ADT lawsuit settled


A patent lawsuit, dating back to 2006, filed by Paradox Security Systems of Montreal originally against ADT and DSC and eventually also including Protection One and Monitronics appears to have been put to rest.

Here’s a very convoluted legalese-ridden take on the recent judgment from

Not easy to figure out what happened from that document, right?

A news outlet called Law360 translated that for me. They reported that on July 19 the U.S. Court of Appeals for the Federal Circuit in East Texas dismissed Paradox Security Systems Ltd. infringement suit against ADT Security Services Inc. and others over home security system technology.

From the report:

“The Federal Circuit agreed with the U.S. District Court for the Eastern District of Texas that Paradox, a Montreal-based security services provider, had failed to provide enough evidence of infringement.”

I couldn’t get the whole Legal 360 story online, so had to go back to to find out what the patent in question had to do with. I gather it has something to do with alarm transmissions, but I’ll let you read for yourself.

The ‘406 patent relates to protective elements for home security systems that communicate with a central security office via telephone lines. Protective elements are frequently integrated into the circuitry of such systems to prevent damage from power surges. The preferred embodiment disclosed in the ‘406 patent employs two opto-couplers, in contrast to the four or more employed in the prior art. These opto-couplers protect elements of a home security system during both incoming calls from the central security office and outgoing calls from the home.

Still awake? If you’re wondering who Paradox Security Systems is, here’s a company intro I found online, which, fortunately was not written by

Since 1989, Paradox Security Systems started with an impressive line of motion detectors whose patents are still used in our products today. In 1996, we introduced the Digiplex series of security systems, featuring our encrypted expandable bus system. In 2001, we introduced an extensive range of wireless systems, including the award-winning Magellan all-in-one console. Over the last few years, our focus has shifted progressively towards software development. In 2007, we revamped and shifted many products to new platforms, including the MG, SP and EVO series. We also introduced advanced communication modules using GSM and IP, and in-field firmware upgradeable hardware. We are also proud of our history, and showed it by re-introducing the Elegance a beautifully styled motion detector that we first produced 15 years ago.


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<p class="comment_author">July 30th, 2010 at 10:35 am</p>
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<p>I was an employee and it is a shame that due to lack of evidence this was lost. I saw the engineering and Paradox did patent the opto-coupler dialer before DSC copied it.</p>
<p>If you are wondering why it&rsquo;s important, when lighning strikes the phone line (which happens a lot), the alarm panel would be fried without this feature. Also a thief could take advantage by cutting injecting high voltage into an exposed phone line.</p>
<p>The couplers completely separated the phone circuitry from the alarm system&rsquo;s. So if it fried, it would not be able to dial out but the local siren would work and perhaps a radio backup depending on how it was connnected (via relay or siren)</p>
<p>Well, let&rsquo;s see if there is an appeal or if they just let it go.</p>