There are several different types of patent searches and opinions that may be created. First, the “search” phase may have different purposes, and second, the “opinion” phase may be directed to different needs.
a. Patentability Search - For the patentability search and opinion, the purpose is to determine if an invention is disclosed in other references, such as patents or other publications. That is, do other patents or publications teach how to make the invention, either within a single patent or publication, or through a combination of patents and publications that are in the same general technical field (called a "field of art" in the patent vernacular). The reasons for performing a patentability search are that the United States Patent & Trademark office (USPTO) will reject a patent application for lack of novelty if it is completely taught within a single reference patent or publication, or if they deem the invention to be obvious, through a combination of other patents and/or publications. Because the claims in a patent or published patent application must be supported by a description in the specification portion of the patent and in the drawings, a patentability search and opinion focuses on the text and drawings to determine whether the subject invention has been taught before. If the entire invention is found disclosed within a single patent, the opinion will reflect that the subject invention lacks novelty. If all the features of the subject invention are not found in a single patent, but can be found in two or more patents or other publications in the same field of art, the opinion will reflect that the subject invention lacks non-obviousness. If a single feature of the invention cannot be found within the references located during the search, the opinion will reflect that the invention should be patentable. While experienced searchers will generally find nearly all of the references that might be applicable towards a particular invention, it is always possible that a reference may be overlooked. Additionally, an examiner at the USPTO may believe that a reference discloses something different than the view of the person who wrote the opinion. Further, an examiner at the USPTO is at liberty to select any reference, that is, any published material that may exist. Thus the examiner may draw upon publications that are not patents or patent applications. Additionally, during the patent examination process, patent applications are secret for a period of time (typically 18 months), during which no one outside the USPTO can access them to determine whether they might impact the patentability of a particular invention. Lastly, an examiner may draw upon foreign references. While an exhaustive search of foreign patents, patent applications and other non-patent published material may be made, such would come at a typically prohibitive cost. Accordingly, during the search portion for a patentability opinion for filing of an application for a United States patent, only a search of U.S. patents and patent applications that are published will be made. Further, such patentability search may be limited to a particular time frame, typically since 1976, because U.S. patents prior to 1976 are only stored as image files at the USPTO and may not be keywords searchable. Patents prior to 1976 are typically searched by the classification number in which the fall along with the title of the invention, which can be searched by keyword. (It should be noted that the USPTO me soon require foreign searches to be made as part of a special process to accelerate the examination of a patent application. However, the scope of such foreign search has not yet been defined and may add substantially to the costs of obtaining a search for this purpose.)
b. Infringement Opinion - An infringement opinion is performed for an entirely different purpose: That is, to determine whether the invention will infringe a currently valid patent. While an infringement opinion may be rendered for a product to be made, used, offered for sale, sold, or imported into the United States, it may also be made based on patents of a particular foreign country. However for the sake of determining whether an invention would result in infringement under United States laws, only United States patents must be reviewed. (As a cautionary measure, published patent applications may also be reviewed, as these may later result in patents that could be infringed.) An infringement opinion maybe related to reviewing an invention versus a particular patent that is known to exist. (This will typically occur when someone is threatened by a competitor who is asserting that they have a patent on the invention, or where an inventor wishes to know whether the practice of their invention would infringe upon specific known patent or patents.) Alternately, a broad infringement opinion often called a “clearance opinion” may be rendered in which a general search is made to locate all patents related to the subject invention and then the subject invention is subsequently compared to the claims of those patents found.
c. Product clearance opinion - A particular type of opinion is rendered to determine non-infringement of patents related to a particular new product that may be under consideration for introduction to the marketplace. Such opinions are typically quite costly (but far less costly than payment of damages for infringement) are usually undertaken only by well-established companies. The company will usually know its main competitors and will often be very aware of new patents and publications issued to those competitors. Accordingly, the product clearance opinion may be restricted to such a group of patents. Ultimately, a broad search may be made to determine any apparently valid patents or publications that could potentially lead to infringement actions against the company.
d. Patent validity (or invalidity) opinion - A patent validity opinion is undertaken to determine whether a particular patent or group of patents may be asserted against someone introducing a related new machine, product, process or composition of matter. If for any reason (as discussed below) a patent is not valid, it cannot be infringed. Thus, a patent validity opinion may well be part of an overall patent infringement opinion. (Such a patent validity opinion may lead to a broader search for other patents or publications that may be used to invalidate the patent.) Therefore, the first step is to determine if the term of the patent has run, or whether the patent still appears to be enforced. This will begin with a determination of when the patent issued (for patents prior to June 8, 1995, their life is 17 years from the date of issue) or when the patent application from which the patent resulted was filed (since June 8, 1995, the life of the patent has been 20 years from the date of filing). Thus, if the term of a patent has run, it is no longer valid and cannot be infringed. Further, since December 12, 1980 , United States patents have required maintenance fees to keep them in force. If the maintenance fees have not been timely pay, the patent will have expired and cannot be infringed (subject to the possible reinstatement of the patent to valid status, after which he will again become capable of being infringed - although it cannot be infringed during the period of invalidity). Thus, if the maintenance fees have not been paid and the patent has expired, the opinion will reflect that the patent is not currently in force and cannot be infringed. If, during the patent application process, a reference (either a U.S. patent or published patent application, a foreign patent or foreign published application, or any other material available to the general public) was not considered, the subject patent may not be valid. If it can be shown that the subject patent was disclosed in any other reference more than a year prior to the filing date of the subject patent, and that such was never considered during the examination process (or possibly may have been misinterpreted during the examination process), the subject patent may be a candidate for re-examination. During such re-examination, the patent may be upheld or may be rendered invalid. If the latter is the case, it cannot be infringed.
e. Field Search - Occasionally, an inventor wishes to know generally the scope of patents related to his invention. An inventor may wish to identify deficiencies in the current patent literature, identifying opportunities for an improvement. In such case, a general field search may be made to merely obtaining related patents without an associated opinion. Such searches are useful to the inventor in the formative stages to guide the inventive process. Accordingly, the inventor may order a general field search to identify a variety of patents related to the subject invention.
f. Foreign Searches - In order to locate references such as patents and published patent applications as part of a foreign search, it is typically necessary to utilize the services of foreign search firms who are familiar with the procedures of their particular countries.