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Archived updates for Sunday, January 21, 2007

Patent Searching In the Product Development Process

This article summarizes the five basic types of patent searches in chronological order according to their usefulness in a typical new product development project.

1. State-of-the-Art Search

A state-of-the-art search, also know as a "collection search," is the broadest and most general type of patent search. It is essentially a background investigation that attempts to provide a broad survey of all technology in a particular field. A state-of-the-art search typically costs around $500-$1000 and requires one to three weeks to complete. Upon completion of the search, you will usually be provided with a brief reporting letter identifying the scope and field of the search along with copies of the references that were located during the search.

State-of-the-art searches are typically conducted, if at all, during the conceptual design phase of a project in order to determine the rough extent of the technological evolution in a particular area. State-of-the-art searches may also be used to help identify technology that is disclosed in expired patents and may therefore be freely copied by anyone.

In particular, U.S. design patents (identified as "DXXX,XXX") expire 14 years after the issue "Date of Patent" typically listed in the upper right corner of the first page. Utility patents ("X,XXX,XXX") and plant patents ("PPXX,XXX") issuing from applications filed on or after June 8, 1995 expire 20 years from their earliest filing date, typically listed near the middle of the left column on the first page. Utility and plant patents that issued on applications filed before June 8, 1995, or that were in force on June 8, 1995 provide a term of protection that is the longer of 20 years from the earliest filing date or 17 years from the issue date. Under certain circumstances, these terms of protection may be further extended.
Utility patents may also "lapse" for failure to pay maintenance fees at 4, 8, and 12 years after the issue date. However, patents that have lapsed for less than two years may be reinstated by merely paying a surcharge fee. Patents that have lapsed for more two years, on the other hand, may be reinstated only upon proving that the delay was unavoidable even though reasonable care was taken to ensure that the maintenance fee was paid on time.

Some individuals choose to do their own state-of-the-art patent searches on the Internet using the U.S. Patent Office’s ("USPTO’s") patent image database at and/or the European Patent Office’s ("EPO’s") patent database at The USPTO patent database allows full text searching on any field in a U.S. patent, while the EPO database only allows up to four-word searches of only titles and/or abstracts of most U.S. and foreign patents. English-language abstracts are provided for most foreign patents on the EPO database. Multi-page, concatenated paper copies of these patent documents can then be obtained at no charge by going to

2. Patentability Searches

A patentability search, also known as a "novelty search" or "prior art search," is used to determined what scope of protection, if any, may be available for a particular embodiment of an invention. Often a patentability search will also locate expired and/or lapsed patents disclosing technology that may be freely copied in order to improve the invention.

A patentability search typically costs around $750-$1250 and requires two to four weeks to complete. Upon completion of the search, you will be provided with an opinion letter identifying the scope and field of the search, and enclosing copies of the references that were located during the search. In addition, the opinion letter will discuss the most pertinent references with respect to their effect on the scope of patent protection available for the invention. The claims of the cited patents will also be reviewed in order to make a preliminary determination as to whether there is a significant risk of being held liable for infringing the noted patents. However, an infringement search may still need to be conducted before making, using selling, offering for sale, or importing the invention in the U.S.

Patentability searches are typically conducted after any market research or conceptual engineering has been completed to the extent that at least an informal sketch, or operational description, of an invention can be provided with the search request. In order to accurately document a date of "conception" and any "reduction to practice" that might affect of the patentability of the invention, an "Invention Disclosure Record" should be used to memorialize the pertinent information.

Similar to a state-of-the-art-search, a patentability search typically begins with queries of various patent databases. The field of the search will then usually continue with a review of all U.S. and/or foreign patent document that have been indexed in various technical classifications defined by the U.S. Classification Manual. The U.S. Patent classification system is generally described on the internet at while the formal definitions for various subclasses are available at Since the accuracy of the search will depend on whether the appropriate classes and subclasses were considered, patentability searches are typically left to experienced searching professionals who will often consult with a Patent Examiner in planning the scope an field of the search.

The results of a patentability search will be reported with a formal opinion letter identifying the scope and field of the search and providing copies of the documents that were identified during the search. A brief discussing of the most relevant documents will also be provided along with a detail analysis of their effect on the scope of patent protection that may be available for the invention. An informed decision can then be made as to whether the available scope of protection is worth the $5,000-$10,000 cost of obtaining a patent.

It is generally a good idea to obtain a patentability opinion and file any patent application as soon as possible after your invention is fully developed, preferably within one year from the date that it was conceived. Even if you promptly and adequately record your invention, you may still jeopardize your patent rights in other countries if you disclose your invention to the general public, describe your invention in any publication, or offer your invention for sale before you file a patent application in this country. Although U.S. law generally provides inventors with a one-year "grace period" in which to file a patent application after disclosing or exploiting their inventions, most other industrialized countries are not so lenient. Appropriate pre-disclosure confidentiality agreements can help minimize, but not eliminate, the risk of any inadvertent public disclosure of your invention.

4. Infringement Search

An infringement search, also known as a "right-to-use search" or "clearance search" focuses on the claims of unexpired patents in a small number of subclasses. The purpose of an infringement search is to determine whether there are claims in these patents that might be construed to cover a well-defined, commercial embodiment of an invention. If a particular competitor is known to have similar products, then the competitor’s patents may also be reviewed.

For utility patents, the claims are numbered at the end of the text while, for design patents, the claims are the drawings. Literal infringement requires that the accused product or process include each and every element of the claim. Consequently, if one or more elements of the claim are not satisfied, then the requirements for literal infringement are not met. However, even if a claim does not literally "read on" an accused product or process, it may still be infringed under the Doctrine of Equivalents if the differences between the accused product or process and the claims are insubstantial. The Doctrine of Equivalents must be applied to the individual elements of the claim rather than the invention as a whole. In this regard, courts have considered evidence of known interchangeability, copying, and designing around the element recited in the claim for determining whether the corresponding feature in the accused device is substantially different from the claimed structure. Other courts have used the so-called "Tripartite" test to find equivalence under the Doctrine where the accused device performs substantially the same function, in substantially the same way, in order to achieve the same result as the element recited in the claims. Since patent infringement analysis can be quite complex, it is best to contact a qualified attorney if you are concerned about any particular claims.

Due to the tedious nature of claim interpretation, an infringement search typically costs around $3,000-$10,000, or more, and requires four to six weeks to complete. Therefore, an infringement search should be conducted only after a commercial embodiment is fairly well defined, but before an irreversible commitment of time and resources has been made. An infringement search can often be conducted simultaneously with a patentability search.

Upon completion of the infringement search, the requestor will typically be provided with a reporting letter containing copies of any noted patents along with a brief description of the scope and field of the search. The report may also provide suggestions for designing-around a particular patent. Further review of some of the patents will often be required in order to determine whether the commercial embodiment includes substantially the same features as recited in the claims.

4. Validity Search

A validity search attempts to locate U.S. and foreign patents, technical journal articles, marketing brochures, doctoral dissertations, speech transcripts, or other published "prior art" documents that appear to disclose each of the features recited in a particular patent claim, but that were not considered during the examination of the corresponding patent application. Any such publication will preferably have been available to the public more than one year before the filing date of application from which the patent issued. Other sources of "prior art" may also be reviewed.

It is important to keep in mind that, under U.S. law, a patent is presumed to be valid unless it can be shown otherwise by "clear and convincing evidence." Therefore, an invalidity determination should not be made without the aid of an experience patent professional.

5. Patent Watch

In order to spot potentially-problematic patents before they turn into real problems, some firms also periodically review all patent documents that are published over a certain period under particular class/subclass codes from the Manual of Patent Classification and/or under assignee names of major competitors. This can be particularly helpful for patents that were not available before a new product was launched. For more information on setting-up a patent watch service for your business, contact Bill Heinze ( at Thomas, Kayden, Horstemeyer & Risley, L.L.P.

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