• Home
  • About
    • Client Reviews
    • Patent Samples
    • Accolades
    • About Firm
    • Technologies
    • FAQs
  • Services
    • Patent
      • Utility Patents
      • Design Patents
      • Patent Application
      • Patent Defense
      • Patent Enforcement
      • Working with In-House Attorneys
    • Trademark
      • Trademark Search
      • Trademark Application
      • Trademark Enforcement
      • Trademark Defense
    • Licensing
    • Worldwide IP
    • Risk Management
    • Due Diligence
  • Industries
    • Browse Patent Samples
    • Automotive Patents
    • Construction Patents
    • Consumer Products Patents
    • Electronics Patents
    • Food, Beverage, & Other Culinary Patents
    • Manufacturing Patents
    • Medical Products & Devices Patents
    • Optics Patents
    • Software & App Patents
    • Tools & Equipment Patents
  • Learning Resources
    • First-Time Inventor?
    • Why Patent Your Invention in a Bad Economy?
    • Videos on Patents
    • Search 180+ Articles
      • Patent process
        • Overview of Patent Process
          • Patent process timeline and major milestones
          • Patent Process: Invention to Patent Granted (Simplified)
          • Patent process, overall steps and procedures
        • Overview of the examination process within the USPTO
          • Highs and lows of securing patent protection for your invention
          • What is the Patent Office procedure after filing a patent application?
        • Benefits of a Patent Search
          • What is a patent search and How to do it?
        • Patent attorneys, agents and the USPTO can help with the patent process
        • USPTO Website
      • Invention Agreements
        • What is an NDA and when to use them?
        • How to use a contract to protect your invention?
        • Working with others without losing your IP rights
        • Patent Assignments for Independent Contractors
        • Losing Invention Rights When Hiring or Collaborating with Others
        • Avoid Problems: Get an Invention Assignment Agreement
      • Protect Inventions
        • Misconceptions of Provisional Patent Applications
        • Do you need to get your patent attorney to sign an NDA?
        • Can a confidentiality agreement protect me like a patent application?
        • Four types of intellectual property to protect your idea and how to use them
          • Overview of Patents and Intellectual Property
          • Patent protection benefits and why every inventor should consider getting one
          • 8 tips to successfully protect your idea
          • Benefits of Patent Protection
          • Best uses for design patents
        • Reasons to only market your invention after securing patent pendency
          • Dangers of 1 yr grace period under first-inventor-to-file system
          • File a patent application before telling others about the invention
        • Risks and benefits of securing software patent protection
          • Strategy to overcome patentable subject matter rejection
        • Pros and cons of filing a continuation-in-part application
          • What is a continuation patent application?
      • How Patent Applications Work: the Basics
        • How to respond to an office action?
        • Request for non-publication of a patent application
        • Anatomy of a Patent Document
        • How to write a broad patent application?
        • Design patents: pros and cons
      • Patent costs
        • How much does it cost to get a utility patent?
        • Provisional Patent Application: Cheap Alternative?
        • Patent Cost Framework and cash flow
        • Provisional patent application: a cheap option?
        • Cheap provisional patent applications
      • Patent infringement
        • Basics of writing a patent claim for a patent application
        • Patent Marking: Everything you wanted to know
        • Avoiding Patent Infringement
        • Can I Copy My Competitor’s Product?
        • Can I Copy My Competitor’s Product? (Design Patent)
      • Worldwide patents
        • Pros and cons of securing worldwide patent protection and their steps
        • Foreign patent filing to secure protection in other countries
      • Responding to Office Actions
        • Overview of Office Actions
      • Trademarks
        • Trademark Registration: common law, state and federal
        • How to obtain a federal trademark registration?
        • How to select a trademark?
          • Protect your idea when pitching to an investor, potential licensee, or buyer
  • Schedule Consultation
  • Contact

Top-Rated Orange County Patent Lawyer | Helping Inventors in Orange County, Los Angeles County & Beyond | OC Patent Lawyer, Irvine CA

Orange County Patent Attorney

(949) 433-0900
You are here: Home / Patent Infringements / Reducing Scope of Doctrine of Equivalents Via Ensnarement Defense

Reducing Scope of Doctrine of Equivalents Via Ensnarement Defense

June 26, 2009 by James Yang

As previously discussed in “Avoiding Patent Infringement,” the claims define the metes and bounds of patent protection afforded under a patent.  The claims can be infringed either literally which means that the alleged infringer practiced the claimed invention without any deviation.  If the alleged infringer practiced a variation of the claimed invention, then liability for patent infringement may still be found under the doctrine of equivalents.  This doctrine prevents others from making insubstantial changes and easily avoiding the claims.  Otherwise, the value of the patent would be greatly diminished.  However, this doctrine is still limited to the extent that the patentee made limiting statements during prosecution (i.e., examination) of the patent.
In Depuy Spine, Inc. v. Medtronic Sofamor Danek, Inc. 2008-1240 (Fed. Cir. 2009), the jury found that the alleged infringer did not literally infringe the claims of the patent but did infringe under the Doctrine of Equivalents.  The alleged infringer contended that the doctrine of equivalents cannot operate to broaden the claims to cover the accused device because doing so would “ensnare” the prior art.

Ensnarement bars a patentee from asserting a scope of equivalency that would encompass, or “ensnare,” the prior art.  As a helpful step in the ensnarement defense analysis, a hypothetical claim that covers the accused device is drafted.  Next the court determines whether the patentee has carried its burden of persuading the court that the hypothetical claim is patentable over the prior art.

In Depuy Spine, Inc., the patented technology involved spinal screws.  The accused device involved a screw in a receiver with a compression member such that the screw is “rigidly” secured.  The alleged infringer brought forth two references, namely, Puno and Anderson asserting that the hypothetical claim is not patentable over these two references.  The patentee and the accused infringer agreed that Puno disclosed all of the limitations of the hypothetical claim except for a compression member.  Anderson taught the compression member.  After consideration of the references, the Federal Circuit held that Puno taught away from incorporating the compression member into the Puno device.  The reason is that the Puno device discussed the benefits of a “shock absorption”.  If the compression member is incorporated into the Puno reference, then the Puno device would no longer have this “shock absorbing” effect which is useful for spinal screws.  Hence, the Federal Circuit held that the proposed combination is non-obvious.  Thus, the Court denied the accused infringer’s ensnarement defense.

Should you have any questions, please feel free to contact me.

Related Articles for Patent Infringement

  • Basics of writing a patent claim for a patent application
  • Avoiding Patent Infringement
  • Can I copy my competitor’s product?
  • Can I copy my competitor’s Product? (Design Patent)
  • Attacking patent claims as indefinite made easier
  • Reducing Scope of Doctrine of Equivalents Via Ensnarement Defense
  • Broken chain of priority invalidates patent
  • Combine Claim Elements to Avoid Infringement
  • How to invalidate a patent based on a restriction requirement
  • Active inducement of infringement in physician patient relationships
  • Irreparable harm easier to prove for grant of patent based injunction
  • Everyone in the supply chain could be sued for patent infringement
  • Penalty for False Patent Marking
  • CAFC defines competitive injury for false patent marking
  • Process patent blocks importation of product

Author

James Yang is a patent attorney. For more than 16 years, James Yang has been representing clients to secure patent protection for their inventions and register trademarks to protect their brands. If you need help, call him at (949) 433-0900. Read More…

Popular Posts

  • Patent process overview
  • Patent process explained
  • How much does a patent cost?
  • Why patent your invention in a bad economy?

Patent Book

Navigating the Patent System - new book by Orange County patent attorney, James Yang

Navigating the Patent System: Learn the patent process and strategies to protect your invention

Read for Free
Buy at Amazon

RECEIVE PATENT ARTICLES

Stay up to date on major changes and get tips on the patent process.

We respect your privacy.

Popular Posts

Patent process overview
Patent process explained
How much does a patent cost?
Trademark process and costs
Patent process and costs

 

Services

Utility Patents
Design Patents
Patent Prosecution Services
Patent Defense Services
Patent-Law Counsel for In-House Attorneys
Trademark Prosecution Services
See All Services

Industries

Automotive Patents
Consumer Products Patents
Culinary Patents
Manufacturing Patents
Medical Patents
Optics Patents
Software & App Patents
See All Industries

Contact

James Yang
OC Patent Lawyer
2372 Morse Ave., Suite #178
Irvine, CA 92614
Tel: (949) 433-0900

Connect

  • Facebook
  • LinkedIn

Sitemaps

Sitemap: Pages | Sitemap: Posts

Terms of Use and Privacy Policy

By accessing this blog, you agree that no attorney-client relationship is formed except by a subsequent written retainer agreement. Also, you agree to not send confidential information unless directed by me to do so. The information posted on this blog is legal information and not legal advice.
Complete Terms of Use
Complete Privacy Policy

ADA Compliance

OC Patent Lawyer aims to ensure that its services are accessible to people with disabilities.
Accessibility Statement

Service Area

From our office in Irvine, California, we serve clients from all areas within Orange County and Los Angeles County, California.

© 2023 · James Yang, Your Entrepreneur and Mid-Size Business Patent Attorney