We have:
Patent A, filed Nov. 29, 2006 in the US, claimed the benefit of a DE application, filed Feb. 02, 2006,(there is a PCT application filed Nov. 29, 2006 with the publication date Aug. 30, 2007, designated US, in German);

Patent B, filed Jul. 19, 2006.

That is, Patent A has a priority date Feb. 02, 2006 and a US national filing date (also an international filing date) Nov. 29, 2006.
Patent B (US patent) has a filing date Jul. 19, 2006.

So, can Patent A be considered as a prior art over Patent B? Is there any legal basis?

1 Answer 1


Due to the application beeing pre AIA, I had to revise my previous answer

Lets start with two of the three conditions for patentability - novelty and non-obviousness (the third is usefulness). Prior art for both is the same (see mpep 2141.01) ! This is based in:

(Post AIA, so for your question the next section is not relevant, however I find it very important as it is the current state of the law).

35 U.S. Code § 101 - Inventions patentable:

Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.

Emphasis added.


35 U.S. Code § 102 - Conditions for patentability; novelty

(a)Novelty; Prior Art.—A person shall be entitled to a patent unless— (1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention; or (2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.

35 USC 102 (b) and (c) describe excemptions, I won't cite them, but please read them.

(d)Patents and Published Applications Effective as Prior Art.—For purposes of determining whether a patent or application for patent is prior art to a claimed invention under subsection (a)(2), such patent or application shall be considered to have been effectively filed, with respect to any subject matter described in the patent or application— (1) if paragraph (2) does not apply, as of the actual filing date of the patent or the application for patent; or (2) if the patent or application for patent is entitled to claim a right of priority under section 119, 365(a), 365(b), 386(a), or 386(b), or to claim the benefit of an earlier filing date under section 120, 121, 365(c), or 386(c), based upon 1 or more prior filed applications for patent, as of the filing date of the earliest such application that describes the subject matter.

So for novelty, anything published before the effective filing date is prior art and patent applications filed before or based on a priority document filed before the effective filing date (of the patent application assessed for novelty) if published later. This is called the first to file principle. But this only applies for AIA patent applications (after March 16th 2013). I'll get to pre AIA later.

Note that there is no "in this country" or "in english" post AIA!

Pre AIA (filed before March 16th 2013):

The US was a first to invent country pre AIA, therefore there are some differences. Also, prior art for novelty had to be used/known "in this country" (the US) or published elsewhere. As we are talking about a published publication or a hidden earlier application, this doesn't matter.


(e) the invention was described in — (1) an application for patent, published under section 122(b), by another filed in the United States before the invention by the applicant for patent or (2) a patent granted on an application for patent by another filed in the United States before the invention by the applicant for patent, except that an international application filed under the treaty defined in section 351(a) shall have the effects for the purposes of this subsection of an application filed in the United States only if the international application designated the United States and was published under Article 21(2) of such treaty in the English language.

Pre-AIA 35 U.S.C. 102(e) allows the use of certain international application publications and U.S. patent application publications, and certain U.S. patents as prior art under pre-AIA 35 U.S.C. 102(e) as of their respective U.S. filing dates, including certain international filing dates. The prior art date of a reference under pre-AIA 35 U.S.C. 102(e) may be the international filing date if the international filing date was on or after November 29, 2000, the international application designated the United States, and the international application was published by the World Intellectual Property Organization (WIPO) under the Patent Cooperation Treaty (PCT) Article 21(2) in the English language.


Pre-AIA 35 U.S.C. 102(e) is explicitly limited to certain references “filed in the United States before the invention thereof by the applicant” (emphasis added). Foreign applications’ filing dates that are claimed (via 35 U.S.C. 119(a)–(d), (f) or 35 U.S.C. 365(a)) in applications, which have been published as U.S. or WIPO application publications or patented in the U.S., may not be used as pre-AIA 35 U.S.C. 102(e) dates for prior art purposes.

Which should answer your question. The reference date for the US assessment of novelty is the date in which a US application was filed or a PCT application was filed which included the US as designated country and was published in english under PCT article 21(2) (see MPEP section a little below the previous cited).

If any of the applications had been published before the filing date of B - in any language - it would be prior art. If that was not the case, A is not prior art for B.

  • I've checked the MPEP and 35 USC.
    – J. Gong
    Commented Apr 17, 2017 at 16:48
  • I've checked the MPEP and 35 USC. Pre-AIA 35 USC 102 (e)(2), MPEP 2136 and MPEP 706.02(f). Specifically, the MPEP 2136 states that (A) If the international application meets the following three conditions: (1) an international filing date on or after November 29, 2000; (2) designated the United States; and (3) published under PCT Article 21(2) in English, the international filing date is a U.S. filing date for prior art purposes under pre-AIA 35 U.S.C. 102(e). It seems that DE application and its PCT application both fail to meet those requirements.
    – J. Gong
    Commented Apr 17, 2017 at 17:22
  • 1
    AS the PCT application is filed and published after Patent B, and is NOT published in ENGLISH. The DE application does not meet other requirements in pre-AIA 35 USC 102 (a) or (b). At this sentence, is the DE application still valid to be a prior art against Patebt B?
    – J. Gong
    Commented Apr 17, 2017 at 17:23
  • 1
    @J.Kong I revised my answer, there was a pre AIA technicality I didn't know (forgive me for I am not from the US).
    – user18033
    Commented Apr 17, 2017 at 20:16
  • 1
    Thanks, it really makes sense. In this case, the PCT application was filed at the same to its equivalient US application and published after Patent B and NOT in ENGlISH. Of course, the DE application is published after Patent B. Accordingly, it would be as you said, A is not prior art for B.
    – J. Gong
    Commented Apr 18, 2017 at 2:25

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .