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5.6.5.1 Determining Novelty

Date Published

Key Legislation:

Patents Act:

  • s7 Novelty
  • s18 Patentable inventions
  • s24 Validity not affected by making information available in certain circumstance
  • s102 What amendments are not allowable?
  • s104 Amendments by applicants and patentees  
  • Schedule 1 Dictionary

Patents Regulations:

  • reg 2.2 Information made publicly available--recognised exhibitions
  • reg 2.2A Information made publicly available--learned societies
  • reg 2.2B Information made publicly available--reasonable trial of invention
  • reg 2.2C Information made publicly available--other circumstances
  • reg 2.2D Information made publicly available without consent--period

The Test for Novelty

The test for determining whether an invention lacks novelty is the "reverse infringement test". This was set out in Meyers Taylor Pty Ltd v Vicarr Industries Ltd (1977) CLR 228 at page 235; 13 ALR 605 at page 611, where Aickin J stated:

"The basic test for anticipation or want of novelty is the same as that for infringement and generally one can properly ask oneself whether the alleged anticipation would, if the patent were valid, constitute an infringement."

Infringement of a claim occurs when all the features of that claim have been taken.

This section explains how to apply the test for novelty and read the specification to determine the essential features. It also discusses general disclosures and selection patents.

Note that the term "anticipation" used here and in the following parts of this chapter is synonymous with "lack of novelty".

Applying the Test for Novelty

It follows from the reverse infringement test that:

  • if a citation discloses all the features of a claim, the claim will lack novelty;

  • if the citation does not disclose all the features of the claim, the claim will still lack novelty provided the citation discloses all the essential features of the claim; and

  • if an essential feature is not disclosed in the citation, the claim is novel.

To determine whether a claim is novel in view of a citation, examiners must:

  • establish that the citation is a relevant prior art document that can be considered for the purpose of a novelty objection (see 5.6.4.1 Prior art – what is included and 5.6.5.2 Whole of Contents);

  • interpret the citation to determine what it disclosed to the skilled addressee at its date of publication (see 5.6.4.2 Construing a citation);

  • determine whether the citation discloses all the features of the claim (if so, the claim is not novel);

  • if there are any differences between the features of the claimed invention and the disclosure of the citation, construe the specification and claim and identify whether those features are essential (or inessential) features of the invention (see Not All Features of Claim Disclosed in Citation below); and

  • determine whether the citation discloses all the essential features of the claimed invention (if so, the claim is not novel).

Test for Novelty - Legal Principles and relevant case law

See also Rodi and Wienenberger AG v Henry Showell Ltd (1969) RPC 367 at page 391.

For case law around essential and non-essential features, see:

  • Nicaro Holdings v Martin Engineering 16 IPR 545;

  • Catnic Components Ltd v Hill and Smith Ltd (1982) RPC 183; and

  • American Home Products Corporation Application [1994] APO 58.  ​​​​​​​

All Features Disclosed in Citation

If examiners determine that all the features of a claim have been disclosed, after properly construing the citation, a novelty objection should be taken. In most cases, it can be assumed that claims which are not novel also lack inventive step, so separate consideration of any lack of inventive step is not required. However, the novelty objection should include a statement that the claims are not inventive.

Not all features of Claim Disclosed in Citation

As noted in the previous sections it is possible for a claim to lack novelty where a citation does not disclose all the features of the claim. A claim will still lack novelty provided the citation discloses all the essential features of the claim.  

When considering the novelty of a claim it is therefore important to identify the essential features and distinguish them from any inessential features. An essential feature is one which materially affects the way the invention works. It will normally have a working or potential working interrelationship with other features of the claim. ​​​​​​​

If not all the essential features are disclosed in the citation, the claim is novel. Examiners should then proceed to consider whether the claimed invention involves an inventive step.

Determining Essential Features (General Considerations)

There is no formulistic approach to the process of determining whether or not a feature is essential.  Examiners will need to determine if a particular feature is essential by properly construing the claim in light of the specification and understanding how the invention works. The question as to whether a feature is essential or not, is to be answered from the position of the person skilled in the art.

As an initial starting point, all features of the independent claims should be considered essential.  However, examiners should note the mere presence of a feature in an independent claim is not conclusive proof that it is essential. Examiners will need to properly construe the specification to definitively determine the essential features of the claim, using the general rules of construction, in particular:

  • construe the specification as a whole;​​​​​​​

  • construe the specification as a skilled addressee;

  • read in the light of common general knowledge;

  • construe as at the priority date of the relevant claim;

  • purposively construe the specification; and

  • determine the true ambit of the claim, including proper consideration of words of purpose.

A feature should only be considered inessential if it is readily apparent that a feature does not materially affect the way the invention works.

If there is no working interrelationship, nor potential working interrelationship between the feature and the other features of the claim, the feature will likely not materially affect the way the invention works. Such a feature cannot be an essential feature of the invention, unless it is clear from the specification that the feature is intended to be essential.

If after reading the complete specification it is apparent that a feature is inessential, it is possible to take a novelty objection. However, such an objection is likely to not be a very strong objection and a well-reasoned inventive step may be more appropriate from a strategic examination perspective.​​​​​​​

Determining Essential Features (Specific Considerations)   

Objects of the Invention, Statements of Prior Art

If the specification under consideration contains statements of prior art and/or the problem to be overcome, these may be of assistance when ascertaining the essential features.

The significance or emphasis placed on a particular feature or function in such statements may indicate that the feature is essential.     

It should be noted that the consideration of such object statements and any emphasis on particular features should be done as part of the construction of the specification as a whole. Stated more simply; the object statements may point toward potential essential features, but the determination of whether a feature is essential must be done by following the general principles of construction.  

Use of specific words and phrases

The use of specific words and phrase in the consistory statement or other parts of the specification may provide an indication as to whether a feature is essential.  For example, words such as "must include", and "necessarily” would indicate that the feature may well be essential whereas terms like "preferably", and "for example" would tend to indicate that the feature may not materially affect the way the invention works.

Additionally, examiners should consider whether a feature needs to be present in the broadest claim and whether the feature needs to be precisely what the claim specifies.

While various words and phrases may be of assistance in determining whether a feature is essential, examiners are reminded that they should not rely solely on the use of such phrases to make the determination.  The determination must be made on the proper construction of the specification as a whole.

Legal principles and relevant case law

For more examples on the use of words and phrases in the specification to determine essential features, see:

  • Populin v HB Nominees Pty Ltd (1982) 41 ALR 471 and;

  • Rhone-Poulenc Agrochimie SA v UIM Chemical Services (1985) AIPC 90–251.

Conflicting Statements

In situations where a specification has conflicting statements or inconsistencies, it may be difficult to determine whether a feature is essential based on a proper construction of the specification.

Generally, features should be considered essential unless it is clearly apparent that the feature is inessential. If however there is doubt if a feature is essential due to inconsistencies, examiners can assume that feature is inessential until the inconsistency is resolved.

Where a novelty objection is taken in these circumstances, the objection will need to:

  • specify the basis on which the feature has been interpreted as inessential; and

  • identify the conflicting passages in the specification that support the interpretation of the feature as inessential.

An objection of lack of novelty in these circumstances may be overcome by amending the description rather than the claims, provided the requirements of s102 are satisfied.

Consideration of Independent and Dependent Claims

Where an independent claim lacks novelty, examiners will also have to consider the novelty of the dependent claims. It is likely the applicant will promote a feature in a dependent claim into the independent claim to overcome the novelty objection.

Where a dependent claim adds a trivial feature that does not materially affect the working of the invention, it is unlikely that the feature will constitute an essential feature of the claim. Therefore, a lack of novelty objection taken against an independent claim should also be taken against the relevant dependent claims.

Where a dependent claim adds a feature that does materially affect the working of the invention, it is likely that the feature is an essential feature of that claim. If that feature is not in the citation, the claim will be novel. The novelty objection should not be raised against that claim or claims dependent thereon. Examiners will then need to consider the inventiveness of the dependent claims as features that confer novelty may not establish inventiveness. 

Where the claims involve complex dependencies, it may be that:

  • the novelty of a particular claim depends on which claim it is appended to; and

  • there may be more than one claim containing a novelty-conferring feature to which that claim is appended.

In this situation, examiners should make a judicious assessment of which features of the claim are essential and then assess novelty on that basis.

Collocations and Kits

Where a claim defines a number of integers with no working interrelationship, the claim is said to be for a collocation of integers. Typically, the apparent novelty of such a claim resides in one of those integers and examiners should base their search strategy on that integer.

A claim to a collocation of integers is novel if any integer of that collocation is itself novel.

Where a claim is directed to a collocation of known integers, such as a kit of parts, the claim is not in respect to a manner of manufacture. (See 5.6.8.16 Combinations, Collocations, Kits​​​​​​​ for further information).

Novelty Essential Features - Legal principles and relevant case law

Catnic Components v Hill & Smith Ltd (1982) RPC 183 is the relevant case law for novelty and essential features.

Examiners should initially assume that all features of the independent claims are essential (page 227):

"An applicant for a patent will want his leading claim to be as wide as is possible consistently with its validity. He will wish to avoid any unnecessary restriction of it. So he will want to avoid claiming any feature which would unnecessarily restrict the scope of the claim. A well drawn leading claim will accordingly specify only those features which are essential to the invention claimed. It follows, in my opinion, that the applicant probably regards all the features of his leading claim as essential features of the invention."

However, the mere presence of a feature in an independent claim is not conclusive proof that it is essential (page 228):

"The fact that a claim incorporates a particular feature does not alone suffice to make that feature an essential one. If this were not so, no feature of a claim could ever be inessential, but the speeches in Rodi and Wienenberger* all assume that a claim may include an inessential feature."

The issue of determining essential features was further discussed at page 228:

"... I think that one can venture upon the following generalisations on the question of essentiality. (1) If that feature of the claim which is under consideration is in fact essential to the working of the claimed invention, then it must be an essential feature of the claim. (2) If the feature is not in fact essential to the working of the claimed invention, the applicant for a patent may nevertheless have made it an essential feature of the claim, that is to say, he may by the terms of the claim as properly construed have clearly limited his claim to a subject matter having that particular feature. If so, that feature will be an essential feature of the claim and anyone who makes a product or carries out a process which has all the features of the claim except that particular feature will not infringe the claim. But (3), all claims are not perfectly framed. Sometimes a draftsman may include some feature in a claim, either explicitly or by implication, which is not in fact essential to the working of the claimed invention and which the applicant has not by the terms of his specification and claim clearly indicated as a feature which he regards as an essential feature of his monopoly. In such a case an alleged infringer may be held to have infringed the claim notwithstanding that his product or process does not incorporate the feature in question or substitutes some equivalent for it. (4) The fact that a claim incorporates a particular feature does not alone suffice to make that feature an essential one. If this were not so, no feature of a claim could ever be inessential, but the speeches in Rodi and Wienenberger* all assume that a claim may include an inessential feature."

*Rodi and Wienenberger v Henry Showell Ltd (1969) RPC 367.

Determining if a feature materially affects the way an invention works is required to assess if a feature is essential. Page 243 of Catnic Components v Hill & Smith Ltd (1982) RPC 183 states:

“The question in each case is: whether persons with practical knowledge … would understand … a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention ...

The question, of course, does not arise where the variant would in fact have a material effect upon the way the invention worked.”

In Ryan v Lum (1989) 14 IPR 513, which concerned a method of cleaning silver involving a sheet of aluminium with a regular pattern of holes, the court observed:

"Neither in the specification nor anywhere else is it claimed that it is the holes themselves which are important in the process. Indeed, the fact that the specification is so general about the number and types of holes that are needed negates to my mind the view that the holes are of great significance to this invention."

See also Rodi and Wienenberger AG v Henry Showell Ltd (1969) RPC 367.

In Sebel Properties v Fagaleo Pty Ltd (1989) 14 IPR 524, claim 1 defined a writing tablet for a chair or other furniture which comprised a support bracket, a pivot on the support bracket making an angle of about 45° with the vertical, and a writing tablet pivoted on the pivot and making an angle of about 45° with the pivot. In use, the support bracket could be secured to a chair, or to the floor adjacent the chair, allowing the tablet to be rotated about the pivot from a horizontal (writing) position. The prior art disclosed a rotating writing tablet which operated in the same way, but which in use was secured directly to the chair without using a support bracket.

The court decided that the support bracket was an "immaterial variant" of the prior art device and was therefore inessential. However, the significance of this feature could also be deduced from the stated object of the invention, which was to simply provide a tablet which could be rotated in a single movement from a horizontal or writing position. No emphasis was placed on the means by which the writing tablet was secured to the chair or other furniture. On the basis of this statement, it could be logically argued that the inclined pivot arrangement, not the support bracket, was essential to the invention.

Amended Reasons

Amended Reason Date Amended

Published for prod

Published for testing
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