Should I have a patent search performed?

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There are many reasons to search the patent archives for prior patents. For example, before filing a patent application on a new invention, it is often a good idea to search to determine whether someone else has already patented the invention. A search to determine whether an invention is new is called a novelty search. Performing an invention novelty search prior to filing a patent application can significantly reduce the likelihood of having your patent application rejected due to prior similar inventions. Obviously, there is no point in filing a patent application if someone else has already patented the exact same idea. Also, performing a patent search will help provide a clearer picture of what aspects of your invention are new and which ones have already been protected or claimed by others.

For example, some years ago I was working on a brassiere patent for a new client, and my client asked me whether a certain structural feature on his new bra design would be patentable. Admitting that my knowledge of the subject was somewhat limited, I performed a search of the Patent Office files on brassieres. If you ever doubt the vast storehouse of knowledge contained in the Patent Office, you need only search for some unusual or off-the-wall subject. In this case, my search uncovered literally hundreds of patents related to brassieres, most of which had long since expired. I narrowed the search to support structures for holding the brassiere in place and found a dozen or so patents that described straps, clips, snaps and buttons related to my client’s invention. As it turned out, we did not find any patents that would have blocked or anticipated the new bra invention, but my client did get some very clever ideas from some old expired patents which he then incorporated into some of his new designs. By performing this patent search, my brassiere client received some validation of the novelty of his invention in addition to being able to improve his invention by incorporating some ideas from the prior inventions of others.

Two other benefits also came out of the patent search on the brassiere patent. First of all, because I had a clearer idea of what the prior art or previous improvements in the brassiere industry looked like, I was able to draft a much more effective patent application, focusing specifically on the improvements made by my client. Second, since we had performed a prior art search I was able to take advantage of a Patent Office procedure that enables inventors who perform their own patent searches to have their patent applications expedited or taken out of turn by the Patent Examiner. This process for special status examination requires the applicant to perform a patent search of related patents and provide a written description of how the identified reference patents compare to the claimed invention. The new application, having been granted special status, will be taken up by the Examiner before all other categories of applications, except those clearly in condition for allowance and those with set time limits. This special status filing, enabled by a patent search submitted with the patent application, can significantly shorten the period of time the application sits in the Patent Office waiting to be examined.

Patent Search Limitations

As helpful as patent searches can be in certain circumstances, there are a couple of limitations which need to be considered before searching. First of all, patent searches are not completely reliable, since searching does not provide access to pending patent applications which have not yet been published. Historically, only issued patents and not pending patent applications have been available to the public. As of November 29, 2000, patent applicants can elect to have their applications published and available for public searching. This publication of pending patent applications occurs approximately 18 months after the priority filing date of the application. Since about 350,000 patent applications are filed each year, you can expect that about half a million of the most recent United States inventions are not even accessible for searching. If your invention relates to a recent or quickly developing area of technology, there is a reasonable likelihood that some of the patents you would like to search are inaccessible, buried in the large stack of unpublished applications.

The other reliability problem associated with searching is that the available search tools are not perfect. Until very recently, patent searches were performed largely by professional searchers in tennis shoes who would race through the millions of shelved patents in the Patent Office, searching through stacks of documents for specific related art. Trained searchers could proficiently scan quickly through boxes of patents, rapidly checking titles, abstracts and figures for hints of a specific invention. These traditional searches, although time consuming, produced surprisingly good results. The problem with these manual searches, however, was that if specific patents were missing from the shelves being searched, significant searching errors could occur. Keeping the patent stacks in pristine condition for searching has always been a losing battle for the Patent Office.

Over the past two decades or so the Patent Office has become computerized, providing much greater accessibility and improved availability of patent documents. With documents available electronically, past limitations such as having patents physically missing from the shelves, or Patent Office restricted operating hours, no longer apply. Unfortunately, searching patents by computer is in many ways different and in some ways less effective than searching by flipping through related stacks of documents. Current patent searching by computer is generally performed by searching specific terms or key words. Early inventions in a specific technology, however, by their very nature may lack a common language with which to describe the technology. An example of this can be seen in describing certain electronic circuits.Although the function of a circuit might be easily identified, the structure might be such that five different engineers might characterize the invention in five different ways. Over time a common vocabulary will evolve around the circuit, making document searching possible, but those earlier patents relating to the technology may or may not use any of the later adopted terms or vocabulary. Without well-defined words to characterize an invention, searching by key words can be difficult or impossible.

A second difficulty with computer searching is that some inventions, especially those that are mechanical in nature, are most effectively searched by looking at figures or schematics of the invention. For example, a conventional paper clip is easily recognized by its appearance, but using a keyword search to describe the structure of a standard metal paper clip, or to find a patent of a device of similar shape but having some other function, would be extremely challenging.

The point is that patent searching is not an exact science, and whether searching manually or by computer, expect that pretty decent searches are possible but exhaustive searches are not.

Another down side to patent searches, aside from the fact that they are not perfect, is that they are expensive. Although it is possible to do your own patent search, the most reliable searches are conducted by outside search firms with fulltime professional patent searchers. My preference is to hire a firm that combines both physical searches of the patent stacks with computer searching of the Patent Office database. These searches typically cost around $1,000.

To commission a patent search, I suggest meeting with your patent attorney first to determine whether a novelty search is advisable. If so, ask your attorney to help you to order the search. When spending $1,000 or more searching a specific technology or invention, it is critical to make sure you ask the right questions. One of my favorite bits of wisdom from life experience is to make sure you point the missile before you light the fuse. It is really frustrating to order an expensive patent search, wait two or three weeks for results, and then receive a stack of patents from the searcher that has nothing to do with your invention. Your patent lawyer can help you prevent this from happening by focusing the search on the exact point of novelty in your invention.

To summarize, patent novelty searches can help determine whether your invention is indeed novel or whether someone has previously patented your idea. Although patent searches are expensive, they are much less expensive than the cost of actually filing a patent application, and they can help you prepare a more effective application. Additionally, the patent search can be used as the basis for seeking expedited examination in the Patent Office. Keep in mind, though, that patent searches are not perfect, and it is not uncommon for patents to turn up later that were not discovered in the initial patent novelty search.

Contact John Ferrell at if he can further assist you. 


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About the Author

John Ferrell is a founding partner of Carr & Ferrell LLP, one of Silicon Valley's foremost technology law firms, and specializes in patent and intellectual property law matters. He is the Chair of the firm's Intellectual Property Practice Group.