The validity of a patent determines whether it can truly be enforced. A valid patent gives its owner the legal right to exclude others from making, using, or selling the protected invention, thereby strengthening their competitive position. These exclusive rights also support critical aspects of IP strategy, such as licensing, monetization, enforcement, and attracting investment.
Because of this, evaluating patent validity is central to various aspects of the IP process. In patent litigation, companies facing infringement claims may seek to invalidate the asserted patent’s claims. This typically involves commissioning an invalidity search to uncover prior art that can challenge the patent’s validity before the court or through the Patent Trial and Appeal Board (PTAB). Patent owners and licensors, on the other hand, may conduct a validity search to confirm for due diligence purposes: assess the strength of their patent, identify vulnerabilities, and reinforce the value of their portfolio.
In this guide, we’ll cover the basics of a patent validity or invalidity search and why they are a critical part of managing and protecting intellectual property.
In this guide
- What is a patent invalidity search?
- Why is a patent invalidity search conducted?
- How do I conduct a patent invalidity search?
What is a patent invalidity search?
A patent validity or patent invalidity search is conducted to identify prior art that may disclose, and potentially challenge the novel and inventive features claimed by a patent.
Also called a patent invalidation or opposition search, the goal of this search is to find prior art that was not considered during the patent examination process. This type of prior art search is typically conducted to challenge the validity of a granted patent: whether in the context of litigation, as a defense against infringement claims, or as due diligence, to assess the patent’s overall strength.
Why is a patent invalidity search conducted?
1. Patent litigation
The primary reason for conducting a patent invalidation or patent invalidity search is to challenge the validity of a patent, or specifically one or more of its claims. Apart from proving non-infringement, taking an invalidity position is one of the defenses one could take in a patent infringement case. In the United States, federal courts have the power to decide on the validity and enforceability of a patent.
2. Post-grant proceedings
An alternative to federal court litigation is to challenge the validity of the patent through post-grant proceedings at the USPTO Patent Trial and Appeals Board (PTAB). A party accused in a patent infringement case can gather prior art as evidence, build a case and petition a review. The PTAB has various patent invalidation mechanisms such as the inter partes review and post grant review.
3. ITC Section 337 Investigations
An ITC (International Trade Commission) Section 337 investigation is a legal proceeding conducted by the United States International Trade Commission under Section 337 of the Tariff Act of 1930. Section 337 prohibits unfair practices in import trade, such as intellectual property rights infringement or unfair competition by imported goods.
The purpose of a Section 337 investigation is to address unfair acts in the importation of products that harm domestic industries. These unfair acts can include:
- Patents
- Copyright
- Trademark infringement
- Trade secret misappropriation
- False advertising
- Other forms of unfair competition
While these investigations seek to address various forms of unfair competition, majority of complaints involve patent infringement.
An entity named as respondent in a Section 337 investigation may prove non-infringement, cite exempted uses, or challenge the validity of the asserted patent. While the ITC works independently of the USPTO, it may take into consideration various sources of evidence, including PTAB rulings. However, there are still significant improvements needed in how these two independent bodies decide on patent infringement and validity.
4. Patent enforcement
When a patent holder chooses to enforce their patent, they may conduct a patent stress test in the form of a patent validity search. This aims to assess a patent’s strength and identify potential weaknesses before engaging in patent litigation.
This enables patent holders to anticipate and prepare for potential challenges that could be raised during legal proceedings.
5. Patent licensing, sale or monetization
Before buying a patent, the acquiring party must assess the validity and enforceability of the patent in question.
Licensing a patent without thoroughly evaluating its validity can expose the licensee to legal risks. If the patent is later found to be invalid, the licensee may face financial damages, and potential disruption to their operations.
A patent validity search helps identify any potential risks and allows the licensee to make informed decisions before entering into the licensing agreement. This is particularly important in licensing Standard Essential Patents (SEPs), as it is possible that not all declared SEPs are valid.
6. Patent due diligence
A patent invalidity or validity search must be conducted during due diligence activities in mergers and acquisitions. By identifying any potential invalidity issues, the acquiring company can make informed decisions regarding the value of the target company.
How do I conduct a patent invalidity search?
A prior art search, specifically a patent invalidity search is not a straightforward task and requires a lot of optimization before you get relevant results. Here are some helpful tips to get you started.
1. Analyze the patent claims and set the scope
Before starting a patent invalidity search, the subject matter must be understood by each individual involved in the search.
The scope of the search is very important. Identifying the “effective filing date” of the asserted patent or its claims will set the parameters of your search.
2. Plan out a search strategy.
Plan out a strategy for conducting a text search, patent classification (CPC) search, and a patent citation search.
If the technology described in the patent has broad applications, list out all possible industries, technology areas, jurisdictions relevant to the invention.
3. Identify the inventive step
Determining the inventive step or “inventive concept” allows you to prepare a good set of keywords for your search.
- Review the patent file wrapper or prosecution history to identify which parts of the claims were deemed to be novel and inventive by the patent examiners. This can be accessed through the Patent Center of the USPTO.
- Examining amended or added claim elements in previously rejected claims can offer clues.
- If the examiner allowed a claim after an amendment, it indicates the inventor’s perceived inventive step or concept.
4. Build search strings and optimize keywords
- Take note of keywords and search strings that yield relevant and irrelevant results may help in trial and error.
- Keywords that are too specific may result in high relevance but miss out on other references of interest.
- Identify synonyms of important keywords to be able to expand the search and capture as many relevant references as possible.
- For CPC searching, list out all possible classifications relevant to the invention. The CPCs related to the asserted can be a a good place to start, and then build from there.
5. Make use of publicly available databases
Individual prior art researchers may not typically have access to commercial databases. Several public online databases cover various topics and subject matter.
For patent literature here are some helpful publicly available patent databases:
For non-patent literature (NPL), some of the databases are:
- Google Scholar
- ScienceDirect
- IEEE
- BioMed Central
- SciTech Connect
- arXiv.org
- EBSCO
- MEDLINEPlus Health Information
- Computing Research Repository
- Science.gov
There are also patent search tools that use AI to enhance your prior art or patent invalidity search. One such tool is PQAI, an initiative by AT&T. Try the AI-powered patent search tool for free.
5. Map the patent claims to the your references
Once you have a list of references deemed relevant, it helps to visualize how your results stack up against the claims. Patent invalidity search reports include a claims mapping chart, where each element of a claim is mapped against the features disclosed in a prior art reference.
Visualizing the results helps assess how “strong” or “weak” a reference is by showing how many elements are met by the reference or how strongly are the elements matched.
6. Get a team of patent research experts
While anyone can conduct a patent validity or invalidity search, it is a complex and time-consuming process. Depending on the complexity of the subject matter, it oftentimes becomes imperative to seek the help of a team of subject matter experts, researchers, and patent professionals.
Engaging patent research providers can become a cost-effective tool, especially when you have decided to go to court or petition a review before the PTAB and challenge the asserted patent.
A thorough, well-informed search can also help mitigate costs attributed to litigation, infringement, licensing.
Patent Invalidity Search Services
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Parola Analytics specializes in U.S.-registered patent attorney-led prior art searches. An approach to prior art search which combines both legal and technical fronts can ensure relevant, high-quality results.
