Often in the course of analyzing a patent, one or more claim terms are difficult to interpret in light of the patent specification, and so in that case it can sometimes be helpful to review the patent’s prosecution history (aka “file wrapper” or “file history”) to ascertain the proper scope for ambiguous terms. Additionally, during prosecution the applicant or the applicant’s representative may disclaim specific scope, whether through explicitly doing so during arguments and/or through making a narrowing amendment to a claim to overcome an examiner rejection. The patent owner will likely be precluded from invoking the doctrine of equivalents to broaden the scope of the claim to cover subject matter ceded by this narrowing amendment. This is often called “prosecution history estoppel”, and it is an important reason to normally include prosecution history review as part of a complete patent analysis. There are many other reasons to review a patent’s prosecution history, many having to do with review of applicant patent practitioner conduct or procedural issues.
However, when reviewing the prosecution history specifically to facilitate determination of claim interpretation, one can narrow the scope of the review in order to hasten the review process, and this allows for review of only specific documents in the overall history’s collection of documents. I have found through practice that using a browser with search result highlighting, one can quickly gather the relevant prosecution history documents from the USPTO’s Public PAIR system.
For this example, I have picked my handy favorite patent number 7654321 (it’s also in a technology area outside of my comfort zone).
1. Use PAIR to pull up information on the patent under review, then select the “Image File Wrapper” tab.
2. Next use the browser’s search result highlighting to find the prosecution history documents of interest. There are mostly documents that you can safely ignore in this review, and I have found a specific set of keywords that I leverage which are helpful in collecting the relevant documents. These keywords are “claim” (for claims and the final index of claims), “amend” (for amendments and arguments), “reject” (for examiner rejection), “allow” (for notice of allowance and the associated examiner feedback), “interview” (for outcome and information pertaining to an interview between the examiner and the applicant), “disclaim” (for a terminal disclaimer, because an applicant might argue claim scope), and “action” (in case an office action was missed through searching for “reject”). The first three keywords will capture everything in the majority of cases. Obviously, for a more thorough prosecution history review, you’ll want to review other documents, such as those pertaining to abandonment, information disclosure statements, petitions, declarations, and the like. However, in a review which concentrates on specific claim term interpretation, only this limited subset of documents will be of particular relevance. For each document of interest, select the associated checkbox in the far right-hand PDF column.
3. Once all desired documents have been selected, activate the PDF button in the top row and save this PDF file (with whatever name you find helpful) so you can review its contents.
4. Review the downloaded PDF file. While it is helpful to have context of the examiner’s rejection rationale, it is only important what the applicant (or representative) files, argues, and amends.
The associated PDF file is available for download, if you’d like to see more detail: US7654321 (ser no 11616583) – partial file history.
In this example case, only 20% of the total prosecution history documents need to be acquired and reviewed using the method described above.
The patent claims tree Chrome browser extension I created in 2012 provides a patent claims tree for a given patent document, and it has become fairly popular, with several hundred users as of this writing. The tool is available at the Chrome Web Store, and is described in more detail here.
I have recently made a couple of improvements to the tool for EP and WO (PCT/WIPO) patent document handling. For one, claim tree creation is now supported for both EP and WO patent documents on Google Patents. Additionally, rudimentary support for German and French for EP patent documents in Google Patents has been added. While the claim type is not handled for German and French, claim tree creation is now provided. Additionally, it should be noted that Google Patents provides kind code B (i.e., issued patent) claims text for EP patents (while Espacenet does not as of this writing — the kind code B issued claims are only available in a PDF file). See this other PatentAnalyst blog post regarding consideration of kind codes for EP patent documents.
The screenshot below shows a claims tree for an issued EP patent viewed in Google Patents. Noteworthy is that not all formats of multiple dependent claims are fully handled in the Patent Claims Tree tool. These types of claims are more common in EP patent documents than in US patent documents.
Patent claim construction involves an analysis of intrinsic evidence primarily, and then extrinsic evidence as needed.
Intrinsic evidence includes the following, in this priority order: patented claims, patent specification, and prosecution history. With regard to the prosecution history, this includes not only the prosecution history of the reviewed patent, but also the prosecution histories of all US family members — that is, prior related US applications, prior related CIPs, related US siblings, related US children, and related US grandchildren. For prosecution history review, focus is placed on office actions and office action responses, and reviews look for the possible presence of two types of estoppel: 1) Argument-based prosecution history estoppel where the applicant explicitly indicates claim interpretation through arguments made in office action responses; and 2) Amendment-based prosecution history estoppel where a narrowing amendment is “made for a ‘substantial reason related to patentability’ when the record does not reveal the reason for the amendment.” (Festo)
Extrinsic evidence includes, for example: dictionaries and expert / inventor testimony. Extrinsic evidence may be considered to inform claim construction based upon the intrinsic evidence, but in most situations intrinsic evidence alone suffices to construe claims, and in many cases it is improper to rely on extrinsic evidence at all.
The following is a non-exhaustive set of terms commonly used in patent claim analysis. This list is not meant to be comprehensive, nor is it meant to cover all terminology for patents in general, patenting processes, or patent litigation (e.g., terms like clearance, IDS, post-grant proceedings, licensing, treble damages, etc.). Descriptions have a US-based focus and so are not necessarily applicable for other jurisdictions.
Concentration is placed on those terms most used in the course of patent analysis, where this analysis always focuses on the patented claims. The list will be supplemented over time, and suggestions for additional terms are welcomed.
- Antecedent basis: A claim term (word or phrase) is referred to in a definite form using “the” or “said” and has been been previously introduced in the current claim or in an ancestor claim using the same term. Lack of antecedent basis can lead to claim scope being indefinite. Also, the patent specification (per 35 USC 112) needs to provide guidance on the meaning of claim terms (i.e., support or antecedent basis), although the same words need not be used therein.
- Anticipation: A specific type of description or event which demonstrates that a claimed invention does not meet legal novelty requirements for patenting. Anticipation is determined on a claim-by-claim basis, and a single prior art reference (e.g., a printed publication) or event (such as a sale) must disclose every claimed limitation, whether explicitly or inherently.
- Beauregard: A claim type that claims an article of manufacture embodied as a computer-readable medium (CRM) and associated instructions. The name originates from a Federal Circuit case In re Beauregard (1995). However, a more recent case at the Federal Circuit in 2012 (Digital-Vending Services International, LLC v. The University of Phoenix, Inc.) interpreted Beauregard claims as method claims rather than as apparatus or composition of matter claims. Further complicating scope interpretation of Beauregard claims is that the USPTO now instructs examiners to reject Beauregard claims because computer-readable media can include signals, which were found to not be patentable subject matter under 35 USC 101 in the Federal Circuit case of In re Nuijten (2007). To get around this type of invalidity, the computer-readable media should explicitly be limited to be “non-transitory”.
- Body: The portion of a patent claim which recites claimed elements and describes how these elements interoperate in order to form a claimed invention. The claim body follows the preamble (introduction) and the transition phrase (link).
- Claim construction: Interpretation and determination of the meaning of a patent claim. Construing the proper meaning of a claim is a necessary step prior to determination of potential use.
- Claim type/category: A category covered by a given claim. 35 USC 101 indicates the following basic categories as statutory classes: “process, machine, manufacture, or composition of matter”. A claim covering an activity (process or method) is often referred to as a “process claim”, a “method claim”, or a “use claim”. A claim covering a physical entity such as a product or apparatus (e.g., machine, article, composition, device, system, etc.) is often referred to as a “product claim” or an “apparatus claim”. My Patent Claims Tree tool attempts to determine the type/category of claim for each independent claim based on semantic analysis of language used within the claims. The claim category for a given claim determines its scope and coverage of use.
- Dependent claim: A claim which depends upon at least one other claim and which inherits limitations from its ancestor claims. A dependent claim provides additional specificity and claims a narrower embodiment.
- Direct infringement: This occurs when a party makes, uses, sells, offers to sell, or imports a patented invention in the United States during the term of the associated patent. See also “Indirect infringement” and “Divided use/infringement”.
- Divided use/infringement (multi-actor): Joint infringement when two or more different parties together make, use, sell, or offer to sell a solution that would be judged to infringe upon a patented claim.
- Doctrine of claim differentiation: A rule that every claim in a patent is presumed to have different scope from every other claim. This doctrine means that if a dependent claim of a parent claim specifically has narrower limitations, then the parent claim must necessarily be different – that is, it has a broader interpretation. As an example, for an independent claim that recites a chair with a plurality of legs, with the independent claim having an associated dependent claim requiring a chair with 4 legs, the independent claim is therefore not limited to what is recited in the dependent claim. The dependent claim in this example protects chairs with 4 legs specifically, and therefore the independent claim must logically cover chairs not only with 4 legs, but also chairs having any number of legs greater than one (i.e., a “plurality”). It would be improper to read the 4-leg limitation into the independent claim.
- Doctrine of equivalents: A legal rule that allows a court to hold a party liable for patent infringement even when every element of a patented claim does not literally read on a product or process. Equivalents can be determined when alterations are “insubstantial”, though there are many limitations to the doctrine of equivalents.
- Element: A component of the claim body indicating a part, step, structure, substance, etc. that together with the other claim elements forms the process, machine, article of manufacture, or composition of matter named in the claim preamble.
- Extrinsic evidence: Evidence and support from sources external to the patent itself and its associated prosecution history. Extrinsic evidence may include expert or inventor testimony/opinion, dictionaries, and the like. Normally, review of intrinsic evidence alone suffices to resolve any ambiguity in a claim term, but extrinsic evidence may in some cases inform claim construction based upon the intrinsic evidence.
- Independent claim: A standalone claim that does not refer to or depend upon another claim. An independent claim may have zero or more dependent claims which inherent limitations from it. An independent claim is therefore broader than all its dependent claims.
- Indirect infringement: Here, a party induces another party to directly infringe a patent (inducement) or the party contributes to the direct infringement of the patent by another party (contributory infringement). A party is a contributory infringer only if the party provides a component of a patented invention, and the party knew that the combination for which the component was especially designed was both patented and infringing, and the component must not be a staple article or commodity of commerce suitable for substantial non-infringing use.
- Interpretation: Determination of the meaning of a patent claim. Construing the proper meaning of a claim is a necessary step prior to determination of potential use. See also “Claim construction” and “Markman”.
- Intrinsic evidence: Evidence and support from 1) Claims, 2) Specification, 3) Prosecution History, in that priority order, for determining claim interpretation. With regard to #3, the prosecution history (aka file history, file wrapper, etc.), this includes not only the prosecution history of the specific patent, but also the prosecution histories of all its US family members — i.e., prior related US applications, prior related CIPs, related US siblings, related US children, and related US grandchildren.
- Invalidity: A determination that a patent claim should not have issued due to the associated claimed invention not having been novel or nonobvious, requiring clear and convincing evidence because there is a presumption of validity bestowed on an issued patent. Claims can also be found invalid through other means beyond anticipation or obviousness.
- Limitation: A limitation often refers to an adjective, adverb, or other phrase that modifies a claim element. However, many patent professionals use the term “limitation” interchangeably with the term “element”.
- Markman: A pretrial hearing in which a judge determines appropriate patent claim interpretations as a matter of law.
- Means-Plus-Function (MPF or M+F): A type of claim language which claims a structure only in terms of its functionality. In the US, means-plus-function claims are provided for in 35 USC 112, paragraph 6. Whereas this type of claim was often used to broadly encompass various structures, MPF claims are now construed much more narrowly, encompassing only those structures defined within the patent specification, along with equivalents with insubstantial difference. As a result, and due to the scope uncertainty of MPF claims, this type of claim has fallen more out of use in recent years. Also, while claim construction is a question of law, a determination of the scope of equivalents under 35 USC 112, paragraph 6 is a question of fact (therefore requiring a jury decision).
- Non-obviousness: A patentability requirement which mandates that a claimed invention must not be obvious in that a person having ordinary skill in the art would not know how to solve the problem for which the claimed invention is provided by using the same solution. This requirement is of course applied inconsistently and is normally the most difficult to apply or defend against, and there are and have been many different factors and tests applied to determine nonobviousness (e.g., “Graham factors”, “Teaching-Suggestion-Motivation” (TSM), etc.).
- Novelty: A patentability requirement which mandates that a claimed invention must not have been known to the public before the patent’s priority date (there are some specific date exceptions). Otherwise, the claimed invention is anticipated if one prior art reference or event discloses all the claim elements and limitations and enables a person having ordinary skill in the art to make and use the claimed invention.
- Preamble: An introductory statement for a patent claim that indicates the type of claim (or statutory class) and that names the product or process claimed.
- Prior art: Information which was publicly available in any form before a specific date that might be of relevance to the originality (novelty and nonobviousness) of a claim.
- Prosecution history (file history, file wrapper): Patent prosecution is the interaction between a patent applicant and a patent office with regard to a patent or patent application, and the prosecution history is the collection of these interactions between the applicant (or its representatives) and the office. For the USPTO, the prosecution histories for patents and patent applications is available for retrieval and review through PAIR. Public PAIR provides access to patent histories for published patent documents (usually after 18 months following the priority date), and Private PAIR additionally provides access to prosecution histories for those patent documents that are currently unpublished.
- Subject matter eligibility: Claimed subject matter is eligible or ineligible to be patented based upon the type of subject matter claimed, independent of requirements pertaining to novelty and non-obviousness. Certain types of subject matter are ineligible for patent protection in the US such as literary works, compilations of data, music compositions, legal documents, forms of energy and signals, natural phenomena, mental processes, and abstract intellectual concepts.
- Transition: A transitional word or phrase between the claim preamble and the claim body. Usually this word is “comprises” or “comprising”.
- Transitory signal: Subject matter that is ineligible for patent protection according to the Federal Circuit In re Nuijten (2007) ruling which concluded that articles of manufacture do not include intangible, incorporeal, transitory entities (which the court indicated that signals are).
- Use / Infringement: A product or process is read upon by a patented claim.
- Written description: Portion of a patent specification which describes, among other things, inventive embodiments. Claim elements and limitations need to be disclosed in the written description in order to be allowed.
I spend a fair amount of my time reviewing wireless air interface and data communications inventions, and so I often need to reference appropriate related standards and specification documents. Below is a very partial list of wireless and general data communications standards and specifications along with their associated website links. I hope you find these references helpful and that these hasten your standards document searches.
LTE (and LTE-Advanced) air interface (E-UTRA): published by 3GPP: http://www.3gpp.org/ftp/Specs/html-info/36-series.htm
UMTS/HSPA air interface (UTRA): published by 3GPP: http://www.3gpp.org/ftp/Specs/html-info/25-series.htm
Wi-Fi (802.11): published by IEEE:
- IEEE 802.11a protocol: http://standards.ieee.org/getieee802/download/802.11a-1999.pdf
- IEEE 802.11b protocol: http://standards.ieee.org/getieee802/download/802.11b-1999.pdf
- IEEE 802.11g protocol: http://standards.ieee.org/getieee802/download/802.11g-2003.pdf
- IEEE 802.11n protocol: http://standards.ieee.org/getieee802/download/802.11n-2009.pdf
- Current release of standard (as of Oct 2013): http://standards.ieee.org/getieee802/download/802.11-2012.pdf
Bluetooth: published by Bluetooth Special Interest Group: https://www.bluetooth.org/Technical/Specifications/adopted.htm
Near Field Communication (NFC): published by NFC Forum: http://www.nfc-forum.org/specs/
WiMAX (802.16): published by IEEE: http://standards.ieee.org/about/get/802/802.16.html
CDMA2000 (incl. EV-DO, etc.): published by 3GPP2: http://www.3gpp2.org/public_html/specs/
Internet communications (e.g., HTTP, SIP, DNS, etc.): published by Internet Engineering Task Force (IETF): http://www.ietf.org/rfc.html
Web application technologies (e.g., HTML, CSS, XML, SOAP, DOM, etc.): published by World Wide Web Consortium (W3C): http://www.w3.org/standards/
SIM/USIM: published by 3GPP: http://www.3gpp.org/ftp/Specs/html-info/31-series.htm
Mobile device APIs (e.g., device management, M2M, etc.): published by Open Mobile Alliance (OMA): http://technical.openmobilealliance.org/Technical/current_releases.aspx
Prior to my attendance and panel participation at the SUITS conference in August 2013, TMC published an interview they did with me titled “Three Areas of Intellectual Property You Need to Understand” — this article is available here: http://www.tmcnet.com/topics/articles/2013/08/15/349616-three-areas-intellectual-property-need-understand.htm. Much of what is published there has been covered in earlier posts on this blog, such as in “Clearance Search Review” and “Invention Disclosure Highlights and Considerations”.
However, there is also additional new perspective pertaining to the biggest misconception in terms of how companies can understand, enforce, and protect their patents and intellectual property. This largest misconception in terms of how companies can understand, enforce, and protect their intellectual property is one held by a large portion of companies’ R&D engineering communities – that is, that an inventor’s novel and non-obvious invention is obvious and one that would have been formulated by any other engineer in a similar situation. This misconception leads to many inventions never being considered for patent protection. The issue can at least partially be overcome by continual inventor training to educate engineers to recognize the features of designed products and services that indicate the desirability of protecting aspects of these designed products and services with patents. This training should include information about patents, their history and intent, patentability rules, and examples of patented solutions within the given company’s technology areas. In particular, patent examples often inspire an “aha moment” within engineers that lead them to become prolific inventors and patent protectors.
More and more web applications typically encrypt communications with a user browser using Transport Layer Security (TLS), making determination of how the web application works more difficult. However, as part of patent analysis it can be quite helpful to peek into client-server communications to better ascertain how functionality works.
Packet capture tools such as Wireshark capture all Ethernet communications at a network adapter, and so cannot see inside encrypted packets like TLS packets used for securely transferring data via Hypertext Transfer Protocol Secure (HTTPS). TLS encrypts packets using symmetric cryptography between communication counterparts, so that unless you’re the NSA it should be challenging to be a “man-in-the-middle” and read the communications in the clear. For this reason, what is needed is insight at a counterpart endpoint, and in the client case for a web application this is the web browser. The web browser itself obviously must be able to encrypt and decrypt communications with a web application server, so it is here that one can capture and analyze HTTPS packets in plaintext format.
There are a variety of browser-specific add-ons that are available to capture and present sent and received HTTPS communications in plaintext format. One example that I have found helpful is HttpFox, an extension for Mozilla-based browsers such as the Firefox browser. HttpWatch is another solution that works for Firefox and on iOS devices (iPhone, iPad) as its own browser.
It should be noted that while browser extensions such as HttpFox are helpful for capturing and analyzing secure encrypted communications with browsers, these are not helpful for decrypting communications to/from other client applications because these other applications are TLS counterpart endpoints that are using cryptography without providing insight into the communications.