Patentability Requirements from a Patent Drafting Perspective

Patentability Requirements from a Patent Drafting Perspective

Patent drafting


(Written by: Huang Liangshu)


As discussed previously, for your invention to be eligible for patent protection, it must meet subject matter eligibility requirements. This should be determined early in the patent drafting process to avoid wasting unnecessary time and effort and perhaps most importantly money to attempt to protect something that may not be fundamentally patentable to begin with.

If the subject matter is indeed eligible, do not be quick to congratulate yourself just yet! We must now determine if you the inventor has upheld his or her end of the bargain, that is, the right to a 20-year monopoly on the patented invention in exchange for disclosing to the public at large a new and innovative invention and the means to replicate it.  This is encapsulated in three main requirements for patentability namely: novelty, inventive step and industrial applicability, which will be discussed in the context of patent drafting below.

While these requirements will only be assessed during the examination phase of a patent application, it is important to consider these requirements when drafting the patent specification as once a patent is filed, no new content can be added (and in some circumstances, deleted) to overcome objections raised by a patent examiner. Failure to overcome these objections typically means the patent application will be refused.

Your Invention vs the World

The novelty and inventive step assessment involve comparing the invention as claimed to that of individual disclosures (known as prior art) that form the general body of publicly available knowledge before the patent application was filed. This ensures that the patent specification discloses a genuine contribution to the state of the art. It would not make sense to award a patent to an “invention” that is already public knowledge!

It does not matter if the prior art dates back to the Soviet Union at its inception in the 1920s or, was made in an earlier disclosure by you, much to the chagrin of some of inventors.  So long as the prior art was accessible by the public before the patent application was filed, it affects novelty and inventive step. It is therefore essential to keep your invention secret and out of the public domain to avoid having a prior disclosure made by you to be cited against your later patent application . If you have to disclose your invention to someone before a patent is filed, it should be done only after an appropriate non-disclosure agreement is signed by that person to safeguard your interests. While a 12-month grace period exists for disclosures originating from the inventor for patent filings in Singapore, reliance on the grace period should only be a last resort as it may complicate later foreign filings where a grace period may not apply.

It is also crucial to identify relevant prior art early in the drafting process and give it due consideration to ensure novelty and/or inventive step objections are proactively avoided. This process can be greatly accelerated if you are aware of known solutions, for example competitor’s solutions and is readily able to point out differences to the patent attorney. A prior art search can be performed to identify relevant prior art once the invention has been properly identified. When performed by a competent and experienced individual, a prior art search can effectively identify relevant prior art. However, it is not possible to guarantee that even the most thorough search can locate every relevant prior art document.

If it is not readily possible to differentiate your invention from a known solution, a decision as to whether a patent should be pursued at all in view of the possibility of not being able to overcome novelty and/or inventive step objections will need to be made.

Identifying the invention

It is not uncommon for an inventor to regard his or her entire product or process as the invention and perhaps rightfully so. However, in most instances, patentable inventions are by far and large improvements over existing products and the invention lies in these improvement(s) which confer a technical benefit over known designs. By identifying the structural feature(s) responsible for a technical benefit, a more focused patent search yielding more reliable results can be performed. Accurate identification of the invention is beneficial not only for the patent search and novelty/inventive step enquiry, but also aids in determining key features of the invention to be protected.


Practically speaking, an invention lacks novelty if a disclosure that describes all the functional features for which patent protection is sought became publicly available before the patent was filed. This includes selling a product to the public that can be reverse engineered. Conversely, selling a product made from a proprietary process may not result in loss of novelty for the process if the process cannot be discerned from the finished product.

The novelty requirement is fairly easy to meet since having more features or having a feature that is a variant of a known feature is enough to render your invention novel. For example, if the prior art discloses a square-shaped aperture, having a circular aperture may render an invention novel. However, this difference may still lack an inventive step which will be discussed next.

Inventive Step

The inventive step requirement, sometimes known as non-obviousness becomes relevant when a difference between the claimed invention and a close prior art document is deemed too small. It either does not lead to a technical benefit or if the technical benefit is obvious to a person with the relevant technical knowledge and skill in the design and fabrication of the invention. Returning to the aperture example, if the circular aperture yields no discernible technical benefit, it could face an inventive step objection for being a mere design choice. However, if the circular aperture along with some minor modifications to associated components resulted in an unexpected technical benefit over a square aperture, it may meet the inventive step requirement. As another example, replacing a metal with a more corrosion resistant metal to adapt it to use near the sea is probably an obvious difference that will face an inventive step objection since the technical benefit is to be expected. Minor differences that amount to little more than a workshop or routine modification are not likely patentable. The differences must advance the state of the art and make a genuine technical contribution in the relevant field. It is therefore unsurprising that meeting the inventive step requirement is key to obtaining a patent.

One should bear in mind that simplicity is no barrier to meeting the inventive step requirement. So long as the invention demonstrates a spark of ingenuity that goes beyond routine modification, the inventive step requirement will be met. One example of a simple invention is the paperclip commonly used today. It was patented in 1927 as an improvement over earlier designs. One will notice on close examination that it features equally spaced perpendicular serrations along the entire length of wire to hold papers more securely.

Industrial Application

This requirement has a very low threshold. Most inventions that are made or used in any kind of industry will generally meet this requirement. One noted exception are inventions which appear to operate in a manner that contradicts well-established physical laws. For example, an invention claiming to be a perpetual motion machine that runs indefinitely without any energy source would not be capable of industrial application without sufficient evidence of a reasonable prospect that it can work.

In Singapore, industrial applicability is also used to disqualify inventions deemed to be methods of treatment by way of surgery, therapy or diagnosis performed on the human or animal body.


For an invention to be awarded a patent, it must make a technical contribution that meets all three requirements for patentability. Patentability searches should be performed before filing of a patent to take into account prior art which may affect the novelty and inventive step of the invention during the drafting process. In our next article, we will be giving an overview on how a patent specification is drafted.