Chapter §12.06 How Double Patenting Differs from Anticipation and Obviousness

• Jurisdiction: United States

§12.06 How Double Patenting Differs from Anticipation and Obviousness

[A] Claim-to-Claim Comparison

The double patenting prohibition is traditionally concerned with undue timewise extension of a patentee's right to exclude others. It is fundamental that the scope of the patentee's right to exclude is measured by the language of the patent claims. Therefore, double patenting focuses on patent claims. "Double patenting is altogether a matter of what is claimed."⁶¹

More specifically, the double patenting analysis necessarily involves a claim-to-claim comparison. For example, if one has already obtained a patent and filed an application for a second patent, the double patenting analysis by a USPTO examiner would compare the claims of the patentee's later-filed application with the claims of the patent she has already obtained (sometimes referred to as the "reference patent"⁶²). Importantly, neither the words of the claims in the reference patent nor any of the reference patent's disclosure (i.e., written description and drawings) may be used by examiner in his double patenting analysis as if they were prior art,⁶³ for reasons explained below.

The double patenting analysis is fundamentally different from the analysis for anticipation and obviousness. The question whether a claim is unpatentable or invalid for anticipation or obviousness necessarily involves a comparison of the language of the properly interpreted claim with the prior art. The "prior art" for purposes of determining anticipation and obviousness is defined by 35 U.S.C. §§102–103. For example, when the prior art is a patent or printed publication, the entire content of the document is available for use as prior art. If the prior art reference is a patent, the USPTO examiner (or validity challenger in court or before the PTAB) is not limited to looking at the claims of the prior art patent. The entire disclosure of the prior art patent, including its written description and drawings, are available to the examiner as prior art on which to base an anticipation or obviousness rejection.

Contrariwise, in a double patenting analysis claims are compared against claims, not against the prior art. The issue is whether, for example, an inventor's pending application claims are patentably distinct over the claims of the inventor's patent. Importantly, the disclosure of the patent relied on to invalidate another patent or application on the grounds of double patenting (i.e., the "reference patent") must not be used as prior art. A long line of precedent supports this rule.⁶⁴

[B] Prior Art Is Not Involved

A fundamental and limiting characteristic of a double patenting situation is that the "two or more patents or applications [involved in the analysis] must have at least one common inventor and/or be either commonly assigned/owned. . . ."⁶⁵ This limiting factor helps explain why prior art is not involved in a double patenting analysis.

In some potential double patenting situations, the two or more patents or applications have exactly the same inventor(s). When inventorship is identical, as long as no statutory bars apply under 35 U.S.C. §102 (2006),⁶⁶ then the earlier-filed patent to the same inventor does not qualify as prior art under 35 U.S.C. §102 (2006) because it does not disclose the invention of "another."⁶⁷ Under such circumstances, it would be analytically incorrect to view the double patenting analysis as involving the use of the content of the inventor's earlier-filed patent as prior art against the inventor's later-filed application.

In many double patenting situations, the two patents involved may have issued from co-pending applications (for example, applications related as parent and continuation applications under 35 U.S.C. §120). To qualify as co-pending applications, the inventorship need not be identical but merely overlapping (that is, involving at least one inventor common to both applications).⁶⁸ In such a case, both applications would have as their effective filing date the earlier filing date of the parent application (assuming the requirements of §120, incorporating §112, ¶1, are satisfied).⁶⁹ Hence neither application would be considered "prior" in time to the other. Again, it would be analytically incorrect to view the double patenting analysis as involving the use of the content of one of the co-pending applications (or patent issuing therefrom) against the other as prior art.⁷⁰

[C] Similarities

The comparison of claim versus claim, rather than claim versus prior art, is the fundamental difference between the analysis for double patenting and the analysis for anticipation or obviousness. To what degree the two analyses share similarities is somewhat less clear.

For example, the USPTO and the Federal Circuit take conflicting positions on the question whether certain of the factors from Graham v. John Deere Co.,⁷¹ the Supreme Court's modern foundational decision on the nonobviousness requirement of 35 U.S.C. §103, apply to obviousness-type double patenting. The USPTO takes the position that they do, stating in the Manual of Patent Examining Procedure that

[s]ince the analysis employed in an obviousness-type double patenting determination parallels the guidelines for a 35 U.S.C. 103(a) rejection, the factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are employed when making

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