8.7.2.5 "Essential Features" of the Invention

Also in this Chapter:

• 8.7.2.1 General Considerations

• 8.7.2.2 Approach in Lockwood v Doric

• 8.7.2.3 Consistory Clause

• 8.7.2.4 Requirement for Critical Analysis​​​​​​​

Key Legislation:

Patents Act:

• s40 Specifications

Lockwood v Doric [2004] HCA 58 at paragraph 68 states:

“The comparison which s40(3) calls for is not analogous to that between a claim and an alleged anticipation or infringement.  It is wrong to employ "an over meticulous verbal analysis".  It is wrong to seek to isolate in the body of the specification "essential integers" or "essential features" of an alleged invention and to ask whether they correspond with the essential integers of the claim in question”.

The concept of “essential features” is therefore limited to the infringement environment. When considering the question of fair basis, the starting point is to determine the features of the invention that is the intended subject of the claim.

A specification may contain a clear statement that an integer is “essential” to the invention.  While such statements often identify the core elements of the invention, this is not necessarily always true and consideration must be given to other parts of the specification.  Examiners should therefore determine whether the word “essential” means that a specific feature is a core element of the invention, or merely essential for the working of the preferred embodiment.

As noted in Rehm Pty Ltd v Websters Security Systems (International) Pty Ltd 11 IPR 289:

"The circumstance that something is a requirement for the best method of performing an invention does not make it necessarily a requirement for all claims; likewise, the circumstance that material is part of the description of the invention does not mean that it must be included as an integer of each claim.  Rather, the question is whether there is a real and reasonably clear disclosure in the body of the specification of what is then claimed, so that the alleged invention as claimed is broadly, that is to say in a general sense, described in the body of the specification."

Note: Where an invention relates to a machine, apparatus or process, a claim need not enumerate all the required, but well established features, of that machine, apparatus or process. In this situation, examiners should not take an objection that the claim is not fairly based on the specification on the grounds that it omits required features of the invention, since the alleged omitted feature is merely a required feature of the whole machine, apparatus or process and has no direct connection with the invention.