Cheaper Patenting: Writing Your Patent Specification

Part of a series teaching you how to reduce patenting costs.

OK. You’ve done a search and nothing appears to anticipate your idea.  You’ve got the green light to proceed with a patent application. What do you do?

You now need to prepare a patent specification. This will be the document that is filed at a national patent office to begin the process of obtaining a patent. The process of writing a patent specification is referred to as “drafting”.

As your legal rights are defined by the contents of the patent specification, in particular a section at the end of the specification called the “claims”, it is vital that the specification is properly prepared. Having seen a number of inventor-written patent specifications, I strongly recommend involving a patent attorney, if only to make sure the claims are well-drafted. This is because you need to have spent thousands of hours writing, revising and amending claims as well as understanding the law in at least one jurisdiction to properly draft claims; it is unlikely that most inventors will be in this position. Many inventor-written patent specifications are rejected during examination, wasting hundreds or thousands of pounds in official fees.

So if you need to hire a patent attorney to write at least a portion of your patent specification, how can you minimise his/her costs?

What is a Patent Specification?

In brief, a legal document usually consisting of around 20-40 pages of written text and a number of drawings or figures. It will be written in a number of iterations with the inventor. It has some similarities with a high-level standards document.

The written text consists of the following sections:

  • “Field of Invention” – This is a short paragraph – three or four sentences – which sets out the field of technology of the described invention. It generally mirrors the wording of the beginning of the main claim. The aim of this section is to guide a person searching for related documents; it may mirror the hierarchies expressed in one or more patent classifications. For example, if your invention is a new form of turbine blade for a wind turbine, the “Field of Invention” may be something along the lines of: “The present invention relates to turbines. In particular, but not exclusively, the present invention relates to a turbine blade and a method of constructing such a blade. The present invention is particularly suited for employment in wind turbines“.
  • Background” – This provides the background to your invention. It is usually one or two pages. Like a good detective story, it should describe the problems faced by existing solutions without hinting at your own particular solution. It is worth keeping this reasonably broad and reasonably brief, what might seem to you, the inventor, to be an obvious problem might not be so obvious to a generic “skilled person” in your field of technology.
  • “Summary of Invention” – This section typically mirrors, or makes reference to, the claims of a patent specification. If the following detailed description does not explain the advantages of your invention, you may wish to add these here. You may also wish to briefly expand on important portions of the claim language. As the “Summary of Invention” may need to be updated as the language of the claims is changed during examination of the patent application, for European practice I typically recommend only referencing the independent claims (e.g. “An aspect of the present invention is set out in claim 1“) and describing any advantages and/or expanding on claim language in the detailed description.
  • Description of the Figures” – This section briefly describes the figures or drawings. A brief sentence is needed for each figure. For example, “Figure 5 is a circuit schematic showing an example of the present invention“.
  • “Detailed Description” – This is the meat of the patent specification. It describes, in detail, each implementation of your invention (referred to as “embodiments”). Typically, the description is based on the figures. The figures may show the structure of an implementation from one or more angles, a flow chart or schematic illustrating a method of manufacture and a flow chart or schematic illustrating a use of the invention. Hence, the description may describe a structure, a method of manufacture and a use of one or more implementations. The figures may illustrate a hierarchy of abstraction – a feature may be illustrated in one figure at a systems level (e.g. a functional box) and in another figure at a detailed level (e.g. a circuit or engineering diagram). Any variation you can think of should be described. The detailed description should present your idea as a non-obvious solution to any problems described in the “Background”. The detail description should describe the general idea as well as the detailed implementations. The detailed description needs to support any claims (enable a general practitioner to replicate or create any product or process defined in the claims).
  • “Claims” – These are a number of paragraphs that set the scope of legal protection, i.e. any monopoly granted by an eventual patent.  They are the most important part of any patent specification. They are numbered. Claim 1 is what is called an independent claim – it does not refer to (i.e. include) the features of any other claim. Claim 1 cannot be anticipated by, nor rendered obvious in light of, any document published before the patent application is filed. However, it should also be broad enough to cover any immaterial modifications (“work arounds”). More features will be typically added to claim 1 during examination of the patent application as published documents relating to your idea are found. Dependent claims refer to other claims and include all of their material, e.g. if claim 1 specified feature A and claim 2 referred to the invention of claim 1 with feature B, claim 2 requires features A and B.

If you bear these sections in mind when providing information about your idea this can save time in drafting and hence save costs.

How Can I Help?

In most cases, the more information an inventor or company provides about an idea the better. The following tips should help reduce drafting costs:

  • The inventor is primarily responsible for the text of the Background and the Detailed Description and the Figures. He/she should concentrate on providing this. A patent attorney can quickly write the Field of Invention, the Summary of the Invention and the Description of the Drawings once this has been supplied and the claims have been drafted.
  • Figures are hugely helpful when drafting. Hand-sketched or computer-generated documents are fine. Flow diagrams and system diagrams are perfect. Editable engineering or network diagrams in a CAD or Visio format are also great. Don’t worry about cleaning these up too much, they will usually need to be edited as part of the drafting process. For example, a large engineering diagram may be broken up into several smaller cutaways. It is also useful to supply any drawings early in the drafting process. A usual number is 5 to 10.
  • For the Claims the most useful input is a series of keywords that the inventor believes covers the invention. It is also useful to indicate any features that he/she believes are essential (i.e. without which the idea will not work or will not have its effect). For the dependent claims, the inventor could attempt to identify any non-essential variations, modifications or specific implementations that have independent (non-obvious) advantages. For example, if claim 1 specifies a “biasing mechanism” but in one implementation a compressible rubber bung is particularly useful as it is easier to mould into a particular configuration then claim 2 could specify this bung.
  • A complete list of acronyms used in any text is useful. Those in a specialised field may not be aware of other abbreviations but a quick look at any Wikipedia disambiguation page shows how ambiguous some acronyms can be. This is especially important in technical fields with their own jargon (e.g. oil speculation, telecommunications etc.).
  • It is helpful if the inventor provides at least three different implementations of his/her idea, even if only one of them may find its way into a product. This is because designs often change during the product lifecycle and a patent specification has to take this into account. The claims should thus cover any changes that can be made which do not affect the underlying technical idea. Three different implementations helps provide basis, i.e. legal support, for any generalisations to accommodate changes. For example, an electronic device may have a display. Over a product lifecycle that display may be implemented by a LED array, a CRT screen and then by an AMOLED panel. Hence, the claims need to specify a display rather than any of the particular implementations. In any description the inventor may say “At the moment we use a LED array but ant display could be used including a projected image or an LCD panel.
  • As well as a description of a structure, a description of use and manufacture is also important. It may not always be obvious to provide this, especially when the inventor may consider it easy to infer these details from the structure. A good idea is to imagine a patent attorney as a well-meaning yet simple teenager; if you have a good attorney they will not be insulted (remember a judge’s or jury’s science education may only be at a high-school or GCSE level). The patent attorney can chose the appropriate level at which to provide the technical detail in the specification.
  • Review any documents provided by a patent attorney in detail and answer any questions in full.
  • Provide any supporting documents that may be relevant to the background of your idea. For example, old manuals, text book entries or old scientific papers. A useful tip is to dig out a shortlist of between 10 to 20 documents then provide the most relevant and informative 5.
  • Make use of change tracking software, such as “Track Changes”, and make your attorney use it too. This saves a lot of time when performing iterations of the text. In-line comments are also handy.
  • If anything does not appear clear or the language seems strange point it out to the drafting attorney. It some cases it may be a quirk of “patentese”, the language of patent attorneys; in many cases, it will get the attorney thinking and improving the specification.


For a patent specification to have any chance of passing examination, and being held up as valid in court, it does need to be drafted by a patent attorney. However, there are many steps an inventor or company can take to minimise the drafting time and thus minimise the drafting costs.

Cheaper Patenting: Searching

Part of a series teaching you how to reduce patenting costs.

OK. You have your idea. You may be an individual inventor, an engineer building a product or an office manager faced with an invention disclosure. You know that initial charges for drafting and filing a patent cost from between 3.5k to 10k pounds (5k to 15k dollars). What do you do?

The answer is some background research in the form of searching. If you find a published document that describes your idea, you have saved yourself the drafting and filing costs. You may have also found a potential partner or competitor.

In an ideal world you would get a search department of a patent attorney firm to perform a search for you. A thorough search and analysis may cost around 1.5-2k pounds (2-3k dollars). However, we do not always live in an ideal world: you may then wish to perform your own search.

Doing Your Own Search: Where to Start?

The obvious answer is Google. Here are some tips:

  • Write down a number of keywords that describe your idea or invention. About 10 should do. Perform searches on pertinent combinations of three of these keywords. About 5 or 6 separate searches as a start.
  • Limit the time you follow links and examine search results. About 10 minutes or 15 minutes for each search should do.
  • Record, record, record. A simple way to do this is a table in a word processor or spreadsheet. Record the search string (e.g. the search keywords) together with the three most relevant results. You can copy and paste the resulting links directly into the table.
  • Iterate. Use the results of the first set of 5 or 6 searches to modify your sets of keywords and search strings. Is there another term that keeps appearing in your most relevant results? Add that to your search string. Can you think of more generic terms or synonyms for your 10 or so keywords? Try them instead. Think in functional terms. For example,  “message” instead of “IP packet”, “clothing” instead of “shirt”, “bias” instead of “spring”, “rotate” instead of “pivot” etc.. Add a divider to your results table (e.g. page break / line), perform and record another 5 or 6 searches with these new keywords.
  • Use image results (“Images” option in Google) as a quick way to find relevant results. If you idea is related to a physical structure you can quickly scan the images displayed for that structure. Copy and paste relevant images, as well as the associated link, into your results table.
Doing Your Own Search: Next Steps, Patent Publications!

Has your Google research returned anything that appears to cover your idea? (“Knock out your idea” in patent slang.)

  • If the answer is a resounding “yes” then it is going to be extremely difficult to obtain a patent. But hey, you’re not going to throw away thousands of pounds or dollars on a new patent application.
    • You may wish to think about modifications that are not covered by the search results.
    • If you are looking to proceed with commercialising an idea, you may wish to check that the search results are not associated with patented technologies. For example, check the website in the search result for the word “patent” (Ctrl-F) or make a note of the company name for the searching described below.
    • Print to PDF the webpage/image/text that appears to describe your idea. Save this somewhere safe. If other try to patent the same idea you may be able to use this result to invalidate their patent and avoid paying royalties.
  • If the answer is “no” then things may be promising. It is time to search another database! Patents this time. The best place for this is a website called “EspaceNet” provided by the European Patent Office.
    • There are three search fields in the “Advanced Search” that are useful: “Keyword(s) in title or abstract”; “Applicant(s)”; and “Inventor(s)”.
    • Use your most relevant search strings from your Google searching in the “Keyword(s) in title or abstract” search box. Record your results – I prefer to save the results page as a PDF.
    • If more than 100 results are returned try to narrow down your search. You can either add more search terms or look to see which classifications are applied to the most relevant results. The classifications are a code such as “H03M1/12”. You may find your relevant results all contain “H03” – hence, when repeating your search type “H03” in the “International Patent Classification” search box.
    • You can also look to see whether any inventors or companies keep appearing in the results. These may be your competitors. Try searching for patent publications from these inventors or companies (the company name goes in the “Applicant(s)” search box). Beware the applicant will be a legal entity – this may differ from the trading name; for example, if your idea relates to washing detergent a relevant applicant name may be “Unilever” as opposed to “Persil” or “Surf” (which are brand names). Also search using inventors’ surnames, as first names are often omitted, or given in the form of initials only.
    • For each relevant result (click on the hyperlink provided in the result list), work forward through citing documents (“View list of citing documents” hyperlink below “Priority Number(s)”) and backwards through cited documents (For EP publications these are listed in the “Cited Document(s)” row).
    • Set yourself 30 minutes of iterating to try to find 3 to 5 relevant patent publication results. Make a note of the numbers and download the PDF publications (click on Original Document after clicking on the hyperlinked search result).
    • Espacenet covers many countries worldwide, including US patent publications, those relating to most European countries as well as those published by the European Patent Office, and a number of Asian countries including Japan, South Korea and China.
Doing Your Own Search: Results

By now you should have documented any Google and patent publication results. Take about 30 minutes to talk through the results – preferably a conversation with the idea originator and someone of managerial level (e.g. someone responsible for funding a patent application).

If nothing has come up, the idea likely has scope to be patented. You may provide your results to a patent attorney or professional searcher to proceed with an application. The results will help focus the drafting process, possibly saving you money by reducing the time needed. If the results are good, you may save yourself a thousand pounds or so of searching costs.

If something has come up, do not despair! It may help to focus your inventive efforts by stimulating modifications and improvements which may be new and inventive. You have also performed an initial IP audit: the results may be used to influence freedom to operate searches. For example, if your idea forms part of a product, it may be that the idea has already been patented and one or more patents are in force and cover your product. You can then look to obtain a license to avoid the prospect of litigation or redesign your product to avoid infringement.


Performing your own search is relatively easy. It may take an hour or two of someone’s time, but apart from that it is free. It provides an initial filter on ideas, making sure you only spend money on what is more likely to be valuable.