How to Read a Patent

As a patent attorney reading patents on a daily basis for over 20 years, I can read a patent document as easily as reading the news. However, many founders do not like to wade through a patent even though it is needed to have a solid legal foundation. Before you start looking at the patent, it’s essential to know what to look for.  This a quick guide on how to read a patent. While the printed patent can look complex, it is quite easy to read if you know what to focus on and what to skim. 

Spoiler alert: if you needed to get the key points of a patent, jump ahead and peruse the drawings and read the claims and map the claims to the description text. That is my approach to quickly understanding what a patent covers.

Parts of a Patent

Patents can be among the most difficult documents to write and read.  The US Supreme Court noted in 1892:

With the above in mind, let’s dive in and understand what a patent is about.

Front Page

For those who have never seen a patent, let’s go through the document to give you a view of the landscape. First let’s look at the front page of the patent with the following structure:

            First named inventor

            Patent Number which is its identification number

            Date of Patent indicating when it issued

            Title: Name of the Patent

            Inventor Name(s): List of Inventors

            Assignee: The Owner via Assignment

            Applicable Notice(s): Typically lists term or life time adjustment

            Application No.: The Serial No. Assigned when case is filed

            Filed: The date on which the patent application is filed

            Prior Publication Number: Date of Publication of the Application (typically 18 months from filing your patent)

            Related Applications: Citation to parent or sister applications

            Search Field used by Examiners to locate prior art

            Cited References: Relevant prior art located by Examiner

            Primary Examiner: Examiner who granted the patent

            Attorney, Agent or Firm: Entity who responded to the Examiner or worked on case

            Abstract: Brief summary of the invention

            Representative Drawing: Drawing that illustrates the invention

Now let’s see how this structure appears in the above example patent: US 6,881,119.  A numbered list corresponding to the structure name is as follows:

            (12) First named inventor

            (10) Patent Number which is its identification number

            (45) Date of Patent indicating when it issued

            (54) Title: Name of the Patent

            (75) Inventor Name(s): List of Inventors

            (73) Assignee: The Owner via Assignment

            (*) Applicable Notice(s): Typically lists term or life time adjustment

            Application No.: The Serial No. Assigned when case is filed

            (21) Filed: The date application is filed

            (65) Prior Publication Number: Date of Publication of the Application (typically 18 months from filing)

            (63) Related Applications: Citation to parent or sister applications

            (51, 52, 58) Search Field used by Examiners to locate prior art

            (56) Cited References: Relevant prior art located by Examiner

            Primary Examiner: Examiner who granted the patent

            (74) Attorney, Agent or Firm: Entity who responded to the Examiner or worked on case

            (57) Abstract: Brief summary of the invention

            Representative Drawing: Drawing at bottom of front page illustrating the invention.

Drawing Pages

The drawings explain how the invention works, and typically has numbered elements in each figure:

Description Text Pages

The pages after the drawings have the following sections:

• Title of the invention.
• Related Application.
• Field of the invention.
• Description of Related Art / Background.
• Summary of the invention.
• Brief Description of the Drawings.
• Detailed description of the invention.

Detailed Description

The purpose of the detailed description is to describe the construction/working of the invention in enough detail that a skilled person can perform the method or produce the product described in the patent. Depending on the invention, this section may contain information about the best way to use and/or manufacture the invention. It may also include information about the materials that the invention can be made, as well as the relative amounts of various components. This section could also include definitions of predefined terms used elsewhere in the text to aid interpretation of the terms.

The detailed description explains your invention in great detail and should link to any drawings or figures. Every reference number in a drawing or figure must be explained, and the detailed description will usually also describe any methods or processes for making or using the invention. The detailed description may contain one or more examples that demonstrate the invention’s use. Generally, we prefer meaty, long description describing the parts, the reasons for the path taken, and detailed operations of the machine or software in-depth. Some inventors worry that their description is too specific and limit their patent rights. In reality, the patent descriptions are detailed, the claims control the scope of the patent and thus the claims need to support any features disclosed in the description.

The detailed description will contain a list of patent drawing elements or part list, and it will often discuss the relationship between the parts. The patent figures should accompany the printed detailed description. Comparing the two can help you understand the invention. Occasionally, people say they’ve read a patent description but only reviewed the drawings. It’s better to study both, so you can fully understand them.

Claims

Patents are centered around the claims. They define the legal scope or boundaries of what the patent covers. The patentee is entitled to prohibit others from using, making, or selling only the things described in the claims. Understanding and reading the claims in a patent can help you determine if a product or process is infringing the patent.

Claims can be independent (stand alone such as claim 1) or dependent (depends from a parent claim (such as claim 2 in the example). There are two main types of claims: independent and dependent claims. The independent claim is essential since it is the umbrella for dependent claims. The independent claim should be broad enough to cover a design-around yet narrow enough not to read on prior art. The dependent claim is another type of claim that should be read closely. It’s essential to understand how these claims work together to determine whether a patent has enough protection to be granted.

Claims are numbered sequentially and are often comprised of several sections. The first claim is usually the broadest and begins with a capital letter and ends with a period. Claims are generally numbered from one to twenty, but some patents may have hundreds of claims.

It isn’t easy to read claims, as they are written in a legalistic and formal way. They must be correctly interpreted and explained (or supported) in the patent specification and drawings.

The terms in the claims could be restricted by what the patentee told the US Patent and Trademark Office during the application’s pending (the prosecution record).

Under the “Doctrine Of Equivalents”, some terms in claims may be expanded to cover the element or its equivalent.  For example, if the claim recited “glue” that term could be expanded to include other attachment methods known to skilled artisans such as screws or nails to attach the parts, for example.

One proxy for claim language centrality is the number of times the word appears in the specification. The specification is a detailed narrative description of the invention, including preferred embodiments and background information about the field of invention. The claims form the boundary of the patent. All words in the claim must be explained in the specification. Consequently, if a claim includes text that is not elaborated in the description, it may not be “supported” by the description and defense lawyers may argue that the claim is invalid due to vagueness under Section 112.

The patent claims are critical for identifying infringement. Without a proper understanding of the claims, you will have no idea whether your product might infringe on another person’s patent. Hence, you need to seek professional help to read patent claims. Besides, the knowledge you gain from these documents will help you develop better products and save you money. In addition, you’ll be able to protect your business from unwanted expenses if you take proactive steps to avoid infringement.

With that in mind, let’s read first two claims in the ‘119 patent:

1. A stuffed toy, comprising:

• A flexible, soft outer covering defining at least a primary internal compartment, wherein the outer covering defines a central body region containing at least a substantial portion of the primary internal compartment, and further wherein the outer covering further defines at least one component that extends from the central body region and is selected from the group consisting of at least one of a head, an arm, a leg, a fin, a tail, a mouth, an ear, and a nose; and
• A resilient deformable bladder enclosed within the outer covering and at least substantially positioned within the primary internal compartment, wherein the bladder includes an outer shell and is filled with a fluid substance, wherein the bladder is selectively deformable between a non-actuated state and an actuated state upon application of external user-applied pressure to the body region, wherein in the non-actuated state the bladder occupies a region of the primary internal compartment and retains its shape when the external user-applied pressure is not imparted to the bladder, wherein in the actuated state the bladder extends at least proximate to at least one of the components to urge a predetermined movement of the at least one of the components from a first position that corresponds to the non-actuated state of the bladder and a second position that corresponds to the actuated state of the bladder, wherein the bladder is biased to resiliently return to the non-actuated state upon removal of the external user-applied pressure.

2. The toy of claim 1, wherein the bladder is at least substantially filled with a fluid substance other than a gas.

As you can see, the claims are hard to read, and the best way to read the claim is to see how the claim elements are shown in the drawings and in the description text.  This match up process is laborious, and to help inventors ascertain the scope of the claims, we have provided a free tool to do this automatically.

The software automatically identifies key terms in the claims and show where they are mentioned in the description.  The software also automatically generates a parts list for the patent.  Further, for key elements that are described but not claimed, the software highlights these elements so you know what you have not claimed:

If you want to try the tool, pls click here!