FINDING AND UNDERSTANDING PATENT DOCUMENTATION

PATENT NUMBERING

A patent number comprises three elements – the country code, a running number, and the kind code.

The country code indicates the patent office that granted the patent, or is examining the application. Each office has its own code. In this case, it is the European Patent Office (EPO).

The list of current codes is given in WIPO document ST.3, ‘Recommended standard on two-letter codes for the representation of states, other entities and intergovernmental organizations’.Footnote ³ The list does not include obsolete codes such as SU, which was the code for the Soviet Union. (Yes, the Soviet Union did recognise patents!)

The number is simply a running number, and each patent is given the next number in the sequence. This number may match the number of the published application, for example for EP and GB patents, or it may differ, as in US and JP patents. For most offices, this number consists of seven digits but this is not universal, and certainly older patents will have fewer numbers. Most databases use seven digits and so additional leading zeroes will have to be included in order for the database to find the record.

The kind code is possibly the most important element, and also the one with most variations. It is important because it indicates the type (kind) of document you are looking at – is it a published application, a granted patent, or possibly some other document? Kind codes can be difficult for two main reasons: there are quite a lot of them; and they change over time. A kind code for a document published 20 years ago may indicate a different type of document with the same code published today, even by the same office. We therefore need to be careful when looking at kind codes.

The kind code itself usually has two elements – a letter and a number. The letter refers to the level of publication, and the number refers to the document history within that level. What does this mean?

If we recall the patent prosecution process (that is, the process for successfully registering the patent, and not to be confused with patent litigation), the first step before the patent office is to file an application. This is unpublished. After a period of time, the application is published – this is the first level of publication. If the application proceeds to grant, it will be published as the granted specification – this is the second level of publication. There may be occasions where a patent is republished after grant (such as where it has been amended). This is the third level of publication. (Note, however, that some offices reissue an amended patent as the same level of publication, notably the EPO.) There is a useful list of the various documents and their publications produced by WIPO, ‘Examples and kinds of patent documents listed according to code’.Footnote ⁴

For practical purposes, most current patent documents will use the letter A for published applications and B for patents. The major exception to this rule is that before 1999 US patents were granted without prior publication of the application. Any US As from before 2001 are patents, not publications.

Numbers are used for ease of understanding as it is possible for there to be multiple publications at the same level. For example, EP As may be A1, A2 or A3. A1 is the publication of the application with the search report; A2 the publication of the application without the search report; and A3 the subsequent publication of the search report.

Understandably, this leads to a proliferation of kind codes. WIPO has produced a standard for these codes (ST.16 ‘Identification of different kinds of patent documents’),Footnote ⁵ but this doesn't list all available codes. The EPO produces a regularly updated number format concordance for publication numbers (and another for priority and application numbers) which has a much more comprehensive listing.Footnote ⁶ Commercial patent information providers also tend to make lists of the kind codes used in their databases freely available on the internet (e.g. CAS),Footnote ⁷ and these tend to be easier to read. Note that there may be variations between providers, especially for older documents which were published before kind codes were established or standardised.

THE FRONT PAGE OF A PATENT DOCUMENT

Let us now look at the front page of our example (Figure 1). What does it tell us about the patent?

Figure 1 The front page

This front page provides a lot of information, but the manner in which it is presented can make it difficult to interpret. Helpfully, each facet is given a standardised code number (known as the INID code) which identifies the information presented. INID codes are published by WIPO in appendix 1 to ST.9 ‘Recommendation concerning bibliographic data on and relating to patents and SPCs’.Footnote ⁸ Because these codes are standardised, we know where to look for certain types of information, even in foreign-language documents. Even if we cannot read the document, we know where to find the publication date and the application number.

The number of the document is always given in the top-right corner, and has the INID code (11). If no kind code is included in this number, it will be found in the field with the code (13). The (12) field gives a plain-language name to the type of patent document.

Data relating to the application is found in the 20 range – so the date of application (also known as the date of filing) is given in field (22) and the number of the application in field (21).

Priority information is given in the 30 range. Priority is important in determining the novelty element for a patent. Priority documents establish the priority date, which is the earliest filing date of a patent application.

Publication information is found in the 40 range – the date of the application's publication is field (43) and the patent's publication date is field (45).

The title of the patent is field (54), and the 70 range contains details of the various parties connected to the application, such as the inventor (72), applicant (71) (not shown in this example), proprietor (73) and agent (74).

With these codes in mind, we can look through the page and find quite easily that this is a patent for a fan that is held by Dyson Technology Ltd. However, the inventor wasn't James Dyson, but a Peter Gammack. We can see that the address given for the inventor is also that of the proprietor and the representative, so we can assume that Gammack is (or was) an employee of Dyson Technology. The application was filed on 18 February 2010, and was granted on 8 June 2011. This is important, as it tells us that – assuming that the renewal fees are paid and there is no litigation that revokes it – the patent will be in force until 18 February 2030 (20 years from the date of filing). After this time, the patented technology is free for anyone in the world to use.

One feature of patents that may be apparent from this example is that it is very difficult, and in most cases practically impossible, to find a patent based on the title alone. Searching a patent database for ‘fan’ in the title field will retrieve a large number of results; in fact, 187,707 on Espacenet, the European Patent Office database of patents, while even the more specific search of ‘a fan’ retrieves 2928 results.

One other important feature that we can see is that the application was filed as an international application through the Patent Co-operation Treaty (PCT). The international application number is given in field (86), and the publication of the application in field (87). This can be important as a patent that starts as a PCT application will often have a WO publication as the published application. In our example, although we might expect the related published application to be EP2276933A1 (or perhaps A2), and we can see an entry for EP2276933A1 on Espacenet, the actual document that published the application is WO2010100454A1. Clicking on the EP A1 on Espacenet takes you to the WO with an additional page numbered EP2276933A0, which is a ‘dummy’ number.

We know from reading field (87) that the WO was published on 10 September 2010. However, the publication of the EP was on 26 January 2011 per field (43). The reason for this seeming discrepancy is that a PCT application consists of two phases: the international phase, and the national or regional phase. The publication of the WO takes place as part of the international phase. The applicant must decide with which countries they wish to proceed, and proceeding in the desired countries is known as entering the national phase. The EP publication date represents the notification in the EPO Bulletin of the PCT application having been accepted into the regional EP phase, and when it received its EP designation and number in addition to the WO. Essentially, the EP publication number acts as a reference to the WO publication number. There is one published document (i.e WO2010100454A1) but there are other publication numbers that refer to it in their respective national or regional contexts. This brings us to the concept of the patent family.

PATENT FAMILIES

All patents or applications relating to a common priority application are brought together in what is known as a patent family. Each member of the family is known as an equivalent. This is because each provides equivalent protection of the patented technology in the relevant territory. For example, the US equivalent of EP2276933B1 provides the protection of the fan in the US.

If we look at the family of our example provided by the EPO (Figure 2), we see that Dyson's fan has protection in a number of countries outside of Europe; namely Australia, Canada, China and Hong Kong, Russia, South Korea and the United States.

Figure 2 The patent family for EP2276933B1

Most of these are derived from the PCT application, but the CN, JP, and US are direct filings with the national offices. This isn't apparent from the family provided by the EPO as application dates are not included, so when dealing with PCTs it's important to check the information WIPO keeps.

Looking at the family provided by WIPO gives us a slightly different picture. This family lists an additional patent that isn't included in the other family, an Indian (IN) patent, IN4465/DELNP/2011. Searching for this patent by this number in Espacenet doesn't return any hits, and searching by title returns a different New Zealand patent, as shown in Figure 3. But why is this?

Figure 3 Searching Espacenet by title retrieves an additional New Zealand patent

Patent information is collected by various bodies, and collected and presented in different ways. Espacenet uses data provided to the EPO and to INPADOC. INPADOC is an office of the EPO – the International Patent Documentation Centre. It collects information on patents worldwide but is dependent upon receiving the information from national or regional offices. If they don't send information (now usually in the form of bulk data uploads), INPADOC won't have it. Often when national offices do provide information, they provide it at a later date.

On the other hand, WIPO receives information relating to PCT applications through separate channels. In our present example, it is likely that the Indian IPO has provided WIPO with information but not INPADOC. If we go to the Indian IPO's search (Figure 4), we can see that the PCT has become an Indian patent with number 313607. This number isn't provided by WIPO. We can see that it is therefore necessary to not rely upon just one source of information when investigating patent families.

Figure 4 The Indian patent entry on the Indian IPO website

There is a further complication when looking at this family. In addition to the EP, there are also entries with country codes matching member states of the EPC – these are AT, DK, PL, and PT. However, these are not national patents. If we look at the kind codes of these patents, we see that they are given as ‘T’, indicating that they are translations into the appropriate national language of the EP. Despite appearing to have a national number, they are not separate patents but the national part of the EP.

So we can now review what we have learnt about our example patent (Figures 5 to 7). In summary:

• • An application was filed in the UK (date, number)

• • A later application was filed under the Patent Cooperation Treaty (date, number). The first GB application was the priority application for this PCT application. This application was published later as WOxxxx

• • Later national applications were also filed with the national patent offices in China, Japan, and the US. GBxx was also the priority application

• • From this set of applications, a number of granted patents have resulted

Figure 5 The home page of the Espacenet database

Figure 6 The search results when searching for ‘EP2276933’ on Espacenet

Figure 7 Accessing the text of the original document from Espacenet

There are therefore a large number of documents that are related to each other and represent different stages of applications in different territories, but all of which are equivalent to one another.

OBTAINING PRIORITY DOCUMENTS

Priority documents can usually be obtained from the file of the related application. This is useful, as often priority applications are unpublished and so would otherwise be unobtainable (Figures 8 to 10).

Figure 8 How to access the register of the patent from Espacenet

Figure 9 Select ‘EP All Documents’ to see the full list of documents on the patent file

Figure 10 The patent file, with the priority documents highlighted

CHECKING STATUS OF APPLICATIONS AND PATENTS

Once a patent has been granted, it lasts for its term (currently usually 20 years from the date of application) provided that:

1. 1) The required maintenance, or renewal, fees are paid on time. (Most countries require renewal fees to be paid at regular intervals, normally increasing over time.) If the fees are not paid, the patent lapses. There is normally provision for a lapsed patent to be reinstated if the due fees and a penalty are paid within a short period of its lapse.

2. 2) It is not successfully challenged in an administrative action or in court. A patent which is successfully challenged is known as revoked (it is also possible for a patent to be amended after grant or to be revoked in part).

It is therefore important to check the status of a patent, similar to updating case law for any subsequent judicial treatment.

To check the status of a patent, you will need to consult the relevant national register. (An important point to remember when dealing with European patents is that although prosecution and grant takes place centrally before the EPO, matters subsequent to grant are the responsibility of national offices. It is possible, and quite common, for maintenance fees to be kept up to date in some countries but the patent allowed to lapse in others. There is also a central revocation procedure before the EPO that allows an EP to be revoked in toto.) Most national registers are available online, although they differ widely in their accessibility and ease of use.

If we take our example patent, the easiest place to start is with the EPO register. This allows us to check that there have been no oppositions (administrative actions before the EPO which allow third parties to oppose the grant of a patent and seek its revocation or amendment) or other central actions. The federated register link also helpfully guides us to the national registers. The EPO register does have a legal status section, but this is often unreliable for post-grant information.

Looking at the federated register, it shows us that the patent has been allowed to lapse in all the countries originally designated other than three: Germany (DE), France (FR), and the UK (GB). There are a number of states for which no data is available. In these cases, each register will need to be checked individually, although it is quite reasonable to assume that the patent has likely lapsed in those countries too. It isn't necessary to check the status in countries you are not concerned with.

It is good practice to always check the relevant national register as well. If we look at the GB register, we can see that it is marked as ‘granted’, and that the fees for the 14th year were paid in December 2022, with the next renewal fees due in February 2024. Fees are generally due on the anniversary of filing, so it looks as if the last fees were paid early. (Looking at the ‘forms filed’ tab, we can see that this is their usual practice for this patent.)

It should be noted that registers are a supplement to the official bulletins or journals/gazettes of national offices, which publish notifications relating to patents, such as the publication of an application or the grant of a patent. The official UKIPO journal is online at https://www.ipo.gov.uk/p-pj. The EPO bulletin is at https://www.epo.org/searching-for-patents/legal/bulletin/archive.html, with a detailed search engine at https://data.epo.org/expert-services/index.html. Most bulletins are published on a Wednesday.

WIPO produces a list of national offices, available at https://www.wipo.int/patentscope/en/national_databases.html

Unfortunately, checking the litigation status of a patent is less straightforward. Registers should indicate if a patent has been revoked by a national court, but there can be delays in updating. The author is aware of at least one instance where a patent had been revoked by a court but the register didn't reflect this until around four months later. Anyone relying upon the register would have been given the false impression that the patent was in force.

Access to a specialist commercial patent information service or dedicated IP litigation database will be helpful in assessing whether there is any litigation affecting a patent, but even these are not entirely comprehensive or reliable. Searching case law databases by the patent title or number should be done, but if searching by number be aware that the formatting may differ, so it is useful to search using the final three numbers of the patent and the country code using a ‘within’ connector.

Decisions of the UKIPO relating to patent administrative actions are collected in a series known as the ‘O’ series (O for office). These are accessible on the UKIPO website at https://www.ipo.gov.uk/p-challenge-decision-results.htm. Older decisions (those before 1998) are held at the British Library, and can be consulted at their St Pancras site or requested through the document supply service. Selected older decisions can also be found on the gov.uk site at https://www.gov.uk/government/collections/results-of-past-patent-decisions-issued-before-1998, but there is no search function.

Older first instance court decisions are collected at the British Library in the ‘C’ series.

The EPO Boards of Appeal hear appeals against oppositions or other decisions of the EPO. There are a number of boards, but for present purposes the most important are the Technical Board of Appeal and the Enlarged Board of Appeal, which acts as an appellate division. Decisions of the Technical Board of Appeal are prefixed ‘T’ and look similar in format to decisions of the EU's Court of First Instance. Enlarged Board of Appeal decisions are prefixed ‘G’. Decisions can be found at https://new.epo.org/en/results?sortField=&sortDirection=&q=&filters=%5B%5D&tab=boa, with recent decisions at https://new.epo.org/en/case-law-appeals/decisions/recent.

Decisions of the USPTO's Patent Trial and Appeals Board can be found at https://developer.uspto.gov/ptab-web/#/search/decisions.