United States: Laches Defense Loses Its Luster In LED Patent Dispute

In determining whether a laches defense applies to thwart a claim of patent infringement, courts must often shine a light upon murky and complicated factual scenarios. A Massachusetts court recently navigated such a scenario in granting the plaintiff's motion for judgment, deciding that the complex web of facts did not support a defense of laches as argued by the defendants.

Plaintiff Boston University (“BU”) is the owner of a patent that covers aspects of gallium nitride (“GaN”) thin films, which are used in light-emitting diode (“LED”) chips. Defendants Everlight and Epistar are closely-connected companies in the business of manufacturing and distributing LED chips and packages. Epistar produces LED chips, which are purchased by Everlight for integration into its LED packages.

In 2012, BU sued Everlight and Epistar alleging infringement of its GaN film patent. After an eleven-day trial, the jury found BU's patent to be valid and infringed by Defendants—and awarded BU damages of approximately $10m. BU thereafter moved for an entry of judgment, and asked the court to impose pre-judgment and post-judgment interest. Defendants countered this motion with a defense of laches, arguing that BU unreasonably delayed filing suit against them and the delay resulted in material economic prejudice.

To decide if laches was applicable, Judge Saris had to unpack a dense set of facts relating to the timing of BU's knowledge of the Defendants' (or their predecessors') infringement of the patent-in-suit. At certain points from 2002 through 2010, the evidence suggests that BU—through its licensing and enforcement partner, Cree—had known of potential infringement by, or had communicated its belief of infringement to, various entities that would be connected to Epistar or Everlight.

For Epistar:

  • In 2002, BU identified United Epitaxy (UE) as producing infringing LEDs; Epistar later merged with UE but discontinued all of UE's products.
  • In 2005, Cree sent a letter to Epitech accusing it of infringement; Epistar later merged with Epitech but discontinued all of Epitech's products.
  • In 2010, Cree met with Epistar to discuss licensing opportunities; it identified the GaN patent but did not accuse Epistar of infringing it.

For Everlight:

  • In 2004, Cree accused Fairchild Semiconductor (a distributor of Everlight LEDs) of infringing the patent; Everlight later acquired the Fairchild LED business.
  • In 2007, Cree met with Everlight and accused it of infringing the patent; Everlight then reached out to Epistar for assistance in defending the infringement allegations.

In view of the above facts, the Court first wrestled with the issue of whether the presumption of laches should apply to each Defendant—as both Defendants relied on a tacking theory to cast BU's knowledge back in time. The Court found that Epistar's tacking theory failed and the presumption of laches did not apply because Epistar could not prove that its predecessors' products were the same or substantially similar as the accused products. With respect to Everlight, however, the Court ruled that the presumption of laches did apply because, in purchasing Fairchild's LED business, Everlight became a successor-in-interest to Fairchild and BU's knowledge of Fairchild's infringement went back to 2004.

Turing to whether a laches defense should apply to relieve Epistar of infringement liability, the Court determined that BU's delay in filing suit—from late 2010 when BU and Epistar discussed licensing, to late 2012 when the suit was filed—was not unreasonable. Judge Saris reasoned that the parties' licensing discussions and BU's pre-suit investigation for the bulk of 2012 were sufficient excuses for the delay. As a result, she declined to explicitly address whether BU's delay resulted in material economic prejudice to Epistar, and found for BU on the issue of laches.

For Everlight, the Court partitioned the period from 2004 to 2012 in determining whether BU's delay was unreasonable. Judge Saris found that because BU was engaged in patent litigation against another entity from Sept. 2006 to March 2009, its delay in filing suit against Everlight was excusable for this three-year window. But, she determined that BU had no acceptable excuse for the remainder of the eight years—and concluded that BU had failed to rebut the presumption of laches on the unreasonable delay prong.

However, Everlight's laches defense burned out on the issue of economic prejudice. First, Everlight claimed that it could have switched from using Epistar LED chips to non-infringing Cree chips—but the evidence showed that the Cree chips were much more expensive and would have required a different LED package design for Everlight's customers. Everlight also argued that it could simply stop purchasing Epistar chips—but such an act would have economically harmed its closely-connected partner. Finally, Judge Saris found that Everlight's reliance on indemnification from Epistar and its belief in non-infringement would have caused Everlight to stay the course and continue using Epistar chips. In light of these facts, the Court dissolved Everlight's laches defense and found for BU.

Judge Saris' opinion illuminates the difficulty that defendants may face in convincing a factfinder that laches applies to their case. While some defendants may consider a laches defense as a beacon of light to combat delayed infringement claims, it should be noted that the facts surrounding laches are almost never crystal-clear.

The case is Trustees of Boston Univ. v. Everlight Electronics Co., Ltd., Civil Action No. 12-11935-PBS, before Chief Judge Patti B. Saris. A copy of the opinion can be found here.

Laches Defense Loses its Luster in LED Patent Dispute

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on Mondaq.com.

Click to Login as an existing user or Register so you can print this article.

In association with
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Check to state you have read and
agree to our Terms and Conditions

Terms & Conditions and Privacy Statement

Mondaq.com (the Website) is owned and managed by Mondaq Ltd and as a user you are granted a non-exclusive, revocable license to access the Website under its terms and conditions of use. Your use of the Website constitutes your agreement to the following terms and conditions of use. Mondaq Ltd may terminate your use of the Website if you are in breach of these terms and conditions or if Mondaq Ltd decides to terminate your license of use for whatever reason.

Use of www.mondaq.com

You may use the Website but are required to register as a user if you wish to read the full text of the content and articles available (the Content). You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these terms & conditions or with the prior written consent of Mondaq Ltd. You may not use electronic or other means to extract details or information about Mondaq.com’s content, users or contributors in order to offer them any services or products which compete directly or indirectly with Mondaq Ltd’s services and products.


Mondaq Ltd and/or its respective suppliers make no representations about the suitability of the information contained in the documents and related graphics published on this server for any purpose. All such documents and related graphics are provided "as is" without warranty of any kind. Mondaq Ltd and/or its respective suppliers hereby disclaim all warranties and conditions with regard to this information, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. In no event shall Mondaq Ltd and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of information available from this server.

The documents and related graphics published on this server could include technical inaccuracies or typographical errors. Changes are periodically added to the information herein. Mondaq Ltd and/or its respective suppliers may make improvements and/or changes in the product(s) and/or the program(s) described herein at any time.


Mondaq Ltd requires you to register and provide information that personally identifies you, including what sort of information you are interested in, for three primary purposes:

  • To allow you to personalize the Mondaq websites you are visiting.
  • To enable features such as password reminder, newsletter alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our information providers who provide information free for your use.

Mondaq (and its affiliate sites) do not sell or provide your details to third parties other than information providers. The reason we provide our information providers with this information is so that they can measure the response their articles are receiving and provide you with information about their products and services.

If you do not want us to provide your name and email address you may opt out by clicking here .

If you do not wish to receive any future announcements of products and services offered by Mondaq by clicking here .

Information Collection and Use

We require site users to register with Mondaq (and its affiliate sites) to view the free information on the site. We also collect information from our users at several different points on the websites: this is so that we can customise the sites according to individual usage, provide 'session-aware' functionality, and ensure that content is acquired and developed appropriately. This gives us an overall picture of our user profiles, which in turn shows to our Editorial Contributors the type of person they are reaching by posting articles on Mondaq (and its affiliate sites) – meaning more free content for registered users.

We are only able to provide the material on the Mondaq (and its affiliate sites) site free to site visitors because we can pass on information about the pages that users are viewing and the personal information users provide to us (e.g. email addresses) to reputable contributing firms such as law firms who author those pages. We do not sell or rent information to anyone else other than the authors of those pages, who may change from time to time. Should you wish us not to disclose your details to any of these parties, please tick the box above or tick the box marked "Opt out of Registration Information Disclosure" on the Your Profile page. We and our author organisations may only contact you via email or other means if you allow us to do so. Users can opt out of contact when they register on the site, or send an email to unsubscribe@mondaq.com with “no disclosure” in the subject heading

Mondaq News Alerts

In order to receive Mondaq News Alerts, users have to complete a separate registration form. This is a personalised service where users choose regions and topics of interest and we send it only to those users who have requested it. Users can stop receiving these Alerts by going to the Mondaq News Alerts page and deselecting all interest areas. In the same way users can amend their personal preferences to add or remove subject areas.


A cookie is a small text file written to a user’s hard drive that contains an identifying user number. The cookies do not contain any personal information about users. We use the cookie so users do not have to log in every time they use the service and the cookie will automatically expire if you do not visit the Mondaq website (or its affiliate sites) for 12 months. We also use the cookie to personalise a user's experience of the site (for example to show information specific to a user's region). As the Mondaq sites are fully personalised and cookies are essential to its core technology the site will function unpredictably with browsers that do not support cookies - or where cookies are disabled (in these circumstances we advise you to attempt to locate the information you require elsewhere on the web). However if you are concerned about the presence of a Mondaq cookie on your machine you can also choose to expire the cookie immediately (remove it) by selecting the 'Log Off' menu option as the last thing you do when you use the site.

Some of our business partners may use cookies on our site (for example, advertisers). However, we have no access to or control over these cookies and we are not aware of any at present that do so.

Log Files

We use IP addresses to analyse trends, administer the site, track movement, and gather broad demographic information for aggregate use. IP addresses are not linked to personally identifiable information.


This web site contains links to other sites. Please be aware that Mondaq (or its affiliate sites) are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of these third party sites. This privacy statement applies solely to information collected by this Web site.

Surveys & Contests

From time-to-time our site requests information from users via surveys or contests. Participation in these surveys or contests is completely voluntary and the user therefore has a choice whether or not to disclose any information requested. Information requested may include contact information (such as name and delivery address), and demographic information (such as postcode, age level). Contact information will be used to notify the winners and award prizes. Survey information will be used for purposes of monitoring or improving the functionality of the site.


If a user elects to use our referral service for informing a friend about our site, we ask them for the friend’s name and email address. Mondaq stores this information and may contact the friend to invite them to register with Mondaq, but they will not be contacted more than once. The friend may contact Mondaq to request the removal of this information from our database.


This website takes every reasonable precaution to protect our users’ information. When users submit sensitive information via the website, your information is protected using firewalls and other security technology. If you have any questions about the security at our website, you can send an email to webmaster@mondaq.com.

Correcting/Updating Personal Information

If a user’s personally identifiable information changes (such as postcode), or if a user no longer desires our service, we will endeavour to provide a way to correct, update or remove that user’s personal data provided to us. This can usually be done at the “Your Profile” page or by sending an email to EditorialAdvisor@mondaq.com.

Notification of Changes

If we decide to change our Terms & Conditions or Privacy Policy, we will post those changes on our site so our users are always aware of what information we collect, how we use it, and under what circumstances, if any, we disclose it. If at any point we decide to use personally identifiable information in a manner different from that stated at the time it was collected, we will notify users by way of an email. Users will have a choice as to whether or not we use their information in this different manner. We will use information in accordance with the privacy policy under which the information was collected.

How to contact Mondaq

You can contact us with comments or queries at enquiries@mondaq.com.

If for some reason you believe Mondaq Ltd. has not adhered to these principles, please notify us by e-mail at problems@mondaq.com and we will use commercially reasonable efforts to determine and correct the problem promptly.