Software Litigation Consulting

Andrew Schulman
Consulting Technical Expert & Attorney

Patent Litigation book

Patent Litigation: An Introduction to Using Patent Claims and Limitations in Disputes over Infringement and Invalidity

 

by Andrew Schulman

This forthcoming book will be based on (but significantly expanded from) a 6-part series which was published by DisputeSoft.com. Contact the author for more information. There is a discussion page at academia.edu .

I resumed serious work on this book in June 2025, working with Google’s NotebookLM to try to whip my hundreds of pages of rough notes and outlines into a coherent outline from which I can finish writing the book. See page on using NotebookLM to finish writing the Patent Litigation book. I won’t be delegating much if any actual writing to NotebookLM or other AIs, but I’ll be using NotebookLM, the Gemini chatbot embedded in Google Drive, Anthropic Claude, and OpenAI to help organize my material.

Summary outline

  • Preface
  • Introduction
  • Chapter 1: Patents, Infringement, and Litigation (or, What is a Patent, Really?)
  • Chapter 2: Patent Claims and Limitations
  • Chapter 3: Carefully Examining a Patent Claim
  • Chapter 4: Using a Patent Claim to Look for Infringement, and as a Tool to Examine an Accused Product
  • Chapter 5: Using a Patent Claim to Look for Invalidity, and as a Tool to Examine Prior Art
  • Chapter 6: Patent Litigation: Plausibility, Pre-Filing Investigation, Claims Charts, and Discovery
  • Conclusion
  • Glossary & Abbreviations
  • Checklists
  • Bibliography
  • Cases Cited

Detailed outline

Preface

  • About the reader (intended audience: associate attorneys; technical consultants; and patent litigation students)
  • About the author (attorney and computer programmer; has worked for 20+ years on factual side of software/network patent litigation; about equally defendants & plaintiffs, including some NPEs)
  • Plaintiff/defendant neutral
  • Largely USA-centric (though see section on international aspects, including import, export, ITC)
  • Largely utility patents
  • The book might have been subtitled “How to get down in the weeds”; the book is definitely for those who want to do that, rather than stay at a 30,000 foot level (though also see lengthy section on patent strategy)
  • Acknowledgements

Introduction

  • Patent claims are tools to do something, not merely passive descriptions of technology
  • Really an entire book focusing on the minutiae of patent claims?; yes, even billion-dollar patent judgments end up being based on a few words in a patent claim
  • The book’s focus is on litigation (how to actually use a patent), rather than on patent prosecution (getting a patent in the first place)
  • Focus on claims, and on the limitations (elements and steps) that make up claims
  • Focus on facts (factual investigation and marshaling facts), more than on patent law as such
  • Focus on technical facts, more than on economic/accounting (though see section on remedies, and interaction of technical & economics experts)
  • Focus on using claim construction as a tool, not simply providing the usual rehash of the “canons” of claim construction
  • Who cares? Why aren’t we talking about weighty issues like “patent reform” and subject-matter eligibility, and instead focusing on seemingly-little things like claim charts?; in part because there are simpler procedural fixes to perceived patent problems (such as unpredictability, or beliefs that patents are “too strong” or “too weak”); Local Patent Rules (LPRs) are more tractable tools for controlling “patent abuse” than is 101.

Chapter 1: Patents, Infringement, and Litigation (or, What is a Patent, Really?)

  • Opening lengthy example of Caltech v. Apple/Broadcom: how do a few patent claims turn into a billion-dollar judgment (albeit one in which the damages amount has now been successfully appealed)?
  • Patents: a negative right to (try to) exclude
  • Patents: enforceable boundaries for inventions
  • Patents have boundaries: what is property?
  • Patents and IP
  • How patents relate to the patent owner’s products: what does it mean for a patent to “cover” a product?; why no “working requirement”
  • Infringement, and the right to exclude
  • Patents are not self-acting, and the “patent police” are not on their way
  • Patent litigation in federal civil court (experienced attorneys can skip this section)
    • Venue & forum shopping
    • Briefly here on other “venues”; ITC; PTAB
    • Trial, and the role of judge & jury
    • Most litigation is pretrial, and most cases don’t go to trial (see section on settlement)
    • Appeals and the CAFC
  • Showing infringement
    • Briefly here on indirect infringement
  • Patent infringement is based on patent claims and limitations
    • Briefly here on design and plant patents, without claims/limitations
    • Some parts of claims that look like limitations are actually non-limiting (preconditions, most preambles)
  • Patent strategy: A claims-based approach
    • Some goals for patents, and for patent litigation
    • Pros: Some reasons behind (or causes for) patent litigation
    • Cons: Some bad reasons for patent litigation, and reasons NOT to litigate
    • Non-litigation uses of patents, and alternatives to litigation
    • Alternatives to patenting
    • Patent valuation: A claims-based approach; see also Remedies below
    • Settlement of patent litigation
    • Patent licensing
    • Pre-litigation patent enforcement
    • Strategy & tactics within litigation, including defense
    • Patent portfolios: quantity & quality
  • Patents: Who cares?
    • Does the patent system function as an incentive to R&D, and to innovation generally?
    • How do patents compare to alternative IP and non-IP incentives to R&D?
    • COVID-19 vaccines as an example of the positive, negative, or neutral role of patents in innovation

Chapter 2: Patent Claims and Limitations

  • A sample patent claim (for printer toner)
    • Dependent claims, and their uses
  • A sample patent claim for a method (for an image-forming method)
    • Other types of patent claims: CBM, system, CRM (media), sequences/structures
    • General distinctions: function vs. structure; device/apparatus vs. process/method, etc.
  • Patent claims are made of “limitations”
    • Limitations are elements/components/parts of devices, or steps of methods/processes
    • Briefly here on sub-limitations (much more in Ch.4 on parsing lengthy/complex/multi-part claim limitations)
  • How a selective parts list marks a patent boundary
  • Patent claims are devices/tools for testing infringement (and for testing their own validity/invalidity)
  • Claim scope’s inverse relation to size/complexity: less is more
  • The role of claim construction in patent litigation
    • Nomenclature, terminology: see Ch.3, 4
    • Relationship of claims to the rest of the patent specification: context/definition, but not “importing”
    • Markman claim-construction hearing
    • Using claim-construction rules (including “canons”) as tools in patent litigation
    • Threading the needle: how broad and narrow scope relate to plaintiff’s and defendant’s postures for infringement and invalidity
    • Plain and ordinary meaning
    • “Canons” of claim construction: “for each and every canon, there is an equal and opposite canon”
    • Inventor as “own lexicographer” with specification as dictionary for claims
    • Claim differentiation, including using dependent claims to understand independent claims
    • The importance of short non-technical words; “whereby” vs. “wherein”
    • The importance of word suffixes: -ed vs. -ing vs. -able
    • The importance of seemingly-vague connectives, such as “based on”
    • Using adjectives to understand claim terms
    • Using small differences between claims, or between claim limitations
    • The (rebuttable) presumption of consistency
    • Using examples and embodiments in the specification
    • Non-limiting claim language, including (usually) preambles, and preconditions
    • The perspective of the PHOSITA at the time of filing
    • Party’s claim construction implied from its infringement posture
    • Intrinsic vs. extrinsic evidence, including the roles of dictionaries and of experts
    • Why broad claim scope is not always good for the patent owner
    • Having fought hard for a particular claim construction, remember to actually USE it in analyzing infringement and invalidity
  • Monitoring the marketplace for patent infringement
    • Why is there no “patent police”?; why is monitoring patent infringement different from what ASCAP/BMI do for music copyright?; perhaps so-called “trolls” function as quasi “patent collection societies”?
    • Which patents to assert from a larger portfolio?; portfolio ranking
    • Who to asset patents against?; finding potential/candidate targets
    • Reasonable pre-filing investigation under Rule 11, Iqbal/Twombly (“plausibility”), and Local Patent Rules (LPRs)
    • Difficulties in acquiring access to possibly-infringing products/services/in-house methods (“instrumentalities”)
    • Reverse engineering (or its equivalent) as a litigation tool for detecting and assessing infringement
    • What to do when detecting infringement is difficult before discovery
    • “Information and belief” and its over-use when publicly-accessible detailed information has not been diligently mined
    • Pre-filing enforcement, the demand letter, and declaratory judgment (DJ)

Chapter 3: Carefully Examining a Patent Claim

  • Treating a patent claim as a parts list…
  • … But not just a parts list
  • What’s in a name?: infringement & nomenclature/terminology
  • Defense; D’s options include:
    • Showing non-infringement (show absence of 1+ elements, ideally from each & every asserted claim)
    • Showing invalidity: anticipation, obviousness, lack of enablement; but: presumption of validity; clear & convincing evidence
    • Inter-partes review (IPR)
    • Claim construction disputes; balancing narrow construction on infringement & broad construction on invalidity
    • Motions to compel, dismiss, exclude, preclude, strike, stay re: P’s pleadings, contentions, experts, evidence, etc.
    • Summary judgment (SJ), including “failure of proof”
    • Declaratory judgment (DJ) actions
    • Reducing damages: royalty rate, royalty base, lost profits, non-infringing alternatives
    • Settlement
  • A simple software patent claim (the book’s major example: “facade server”, and how/why it was selected)
  • Walking through claim limitations
  • “Facade server”: interpreting terms in a patent claim (specific example of using claim construction)
  • The “core” of the claim may not look like much
    • How patent claims change while the PTO is examining the patent application; claim evolution

Chapter 4: Using a Patent Claim to Look for Infringement, and as a Tool to Examine an Accused Product

  • Investigating infringement of a software patent claim
  • Brainstorming search terms (nomenclature, terminology, synonyms, non-limiting examples)
  • A possibly-infringing product
  • Limitation-by-limitation comparison of a patent claim with an accused product
  • Structuring the comparison of a single limitation with a product attribute/feature/element
    • Parsing claims and limitations, including lengthy/complex limitations
    • Sub-limitations, both explicit and implicit
    • Deceptively simple-looking limitations (e.g. “a facade server”; when patentee “acts as his own lexicographer”)
    • Features/attributes/adjectives of limitations
    • Negative limitations, and absences (e.g. with closed “consisting” preambles)
    • Limitations with choices
  • Other possibly-infringing products (this section includes valuable research by GreyB, as a detailed example of a real-world patent-infringement search)
  • “Means for”: so-called functional claiming (finding structural details in the specification)
  • Equivalence (DoE) and the function/way/result (FWR) test
    • Design-around, and its relationships with equivalence (including PHE) and with non-infringing alternatives (NIA)

Chapter 5: Using a Patent Claim to Look for Invalidity, and as a Tool to Examine Prior Art

  • Patent invalidity: how D can pull the rug out from under P’s property
    • How dependent claims intersect with infringement & invalidity
  • Investigating prior art for a software patent claim
    • Alice and the subject-matter validity of software patents
  • What counts as prior art
  • How a patent (claim) is compared with prior art; anticipation; “reinventing the wheel”
  • Prior art already found by the PTO; reading the file wrapper
  • Searching for a negative limitation (required absences) in prior art
  • An extended prior-art example
  • Limitation-by-limitation analysis of a prior-art reference
  • Other prior-art examples (this section includes valuable research by Patspade IP as a further detailed example of a real-world prior-art search)
  • Obviousness
    • Both a mere fall-back position from anticipation, and also the “crown jewel” of the patent system
    • “Motivation to combine”; TSM+
    • The PHOSITA’s perspective
    • Secondary considerations: are they really secondary?
  • On-sale & public use bars: P can trip itself up with its own prior art
  • Lack of enablement as another way to invalidate patents
    • Enablement basics from 35 USC 112(a)
    • What types of information must be disclosed?
    • Enabling the full scope of the claim, including (but not limited to) the claim as construed/asserted in litigation
    • Enablement also required for prior art (except patent owner’s own on-sale, public-use)
    • If “the name of the game is the claim,” why do we care about the spec?; enablement and the underlying purpose of the patent system
    • Does the patent system truly treat disclosure as its ultimate goal?; and, what happened to “best mode”?
    • Do patents actually disclose new information that would be useful to engineers?
    • Are patent disclosures used by engineers?
    • Patents vs. trade secrets
    • The “ostrich position” (deliberate avoidance of reading patents), willful infringement, and indirect infringement
  • Unstable property: unpredictability, and the risk of patent invalidity

Chapter 6: Patent Litigation: Plausibility, Pre-Filing Investigation, Rules, Claims Charts, Discovery, Experts, and Remedies

  • A plausible case
    • Rule 11, reasonable pre-filing investigation
    • “Plausibility” under Iqbal/Twombly
    • Summary judgment (SJ) & “failure of proof”
  • Local Patent Rule (LPR) requirements for infringement & invalidity contentions
    • Explaining and contending
    • Sufficiency of contentions can drive other side’s disclosure requirements
  • Claim charts for analyzing infringement and invalidity
    • See author’s articles and draft book on claim charts
    • Briefly on charts for design patents (Crocs example)
  • Discovery: Getting information from the other side
    • Only briefly here on the major discovery mechanisms: rogs, deps, doc production, etc.
    • This section also covers “informal discovery” and mandatory disclosures under LPRs
    • First diligently mine public information — there’s likely more than you think
    • Protective orders (POs), confidential business info (CBI), and attorney-eyes only (AEO)
    • Third-party subpoenas
    • Discovery requests tailored to what experts will need
    • “Stop and think” (FRCP ACN on discovery) vs. kitchen-sink requests
    • “Careful what you ask for, you just might get it”
    • Using public information to fine-tune formal discovery requests; how internal/confidential info relates to public info (e.g., how confidential source code relates to actual products on the market; how company emails relate to public pronouncements)
    • Discovery mutually-assured destruction (MAD) balance upset by “trolls” (asymmetrical discovery from NPEs)
    • Knee-jerk responses (not every burden is unduly burdensome) are as common as knee-jerk requests (kitchen sink)
  • Experts
    • Technical & economics experts
    • Expert choices: specialist vs. generalist; academic vs. industry; early vs. late (sunk costs vs. fait accompli); single vs. bifurcated (separate infringement and invalidity experts); testifying vs. non-testifying consultant
    • Expert relation to hiring party; witness not “team member”; conduit; ghostwriting
    • Testifying expert relation to consulting expert; pros & cons of consulting experts
    • Daubert, Kumho Tire, FRE 702-705
    • Using Daubert factors to structure report and testimony
    • Falsifiability, peer review, error rate, non-litigation use of method, standards for methods
    • FRCP 26 on expert report; expert affidavits; report timing; rebuttal reports; drafts & “rolling report”; amending reports; materials considers vs. relied-upon
    • Opinions vs. faux-naive “I just let the facts speak for themselves”
    • Conclusory opinions vs. providing basis and methodology, alternate conclusions considered
    • Basis/methodology/experience provide expert opinion’s value, vs. “well, that’s just your opinion”
    • Experience, qualifications, and ipse dixit
    • Weasel words, “consistent with”, degrees of certainty, and “fit”
    • Battle of the experts; legitimate expert disagreement
  • Remedies (ideally, this would be towards the front, not the back, of the book)
    • Injunctions and TRO; eBay v. MercExchange and NPEs
    • Reasonable royalties; Georgia-Pacific factors; importance of royalty base as well as royalty rate
    • Royalties and standards: SSOs, SEP, and FRAND
    • Remedies when the patent covers only part of the product: EMV, SSPPU
    • Patent claim valuation generally: see earlier Strategy section
    • Lost profits, Panduit factors, including absence of NIAs
    • ITC non-importation order, and “domestic industry” (working/practicing requirement)
    • Interaction of technical experts with economics/accounting experts (e.g. tech expert may provide econ expert with list of part numbers to include/exclude in damages calculation)
    • Attorneys fees
    • Litigation funding
    • Patent infringement insurance
  • Multiplicity
    • Multiple claims, multiple patents asserted in a single case
    • Multiple accused products, and choosing “representative instrumentalities”
    • Multiple prior-art references: either obviousness combination, or alternative prior-art references
    • Multiple defendants, and joinder; the problem of so-called “joint” or “divided” infringement; third parties
    • Multiple locations, including multidistrict litigation (MDL)
    • Multiple international jurisdictions (including attempted consolidation of invalidity hearings across multiple patent-granting jurisdictions)
    • Multiple potential claim constructions

Conclusion

  • Recap of major points, themes of book
  • Trends in patent litigation: AI, quantum, blockchain, climate change/sustainable tech?; COVID-19 vaccines
  • Taking some fact-investigation methods here, and applying to other areas of software-related litigation
  • Need for greater IP predictability
  • International aspects of US patent litigation
    • This US-centric book may look narrow/parochial in a few years, if it does not already
    • WTO TRIPS, Europe, UK, China
    • ITC importation actions, and “domestic industry”

Glossary & Abbreviations

Checklists

Bibliography

Cases Cited

This forthcoming book will be based on (but significantly expanded from) a 6-part series which was published by DisputeSoft.com. Contact the author for more information,

 

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