matter which is implicit to a person skilled in the art in what has been expressly mentioned."
The phrase "the content of the application as filed" is strikingly similar to the phrase "the content of European patent applications as filed" used, in Article 54(3), to define the state of the art for novelty purposes as including the "whole contents" of earlier applications. And this link between the novelty provisions and the subject matter provisions has led to the adoption of a novelty-type analysis by the EPO in considering additional subject matter (4). The original application as filed thus represents
"a `reservoir` from which the applicant can draw when amending the patent application",
in the words of the Technical Board of Appeal in Decision T 190/83 (5).
For novelty purposes, the disclosure of a document primarily consists of what it explicitly discloses. Following the previous UK case law, an application is not considered to "disclose" obvious or well known equivalents to the embodiments it actually describes (6) . On the other hand, it is considered to disclose anything which is "implicit", in the sense of being an inevitable consequence of carrying out the explicit disclosure of the application(7). Extending this rigorous approach to novelty, a generic disclosure does not (necessarily) disclose any specific example within the genus (8).
The narrow novelty approach may be contrasted with the more generous approach traditionally used to judge entitlement to priority, in which a broader claim may be entitled to claim priority from an earlier disclosure. However, the EPO view has always been that the same test, broadly speaking, is applicable to priority as to novelty, and that this test is also applicable to judging the allowability of amendments (9).
On the face of it, it might seem surprising that a claim should be considered to disclose anything of a technical nature; after all, the purpose of the claims is to "define the matter for which protection is sought" (EPC Article 84), and it is the description which is required to "disclose the invention" (10). However, EPC Rule 29(1) requires that;
"The claims shall define the matter for which protection is sought in terms of the technical features of the invention."
And in defining the status of subclaims, Rule 29(3) states that;
"Any claim stating the essential features of an invention may be followed by one or more claims concerning particular embodiments of that invention."
Thus, an independent claim is a statement of the essential technical features of the invention and, it is submitted, its effect is the same as that which would be achieved by a statement in the description that "The essential technical features of the invention are..." followed by the integers of the claim.
There is, however, no reason to assume that the claim is an explicit or implicit statement that everything covered by the claim would work, or be useful, or solve the technical problem faced by the invention (11).
In addition to this primary purpose of the claims, they may also contain actual technical descriptive matter (12).
Early EPO decisions applied a novelty-type analysis to determining added subject matter. The first test for the presence of added subject matter in an amended claim was developed by the Technical Board of Appeal in T 201/83 (13). In that case (which concerned a lead alloy containing calcium), the applicant sought to import into the claimed calcium content range a figure taken from an example in the description, to limit the range. The Board analyzed the amended claim, and concluded that the reduced range was not different in kind to the original range, but merely represented a quantitative, rather than a qualitative, change in the invention. Accordingly, as compared to the original application, the claim "lacked novelty"; in other words;
"The claim contains only information as regards its individual features and as a combination of the lower limit with the rest of the integers which the skilled person would have recognised as being expressed or implied by the disclosure."(14)
This "novelty test" was summarised in the then current Release No. 21 (1986) of the European Patents Handbook in the following way;
"A useful method of checking that there has been no extension of subject matter is to compare the effect of a notional publication of the original specification against the amended claims. Provided that the original would totally invalidate the amended version of the claims, there has been no extension of subject matter."
In case T 17/86 (15), this analysis was applied where an applicant wished to extract one of two linked features from a subclaim, and add it as a limitation to the main claim. This was allowed because the new claim was supported by the description as filed, which thus `anticipated` the amended claim.
In case T 190/83 (16), a main claim was amended by deleting some features and adding others. The Board stated that:
"Viewed by itself,the omission of features from an independent claim cannot constitute a breach of Article 123(2) since it does not go beyond the `reservoir` of the disclosure"(17)
According to the Board, the test was whether any new combination of features was disclosed by the claim; in other words, whether the originally filed disclosure would take away the novelty of the amended claim.
When this simple novelty test is applied to amendments which narrow a claim by adding to, substituting or modifying its integers, it works as intended in T 201/83. When it is applied to amendments which merely broaden a claim, on the other hand, it has little impact (provided that the new claim continues to be supported by, or "read onto", the previous claim or description) because any broadened claim which continues to encompass the original claims or embodiments would be "invalidated" on such a comparison, on the well-established principle that specific disclosures take away the novelty of generic disclosures (18). This first novelty test is therefore generous to patent applicants (and corresponds somewhat to the current practice in the US Patent Office).
In stark contrast, another line of EPO decisions apply a "novelty test" which is much harder to meet. In Decision T 194/84 (19) , an applicant sought to delete the word "natural" from the term "natural cellulose fibres" in a claim. The Board of Appeal recognised that applying the original novelty test would generally allow claim broadening. Accordingly, they decided that in applying the "novelty test" it was necessary to first isolate the "change in content" of the application and then test whether that change would lack novelty over the application as filed. The "change in content" is determined by subtracting the scope of the old claim from that of the amended claim; thus, in this case, the change in content corresponded to cellulose fibres which were not natural. Since there was no disclosure in the original description of any such thing, the amendment was refused. There had been a broader passage in the introduction, but this referred only to fibres, and did not mention cellulose of any kind.
T 416/86 (20) appears to be another example of this reasoning. In this case, a structural limitation in a claim ("the aperture surface is substantially in the shape of a cone") was replaced by a functional limitation ("the aperture surface is so designed and positioned that it virtually completely blocks out extraneous peripheral rays"). The Board recognised, correctly, that the new claim would cover new structures not disclosed in the original application. This then appears to have led to rejection of the amendment, without it being clear whether the Board saw such new structures as also being disclosed merely by virtue of the broadening of the claim. However, in any event, they also applied the "essentials" test (see below) in rejecting the amendment.
And in T 265/88 (21) a divisional application was filed, in the main claim of which the term "pressure seals" was substituted for the term "sealing beads" in the precharacterising portion of the original claim of the parent application. In fact, one of the nine prior art documents referred to in the application as filed did refer to a pressure seal which was not a sealing bead, and the application as filed said that the described embodiment could be modified to the structure of any of the prior art documents. If T 52/82 (22) had been followed, amendment could therefore "not have been refused". However, the Board of Appeal expressly disapproved T 52/82, and followed T 194/84 (23) in finding that the notional embodiments now covered by the claim (and thus implicitly disclosed, according to the Board) which involved non-bead seals were not disclosed in the original application as filed. The Board also made brief use of the "essentials" test in their reasoning. Divisional status was therefore refused.
In general, this amended novelty test will be seen to lead to a refusal to allow a broadening amendment except in the rare instance where the originally filed claims do not cover all embodiments of the invention disclosed in the description. Having said that, it would seem that where there is a single example in the description outside the scope of the claim then this amended novelty test would allow virtually unlimited broadening; for example, if in T 194/84 there had been an embodiment in the description as filed disclosing one type of artificial cellulose fibres, this would apparently have supported a broadening to fibres per se, rather than just to cellulose fibres.
The novelty tests treat the content of the claims as technical matter, of the same character as the description. An alternative line of case law, developed primarily in non-chemical cases, treats the claims as a recital of "essential technical features" of the invention. When a claim is broadened by deletion of a limitation, it is treated as including a statement that the limitation is not essential, which is treated as new subject matter in the absence of some indication of inessentials in the original application.
In some cases, a feature of a claim may genuinely be essential for technical reasons. At any rate, it may not be possible to envisage any alternatives falling outside the limitation (which is not to say that such alternatives may not be developed in future). However, more usually applicants seek to delete limitations precisely because they have been found to be inessential, although originally presented as such.
An early example is T 52/82 (24), in which a patentee replaced a feature of the pre-characterising part of the claim with a broader formulation which was generic to the closest prior art cited on the search report. The Board said that this type of amendment "cannot be refused" (T 265/88, discussed above, disagrees).
A less generous decision is T 133/85 (25) in which it was held unallowable to delete from a claim a feature which was presented as essential, since the deletion would add the information that the feature was inessential.
This reasoning is certainly open to criticism; the absence of a statement that a feature is essential does not, as a matter of logic, amount to a statement that the feature is inessential, and so simply omitting a limitation need not add anything to the disclosure of the application.
The same line was, however, followed in T 329/89 (26) in which it was held inadmissible to delete a feature "consistently presented as essential"; and in T 260/85 (27), in which the fact that advantages had been ascribed to a feature in the description was held to indicate that it was essential and to prevent it being deleted from the claim.
Likewise, in T 248/88 (28) the Board of Appeal refused to allow the term "tantalum" to be broadened to "a metal", because tantalum was the only metal mentioned in the description, and the introduction discussed disadvantages of other metals used in the prior art, creating an impression that tantalum was essential.
The leading essentials case is the well-known `Houdaille` case, T 331/87 (29), which concerned an opposition to a patent on a machine tool punch press with a laser cutting head. A requirement in the main claim for the laser cutting head to be carried by the main frame had been replaced by a requirement that it be carried "... in fixed horizontal relationship" to the frame. The patent was revoked by the Opposition Division on the ground that this broadening amendment added subject matter. The introduction as filed included a statement indicating that an object of the invention was to provide a single machine tool capable of high speed, and another indicating that an object was to provide a combined turret punch and laser head sharing common control and workpiece moving means. In the light of this, the Appeal Board concluded that carrying the laser head on the frame was only a desired embodiment, not an element of the invention which was indicated as essential, and accordingly the patent was valid.
In this decision, the "essentials" test was codified into three subtests; namely;
1) is the limitation presented as essential in the original application?
2) is the limitation in fact essential?
3) does deleting the limitation require modification of other features to accommodate the change?
The indications in the introduction satisfied all three tests.
Thus, to pass the "essentials" test you need not only to demonstrate that a deleted feature is inessential in practice but also to have an indication of this in the application as filed, and to have described it in such a way that it can be amended in isolation of other features.
In T 691/90 (30), the application was directed to a parenteral infusion apparatus. In the original main claim, a pinch valve was controlled to terminate the flow of solution when the measured flow in a supplementary drip chamber was less than that detected in the primary drip chamber. The patentee then sought to amend the main claim, to replace this limitation by one merely stating that the pinch value was controlled in response to the secondary drip chamber.
The Board of Appeal followed T 331/87 (31), in applying the three-fold test for essentials. However, they commented that:
"The feature in question may be inessential even if it was incidentally but consistently present in combination with other features of the invention."
The Board examined the introduction of the application as filed, which presented the problem with the known prior art which was solved by the invention, and concluded that it would be apparent that measurement of thesecondary drip chamber was what achieved the advantaged claimed for the invention, and that it would be apparent to the skilled person that comparison with the primary drip chamber was not essential in all circumstances (even though this was not stated in the application as filed). They thus concluded that the comparison with the primary drip chamber was not in fact essential, and that it was not presented as essential either. Finally, they viewed the broadly recited control means which was a element of the claim as not requiring any modification when the limitation to comparison with the primary drip chamber was deleted (even though, in fact, the claim required some alternative re-wording and the control means of the embodiment would have needed reprogramming).
This is therefore a much more generous application of the "essentials" test.
In general, where a patentee has succeeded in passing the "essentials" test, it is usually on the basis of some matter in the originally filed application which is inconsistent with the original claim. For example, in T 66/85 (32) deletion of a feature was allowed because it was not present in two of the original drawings, and in T 467/90 (33) a broadly worded passage in the introduction was interpreted as indicating that a claimed feature was advantageous but not essential, and used as the basis for broadening the claim.
Often, however, an independent claim is drafted at the outset to cover all described embodiments, and as the main claim is a statement of "essential" features there will be no indication that any feature of the claim is "inessential" in the original application.
There is, in fact, some similarity between the second novelty test and the "essentials" test, and in several Appeal cases (34) the Boards of Appeal have used both approaches in parallel. In more recent cases, the EPO have held that the two come to the same thing.
T 514/88 (35) concerned a divisional application in which the original main claim of the parent application comprised four structural features, two of which were omitted in the main claim of the divisional application. The patentee argued that the word "and" linking the features was intended to be disjunctive, not conjunctive.
The Board of Appeal made a careful analysis of the case law, and commented that the tests of novelty (amended version) and essentials are both tests of whether the amended text is consistent with the original application. They then applied the threefold test of the Houdaille case, T 331/87 (discussed above) to conclude that the deleted features were essential, and refused divisional status to the application.
In fact, in this case the Board were influenced by the fact that the features in question were absent from the US priority application, but had been inserted into the European application prior to filing. The Board referred to this as an "abandonment" of subject-matter which was both irreversible and binding. It is submitted that, in view of the recent Enlarged Board of Appeal decision G 11/91(36), to the effect that the priority document is not part of the disclosure of the application, this line of reasoning is incorrect; the question of added subject-matter should be determined only by reference to the application papers, which are the documents in which the skilled reader is interested, and not by assumptions as to the applicants intention derived from the file history.
The main line of reasoning in this case was followed in T 527/88 (37), an appeal from a successful Opposition concerning a patent on manufacturing a web of plastic bags. The main claims of the parent application recited a two-stage process for forming seals between bags, and this was also present in each embodiment (although only in the drawings in one case). The main method claim of the granted patent did not include the two-stage limitation, and the description and drawings had also been amended to delete all reference to the two-stage process. The Board (without detailed reasoning) appear to have concluded that the two stage process was essential; they refer to the need for an amendment to have basis in the description as filed, as being synonymous with the requirement for the amended text to have basis. They also commented that the first novelty test (38) was inappropriate to claim broadening. T 136/88 (39) also followed T 514/88.
In T 685/90 (40), the main claim of the application concerned a printer with a rotatable cylindrical platen; several other features of the claim were defined with reference to the platen. After allowance, the patentee sought to delete the `cylindrical` and `rotatable` limitations, arguing that he should be entitled to cover flat, fixed platens. The Board concluded that this amendment failed both the essentials test and the second novelty test, and (following T 514/88 discussed above) that it was therefore inconsistent with the application as filed. The limitations were held essential by virtue of their presence in the original claim, even though the skilled reader might (using some imagination) conceive of alternatives. They did, however, allow some alternative broadening amendments, on the basis of a generous reading of the description of the embodiments.
These cases represent the latest line of reasoning of EPO Appeal Boards; thus far, however, although we have a new test of "consistency", there is no new method of analysing whether any given amendment is allowable.
The first significant High Court case on amendment under the corresponding British 1977 Patents Act is Protoned B.V.'s Application (41). The originally filed main claim was directed to a combination including, inter alia, a mechanical compression spring. The patentee later attempted to delete the word "compression". The Judge assumed, arguendo, that the skilled reader would immediately understand that a tension spring could be used instead of a compression spring (i.e. that "compression" was in fact inessential), and that redesign to take account of the change was trivial. However, he held that deleting the limitation would "notionally add" a range of springs to the specification - merely because they would then becovered by the claim. This was thus, in effect, a ban on pre-grant claim broadening.
Since then, the law has been considered by the Court of Appeal in two cases. In A.C. Edwards Ltd -v- Acme Signs Displays Ltd (42) , the patent concerned an electromechanical digital display, for petrol station forecourts. The originally filed application had a broad main claim to an arrangement in which the segments of each digit were coverable by a pivotable flap, and a narrowly described embodiment in which each flap was held by two studs, each retained by a coil spring and cotter arrangement. The claims were amended before grant to be narrower than the original main claim, by the inclusion of a stud carrying each flap, and spring means retaining each stud. The infringing device had one stud per flap, and employed leaf springs. The infringer therefore argued that, if the granted claim covered his device, matter had been added since no such construction was disclosed on filing.
Fox LJ (following the House of Lords in Asahi Kasei Kogyo KK's application (43) ruled that the disclosure of a claim is merely the same as that of other parts of the description; a claim does not "disclose" all matter which it covers. The particular elements of the embodiment not included in the claim were not essential, and (following T 151/84 and T 467/90) their absence consequently did not add matter.
Staughton L.J. observed that the purpose of the "added matter" provisions is
1) to prevent a patentee securing an earlier priority date for a new invention by amendment, and
2) to limit the extent to which claims can be broadened.
He too held the amendments in the case allowable.
In Southco Inc. -v- Dzus Fastener Europe Ltd (44), a patentee sought to enforce two patents, one of which was a divisional of the other. The patents concerned "pull-up" latches for cabinet doors. The original claim 1 recited a number of elements in "means-plus-function" language, but the granted claim 1 was completely rewritten in structural terms and omitted several of the elements of the original claim. There was a suggestion that the claim had been amended to cover another embodiment the subject of a later patent owned by the patentee, which had a "one-pin" construction, as did the alleged infringement. No "one-pin" construction was disclosed in the application as filed.
In fact, the Court of Appeal found that the claim, when properly construed in the light of the description, did not cover the alleged infringement, still less did it teach a "one-pin" construction. Despite the major differences in claim language, the amended claims related to the same invention as the original application, differently claimed, rather than to a different invention. This is quite a radical conclusion for a British Court, since according to the Patent Act 1977 at Section 125(1), an invention is usually taken to be that which is specified by a claim (as interpreted according to the Protocol on the Interpretation of EPC Article 69).
In Bonzel (T) & anr v. Intervention Ltd (45), another infringement case (decided between the first instance decision in A.C. Edwards Ltd v. Acme Signs and Displays and the appeal judgement discussed above), the patent (a European patent in German) concerned a balloon catheter for dilating an artery. Claim 1 of the application as filed was narrowed in prosecution to include a characterising limitation (not explicitly stated in the application as filed) on the stiffness of the portion of a tube engaging a guide wire, which involved an implication that the guide wire tube had to be short. The application as filed, when properly construed, indicated that the guide wire tube could be as short as the balloon of the catheter. However, in prosecution, the introduction had been revised to acknowledge prior art and to restate the technical problem and solution thereto according to the invention. The introduction as granted indicated that the guide wire tube merely had to be shorter than that in the prior art, which was about fifty times the length of the balloon. This point was critical in determining whether there was infringement, because the guide wire tube of the alleged infringement was about five times the length of the balloon.
The method proposed for determining whether matter had been added was as follows;
1. Ascertain the implicit and explicit disclosure of the original application to the skilled reader;
2. Do the same for the patent as granted (i.e. the amended text);
3. Compare the two disclosures and decide whether subject matter relevant to the invention has been disclosed, whether by deletion or addition. This is a strict comparison, in the sense that matter will be added unless it was clearly and unambiguously disclosed in the original application.
On the basis of this approach the Court held that the alleged infringement would indeed have infringed the patent, but found that subject matter had been added and the patent was invalid.
The same methodology was adopted by the Patent Court in Flexible Directional Indicators Ltd`s Application (46), in an appeal from a decision of the Patent Office on a proposed pre-grant amendment. The main claim of the application as filed related to a traffic bollard of a material made of "a compound of ethylene vinyl acetate (EVA) and at least one other polymer material". In the proposed amended claim, the possibility of EVA alone was mentioned. The applicants argued that zero additional polymer was implicitly disclosed to the skilled person. The Judge held that;
"The section is concerned with what is disclosed, not with what the skilled reader might think could be substituted or could be omitted."
In his view, the teaching of the document would have led the skilled person to believe that the use of EVA alone was deliberately excluded, and consequently the amendment was unallowable.
The methodology adopted by the British Courts in these four recent decisions may be compared with that of the EPO Appeal Boards. Firstly, it will be seen that there is no double comparison; it is the amended text itself, rather than the change in content, which is compared with the original disclosure.
It is submitted that both the second novelty test and the "essentials" test are in error, because both focus on the amendment, rather than the content of the application after amendment.
The second novelty test requires an initial comparison of the original application and the application as amended, to determine the change in content, followed by a further comparison of this change with the original application. Faced with this careful analysis of any changes caused by an amendment, there is of course a predisposition to assume that such changes are significant, and this tends to lead to a rejection of any broadening amendment. This approach does not correspond to what the skilled reader would do, because it presupposes that there is a change in content; the skilled reader, on the other hand, would regard this as an open question and would, it is submitted, merely compare the original text and the amended text directly without a second comparison.
The "essentials" test is based on the assumption that the act of deletion of a limitation in a claim is itself a statement that the limitation is inessential. The original application is then reviewed for basis for such a statement. And indeed, deleting a limitation often does indicate a belated realisation that the limitation is unnecessary. However, whilst this may be apparent to the Patent Office, or from a review of the file wrapper, it is not apparent from the amended application, and this is what counts. Although the presence of a feature in a claim may be construed as a statement that it is essential, the absence of such a feature cannot, as a matter of logic, be construed as any statement whatsoever about that feature.
Secondly, in the British cases the emphasis is on subject matter "relevant to the invention"; it appears that amendments which are not directed to altering the essential nature of the invention but merely the words in which it is described are likely not to be ruled out, whereas amendments which go to the point of novelty of the invention may be excluded.
After 15 years experience of the European bar against additional subject-matter, it is clear that claim broadening before grant is not automatically allowed nor automatically prohibited, although both the EPO and the British Patent Office and Courts have been tending more to refusal than to allowance. Perhaps as a consequence, where an amendment has been allowed before grant, in the small number of cases where this has been in issue, the British Courts have seemed less likely to revoke the patent.
There does seem to be some hope that the somewhat arbitrary, and (in practice) difficult to apply, tests initially employed by the EPO may be giving way to a more comprehensive and flexible test of the consistency of the amended text with the originally filed text, and this is paralleled by the move in the British jurisprudence from the uncompromising Protoned case to the more recent stress on comparing the disclosures of the invention in the amended and unamended texts.
The 1993 Symposium of European Patent Judges discussed the additional subject matter bar, and this will no doubt lead to some further harmony between national and EPO practice.
Finally, it is significant that Japan now has a closely similar bar on additional subject-matter, replacing the previous relative freedom of amendment for patentees. Given the close tripartite harmonisation between the EPO, the Japanese Patent Office and the US PTO, one wonders whether the freedom available to patentees in the US can long withstand the twin drives toward harmonisation and patent office administrative convenience, or whether the rarely invoked "new matter" or disclosure of the invention objections are due for reinterpretation.
1. Implied Added Subject Matter - An Academic Overview, G Dworkin,  CIPA 340-360
2. Implied Added Subject Matter, A PractitionerÕs view of history, A J A Bubb,  CIPA 444-448, and correspondence at  CIPA 34, 35, and 159-160
3. The Significance of the "Novelty Test" for Priority and Amendments to Patent Applications and Patents, P K J Van den Berg,  IIC 696-743
- A.C. Edwards Ltd v Acme Signs & Displays  RPC 131 at 147.
- SHELL/Lead alloys [1979-85] EPOR Vol C. 905
- LANSING BAGNALL/Control circuit [1979-85] EPOR Vol B. 385.
- See, for example, T37/82 SIEMENS/Low-tension switch [1979-85] EPOR Vol B 437; T54/82 MOBIL/Disclosure ([1979-85] EPOR Vol B 469); T201/83, Note 2 above; and T190/83, (unreported; see European Patents Handbook [EPH].
- Ibid., at chapter 103, page 190/83-1.
- See, for example, the Guidelines at C-IV para 7.2 last sentence.
- Ibid., at C-IV para 7.5.
- Ibid., at C-IV para 7.4.
- See the Guidelines Part C, Chapter V, para 2.4, first and second sentences; and P.K.J. Van den Berg, "The significance of the "Novelty Test" for Priority and Amendments to Patent Applications and Patents", IIC Vol. 24 696.
- EPC Article 83.
- See T14/83 SUMITOMO/Vinyl chloride resins [1979-85] EPOR Vol. C 737.
- See, for example, the Guidelines at C-III para 6.6.
- Note 2 above.
- Note 2 above at paragraph 12, page 910.
- SATAM BRANDT/Refrigeration plant  EPOR 347.
- Note 4 above; EPH Chapter 103.
- Ibid., at paragraph 3, page 190/83-3.
- Guidelines C-IV para 7.4
- GENERAL MOTORS/Zinc electrodes (cellulose fibres)  EPOR 351.
- BOEHRINGER/Reflection photometer  EPOR 327 at 331.
- LUNDIA/Diffusion device  EPOR 399.
- RIETER/Winding apparatus [1979-85] EPO Vol. B 459.
- Note 19 above.
- Note 22 above.
- XEROX/Amendments  EPOR 116.
-  OJEPO Supp. 31.
- AMP/Coaxial connector  EPOR 403.
- SGS/Unacceptable generalisation  EPOR 274.
- HOUDAILLE/Removal of a feature  EPOR 194.
- CRITIKON/Infusion apparatus  EPOR 51.
- Note 29 above.
- AMP/Connector  EPOR 283.
- THOMSON-CSF/Spooling process for optical fibre gyroscope  EPOR 115.
- See, for example, T416/86, Note 20 above, and T265/88, Note 21 above.
- ALZA/Infusor  EPOR 157.
- CELTRIX/Correction of errors  EPOR 245.
- WAVIN/Interconnected bags  EPOR 184.
- T17/86, Note 15 above.
- Unreported, discussed in ( OJ EPO Supp. to 6/90 at page 32.
- FUJITSU/Printer  EPOR 183.
-  FSR 110.
- Note 1 above.
-  RPC 585.
-  RPC 299.
-  RPC 553.
-  IPD October at 9, abstract 16125.