Article 83 EPC: Disclosure of the invention

Text of Article 83 EPC

In plain English

Article 83 is the European enablement requirement. Reading the application with common general knowledge, the skilled person must be able to carry out the invention without undue burden and without inventing anything further.

The test applies to the whole scope of the claim, not just one example. Claims defined by a function or a result are most exposed. In T 435/91 a detergent additive defined only by what it did was insufficiently disclosed because the patent gave isolated examples but no general teaching that would let the skilled person find other additives that worked.

Sufficiency and support under Article 84 are two sides of one principle: the scope of the monopoly should match the technical contribution (T 409/91). A claim that covers far more than the examples can be attacked under either.

It is judged on the application as filed. Data filed later cannot cure a disclosure that was fundamentally lacking. For a medical use, the application must make the therapeutic effect credible; a vague indication of a possible use for a compound yet to be identified is not enough (T 609/02).

For biological material that the description cannot enable in words, Rule 31 provides for a deposit with a recognised depositary institution. The deposit details have to be supplied within the Rule 31 time limit and cannot be added later (G 2/93).

Insufficiency is also a ground of opposition and revocation, so a weakness that passes examination can still cost you the patent.

Key decisions

• T 409/91 (Fuel oils) : Sufficiency (Article 83) and support (Article 84) give effect to the same principle: the patent monopoly must be justified by the technical contribution.
• T 435/91 (Detergents) : A functionally defined component is insufficiently disclosed if the patent gives only isolated examples and no concept that lets the skilled person achieve the result across the whole claim.
• T 609/02 (AP-1 complex/SALK INSTITUTE) : Where the application gives only a vague indication of a possible medical use, later evidence cannot remedy the fundamental insufficiency.
• G 2/93 (Hepatitis A virus) : The file number of a culture deposit cannot be submitted after the time limit in the rules on deposits has expired.

Common objections

Claim broader than the teaching

Show, with the description and common general knowledge, how the skilled person would carry out the invention across the claimed range, or narrow the claim to what the examples support.

Parameter cannot be measured reliably

An unusual parameter with no measurement method can make the invention impossible to reproduce. Include the method and conditions in the description.

Medical effect not made credible

Point to data or a mechanism in the application as filed. Post-filed evidence can support it but cannot replace it.

Drafting and prosecution tips

• Give at least one detailed working example and enough variation to justify the breadth you claim.
• For functional features, describe a general principle or a screening method, not only examples.
• Define measurement methods for every non-standard parameter in the claims.
• Include the data that make a medical or technical effect credible before you file.