The History of Partial Priority System of the Paris Convention

K. Shibata (JP)

From a historical point of view, it can be said that the partial priority system of the Paris Convention had effects similar to the first-to-invent system (under Pre-AIA[1]) of the United States in that a subsequent application claiming partial priority makes it possible for the applicant to secure the possession of the basic invention described in the first application. An applicant could exclude any intervening references which occurred during the priority interval and disclosed the invention written in priority applications by showing that the references clearly fall inside the disclosure of his/her first application.
The partial priority system was helpful for inventors (including researchers in academia) who wish or are required to make public their achievements as early as possible. Without the effect of overcoming such references, the inventors would be forced to postpone the publication of the results of their research not only after the filing of the first application but also after the filing of the partial priority application, as well. This is because their subsequent applications, for which priorities were claimed based on the first applications, might be refused if they included some parts not disclosed in the first applications, such as improvement inventions or additional inventions.
On the other hand, if the claiming of partial priority could exclude any publication of the basic invention by the inventor or a third party made during the priority interval, applicants could overcome rejection and secure patent protection on their subsequent applications that include improvement inventions or additional inventions. The author, of course, recognises that the current practice is different from the above-mentioned partial priority system, and does not intend to deny the current practice. It seems so natural that the interpretations of the Paris Convention have been changed. This article aims only to show the historical background around the Paris Union. Incidentally, all opinions expressed in this article are the personal opinions of the author, and do not represent the opinions of the organisation to which he belongs.

Great Exhibition of 1851 in LondonGreat Exhibition of 1851 in London
(Repository: Repository: collections. vam. ac. uk)

1. Before the establishment of the Paris Convention

The first occasion on which the need for some international arrangement concerning patents became apparent was at the Great Exhibition of 1851 in London.[2] Uninhibited “looking”[3] can lead to problems for exhibitors who have not yet put their inventions on the market in the country where the exhibition takes place or, more importantly, have not secured protection for it through a patent. Thus, the threat of free riding by competitors and piracy arose to counterbalance the undoubted benefits of public exhibition. After some considerations, the Protection of Inventions Act 1851 was established, which stipulated that a provisional registration could be obtained from the Registrar of Designs under the Designs Act 1850 upon the Attorney General’s certification of the inventor’s identity and the sufficiency of the description of the invention.[4] This registration gave protection akin to one of a patent for a period of one year from the time of the registration of the certificate without affecting the validity of any letters patents that might subsequently be granted within the term.[5] The provisional protection provided by the 1851 Act was adopted as a general feature of British patent law in 1852. Other nations adopted similar provisional protection for inventions on their own international or universal exhibitions, notably Paris (1855 and 1857), London (again in 1862), and Vienna (1873).

Great Exhibition of 1851 in London
(Source: WIPO)

After the settlement of the provisional protection at international exhibitions, debates on that a patent right should not be protected where the right is not worked in the country occurred in a number of countries, with patent abolitionists such as RA Macfie in the United Kingdom. The Netherlands actually repealed its patent law. However, the International Patent Congress, which was held during the course of Universal Exhibition in Vienna in 1873, ceased such movements. After considerable discussion, pro-patent resolutions were agreed to by the Congress.[6] These pro-patent movements were followed by the International Congress on Industrial Property, which was held at the same time as the Paris Universal Exposition of 1878, and the First Paris Diplomatic Conference 1880. At the First Paris Diplomatic Conference, Jagerschmidt, the French delegate, presented the draft of the Convention and proposed the idea of the right of the priority for the first time as follows:

Artice.3 Any deposit of a patent application…duly made in one of the contracting countries shall constitute for the applicant a right of priority of registration in all the countries of the Union for a period of ― (my translation)[7]

Charles JagerschmidtCharles Jagerschmidt
(Repository:èque nationale de France)

Jules BOZÉRIAN, the chairman of the Conference, gave some explanation of the scope of the article, to inform the discussion as follows:

In France, when an invention received, anywhere and in any manner, any publicity, it cannot validly be patented. It is, in an honest interest, to remove that provision. Wealth is not generally the prerogative of the inventors, and it is hardly so often they can obtain a patent in their own country. If we multiply the charges upon him for filing patent applications in other countries, it will be unable to guarantee his rights. On the other hand, a foreigner often will see his rights lost in France, because he has obtained, prior to the filing that will be carried out, his patent in his own country and that, therefore, his invention will not be new under French law. At the Congress of 1878 a practical way was sought to remedy this situation. It was first thought to allow the applicant to make a declaration in all consuls. But they said rightly that no consuls everywhere and, on the other hand, this mode of procedure would lead to quite considerable expense. Then it was proposed to decide that the declaration in a contracting country would be valid in all other countries. The applicant does not have a patent for it, but he can obtain it within a certain period without incurring forfeiture for lack of novelty.[8]

The delegation from Austria, in which the patent law stipulated novelty similar to French patent law, proposed to amend Article 3 as follows:

If the law of a Contracting State would require the publication of the patent, the character of the novelty of the invention could not be altered by this publication, provided that the patent application will follow for a period of three months from the date of this publication.[9]

According to the chairman’s statement and Austrian amendment proposal, it is understood that priority system originally aimed to prevent collision between a right holder’s act in a first country and a patent in a second country.[10] In the nineteenth century, no countries had systems of substantive examination prior to grant, even for such basic matters as novelty, with the exception of the United States, where such a system had been instituted with the appointment of expert examiners in the Act of 1870, and Germany, where a similar situation applied after the passing of a new federal law in 1877.[11] The United Kingdom, while still not providing for substantive examination, instituted a system of third party oppositions that were heard prior to grant by the Law Officers. At this stage, since the patent was issued without undue delay after the filing in many countries, that is, the invention described in the first application was published in the Patent Gazette before the date of the patent application in the second country, patent publication in the first country might constitute prior art in the second country.

2. Change of the priority periods and the intermediate acts

The successive Acts of Paris Convention for the Protection of Industrial Property 1883, the Article 4, which was the former Article 3 of Jagerschmidt’s draft, was as follows:

A person who has duly filed an application for a patent, or for the registration of an industrial design, or of a trade mark, in one of the contracting States, shall enjoy, for the purpose of filing in the other States, and subject to the rights of third parties, a right of priority during the periods hereinafter started.
Consequently, the subsequent filing in any of the other States of the Union before the expiration of those periods shall not be invalidated through any acts accomplished in the interval, as for instance, by another filing, by the publication of the invention or its exploitation by others, by the putting on sale of copies of the design, or by use of the mark.
The above-mentioned periods of priority shall be six months for patents and three months for industrial designs and trademarks. They shall be increased by one month for overseas countries.

The problem concerning self-collision that J. BOZÉRIAN explained was solved by the introduction of the right of priority, whose duration was six months. After the Paris Convention entered into force on 7 July 1884, as of the Madrid Conference in 1890, applicants became tending to decide to await the grant of the patent before applying in foreign countries. However, a period of six months starting from the first filing was too short for an effective securing of the interests of inventors, especially those who filed their first application in countries in which the system of the previous examination of the invention prevailed. Various suggestions were made with the purpose of making the priority period longer. Thus, the delegation from the United States at the Madrid Conference in 1890 proposed that the period of the right of priority should begin from the date of the official publication of the invention, instead of the date of filing the first application. Actually Mr. Forbes, delegate from the United States, stated as follows:

The amendment that the United States proposes to bring in Article 4 of the Convention aims to make the latter actually beneficial to American inventors who want to protect their inventions in other Union states. It is well known that in its present form, the Convention is of no value to Americans, because of priority periods which start at the filing of the application in the country of origin, often expire (almost always in reality) prior to the issuance of the US patent. By the fact of the expiration of the priority periods, the inventor risks losing, while the patent application is still pending, the rights under the Convention; or, if he tries to take advantage of these rights by filing the application abroad during the said period, the risk is that the foreign patent is issued before the American patent. Then it is exposed to two dangers. The first is that the national patent term is limited by the foreign patent; the second, that his invention is published while it is still kept secret by the US Patent Office (my translation).[12]

The other delegations dissented from this US proposal. The Belgian proposal to the effect that the period be increased from six to twelve months, which was assented to by the United States, was eventually withdrawn at the Madrid Conference. In the Brussels Conference of Revision, in 1900, giving effect to the voeux adopted by the successive Congresses of AIPPI (Vienna, 1897; London, 1898; Zurich, 1899; Paris, 1900), the priority period was extended from six to twelve months.[13]

At the Brussels Conference of Revision, disclosure of the invention by the applicant himself was also discussed. The reasons were described by the International Bureau in the following terms:

Disclosure of the invention by the applicant himself. —It would also help to remove in the same paragraph the words "by a third party." In some trials, we tried to interpret these words in a sense that the publication or exploitation of an invention by the applicant for the patent application himself, would have the effect of invalidating the filing by this same applicant during the priority period. We find examples in United International Bureaux for the Protection of Industrial Property, years, 1801, p. 121, and 1802, p. 82. The courts have not accepted this view, but for now in order to prevent any trouble about it, it is better to clarify the text, by deleting the words above mentioned (my translation).[14]

Eventually the phrase “by the publication of the invention or its exploitation by others” was amended to the phrase “by publication or exploitation of the invention”.[15] In this regard, Dr. Ladas pointed out as follows:

Publication of Invention by the Inventor or Third Parties Is No Bar. … Moreover, the purpose of article 4 was in favor of giving to the applicant the opportunity to publish and work his invention, in order to facilitate his plans and find in other countries persons interested in it. At the Brussels Conference the words “par un tiers” were stricken.[16]

This amendment established the system where applicants will not put themselves in peril if it is they who publish or exploit the invention after priority date.

3. The origin of multiple priorities (Brevets additionnels)

The extension of the period of the right of priority to twelve months made possible the accession of Germany to the Paris Union. Soon after Germany acceded to the Paris Convention, with effect from 1 May 1903, it was faced with the practical question of whether a subsequent application in Germany could claim priority on the basis of more than one prior application in countries of the Union when grouped in a single subsequent application. In other words, the question was whether multiple priorities could be recognised. The question was settled by discussion at a plenary assembly of the Patent Office on 30 November 1904, the decision being in the affirmative.[17]

Seven years later, at the Washington Conference of Revision, in 1911, multiple priorities were first proposed in order to avoid improvements of the original invention having to be prosecuted in applications for patents of addition. The reasons were described by the International Bureau in the following terms:

NEW PARAGRAPH5 – additional patents
It often happens that, after filing a first patent application, an inventor improves his invention while the period of priority is still valid and requests for these improvements either ordinary patents or additional patents or certificates. The problem has arisen of whether the inventor who patents his invention in one or more countries of the Union can combine all of their elements in the same application or whether he must on the contrary apply for as many foreign patents as he has successively obtained for his invention in the country of original deposit. The latter, and more stringent, solution is scarcely in harmony with the spirit of the Convention, which aims to favour and promote the inventive spirit. If the multiplicity of the successive patents in the country of original deposit is a consequence of the fact that they had been requested following the successive improvements, this is not true of the applications in other countries once the invention has been fully adapted. It is only natural for all the elements to be grouped within the same application at that point, provided that the character of the invention has remained unchanged and that it has only been improved and not basically transformed or modified in its principles (my translation).[18]

Great Exhibition of 1851 in London
(Source: WIPO)

The proposal met with the approval all members of the competent Sub-committee except for Great Britain.[19] British representative objected that there would be practical difficulties owing to the different claims, and that it would be too complicated to establish whether the claims corresponded to the relevant prior applications. Although several delegates pointed out that certain countries such as Germany were already practicing the system without encountering any serious difficulties, the British opposition prevented the adoption of the proposed amendment to Article 4.

There are two surprising matters. One is that Germany had already adopted multiple priorities system before the Washington Conference. The other is that multiple priorities aiming combination of the original patent and additional patents. In those days, there were no uniform criteria of inventive step all over the world. Even if the original invention was publicly known, the additional invention would not have been rejected normally due to the lack of novelty of the additional invention. An inventive step provision started to be introduced worldwide between the London Conference of Revision and the Lisbon Conference of Revision. As of the Lisbon Conference in 1958, only the United States, the United Kingdom and Japan stipulated criteria of inventive step. Furthermore, systems that were common, at that time after introduction of criteria of inventive step, were such that, even if the original patent was publicly known, a patent of addition was not questioned regarding the inventive step from the relevant publicly known fact (provided that novelty is required).[20]

At the Hague Conference of Revision, in 1925, the question of multiple priorities was again discussed. There was a French proposal to allow claims to multiple priorities at least up to a total of four, subject to preservation of the unity of invention. It was further suggested that in the case of complex applications division should be allowed provided that the respective partial priorities were respected.[21] Actually the delegation from France stated as follows:

[L]a France propose deux alinéas nouveaux, sous les lettres e) et f), ainsi conçus:
e) Aucun pays de l'Union ne pourra refuser une demande de brevet par le motif qu'elle contient la revendication de priorités multiples, à moins que le nombre n'en dépasse quatre et à la condition toutefois qu'il y ait unité d'invention au sens de la loi du pays. Si l'examen révélait que la demande est complexe, le demandeur pourrait diviser la demande, en conservant comme date de chaque demande divisionnaire la date du dépôt initial et le bénéfice de la priorité.
f) La priorité ne peut être refusée par le motif que certains éléments de l'invention pour lesquels on réclame la priorité ne figurent pas parmi les revendications formulées dans la demande au pays d'origine, pourvu que ces éléments soient nettement précisés dans la description.

The majority of members countries on the competent sub-committee were in favour of allowing multiple priorities, but a smaller group, including Great Britain, rejected the idea.[22] It was finally agreed, however, that in the event of a claim for multiple priorities at least a division of the patent application must be allowed, without affecting the relevant right of priority.[23] Article 4F of the Hague Act reads as follows:

If an application for a patent contains a claim for multiple priorities or if examination reveals that an application relates to more than one invention, the competent authority must, at least, allow the applicant to divide his application in accordance with conditions determined by the domestic legislation, and preserve as the date of each divisional application the date of the initial application and the benefit of the right of priority, if any.

Although this solution overcame the worst inconveniences of the previous situation, it did not constitute a thoroughly satisfactory settlement. The question was therefore placed on the agenda of the London Conference of Revision, in 1934. The program drafted by the host country and the BIRPI noted that strict application of Article 4, according to which a second application could be based on only one of the applications filed in the first country, was an obstacle to inventors and required them unnecessarily to comply with additional formalities.[24] It was therefore proposed that multiple priorities should be allowed, and the competent sub-committee concurred in this view.[25] An appropriate provision was approved in the plenary, and was incorporated as section F of Article 4, the previous section F concerning the filing of complex applications becoming Article 4G. Article 4F of London Act reads as follows:

No country of the Union may refuse a patent application on the ground that it contains multiple priority claims, provided that there is unity of invention within the meaning of the law of the country.

With regard to the interpretation of the effect of the right of priority for improvements of the original invention under Article 4F, there are two possibilities. One is that the right of priority is given rise to with respect to each invention, and the other is that the right of priority is given rise to with respect to each element of an invention. The reason two possibilities occur is that Article 4F makes no mention of the subject-matter of the right of priority. However, this question can be solved by checking legislative example in the Netherlands. In 1956, the new paragraph Article 7(3) was inserted into the Patent Act in order to correspond to Article 4F and 4H of the Paris Convention introduced at the London Conference of Revision. The text is as follows:

Priority may not be refused on the grounds that in the invention more than one right of priority, as referred to in this article is invoked. The priority cannot be refused on the grounds that the invention or any part thereof for which the right of priority is invoked does not specifically require an exclusive right in the application in the country of origin, provided that the invention or that portion in the documents related to this application accurately disclosed such that the invention or part can be understood by an expert and can, on the basis thereof, be applied (my translation).

The comment of the Government on this amendment is as follows:

The purpose of the newly inserted provision is clarifying that the priority extends over every invention or any part of an invention (iedere uitvinding of ieder gedeelte), regardless of whether it is made in the claims of the previous application (my translation).[26]

Returning to the London Conference, it provides the key to solve what the subject-matter of the right of priority is. Namely, Explanatory Memorandum and Proposals concerning new Article 4H reads as follows:

4. IDENTITY OF APPLICATIONS…This is to give this notion of identity applications an essential flexibility that France had presented to the Hague Conference on the proposal to introduce in Article 4 of the Convention a letter f) new as follows: "The priority may not be refused on the ground that certain elements of the invention for which priority is claimed (La priorité ne peut être refusée par le motif que certains éléments de l'invention pour lesquels on réclame la priorité) do not appear among the claims made in the application to the country of origin, provided that these elements are clearly specified in the description" . (V. Acts Hague, p. 337.)[27]

It is understood that Article 4H is also on the premise of multiple/partial priority, and the subject-matter of the right of priority stipulated in the authentic text (French text) of the Convention is not always limited to the invention itself but also can be a part of the invention. In addition, scholars in modern society, there are also those who are showing a similar view. Dr. Francis Gurry, Director General of the World Intellectual Property Organization (WIPO) et al. describe as follows:

Since an invention builds on the prior art, it is possible that it combines features from several different applications that have been filed by the same applicant. Is it possible to claim multiple priorities based on previous applications, or to claim a partial priority for an element of an invention, based on a previous application, while claiming no priority for the rest of the application? …Multiple priorities enable an applicant to claim different prior applications (within the preceding twelve months) in the same application, but the applicant has the advantage of priority for each “invention” or element of an invention only from the date of the corresponding earlier application.[28]

4. The introduction of partial priority

At the Lisbon Conference of Revision, in 1958, Article 4F was again reworded. The initiative came from a suggestion made by the International Bureau that the recognition of partial priority should also be specifically covered. Proposal with Statement of Reason prepared by the International Bureau on the Request of the Government of Portugal states as follows:

Partial priority presupposes that a subsequent application filed in one of the countries of the Union claiming priority within the period of 12 months includes elements that are not stated in the previous application; in this case, priority based on the date of previous filing is available only for “elements of invention” firstly stated in the scope of claims or in the application documents as a whole and other elements belong to the subsequent application; consequently, it causes partial priority; in this manner, belonging of several differently-dated privileges to a single invention causes a special case of multiple priorities(AIPPI Yearbook, Prague Congress, 1938, page 125).
An explicit regulation of the partial priority is lacking in the text of London. This text makes possible, it is true, evading a special provision for partial priorities in the text of the Convention, but in a way inconvenient and expensive. The applicant may file the additional element of the invention in another Union country, meet the demands and claim multiple priorities under Article 4 letter F.
We consider that it would be advisable to supplement the text of the Convention and propose to insert a paragraph 2 to Article 4, letter F, which would read as follows:
2. A patent application cannot be rejected by a convention country on the ground that it claims one or more priorities, or it also contains one or more new elements, provided that there is unity of invention within the meaning the law of the country (my translation, emphasis added ).[29]

During the discussions in the second committee of the Conference, the word “new elements” was controversial. The delegation from the Netherlands stated as follows:

Moreover, it is not desirable to speak of new elements, because the word “new” in the field of patent law, the special meaning of "new compared to the state of the art”.[30]

The proposed text of Article 4F was amended in order to make it explicit that a subsequent application filed with respect to the elements that had not appeared in the earlier application. The Lisbon Conference unanimously agreed to the recognition of claims for partial priority. The new version of Article 4F lays down the clear obligation incumbent on member countries to recognise claims for both multiple and partial Union priority, provided that the general requirements of Article 4 are fulfilled[31] and that there is unity of invention.

It is understood that elements of the invention can be the subject-matter of the right of priority. Furthermore, there is another informative document in the Proposal with Statement of Reason. At the Conference, the International Bureau submitted a proposal for the introduction of a general grace period in Article 4J of the Paris Convention. The text of Article 4J is as follows:

1. The grant of a patent shall not be refused on the ground that the element of the invention which is the subject of the application has been disclosed by a person other than the inventor or his representative within 6 months preceding the application.
2. This provision shall apply where the disclosure is made by the inventor himself or his representative, subject to any restrictions which may be imposed by the domestic legislation of the country in which the patent application is made (my translation).[32]

The Proposal with Statement of Reason states that the reason behind the proposal was inventors often must disclose some elements with its invention before knowing the need to undertake other tasks.[33]

By checking both the provisions of Article 4F and J, it is understood that these proposals aimed that the respective elements, which are gradually being added to an invention, can be the subject-matter of the right of priority and non-prejudicial disclosure. This understanding corresponds to the Netherlands Patent Act which stipulates that portion can be the subject-matter of the right of priority. In this regard, Guide to the Application of the Paris Convention for the Protection of Industrial Property as Revised at Stockholm in 1967 instructs in same manner as follows:

It frequently happens that an invention is not immediately complete, so that, even after a patent application has been filed for it, improvements or additions are found which are made the subject of other patent applications. The Convention makes it possible to claim, in one and the same later application in other countries of the Union, separate (multiple) priorities for the different parts of the invention, based on the various first applications made in respect of each of those parts, provided, of course, that these various applications are filed within the term of priority counted from the first application. …

It frequently happens that, after a first application for a patent has been filed, subsequent applications in respect of the same invention for which the priority of the first application is claimed contain elements of the invention which were not present in the first application and which either no separate patent application has been filed in time to claim multiple priorities or no separate patent application will be filed at all (for example, because the added elements do not, in themselves, have an inventive character). Under the Convention, such additions in later applications will not prevent priority from being recognised for those other elements of the invention which were already present in the first application (emphasis added).

In addition, some scholars even in modern society have shown similar views. For an example, Dr. Sam Riketson, a Professor in the Law School, the Universities of Melbourne, describes partial priority as follows:

This refers to the situation where elements are included in the subsequent application that were not in the earlier application or applications for which priority is claimed. In other words, these are situations where the progress of research and development has occurred and new aspects or components have been identified after the making of the first application, but have not been included in any of these application(s). For obvious reasons, these elements cannot be the basis for claims of priority in subsequent applications filed under the Convention; on the other hand, they should be capable of giving rise to a right of priority in themselves with respect to later applications based on them.[34]

5. Practices concerning partial priority in some countries

In some countries, for example, France, the constitution or constitutional system permits administrative and judicial authorities to apply directly to private parties the provisions of an international treaty, if these provisions are worded in such a way as to make such direct application possible ("self-executing" provisions). In other countries, for example, the United Kingdom, the provisions of an international treaty can bind only the state and are never applicable to private parties without first having been embodied in domestic legislation. In these countries the provisions of the Convention cannot be “self-executing"; although they may, even without being binding, influence an administrative or judicial decision concerning domestic law, they can only become binding by application of Article 25 of the Convention, that is, when the country concerned introduces the rules of the Convention into its domestic law.[35] Then I look at practices concerning partial priority in some countries during the period from the ratification of the Lisbon Act until G2/98 Opinion.

In Germany, there used to be an idea that, regarding element “A” in a claim covering invention “A or B” or invention “A and B” in a subsequent application, partial benefits are enjoyed from the first priority date for “A,” and consequently, a reference that discloses element “A,” which has arisen during the priority period, does not become prior art of the entirety of the claimed invention “A or B” or “A and B”. The idea is the so-called “umbrella” theory. The actual case is Hakennagel.[36] BpatG stipulated as follows:

[A]ccording to Art. 4F Paris Convention concerning multiple priorities, additional features may be present provided that there is unity of invention. The smallest unit of invention is not necessarily the claim; it can also be features or groups of features – for example, “A and B” within “A and B and C.” Therefore, the utility model “A and B,” which was a prior publication in this case, was not considered prejudicial.

Conceptual Diagram of “umbrella”-theoryConceptual Diagram of “umbrella”-theory: A priority (which has the effect of preventing an application from being invalidated) shall not be refused on the ground that a patent application claiming one or more priorities contains element B, which was not included in the basic application.
(© Kazuo SHIBATA, 2011, All rights reserved.)

In the Netherlands, as already mentioned, the Patent Act stipulated that the priority extended over every invention or any part of an invention. It seems to be similar to “umbrella” theory.

In Japan also, “umbrella” theory used to be applied in examination practice because the Japanese Patent Law had not applied multiple claims until 1988. There is a case in which the court dealt with the issues. In the case of “a device for reading information with a read-out light beam”,[37] the interpretation of the subject matter of the right of priority was disputed. The plaintiff argued that “A right of priority under the Paris Convention is given rise to with respect to each invention, and is not supposed to be given rise to with respect to each element of an invention.” The court ruled that where elements are not combined but are aggregated, a right of priority under the Paris Convention is given rise to with respect to each element provided that there is unity of invention.

With regard to the United States, first of all, it is necessary to explain the first-to-invent system. In the United States, an inventor/applicant can overcome a prior art reference (excluding those published more than one year before the filing date of the US patent application) by proving that the date of the invention is prior to the effective date of said prior art reference. Necessary procedures thereof are stipulated as follows in United States of America Patent Regulations Title 37 - Code of Federal Regulations 1.131(b) (Rule 131(b)).

The showing of facts shall be such…as to establish reduction to practice prior to the effective date of the reference, or conception of the invention prior to the effective date of the reference coupled with due diligence from said date to a subsequent reduction to practice or to the filing of the application.

Rule 131 is designed to make the first-to-invent system function effectively. In 1957, the court in Stempel, Re[38] held that, in the case of proving actual reduction to practice by submitting an affidavit, a reference disclosing part of a comprehensively claimed invention (hereinafter called “partial reference”) is antedated if it is proven that said part has been actually reduced to practice prior to the reference. This holding had not been overruled until recently, and is also reflected in the Manual of Patent Examining Procedure (MPEP) (MPEP 715.02 II and MPEP 715.03 I. B.). It is similar to the idea of the effect of the right of priority under the “umbrella” theory, which enables a subsequent application to enjoy a partial benefit that countervails an intervening reference with respect to a subsequent application, based on priority documents. The principle of Stempel is based on the first-to-invent system, and it is not directly related to the interpretation of the effect of the right of priority under the Paris Convention. However, Ziegler, Re[39] in 1965, antedating the partial reference which intervenes between a priority application and the subsequent US application not based on actual reduction to practice but based on constructive reduction to practice was recognised. It was consistent with “umbrella” theory.

In the United Kingdom there was no “umbrella” theory that partial benefits are enjoyed from the first priority date for elements of claim. However, section 5(1) of the Patents Act, 1949 stipulated as follows:

Every claim of a complete specification shall have effect from the date prescribed by this section in relation to that claim (in this Act referred to as the priority date); and a patent shall not be invalidated by reason only of the publication or use of the invention so far as claimed in any claim of the complete specification, on or after the priority date of that claim, or by the grant of another patent upon a specification claiming the same invention in a claim of the same or later priority date.

The provision was succeeded to section 6 of the Patents Act 1977. The section 6 reads as follows:

(1) It is hereby declared for the avoidance of doubt that where an application (the application in suit) is made for a patent and a declaration is made in accordance with section 5(2) above in or in connection with that application specifying an earlier relevant application, the application in suit and any patent granted in pursuance of it shall not be invalidated by reason only of relevant intervening acts.
(2) In this section― "relevant application" has the same meaning as in section 5 above; and
"relevant intervening acts" means acts done in relation to matter disclosed in an earlier relevant application between the dates of the earlier relevant application and the application in suit, as for example, filing another application for the invention for which the earlier relevant application was made, making information available to the public about that invention or that matter or working that invention, but disregarding any application, or the disclosure to the public of matter contained in any application, which is itself to be disregarded for the purposes of section 5(3) above.

Under these circumstances, publication of an application, used as the basis for a priority claim was believed to be a non-prejudicial disclosure under Section 6(1) of the UK Patents Act 1977.[40] This means that where a first priority document discloses a feature A, and a second priority document discloses a feature B for use together with A, and the subsequent application whose claim 1 is A, and claim 2 is A+B, even if A is proved to belong the state of the art between the two priority dates, the subsequent application was not invalidated. However, if A +B is proved to belong the state of the art between the two priority dates, the subsequent application was invalidated. Under the “umbrella” theory, without claim A, claim A+B enjoys the partial benefit, but in the UK it must be claimed A in the subsequent application in order to enjoy the partial benefit. The author thinks that it seems to be connecting with the prior claim approach in the UK old practice.
The “prior claim” approach, which was superseded by the “whole contents” approach, addressed the double patenting issue by rejecting applications including a claim identical with one of unpublished application or patent granted filed before the applications. The “prior claim” approach does not seem to be related directly with claiming priority, but the court in Alfa-Laval Aktiebolag's Application Case, in which the recognition of the right of priority was disputed in relation to the requirements for the “first application”, stipulated as follows:

The question to be answered is whether that earlier Swedish application claimed protection for the invention of this sub-assembly when so incorporated; and for this purpose, having regard to its clarity and comprehensiveness, examination of the main claim of that earlier application affords a sufficient basis for deriving the answer… It is to the invention for which protection was applied for that one must look, and not to some different and other invention which can be spelled out of the document when the reader has been told where to look and how to emphasise (emphasis added).[41]

The “prior claim” approach is inconsistent with “umbrella” theory. Actually, the UK court did not rely on “umbrella” theory. However, there is one case in that the UK court judged fairly generous and applicant-friendly with regard to priority recognition. The court in Canon K.K.’s Application case stipulated as follows:

It would surely be "a development along the same line of thought which constitutes or underlies the invention described in the earlier document". It is not one that "brings something new into the combination which represents a departure from the idea of the invention described in the earlier document". In order to anticipate criticism, perhaps I should also add that I do not think that "a development or addition" within section 4(6) necessarily requires that the invention of the later claim should fall wholly within the scope of the earlier invention as described (emphasis added).[42]

The statement by the court reminds me of the proposal concerning ”NEW PARAGRAPH5 -additional patents“ by the International Bureau at the Washington Conference of Revision. The proposal described that an improvement invention claimed in a subsequent application could enjoy the benefit of plural priorities from multiple applications where the character of the improvement invention had remained unchanged from those of the multiple applications and its principle basically had not been transformed or modified from their principles. Furthermore it is said that the court interpreted the requirements for the “same invention” broadly. Such broad interpretation, however, could cause some tradeoffs for applicants. It is said that, for instance, broadening the interpretation would make the requirement of "the first application" with regard to claiming priority stricter. In this regard, the court in Kopat's Patent affirmed the Comptroller General’s discretion. The Comptroller General, in his decision, stated as following:

This transmission is not specifically described and illustrated in the patentees' specification and no specific protection is, therefore, sought for it in this country. Accordingly, if it could be argued that the invention as defined by claim 1 bears only a remote or chance relationship to this transmission, I should be prepared to decide this matter in favour of the patentees. But, this is not the case; the claim is in fact a very close description of the transmission, every one of the many features of the claim being readily identifiable in the transmission (emphasis added).[43]

The UK old interpretation of the requirements for the “same invention” does not seem consistent with “gold standard” under the EPC. “Gold standard” would have saved Kopat's Patent.
Finally, Board of Appeal in EPO has rarely addressed an issue similar to “umbrella” theory. However, in T301/87, the Enlarged Board consisting of 5 members indicated that, when there is a claim which can enjoy the benefit of priority in the subsequent European application, protection from invalidation by any interim disclosure of the content of the priority document extends not only to claims which are fully or clearly entitled to that priority but to all claims of the European application. The actual statement by the board is as follows:

When priority is claimed for a European patent application under Article 88 EPC, the publication (or any other disclosure within the meaning of Article 4B of the P.C.) of the content of the priority application, in the interval between the filing of that application and the filing of the (final) European patent application cannot be used as state of the art against any claim in the latter application. However, if such publication goes beyond the content of a previously filed application and includes subject-matters not covered by the disclosure of that application, such disclosure may in principle be cited against any claim in the (final) European patent application relying on a priority date subsequent to the publication date. It might be added that a different view on this matter would render the system of multiple priorities rather illusory (emphasis added).[44]

6. Establishment of European Patent Convention

Article 88(2) EPC, second sentence, provides that, where appropriate, "multiple priorities may be claimed for any one claim". During the discussion in preparation for the 1973 Munich Diplomatic Conference, four proposals[45] were made to specifically provide for multiple/partial priorities for any one claim. The prior three proposals were subsequently analyzed in a memorandum drawn up by FICPI. It is said that the FICPI Memorandum is the legislative intent of the EPC. It is also said that the proviso “Where appropriate” was included to clarify that “OR”-claims as described in the FICPI Memorandum can enjoy multiple/partial priorities, but that this does not apply to “AND”-claims as outlined the Memorandum. With regard to “AND”-claims the FICPI Memorandum reads as follows:

It is probably recognized by everybody that where a first priority document discloses a feature A, and a second priority document discloses a feature B for use together with A, then a claim directed to A+B cannot enjoy a partial priority from the first priority date, because the invention A+B was disclosed only at the date of the second priority document. In other words, if A+B is proved to belong to the state of the art between the two priority dates, the claim to A+B must be declared invalid. If A in itself is a patentable invention, and the application contains both a claim to A, and a claim to A+B, the first priority can be claimed for the claim to A, and the second priority for the claim to A+B, thus multiple priorities can be claimed for the application as a whole, but not for any individual claim of the application.

Actually “umbrella” theory seems to be disregarded. However the Memorandum never says that if A is proved to belong to the state of the art between the two priority dates, the claim to A+B must be declared invalid. Then it is possible the legislative intent was a similar idea of Section 6(1) of the UK Patents Act 1977. The interpretation of disregarding “umbrella” theory was made step by step, namely G3/93 Opinion and G2/98 Opinion. At the end of the G3/93 Opinion, the Enlarged Board of Appeal concluded that a decision of the same sort was also made in the United States, by referring to Gosteli.[46] Gosteli, Re in 1989, partial constructive reduction to practice based on a foreign priority application was not recognised in contrast to the above-mentioned Ziegler decision. The Court of Appeals for the Federal Circuit stated, as the reason therefore, that a priority application must support the entire claim of a subsequent US application prescribed in 35 U.S.C. Section 119. Gosteli case was concerning Markush type claim, namely “OR”-type claim. The United States does not allow multiple priorities for a single claim even if it is Markush type claim. Nevertheless Gosteli Case affected that EPO disregard “umbrella” theory.


The “fiction” theory, in which the subsequent application is deemed to have been filed at the filing date of the first application in terms of examining patentability such as novelty, has already become the de facto standard in EPO, USPTO, and JPO. The author does not intend to deny these situations. The priority system was originally designed for the purpose of avoiding self-collision rather than overcoming competitors, although the purpose has been abandoned. Grace Period system in Japan and the United States, in reality, has taken over the purpose, which is to avoid self-collision. Grace Period system under the EPC, however, is so restricted that it does not allow applicants to avoid self-collision practically. Therefore, the priority system under the EPC should be operated in order to avoid self-collisions.

Conceptual Diagram of fiction-theoryConceptual Diagram of “fiction”-theory: Regarding the determination of novelty, inventive step, etc., invention A, which is the same as an invention contained in a basic application, is considered to have been filed on the filing date of the basic application. However, invention “A and B,” which is a different invention, is considered to have been filed on its actual filing date.
(© Kazuo SHIBATA, 2011, All rights reserved.)

The examination that relies on "umbrella" theory may be complicated when the third party incidents occur during the priority interval. However, the author cannot overlook the intention of the delegates at Brussels Conference of Revision where the phrase "par un tiers (by a third party)" was deleted. The author wonders if the phrase "by publication or exploitation of the invention" can be interpreted as "by the publication of the invention or its exploitation by the inventor, or the applicant, himself." In this regard, two noteworthy cases, which partially applied umbrella theory to avoid self-collision, were issued even after G2/98 Opinion was rendered. One is T665/00, points 3.3 to 3.5.1of the reasons. The Comments by the President on referral G 1/15 summarise the case as follows:

In T 665/00 of 13.04.2005, the claim at issue was directed to subject-matter defined in terms of a range of numerical values (specific mass below 0.1 g/cm3). This had been restricted in respect of the invention disclosed in general terms in the priority document (specific mass below 0.5 g/cm3). However, the priority document also disclosed an example corresponding to a specific numerical value (0.04 g/cm3). The board took the view that the claim enjoyed partial priority for that embodiment.[47]

The object of the alleged state of art was public use by applicant himself. Namely the alleged state of art was regarding not Art 54(3) but Art 54(2).

The other is “Prioritätsdisclaimer” in Germany. In a patent invalidation case in which a claim of an improvement invention in a subsequent application should have been invalidated based on the fact of publication of the basic invention during the period of priority, in accordance with the standards for determination in G3/93 Opinion, the BpatG maintained the claim of improvement invention. The proposition in “Prioritätsdisclaimer” decision held by BpatG was that if the priority of a previous application cannot be acknowledged because the claim comprises features that cannot be derived from the original application, but the patent is not patentable without the earlier priority, then the patent can nevertheless be maintained if it is patentable without these features, provided a disclaimer is included into the patent stating that the additional features do not support the patentability in view of the earlier priority. Actually the BpatG held as follows:

Ist in einem Patent die Priorität einer früheren Anmeldung nicht wirksam in Anspruch genommen, weil der Patentanspruch ein Merkmal enthält, das über den Inhalt der Prioritätsanmeldung hinausgeht, und ist der Anspruchsgegenstand wegen seines späteren dem Anmeldetag beim DPMA entsprechenden Zeitrangs nicht patentfähig, kann dennoch das Patent beschränkt aufrechterhalten werden, wenn a) der Patentanspruch eine in der Prioritätsanmeldung offenbarte patentfähige Unterkombination enthält und b) in den Patentanspruch eine Erklärung des Inhalts aufgenommen wird, dass das in Rede stehende Anspruchsmerkmal über den Inhalt der Prioritätsanmeldung hinausgeht und die Patentfähigkeit bei Berücksichtigung des Zeitrangs der Prioritätsanmeldung nicht stützen kann.[48]

Stephen Pericles LadasStephen Pericles Ladas

Dr. Stephen P. Ladas made a tremendous achievement in the study of the Paris Convention and had written a wonderful book, Patents, trademarks, and related rights: national and international protection, published in 1930 and updated in 1975 as the compilation of his study.[49] In a review in the Cambridge Law Review in 1932, AD McNair admired Dr. Ladas’s work in these terms:

Students of international law and of comparative law, and specialist practioners, must join in expressing gratitude to Dr. Ladas for achieving a task which by reason of the detail involved and the inevitable size may at times have been tedious to the author, but which has resulted in a book whose usefulness and comprehensiveness will rank high.[50]

Until the 1990s, specialist practioners at the EPO had probably inherited the intention of Dr. Ladas. In decision T301/87 (αinterferons/ BIOGEN), the Board of Appeals showed an interpretation of Article 4 of the Paris Con vention and also mentioned the purpose thereof.

According to the provisions of Article 4B of the P.C. “any subsequent filing” during the priority year “shall not be invalidated” by, inter alia, the publication of the invention as covered by the first filing in the priority interval. This means, particularly, that such a publication will neither destroy the novelty of the invention, for which priority is claimed in the subsequent filing, nor diminish the inventive step embodied in it, as considered at the date of the first application on which the right to priority is based (cf. Bodenhausen’s Guide to the application of the Paris Convention, BIRPI 1968, pages 40-43). This is, of course, aimed at enabling and even encouraging the inventor to make his invention known at an early stage, which is fully consistent with one of the basic objects of the patent system, namely to promote a rapid spread of information and technology. It also gives him a fair chance to make economic use of the invention within a reasonable period of time (emphasis added).

However, the purpose of Article 4 promoting “a rapid spread of information and technology” has been disregarded later. It seems that even Dr. Ladas could not have foreseen the current chaotic situation caused by the partial priority, such as the improvement invention can be rejected due to the publication of the basic invention. His updated book, one of the best books in the study of the Paris Convention, has still few description of partial priority. It might show that how dramatically the interpretation of partial priority has changed. In addition to Dr. Ladas, no drafters of the Paris Convention could have even guessed such drastic changes of the partial priority.
Finally, I would like readers to think about a simple question that I have not reached an answer of yet. Does the following idea make sense? Provided that element “A” was claimed in a application, element “A or B” was claimed in a subsequent application filed within the application’s priority period and a reference disclosing element “A” had arisen between the filing date of the application and that of the subsequent application, the subsequent application enjoys partial benefits for “A” and the reference is eliminated from prior arts to the entirety of the claimed invention “A or B” in the subsequent application. And I would like to say “Priorité Partielle! Quo vadis?”

  1. The Leahy–Smith America Invents Act.
  2. Sam Ricketson, The Paris Convention for the Protection of Industrial Property A Commentary, Oxford University Press, (2015), p.30.
  3. Louise Purbrick, “Knowledge is Property: Looking at Exhibits and Patents in 1851”, Oxford Art Journal, No253 (1997) p.20.
  4. The Protection of Inventions Act 1851, sIII, sIV..
  5. The Protection of Inventions Act 1851, sVII.
  6. Der Erfinderschutz und die Reform der Patentgesetze: Amtlicher Bericht über den Internationalen Patent-Congress zur Erörterung der Frage des Patentschutzes Pieper, CarlIn Comm. der Schulbuchhandl (1873) s.259.
  7. Actes de la Conférence Internationale pour la Protection de la Propriété Industrielle réunie a Paris 1880 (1902) p.23.
  8. Actes de la Conférence Internationale pour la Protection de la Propriété Industrielle réunie a Paris 1880 (1902) p.40.
  9. Actes de la Conférence Internationale pour la Protection de la Propriété Industrielle réunie a Paris 1880 (1902) p.39.
  10. In Stephen P. Ladas, Patents, trademarks, and related rights: national and international protection, Harvard Univ. Press Ed. (1975), p.475, there is the following instruction: “the real object of the right of priority was to prevent the loss of the novelty of the invention, especially by publication following the application for a patent. Such publication was made soon after the filing of the application in other countries, and therefore it was proper and convenient to have the period of the right of priority start from such filing.”
  11. Ibid, Ricketson, p.17.
  12. Procès Verbaux de la Conférence de Madrid de 1890 (1892) p.93.
  13. Ibid, Ladas, pp. 476-477.
  14. Actes de la Conférence de Bruxelles Première et Deuxième Sessions 1897 et 1900 (1901) p.36.
  15. Both phrases in English were translated by BIRPI in 1960.
  16. Ibid, Ladas, p.496.
  17. Dr. Gerhard Schricker “Fragen der Unionsprioritäte im Patentrecht” GRUR Int, Heft 3 (1967) p.87.
  18. Actes de la Conférence de Washington de 1911(Berńe,1911) p.45.
  19. Actes de la Conférence de Washington de 1911(Berńe,1911) p.277.
  20. For example, in the United Kingdom that had the patent of addition system until legal revision in 1977, the Patents Act put into force in 1950 provided that in the case where the original invention is publicly known, an additional invention is not required to involve an inventive step against the original invention (Section 26(7) of the Patents Act 1949). In addition, in France where the patent of addition system was established in 1844 for the first time in the world, it was provided, even after “activité inventive”, which is equivalent to inventive step, came to be clearly stated in patent law through 1968 revision, that an additional invention is not required to involve activité inventive (inventive step) against the original invention. Furthermore this practice is still alive under the Indian Patent System. The practice ruled in the Patents Act Section 56 was affirmed by the Bombay High Court in 2008 (Ravi Kamal Bali v. Kala Tech). Moreover Australian Patents Act 1990 s25 stipulates validity for patents of addition in the same manner as Indian Patent Act.
  21. Actes de la Conférence de La Haye de 1925(1926) p.337.
  22. Actes de la Conférence de La Haye de 1925(1926) p.430.
  23. Actes de la Conférence de La Haye de 1925(1926) p.539.
  24. Actes de la Conférence réunie à Londres(1934)p.170
  25. Actes de la Conférence réunie à Londres(1934)p.367
  26. Memorie van Toelichting, No. 3, Zitting 1953-1954-3451”, p.2.
  27. Actes de la Conférence réunie à Londres(1934)p.171.
  28. Fredrick Abbott, Thomas Cottier and Francis Gurry, The International Intellectual Property System: Commentary and Materials, Kluwer Law International (1999) p.678, 685.
  29. Actes de la Conférence de Lisbonne(1958)pp.340-341.
  30. Actes de la Conférence de Lisbonne(1958)p.343.
  31. Actes de la Conférence de Lisbonne(1958)p.343: “dans le cas où une priorité aurait été invoquée par erreur, la réaction serait généralement de ne pas reconnaître le droit de priorité (ce qui, de ce fait même entraînerait comme conséquence que le contenu de la demande ne serait plus nouveau et que celle-ci serait refusée pour cette raison) ”.
  32. Actes de la Conférence de Lisbonne(1958)p.350.
  33. Actes de la Conférence de Lisbonne(1958)p.349.
  34. Ibid, Ricketson, p.374.
  35. G.H.C Bodenhausen, Guide to the Application of the Paris Convention for the Protection of Industrial Property as Revised at Stockholm in 1967 (1969)p.14.
  36. Hakennagel, BPatG 22.3.1995; GRUR 1995, 667.
  37. Heisei 1 (Gyo Ke) 115, (Judgment: 22.06.1993).
  38. Stempel, Re 241 F.2d 755, 113 USPQ 77 (CCPA 1957).
  39. Ziegler, Re 347 F.2d 642, 146 USPQ 76 (CCPA 1965).
  40. Ian Muir, Matthias Brandi-Dohrn, Stephan Gruber, European Patent Law: Law and Procedure Under the EPC and PCT, (Oxford University Press, 2002), pp27-28.
  41. Alfa-Laval Aktiebolag's Application R.P.C. (1968) 85 (8): 216.
  42. Canon K.K.’s Application R.P.C. (1980) 97 (4): 133.
  43. Kopat's Patent R.P.C. (1965) 82 (12): 404.
  44. α-interferons/BIOGEN, T301/87 ;OJ EPO 1990,335.
  45. UNICE (cf. M/19, point 8), CIFE (cf. M/22, point 4) , FEMIPI (cf. M/23, point 23) and FICPI (cf. M 48/I, Section C).
  46. Gosteli, Re 872 F.2d 1008, 10 USPQ2d 1614 (Fed. Cir. 1989). Concerning detailed analysis about the judgment, refer to Kazuo Shibata ”Some Problems with the Current Practices Concerning the Priority System“ (2010) E.I.P.R. Issue 10, pp.520-529.
  47. Comments by the President Referral G1/15 (“Partial Priority”), point 73.
  48. Prioritätsdisclaimer, BPatG 30.4.2003; GRUR 2003,953.
  49. Stephen P. Ladas, Patents, trademarks, and related rights: national and international protection, Harvard Univ. Press Ed. Cambridge, Mass, 2nd edn 1975 (1st edn 1930, under the title, The International Protection of Industrial Property).
  50. AD McNair, review of The International Protection of Industrial Property. By Stephen P. Ladas, Harvard University Press 1930, 972 pp. ($7.50) in (1932) Cambridge Law Journal 242.