DIY Patent Search
Basics of a patent search
A patent search is a review of the prior art (i.e., exiting technology) to determine the likelihood
that the United States Patent and Trademark Office would grant a patent on your invention.
Benefits
There are numerous benefits to a patent search. Inventors and business may rely on the
opinion to decide whether to invest additional time and money to develop the idea. Molds,
preparation of marketing materials and pitching the idea to investors all take time and money
that could be avoided if the patent search uncovers prior art identical to your idea. Hence, your
idea would be unpatentable.
The search results may also used in drafting the patent application. The patent application may
focus on those areas not found by the patent search in hopes of increasing the chances of
obtaining patent protection. Moreover, the prior art references uncovered by the patent
search may be used to describe the background section of the patent application.
The claims of the uncovered prior art patent documents may be reviewed to determine
whether there are any infringement problems, at least with those references found by the
patent search. This should not be confused with a clearance search which covers a broader
range of patents and is significantly more expensive. The idea in reviewing the claims of the
prior art patent documents is that since these documents may have disclosed one or more
features of the invention, these patent documents could have also patented or claimed these
features.
Patentability Opinion
A formal patentability opinion produced by a patent attorney is a two step process. The first
step is the search itself. This is what is covered in the links below for a DIY Patent Search. In
this step, a searcher or you if you are doing-it-yourself (DIY) is attempting to find prior art
references related to your invention. Oftentimes, patent attorneys will utilize the services of an
outside search firm to reduce costs. Search firms do not render legal opinions as to
patentability. They just produce the raw data or search results (i.e., a list of patent references).
The second step is the review and opinion step. This is the value added by the patent attorney.
Based on the patent attorney’s experience, an opinion is formed after a review of the prior art
references uncovered as to patentability. In close cases, the patent attorney will inform the
client whether the invention is a thin invention - invention without much merit / uniqueness or
something with a good chance of success.
Prior Art Databases
The databases searched are the issued patents database and the published patent applications
at the United States Patent and Trademark Office. Other foreign databases and trade
magazines may also be searched. For cutting edge technology or inventions which do not have
a large data set at the Patent Office, the search may be expanded to include other sources such
as trade journals, libraries, and the patent databases of other countries.
No Guarantee
The opinion of the patent search is not a guarantee but merely an opinion of counsel as to the
likelihood of whether the United States Patent and Trademark Office will grant a patent on the
invention. As such, it is important to retain an attorney that you trust.
Overview: How to conduct a DIY patent search
The Unites States Patent and Trademark Office publishes their own guide to conducting a
patent search on the USPTO’s website. I’ve broken down the steps suggested by the USPTO
into three different stages to make things easier to remember.
Step 1: Brainstorming Keywords
The first stage of the patent search is the keyword discovery stage. In this stage, brainstorm
various keywords that might be contained in prior art documents that disclose your invention.
When brainstorming keywords, include industry specific terms as well as generic terms. The
search function at the Patent Office website cannot distinguish between the two. Moreover,
the search function does not include synonyms. Try to be inclusive in this stage.
You may have found, if you have already attempted a patent search, that the search result
contains numerous irrelevant references. The reason is that certain words might have different
meanings in different industries. The search function does not place words into context. It is a
pure text string search.
Step 2: Class and subclass look up
The second stage attempts to limit extraneous or irrelevant search results by searching within
one or more classes or subclasses. The USPTO classifies each patent document within one or
more of 450 different classes. Within each class, there are multiple subclasses - literally
hundreds or thousands of subclasses per class. As a result, the subclasses are detailed
subdivisions and categorize different aspects of the class at the granular level.
If a search is made within the right class and subclass, then irrelevant references are less likely
to show up in the search results. The downside is that the all of the right classes and subclasses
must be searched. To ensure that all of the right classes and subclasses are found, the search
process must be treated as an iterative process. After relevant references are found, the
classes and subclasses of those references are checked to determine whether all relevant
references have been found.
Step 3: Search patent and published application databases
The USPTO maintains two different online databases, namely, a database of issued patents and
a database of published patent applications. Both databases must be searched because
although there is an overlap, they both have their own unique set of references. Not all patent
applications mature into a patent. Hence, published patent applications that have not matured
into a patent will not be found in the issued patents database. Also, not all issued patents were
published as a patent application. The inventors could have submitted a request for non
publication. These patents will not be found in the published patent applications database.
Another way to streamline this step is to conduct the search on a third party site such
as www.freepatentsonline.com. Utilize the advanced search and be sure to check the boxes for
patents and patent applications. This should reduce your work in half.
While a review of the references found through the search process is made, you will find
additional keywords and other potential class/subclass for further search and consideration.
The above process is repeated for those additional keywords and classes and subclasses.
Brain Storming Keywords for the DIY Patent Search
In this stage of the patent search, brainstorm as many keywords related to your invention. The
brainstorming session should be inclusive. There will be additional time later during the search
process to eliminate keywords that are not particularly useful.
Heteronyms
Heteronyms are words that have the same spelling but different meanings. The patent search
is a keyword based search. The search function at the USPTO website does not take the
context or meaning of the word into consideration in determining whether to include a
reference in the search results. If the reference contains the keyword string inputted into the
search box, any reference that contains that keyword is included in the search results.
The issue with a simple keyword search is that the one word may be used in different technical
fields. References in other technical fields will be included in your search results. The searcher
or you will have to wade through the search results to manually eliminate the irrelevant
references. This is a waste of time. There is a better way which is to search within a class and
subclass <insert link>. For now, during the brainstorming session, keywords are not eliminated
but included in the list of keywords.
Example
The word clip has different meanings.
A paper clip is used to hold a stack of sheets together.
A video clip is a short video segment.
Another way to grasp the heteronym concept is to see the same words used in a sentence in
two different ways.
Excuse: Please excuse me while I think of an excuse.
Minute: The button was so minute that it took me a minute before I found it.
Industry jargon
The keyword list should include industry specific terminology. These terms are particularly
useful because their use may be limited specifically to a particular industry. If so, the search
results will be more focused on the invention. Irrelevant references within non-related
technical fields will be filtered out of the search results.
Legalese
The patent search searches for patent documents (i.e., issued patents and published patent
applications). Many of the documents are written by patent attorneys meaning that the
documents are full of legalese. To broaden applicability of the patent application, attorneys
may use generic terms instead of industry jargon to describe the invention. Accordingly, the
keyword list should include terms that a patent attorney might use to search for the invention.
For example, a paper clip may be described as a metallic fastener. The point is that the
keyword list should be inclusive and not limited to a particular subset of terms. As you review
prior art references, you will think of additional terms. Add them to your list.
Synonyms
Include synonyms in the keyword list. For example, synonyms for clip may include clasp, staple
and binder. The patent documents in the databases being search might exclusively use only one
of the words but not the other. Hence, synonyms should be included in the keyword list.
As you review the patent documents in the search results, you will begin to understand which
terms are important or not so important. The keyword list can be filtered during that time. For
now, be inclusive in your keyword list.
Finding the right class and subclass for the DIY patent search
The United States Patent and Trademark Office classifies all inventions into one or more of
about 450 different classes. Each class is further divided into numerous subclasses. There may
be up to a 1000 subclasses per class. The classes describe a generic category. The subclasses
describe specific features of each of the categories.
Benefit of searching within a class and subclass
By searching within one or more class and subclass combination, the patent search process is
more efficient. If you perform a keyword based search without specifying the class and
subclass, the search results will include references that are in other unrelated technical fields
which must be manually eliminated. By searching within a particular class and subclass,
irrelevant references are less likely to be included in the search results. No time is wasted
manually eliminating these irrelevant references.
Danger of searching within a class and subclass
If all of the relevant classes and subclasses are not searched, then the most relevant reference
may be missed even if you have the right keywords. Accordingly, it is important to determine
all of the relevant classes and subclasses. The search for all relevant classes and subclasses is
an ongoing and iterative process. Just like keywords, as you review patents and published
patent applications, review the list of classes and subclasses of the relevant documents to check
whether you can identify more relevant classes and subclasses.
Finding relevant classes and subclasses
To find relevant classes and subclasses go to the Patent Classification Main Menu.
Go to Option B. Search USPTO. (see below). Look up your search terms in the index with the
alphabetical index. You can alternatively browse all of the classes by selecting "class numbers
and titles". In our example, Class 24 may be relevant to paper clips.
Go back to the Patent Classification Main Menu. In option A. 2., click the radio button Class
Definition. (see below).Type in 24 in the first box in option A and click submit under A.3. Read
through the definition of Class 24. Try different keywords until you find a relevant class. If
Class 24 is relevant to paper clips, then type in 24 in the first box and click the radio button for
class schedule to look for relevant subclasses. Identify as many relevant subclasses.
You can identify relevant subclasses by doing a text search. Once the class schedule is shown,
press “ctrl-f” to perform a text search for “paper clips”. This search term will not show up. You
must look for “clips” or “clip”. Remember this is a keyword based search. Sometimes, you
have to split up the phrase to find the right class or subclass.
Once you have found potentially relevant classes and subclasses, type in the class and subclass
in option A.1., click the Class Schedule radio button and click submit. Read through the class
and subclass definition to check for relevance.
Updating class and subclass list
During the database search, relevant references may be found which solves the problem that
your invention solves or is similar to your invention. For these references, check the other
classes and subclasses listed on these documents. Check for relevance. If relevant, add these
classes and subclasses to your list.
In the example shown below, U.S. Patent No. 7793449 is also classified in U.S. Class/Subclass
40/641, 40/360, 24/67R. Read through the definition of these classes and subclasses to check
for relevancy. If relevant, add them to the list of classes and subclasses.
Search issued patents and published patent applications databases
After brainstorming keywords related to your invention and finding a list of relevant classes and
subclasses, search the United States Patent and Trademark Office databases or a third party
patent document database (e.g., freepatentsonline.com) for relevant patent documents.
Limitations on search
Upon filing of a patent application, the patent application remains secret for a period of 18
months by default. The publication may be expedited by filing a request for early publication.
Conversely, a non publication request may be filed which prevents publication of the patent
application until and if the patent application matures into a patent. These non-public patent
application cannot be uncovered but is still considered to be prior art to the invention. Hence,
every patent search has limitations.
Issued patent and published patent application databases
The USPTO has one database for issued patents and another database for published patent
applications. The reason is that not all published patent applications eventually mature into a
patent. Additionally, not all patents were published before issuance. For example, design
patents are never published until they issue as a patent. Additionally, non publication requests
prevents the publication of the patent application until the patent application matures into a
patent. Hence, both databases must be searched to conduct a proper patent search.
Go to http://patft.uspto.gov/, click on Search under PatFT:Patents. (see below). In Term 1
enter the class/subclass in the following format “XX/XXX”. In Field 1, select Current US
Classification. In Term 2, enter your keywords. Click search.
Review the titles and click through to relevant titles to read the abstract. Do not read through
the entire reference. Just keep track of the relevant references which will be downloaded later
and reviewed more thoroughly.
Go through this process with each keyword and class/subclass combination. Manually filter out
the relevant references. The list of references will be much shorter than a search conducted
without specifying a class/subclass. Moreover, the references should be more on point than a
search conducted without specifying the class/subclass.
Repeat the keyword search process for the published patent application database. Go
to http://patft.uspto.gov/ and click Search under AppFT: Applications. Perform the keyword
and class/subclass search in this database. Keep track of relevant references.
Review the uncovered references and check its class and subclass to see if you can find other
relevant classes and subclasses for your invention.
Patent searching is an iterative process
As you read through the references, you will develop additional search terms and additional
classes and subclasses, repeat the search until you have searched all of the keywords within the
relevant classes and subclasses.