Introduction
A divisional patent application is a patent application that is filed to pursue an invention that was disclosed in an earlier application but was not pursued in the original application. Divisional applications are commonly used when the U.S. Patent and Trademark Office (USPTO) determines that an application contains more than one independent and distinct invention and requires the applicant to restrict the claims to one invention.
Understanding when and how to file a divisional application can help patent applicants preserve the opportunity to obtain additional patent protection while maintaining the benefit of an earlier application’s disclosure and, when applicable, its filing date.
Question: What patent law is a divisional application based on?
Answer: 35 U.S.C. § 121.
What Is a Divisional Application?
Under U.S. patent law, a divisional application is a type of continuing application that is filed when an applicant wants to pursue a separate invention that was disclosed in a prior application.
A divisional application generally claims subject matter that was disclosed in the earlier application but was not elected for examination in the parent application. The divisional application must contain adequate support for its claims in the earlier disclosure.
The statutory basis for continuing applications is found in 35 U.S.C. § 121, which provides special treatment for applications resulting from a restriction requirement under certain circumstances.
The USPTO discusses divisional applications and other continuing applications in the Manual of Patent Examining Procedure (MPEP), particularly Chapter 2100 and Chapter 800.
Question: What does a divisional application result from?
Answer: A restriction requirement.
Why Does the USPTO Require Restriction?
A patent application may sometimes contain claims directed to multiple inventions. When the inventions are independent or distinct, the USPTO may issue a restriction requirement.
A restriction requirement asks the applicant to select one invention for examination. The applicant generally must identify which group of claims will be examined.
For example, suppose an application describes:
- A computer system;
- A particular method performed by the computer system; and
- A specialized hardware component used with the system.
If the USPTO determines that the claims are directed to independent or distinct inventions, it may require the applicant to elect one group of claims for examination.
The applicant may later pursue the non-elected invention in a divisional application when the applicable requirements are satisfied.
Question: (True or False) An applicant may be required to elect one group of claims for examination.
Answer: True.
Divisional Application and Parent Application
The original application from which a divisional application is filed is commonly called the parent application.
The divisional application must identify the relationship to the prior application and generally includes a specific reference to the earlier application.
For example, a divisional application may state that it is a divisional of a previously filed nonprovisional application.
The relationship between the applications is important because a properly filed continuing application may be entitled to the benefit of the earlier application’s filing date for subject matter that is adequately supported by the earlier disclosure.
The requirements concerning benefit claims and continuing applications are discussed in 35 U.S.C. § 120 and 37 C.F.R. § 1.78.
Question: (True or False) An applicant may be required to elect one group of claims for examination.
Answer: True.
When Should a Divisional Application Be Filed?
Timing is an important consideration.
A divisional application should generally be filed while the parent application is still pending. Filing before the parent application becomes abandoned, issues as a patent, or otherwise terminates can be important for preserving the desired continuation relationship.
Applicants should carefully monitor the status of the parent application and applicable USPTO deadlines.
A divisional application can be filed before or, in appropriate circumstances, after a restriction requirement has been issued, provided the statutory and regulatory requirements for the desired filing relationship are satisfied.
Question: (True or False) A divisional application should generally be filed while the parent application is still pending.
Answer: True.
Does a Divisional Application Get the Parent’s Filing Date?
Potentially, yes.
Under 35 U.S.C. § 120, a later application can receive the benefit of the filing date of an earlier application when the statutory requirements are satisfied.
One important requirement is that the earlier application must provide adequate disclosure of the subject matter claimed in the later application.
Therefore, a divisional application does not automatically receive the earlier filing date merely because it is labeled a “divisional.” The claimed subject matter must have proper support in the earlier application.
Question: What requirement is needed for a divisional application to receive an earlier filing date?.
Answer: The subject matter must have proper support in the earlier application.
Divisional Application After a Restriction Requirement
A common situation is illustrated below:
Parent application → Restriction requirement → Election of Invention A → Examination of Invention A → Divisional application for Invention B
Suppose an application contains claims directed to two distinct inventions. The USPTO issues a restriction requirement and requires the applicant to elect one invention.
The applicant elects Invention A.
If the applicant wishes to pursue Invention B separately, the applicant may consider filing a divisional application directed to Invention B, provided the requirements for a divisional application are satisfied.
This procedure allows separate examination of the different inventions.
Question: (True or False) A parent application must have at least two distinct inventions for filing a divisional application later on.
Answer: True.
Divisional Application vs. Continuation Application
Divisional and continuation applications are both types of continuing applications, but they serve different purposes.
A divisional application is generally used to pursue a distinct invention that was disclosed in the earlier application, often following a restriction requirement.
A continuation application generally pursues additional claims to the same disclosed invention or subject matter.
For example:
- Divisional: Parent application contains multiple distinct inventions, and the applicant pursues a non-elected invention separately.
- Continuation: Applicant wants additional examination or different claim scope directed to subject matter disclosed in the parent application.
Both types of applications can be valuable tools in patent prosecution.
Question: What is a difference between a divisional application and a continuation application?
Answer: A divisional application is based on a non-elected invention of a parent application while a continuation application is directed to subject matter in the parent application for additional examination or different claim scope.
Can a Divisional Application Contain New Matter?
Generally, new matter should not be added to a divisional application.
A divisional application is based on the disclosure of the earlier application. Claims in the divisional must have adequate written-description and enablement support in the earlier disclosure.
The prohibition against adding new matter is reflected in 35 U.S.C. § 132(a).
If an applicant attempts to introduce new subject matter, the USPTO may issue an appropriate rejection or objection depending on the circumstances.
Question: (True or False) A new matter can be added to a divisional application.
Answer: False.
What Happens to the Non-Elected Claims?
The claims that were not elected in the parent application may potentially be pursued in a divisional application.
However, applicants should carefully review the restriction requirement and the precise grouping of claims.
For example:
- Invention I → elected and examined in the parent.
- Invention II → non-elected.
- Invention III → non-elected.
Depending on the restriction requirement and prosecution history, the applicant may pursue the non-elected subject matter in one or more additional applications.
The precise strategy should be determined based on the claims, disclosure, restriction requirement, and prosecution status.
Question: (True or False) A new matter can be added to a divisional application.
Answer: False.
Double Patenting Considerations
Applicants should also consider double patenting when filing divisional and other continuing applications.
Two related applications can sometimes contain claims that are considered patentably indistinct.
A restriction requirement may provide special protection under 35 U.S.C. § 121, commonly referred to as the “safe harbor” provision, when the statutory requirements are satisfied.
However, the safe harbor has specific requirements and limitations. Applicants should not assume that every divisional application automatically receives protection from a double-patenting rejection.
The MPEP provides detailed guidance concerning the relationship between restriction requirements, divisional applications, and double patenting.
Question: (True or False) A divisional application can be rejected based on double patenting rejection.
Answer: False.
Example of a Divisional Application
Consider the following simplified example.
An applicant files an application describing a new medical device containing:
- A sensor assembly;
- A control circuit; and
- A particular method of operating the sensor.
The application contains claims directed to each aspect.
The USPTO determines that the claims encompass distinct inventions and issues a restriction requirement.
The applicant elects claims directed to the sensor assembly.
The parent application continues with examination of the elected claims.
The applicant may file a divisional application directed to an appropriately supported non-elected invention, such as the control circuit or operating method, if the requirements for a divisional application are satisfied.
This allows the applicant to pursue separate patent protection for the different inventions.
Important Requirements for Applicants
Before filing a divisional application, an applicant should review:
- The restriction requirement, if one was issued.
- The claims that were elected and non-elected.
- The disclosure of the parent application.
- Written-description support for the proposed divisional claims.
- Enablement support for the proposed claims.
- The pendency status of the parent application.
- The benefit/priority statement required for the continuing application.
- Potential double-patenting issues.
- Applicable USPTO filing fees and requirements.
Careful review of these issues can reduce the risk of prosecution problems.
Key Takeaway
A divisional application is an important tool in U.S. patent prosecution for pursuing a distinct invention that was disclosed in an earlier application. It is particularly relevant when the USPTO has issued a restriction requirement requiring the applicant to select one invention for examination.
Applicants should remember three important principles:
First, the divisional application must be properly related to the earlier application.
Second, the claimed subject matter must have adequate support in the earlier disclosure.
Third, the timing and prosecution status of the parent application are important.
Because divisional applications can affect claim scope, priority, patent term, and double-patenting issues, applicants should carefully review the applicable statutes, regulations, and USPTO guidance before filing.
References
- 35 U.S.C. § 121 — Divisional applications and restriction requirements
35 U.S.C. § 121 — USPTO Patent Laws - 35 U.S.C. § 120 — Benefit of earlier filing date in the United States
35 U.S.C. § 120 — USPTO Patent Laws - 35 U.S.C. § 132 — Notice of rejection; reexamination; amendment
35 U.S.C. § 132 — USPTO Patent Laws - 37 C.F.R. § 1.78 — Claiming benefit of earlier filing date
- MPEP Chapter 800 — Restriction in Applications
- MPEP § 201.06 — Divisional Application
USPTO MPEP § 201.06 - MPEP § 804 — Double Patenting
USPTO MPEP § 804
Educational disclaimer: This article provides general educational information about U.S. patent prosecution. It is not legal advice and does not create an attorney-client relationship.