Scope and ownership of patents

Types of protectable inventions

Can a patent be obtained to cover any type of invention, including software, business methods and medical procedures?

The statutory requirements for patent eligible subject matter is broad, requiring only that the invention be a process, machine, manufacture or composition of matter. But not everything is patentable. The invention, without more, cannot claim a law of nature, natural phenomena or an abstract idea.

The US Supreme Court has established a two-step approach (Alice/Mayo test) for determining whether an invention is directed to patentable subject matter. First, are the claims as a whole directed to one of the categories of ineligible subject matter, such as an abstract idea? If yes, then step two considers whether other elements of the claim result in an ‘inventive concept,’ which are elements that ‘transform the nature of the claim’ into patent-eligible subject matter.

Thus, patents on software, business methods and medical procedures are allowed if they satisfy the Alice/Mayo test. Thus, for example, complementary DNA (DNA that is synthetically created from messenger RNA) is patentable subject matter. However, isolated genomic DNA (DNA taken from a part of the entirety of an organism’s hereditary information or chromosomes) is an unpatentable product of nature. Moreover, software or business method claims that simply perform mathematical calculations are not patent-eligible. Similarly, a medical procedure that merely performs a medical activity is not patent eligible.

Patent ownership

Who owns the patent on an invention made by a company employee, an independent contractor, multiple inventors or a joint venture? How is patent ownership officially recorded and transferred?

The inventor is the presumptive owner of a patent. However, most companies require their employees to assign their patent ownership to the company as a condition of employment. Even if the employer does not obtain patent ownership, it may still have a non-exclusive and non-transferable royalty-free licence (shop right) to use the invention if the employer’s facilities were used to conceive an invention or reduce it to practice.

In the absence of any agreement to the contrary, each of the joint owners of a patent may make, use, offer to sell or sell the patented invention within the US, or import the patented invention into the US, without the consent of and without accounting to the other owners.

Patent owners may assign or convey their patent rights through a written assignment, which is recorded in the United States Patent and Trademark Office (USPTO). Recording the assignment is important because an assignment is void against any subsequent purchaser, without notice, unless it is recorded in the USPTO within three months from its date or prior to the date of such subsequent purchase.

Patent office proceedings

Patenting timetable and costs

How long does it typically take, and how much does it typically cost, to obtain a patent?

As of January 2021, the average time to the date of final disposition (eg, patent being issued or abandoned) at the US Patent and Trademark Office (USPTO) was 22.8 months. However, the time it takes for a patent to issue varies based on many factors, such as the subject matter, the complexity, and if there is a backlog in unexamined applications. As of January 2021, there were 606,000 patent applications at the USPTO that had yet to be examined, resulting in an average time of 15.7 months from when the application was filed to the date of the first office action (the first response from the patent examiner to the patent applicant).

The costs associated with obtaining a patent consist of statutory fees and the amount paid to prosecute the application. Filing fees vary depending on the number of claims and application type. The regular filing, search and examination fees for a non-provisional utility application begin at US$1,820 for applications with up to a total 20 claims and up to three independent claims. These fees can be reduced by 50 per cent if the patent appli­cant qualifies as a small entity (fewer than 500 employees) and has not licensed the invention to a large entity, or by 75 per cent if it is a micro-entity (an individual inventor with limited pending applications and earning less than a threshold income). Once an application is approved, an issue fee of US$1,200 is due. And after the patent issues, periodic fees (US$2,000 at 3.5 years, US$3,760 at 7.5 years and US$7,700 at 11.5 years after issuance) must be paid to maintain the patent.

The costs related to preparing and filing a utility patent depends on the subject matter and complexity of the subject matter. The cost for preparation and filing of an application ranges from approximately US$7,500 to US$10,000 for a relatively simple invention, to US$12,000 to US$17,000 for more complex inventions and to US$25,000 or more for very involved biotechnology or software inventions. If patent drawings are prepared by a professional technical draftsperson, costs range from approximately US$75 to US$120 per drawing sheet.

Expedited patent prosecution

Are there any procedures to expedite patent prosecution?

As of January 2021, patent applications filed with the USPTO had an average total pendency of 22.8 months. However, there are numerous ways that a patent applicant can expedite patent prosecution.

 Track One programme

The USPTO offers a Track One programme for prioritised examination of utility and plant patent applications. The USPTO’s goal for prioritised examination is to provide a final disposition within 12 months. A utility or plant patent application is eligible if it contains no more than four independent claims, 30 total claims, no multiple dependent claims, and the applicant pays, in addition to the ordinary filing fee, a US$4,200 prioritised examination fee. In 2020, the average time between filing and the first office action in a Track One application was 3.1 months, and, on average, a final disposition was within 10.8 months. The current yearly limit on the number of prioritised examination requests that may be accepted is 12,000.

 Petition to make special

Under these procedures, the USPTO will advance an application out of turn for examination if the applicant files a grantable ‘petition to make special.’ An applicant may be granted expedited review with no additional fee if, for example, the inventor is aged 65 or older, in poor health, or if the invention deals with energy, environmental quality or countering terrorism. A petition to make special on other grounds must be accompanied by an additional fee.

 Accelerated examination

The USPTO also offers ‘accelerated examination’, in which the time from filing to disposition is also approximately 12 months. Although in accelerated examination, the applicant pays only a nominal fee, there are burdensome filing requirements, including conducting a search and submitting an accelerated examination support document characterising those search results. The application must contain three or fewer independent claims and no more than 20 claims total. Because of the extensive filing requirements, including the cost of conducting the pre-examination search and preparing the accelerated examination support document, the expected cost of prosecuting an accelerated examination application can be high. The applicant also must characterise the prior art before receiving any claim rejections, which can put the applicant at a strategic disadvantage if the patent is later subject to litigation.

 Patent Prosecution Highway

The Patent Prosecution Highway (PPH) is yet another option for expedited review that is intended to speed up the examination process for corresponding applications filed in participating intellectual property offices around the world. Under the PPH, participating patent offices have agreed that when an applicant receives a final ruling from a first patent office that at least one claim is allowed, the applicant may request fast-track examination of corresponding claim in a corresponding patent application that is pending in a second patent office. There is no fee under the PPH programmes.

 Expedited examination (design patents)

For design patent applications, the USPTO offers expedited examination. In order to qualify for expedited examination of a design patent application, the applicant must, for example, conduct a pre-examination search, submit the results of the pre-examination search to the USPTO and pay a fee to the USPTO.

 Pilot and other programmes

There are also additional pilot programmes for increasing speed of prosecution, including the ‘After Final Consideration Pilot Program‘, in which the applicant is provided the opportunity to amend pending claims more substantially than generally allowed after a final rejection. And the ‘Collaborative Search Pilot Program’, which allows examiners in multiple patent prosecution offices to share references to help expedite the examination process. Note that the 'Full First Action Interview Program’, in which the applicant had the opportunity to apply for an early interview with the patent exam­iner, was discontinued at the end of 2020. 


COVID-19 Prioritised Examination Pilot Program

In mid-2020, the USPTO launched the Covid-19 Prioritized Examination Pilot Program for accelerating patent protection for covid-19 related products. Limited to the first 500 applications, the program allowed for small and micro-entity applicants to obtain free accelerated review for applications covering a product or process related to covid-19 that is subject to FDA approval for covid-19 use. The goal of this programme was to provide a final disposition within 12 months.     

Patent application contents

What must be disclosed or described about the invention in a patent application? Are there any particular guidelines that should be followed or pitfalls to avoid in deciding what to include in the application?

Under US law a patent specification must include the following disclosures: a written description of the invention; the manner and process of making and using the invention (the enablement requirement); and the best mode contemplated by the inventor of carrying out the invention. However, only the failure to provide adequate written description or lack of enabling disclosure can form the basis for an invalidity determination.

To satisfy the written description requirement, the application must convey to a ‘person of ordinary skill in the art’ that the inventor had possession of the claimed subject matter at the time the application was filed. The required level of detail varies depending on the nature and scope of the claims and on the complexity and predictability of the relevant technology. For broad, general ‘genus’ claims, the written description requirement is satisfied by describing a representative number of species by reducing to practice or disclosing identifying characteristics sufficient to show that the applicant was in possession of the claimed genus.

A patent application must also be ‘enabled’ to ensure that the specification describes the invention in a meaningful way. The standard is whether the disclosure enables one skilled in the pertinent art to make and use the claimed invention without undue experimentation. Detailed procedures for making and using the invention may not be necessary if the description of the invention itself is sufficient to permit those skilled in the art to make and use the invention. Enablement is determined from the filing date of the patent.

A patentee must also set forth the best mode contemplated by the inventor for carrying out the invention. The ‘best mode’ requirement exists to prohibit inventors from applying for patents while at the same time concealing from the public the most preferred embodiment of the inventions. While disclosing the best mode is required for patentability, the failure to disclose the best mode is no longer a basis on which any claim of a patent may be cancelled or held invalid or enforceable.

Prior art disclosure obligations

Must an inventor disclose prior art to the patent office examiner?

All individuals involved in the patent filing and prosecution process (including the inventors, the prosecuting attorneys, declarants, etc) are subject to a duty of candour and good faith in their dealings with the USPTO. This requires disclosure of all material information regarding patentability. This duty exists with respect to each pending claim. The USPTO will not grant a patent if it is found that the duty of disclosure was violated through bad faith or intentional misconduct. The disclosure obligation ends once the patent issues, including the need to submit relevant prior art.

Violating the duty of candour and good faith, if accompanied by an intent to deceive the USPTO, may lead to unenforceability of any patent issuing from the application (and any patent whose priority is based on that application) and could result in an award of attorneys’ fees. A party asserting this unenforceability defence must prove by clear and convincing evidence that the applicant acted with specific intent to deceive the USPTO, and that in the absence of ‘egregious misconduct,’ the patent would not have issued ‘but for’ the mis­representation.

Pursuit of additional claims

May a patent applicant file one or more later applications to pursue additional claims to an invention disclosed in its earlier filed application? If so, what are the applicable requirements or limitations?

An applicant may file multiple applications based on the invention disclosed in the initial patent specification, including a continuation, divisional and continuation-in-part (CIP).

A continuation application has the same specification and priority date as the parent patent application, but it will have different claims. This type of application is often used when the Examiner rejected certain claims of the parent application or the applicant would like to claim different embodiments of the disclosed invention in multiple patents.

A divisional application is filed when a parent application attempts to claim more than one distinct invention. It has the same disclosure and priority date as the parent application and includes claims that were filed with—and restricted from—the parent application. Thus, a divisional application is used when the examiner issues a ‘restriction requirement’ (when an applicant attempts to claim multiple inventions in a single patent) and allows for ‘dividing’ the multiple inventions into one or more divisional applications.

A CIP includes additional subject matter that was not included in the parent application. In this type of application, claims that relate to the subject matter disclosed in the parent will have the same priority date as the parent but any claims relating to the new subject matter will only be entitled to the filing date of the CIP application. These applications are used when there have been advancements or new developments to the claimed subject matter during the pendency of the prosecution of the parent.

In all continuation applications, patentees must be careful to avoid ‘obviousness type double patenting’. This judicially created doctrine prevents the extension of patent term by prohibiting the issuance of claims in subsequent patents that are determined to not be patentably distinct from the claims of the first issued patent in the family (the parent). An examiner may raise an obviousness type double patenting rejection if:

  • there is at least one common inventor, owner or joint research agreement linking the parent application and the continuation application;
  • the subject matter claimed in the application at issue is obvious in view of the subject matter claimed in the parent application (or vice versa); and
  • there must not have been a restriction requirement that resulted in the subject matter at issue being pursued in separate patent applications.


An obviousness type double patenting rejection may be overcome through the submission of a ‘terminal disclaimer.’ A terminal disclaimer dedicates to the public the entire term, or any terminal part of the term of a patent, that would extend beyond the term of the parent patent.

Patent office appeals

Is it possible to appeal an adverse decision by the patent office in a court of law?

An applicant whose patent claims have been rejected twice (or have received a final rejection) may appeal the decision of the primary examiner to the Patent Trial and Appeal Board (PTAB). The applicant files an opening brief, the examiner files a response, and the applicant then files a reply. The appeal is heard by a panel of three administrative patent judges who review the briefs and hear oral argument, if requested. If the PTAB enters new grounds of rejection, the applicant may request a rehearing. Once the PTAB appeal is complete, the application will return to the original examiner for further prosecution.

There are two options for judicial review of an adverse PTAB decision. The applicant may appeal directly to the Federal Circuit, or alternatively, the applicant may file a civil action against the director of the US Patent Trademark Office (USPTO) in the Eastern District of Virginia federal court. In an appeal to the Federal Circuit, the applicant may not rely on any new evidence. However, new evidence may be introduced if the lawsuit is filed in federal court. 

Oppositions or protests to patents

Does the patent office provide any mechanism for opposing the grant of a patent?

Opposing a patent at the USPTO can be achieved either before or after the patent issues. Any member of the public may file a protest to the grant of a pending patent application, provided such a protest is filed prior to the date the application was published or a notice of allowance was mailed, whichever occurs first. The protestor does not participate further, and the examiner will decide whether and how to act upon the submitted material.

The America Invents Act (AIA) has created two post-grant mechanisms for opposing an issued patent. Inter partes review (IPR) can be used to challenge one or more claims of an issued patent. Any party other than the patent owner can file an IPR petition, and the only permissible grounds for challenging the patent are anticipation and obviousness based on written publications. IPR petitions can be filed at any time during the life of the patent, except in the context of a post-AIA appeal, in which case the IPR petition must be filed within nine months of the appeal. Moreover, if a patent is involved in litigation, a litigant wishing to file an IPR petition challenging the asserted patent must do so within one year after the complaint is filed. For an IPR to be instituted, the petition must demonstrate that it is ‘more likely than not’ that at least one challenged claim is unpatentable.

Another patent office mechanism for opposing a granted patent is referred to as post-grant review (PGR). To be PGR-eligible, a patent must have an effective filing date of 16 March 2013 or later, and the petition must be filed within nine months after the challenged patent is granted. A patent may be challenged on any ground of invalidity, such as patent eligible subject matter, obviousness, enablement, written description and indefiniteness. To be granted post-grant review, a requestor must demonstrate that it is ‘more likely than not’ that at least one challenged claim is unpatentable, or an important or unsettled legal question is raised.

Priority of invention

Does the patent office provide any mechanism for resolving priority disputes between different applicants for the same invention? What factors determine who has priority?

The AIA changed US patent law from a ‘first-to-invent’ to a ‘first-inventor-to-file’ system, which aligns the US more closely with existing patent regimes around the world. The AIA applies to any patent application with at least one claim that has an effective filing date on or after 16 March 2013. Under this system, the first inventor to file an application with the USPTO will be awarded the patent. However, unlike much of the rest of the world, there are exceptions to this rule. For example, the law still provides a one-year grace period before filing the patent application for the inventor’s own disclosures, or the disclosures of others who have derived the invention from the inventor. However, there is a risk of waiting to file an application since this grace period does not apply to third parties. This allows for an ‘inventor’ to obtain a US patent by being the second-to-invent but the first to file.

For patent applications filed before 16 March 2013, the US will continue to use the first-to-invent system. In this regime, an applicant who is second-to-file may be awarded the patent if he or she can prove an earlier date of invention and thereby establish priority. Priority is generally awarded to the applicant who can show an earlier date of reduction to practice (where the filing of a patent application is considered ‘constructive’ reduction to practice); however, the later party can win priority under this system by showing an earlier conception date.

To resolve priority disputes, the USPTO conducts interference proceedings before the Patent Trial and Appeal Board. These will become less frequent as the new first-to-file procedures begin applying to more patents. Federal courts have jurisdiction to resolve priority disputes regarding two issued patents.

Modification and re-examination of patents

Does the patent office provide procedures for modifying, re-examining or revoking a patent? May a court amend the patent claims during a lawsuit?

A patent may be corrected or amended in multiple ways, including by: reissue, the issuance of a certificate of correction which becomes a part of the patent, disclaimer, inter partes review (IPR), post grant review (PGR), covered business method review, re-examination and supplemental examination. For example, a patentee may seek to reissue a patent that is deemed wholly or partly inoperative or invalid by reason of a defective specification or drawing, or by reason of the patentee claiming more or less than he had a right to claim in the patent. The reissue claims must be for the same invention as that disclosed in the original patent; no new matter is allowed. And a reissue will not be granted to recapture subject matter that was surrendered to obtain the original patent. A reissued patent cannot expand the claim scope of the original patent unless applied for within two years of the original patent grant.

The America Invents Act (AIA) has created additional post-grant mechanisms for modifying or revoking an issued patent. For example, IPR can be used to challenge one or more claims of an issued patent. Any party other than the patent owner can file an IPR petition, and the only permissible grounds for challenging the patent are anticipation and obviousness based on written publications. IPR petitions can be filed at any time during the life of the patent, except in the context of a post-AIA appeal, in which case the IPR petition must be filed within nine months of the appeal. Moreover, if a patent is involved in litigation, a litigant wishing to file an IPR petition challenging the asserted patent must do so within one year after the complaint is filed. For an IPR to be instituted, the petition must demonstrate that it is ‘more likely than not’ that at least one challenged claim is unpatentable. There are strategic issues to consider before filing an IPR. Specifically, a petitioner in an IPR that results in a final written decision from the Patent Trial and Appeal Board is estopped from raising in a district court litigation, the US Patent and Trademark Office (USPTO), or in an International Trade Commission proceeding ‘any ground that the petitioner raised or reasonably could have raised during that inter partes review.’

PGR is another USPTO mechanism for modifying or revoking an issued patent. PGR eligibility requires that a patent have an effective filing date of 16 March 2013 or later, and the request must be filed within nine months after the challenged patent is granted. A patent may be challenged on any basis for invalidity. To be granted post-grant review, a requestor must demonstrate that it is ‘more likely than not’ that at least one challenged claim is unpatentable, or an important or unsettled legal question is raised. As with IPRs, if the PGR advances to a final written decision, then estoppel applies to the petitioner as to the invalidity positions that were raised or that reasonably could have been raised in the PGR proceeding.

Ex parte re-examination allows a requestor to submit to the USPTO prior art that raises a ‘substantial new question of patentability’ to the issued patent. Anyone can request re-examination and the requestor may remain anonymous, if desired. If the request for re-examination is granted, the patentee may file a responsive statement, and then, within two months, the requestor may file a reply. However, besides this reply, the requestor does not participate in the re-examination procedure. Prior art considered during re-examination is limited to prior art patents and printed publications.

Supplemental examination provides a patent owner with a mechanism to request that the Office consider, reconsider, or correct information believed to be relevant to an issued patent. The information is not limited to patents and printed publications, like it is in ex parte reexaminations. Rather, it may include any information (audio or video, sales receipt, written publication, etc) that the patent owner believes to be relevant. In addition, the information submitted as part of the supplemental examination request may involve any ground of patentability. If the USPTO determines that a ‘substantial new question of patentability’ was demonstrated, then patent will be subjected to re-examination. While supplemental examination has been available since 2012, it is rarely used; only around 30 requests per year have been filed.

Patent duration

How is the duration of patent protection determined?

A patent term begins on the date the patent is issued by the US Patent and Trademark Office (USPTO). For utility and plant patent applications filed on or after 8 June 1995, the patent term expires 20 years from the filing date of the earliest related application or, where there are no earlier applications, the filing date of the application at issue. Design patents granted on applications filed before 13 May 2015 have a term of 14 years, or, if filed after this date a term of 15 years. Regardless of the filing date, the term for design patents is measured from the issue date of the patent.

When determining the expiration date of a patent, it is important to check the prosecution history to determine if the patent is subject to a terminal disclaimer or other modifications. For example, there are circumstances under which a patent term may be extended, such as when the USPTO failed to act promptly in prosecuting the patent, there was a proceeding that delayed the issue of the patent (such as an interference), or when a patent is directed to a product (for example, a pharmaceutical) that was subject to regulatory delays.

The USPTO offers a ‘patent term calculator’, available on the USPTO website, to help determine the expiry date of a US patent.

Law stated date

Correct on

Give the date on which the information above is accurate.

The information in this chapter is accurate as of March 2021.