Extension of Protection After Grant

Principle

This principle mentioned in A123(3) EPC applies only after grant.

Once a patent is granted, an act by a third party that does not constitute infringement cannot become infringement due to a post-grant amendment (T1149/97 and Guidelines H-IV 3.1), even if the description supports such an amendment.

Basis for Assessment

The extension of scope must be assessed in relation to the previous set of claims (Guidelines H-IV 3.3), whether it is:

• the granted set;
• the set maintained in amended form after opposition; or
• the set resulting from limitation.

Evidence

The burden of proof regarding whether amendments extend the scope lies with the proprietor and not the opponent (T2275/17).

Examples

Amendment of Claims

Principle

This is the simplest case: if a limitation is removed (or replaced) in a claim, the protection conferred by the claims is broadened (or shifted) and thus contravenes A123(3) EPC (Guidelines H-IV 3.1).

Prima facie, but without certainty, this applies only to independent claims.

A restrictive wording may be replaced by another less restrictive wording if (T371/88):

• it resolves clarity issues; or
• it is clear from the application that the less restrictive embodiment is part of the invention and was never intended to be excluded.

An incorrect piece of information in a claim may be replaced by the correct information present throughout the rest of the application (T108/91).

Case of a Non-Limiting Feature

The question arises as to what happens when a non-limiting feature is removed.

This may occur, for example, if a feature refers to an object that is not the one claimed (e.g.,

Limitation of a feature in an « open » composition

Consider the following situation in which the claim states « the composition comprises less than 5 % of metal salts« .

If this feature is amended to « the composition comprises less than 5 % of salts metal of zinc« , there is an extension of scope behind this apparent limitation (T1360/11 or T287/11).

Indeed, copper salts (for example), the content of which was limited in the first formulation, are no longer limited.

The same situation arises if we have the feature « the composition comprises less than 5 % of metal salts selected from copper or zinc salts » which is limited to « the composition comprises less than 5 % of metal salts selected from zinc salts »: zinc salts may now be present in any proportion.

Change of claim categories

Principle

A change of category is not necessarily inadmissible under A123(3) EPC (G2/88).

Acceptable changes

The following are admissible:

• product claim → use claim for the product without producing other products (Guidelines H-V 7.1)
• product claim → claim for the manufacture of that product resulting only in that product (Guidelines H-V 7.2 and T5/90)
• process claim using a product → use claim for the product to carry out the process (T332/94 and Guidelines H-V 7.4).

Unacceptable changes

The following are not admissible:

• product claim → use claim for the product with production of other products (since these other products would then be protected via A64(2) EPC) (T1471/14, Guidelines H-V 7.1);
• use of product → product (Guidelines H-V 7.3, T86/90);
• method claim for operating a device → product claim (since other uses of the device are then covered) (T82/93, unless all features of the product were contained in the initial claim Guidelines H-V 7.3, T378/86 and T426/89);
• claim for the manufacture of a product → use claim for the product (T98/85) (Guidelines H-V 7.1).

Modification of the description/designs

Modifications made to the description and designs may also extend the protection conferred by the claims through their interpretation in terms of,

• A69 EPC (T1149/97, G1/93, Guidelines H-IV 3.2) and
• its interpretative protocol (which is an integral part of the EPC, A164(1) EPC).

It is therefore prohibited to add during opposition or limitation proceedings any part of the description or designs that had been deleted during examination (Guidelines H-IV 3.4).

Decision T241/02 tempers this prohibition by stating that this is possible if the proprietor seeks to remedy an insufficiency of disclosure.

Furthermore, if the proprietor modifies the application to provide designs in order to restore those initially filed, there may also be an extension of scope (T1360/13), particularly where the previous figures were more « obscure » and thus less limiting.

Broader dependent claim

It may happen that dependent claims « appear » broader than claim 1. For example, suppose claim 1 specifies a dimension of at least 20nm and a dependent claim specifies a dimension of at least 15nm (T2174/16).

Should this be interpreted as meaning that the post-grant amendment of claim 1 to 15nm is acceptable?

Decision T2174/16 states that this is not possible because the person skilled in the art would have interpreted this inconsistency as an error and redundancy.

Indeed, the purpose of Article A123(3) EPC is to ensure legal certainty for third parties, and one must assume that the third party takes a « conservative » reading of the claims.

A123(2)-A123(3) trap

Principle

If the applicant/proprietor has limited the application/patent with a technical feature not disclosed in the application as filed (and thus contrary to A123(2) EPC), they will not be able to remove it without extending the scope of protection (which would be contrary to A123(3) EPC) (G1/93, Guidelines H-IV 3.5).

Of course, this feature must be a technical feature. A feature that merely excludes part of the claimed subject-matter without providing a technical contribution does not extend the subject-matter beyond the content of the application as filed (G1/93).

It is not possible to avoid this trap by removing the feature and limiting the scope using a disclaimer (T1180/05).

Exceptions concerning non-technical features

It may happen that claims are limited during the proceedings in a non-technical manner (e.g., restriction of the claimed method to only certain times or to only certain parameters).

In this scenario, the boards of appeal appear to consider that such limitations are not prohibited by A123(2) EPC (T1779/09): the principle here seems to be to prevent the proprietor from falling into the « pincer » of A123(2) EPC and A123(3) EPC.