How to read a patent

Patent documents are typically dense with technical information and often include long sections of strange wording far removed from everyday English. Finding what you need is much easier once you learn your way around a typical patent document and understand the logic behind the strange wording.

Anatomy of a patent document

The text and drawings of a patent (or patent application) are known as the patent specification. Usually, the text is divided into sections with headings such as Abstract, Field of the Invention, Background to the Invention, Summary of the Invention, Brief Description of the Drawings, and Detailed Description of the Embodiments.


The abstract is usually a single paragraph that should give a general indication of what the patent is about. Sometimes the abstract includes wording closely tied to the strange wording of the claims. If the abstract is hard work, it’s often best to skip over it.

Field of the Invention

This is usually a short sentence or two indicating the type of technology that the invention is relevant to. Historically, Patent Offices have relied on this section to allocate patent applications to patent examiners with the relevant technical background.

Background to the Invention

Most patent documents include some sort of summary of similar technologies that were publicly known before the initial patent application was filed. Usually, the Background is one of the easier sections to read and provides a context that helps to make sense of the rest of the document.

Summary of the Invention

Sometimes the Summary will start with a paragraph or two that provides great insight. Otherwise, the Summary can be especially hard work and is often best skipped over on the first read of the patent document.

Often the Summary is almost a cut-and-paste of the strange wording of the claims (below) to help ensure that the invention specified in the claims is consistent with what’s described outside of the claims.

Brief Description of the Drawings

This section usually includes a separate one-line description for each of the drawings, e.g. ‘Figure 1 is a perspective view of a mounting assembly’.

It’s often best to skip over this section on the first read of the document, but the Brief Description can be very useful when assessing how certain terms are used in the patent document as ‘ah, so the thing in Figure 1 is what they mean by mounting assembly’.

Detailed Description of the Embodiments

This section is usually an easier read than the Summary and serves to describe embodiments (examples) of the invention. Typically, different features will have reference numerals showing where those features can be found in the drawings.


The claims are critical because they define the coverage of the patent or patent application. Professional advice is strongly recommended when assessing patent coverage.

Often there will be a mix of:

  • independent claims that define the outer bounds of coverage, and
  • dependent claims that refer back to the independent claims.

Generally speaking, to infringe a patent, each and every feature of an independent claim must be taken, although:

  • there are some exceptions,
  • claims can be amended,
  • it’s always prudent to check for closely related patents, and
  • claim interpretation is not always straightforward.

To be valid, the claims must meet a range of legal requirements. Meeting these requirements whilst providing commercially effective patent coverage leads to strange wording far removed from everyday English. By way of example, whereas in everyday English you might say ‘two parts bolted together’, a patent claim might say ‘two portions fixed relative to each other’ to cover off (e.g.) the parts being riveted or welded, or simply formed as two portions of a single piece of metal.

Usually, the claims are not limited to the examples described in the text and/or shown in the drawings – continuing the example above, a claim that mentions a ‘mounting assembly’ likely covers products that have mounting assemblies that do not necessarily resemble what’s shown in Figure 1.

How to read a patent

Step 1 – Very briefly skim the document to get a general sense of what it’s about

The drawings and Background, and sometimes the first paragraph or two of the Summary are often good starting points.

Step 2 – Decide why you are reading the patent

Do you need to know what’s covered? Or, are you interested in learning about the technology that’s described in the patent document?

Step 3 – Assessing coverage – Read the independent claims

If you need to know what’s covered, locate the independent claim(s), that is the claims that don’t refer to any other claims.

As above:

  • generally speaking, to infringe a patent, each and every feature of an independent claim must be taken, although
  • professional advice is strongly recommended when assessing patent coverage.

Step 4 – Understanding the technology – Read the Detailed Description of the Embodiments

Reading the Detailed Description and following the reference numerals to the drawings is usually the best way to understand the technology described in the patent document. It’s often useful to start with the Detailed Description before going back to the Summary and the claims.

Authored by

Ben Mott

Mechanical Engineer & Patent Attorney