Patent invalidation searching in seconds – case study on patent asserted against Toyota, Volkswagen and other global car companies

How long does a patent invalidation search take?

If you were to use a traditional approach, it could be quite a while. You need to work out the keywords for the search, and make sure that you don’t miss any relevant keywords. You might also look up and apply a class code filter to the results, an additional step which could take additional time. 

You would then run this search through a conventional patent search database, and then comes the fun part – sorting the relevant from what could be hundreds of irrelevant patents. Realistically the ratio of relevant to total hits is going to be very low – and you will probably end up finding all of the patents already listed as patent citations.

Many many hours can lost in this way.

But there is another approach, and it can produce results in seconds – all the time while avoiding the risk of missing relevant patents due to inconsistent keywords. Best of all, this process builds on all the prior art searches already done in the same area of technology:  crowdsourcing on steroids, if you will.

This approaches is the Ambercite Cluster Searching patent search tool. To show how this works, we are going to use the example of US patent 8155342, filed by Blitzsafe in June 2006 for a Multimedia device integration system. This  essentially claims the concept of choosing songs streaming from your phone say, by using a controller in your car stereo via a bluetooth connection.


Does your car do that? These days it is increasingly difficult to find a new car that doesn’t. Which is probably why the owner of this patent is busy suing the likes of Toyota, Volkswagen, Honda, Hyundai and Nissan for patent infringement. Who in turn are busy launching PTAB submission about why the patent is invalid. And no doubt running many patent invalidation searches.

So what would such a search look like in Cluster Searching? There are two main ways we can run an invalidation search for a known patent:

  • The really simple way – simply enter the patent number itself into Cluster Searching
  • The slightly less simple way – enter either the known prior art citations, or perhaps the most relevant of the prior art citations (as judged by the searcher or perhaps by the examiner).

In this case study, we are going to go for the really simple way. US8155342 has a filing date of June 2006 and a lot of listed prior art patents. Because there is potentially a lot of money at stake in this litigation, we might ask for the most similar 500 patents. The result search query looks like this:


The results start off like this (double click on this image to get a full size version)



This table shows a ranked list (by similarity) of the similar patents predicted by our algorithms. Perhaps not surprising, at the top of the list is a slightly earlier patent (US2005023434) filed by the same inventor. But as with any set of Cluster Searching results, the full list contains patents filed by a long list of applicants.

While this list provides the key details of the owner, name and filling date of the patents, pressing the blue circle in each row (in the live version) provides much more information about each patent listed, including the full specification in many cases.


Known vs Unknown citations

One of the key columns in the results in the second last column, headed “Citation’. This indicates whether a listed patent is either:

  • “Known”, i.e already known as a citation, discoverable using conventional patent search databases
  • “Unknown” (as citations). These are patents predicted to be similar but which have not yet been listed as citations.

Accordingly, ‘Unknown’ citations can be using in re-examination processes such as the US PTAB hearings, because they have not been cited by the patent examiners or the applicants.

But are they relevant? The column heading includes a simple filter, and so we can set this filter so that only unknown patents are shown. The top few results looks like this:


Are the patents on this list relevant? They are all in the same general area – and some quite similar, for example (these patents are found a little further down the list)

  • US20050044574, filed by Harman International in June 2004 for a Audio/visual server. T discloses a music server that can communicate with a car stereo – and a portable digital music player is a music server. 
  • US20050286481, filed by Apple in June 2004 for a Method for data transmission utlizing a portable multimedia device, and which includes the ability to recieve track information and control the music

And are no doubt many more relevant patents – but these two examples should be enough to show that there is value in these results.

These results also confirm a point made earlier – searching for these sorts of patents can be hard because of the wide range of keywords used for similar concepts. The Harman patent application, for example, uses the terms ‘server’ and ‘computer’ to describe what Apple call a ‘portable multi-media device’ – but ultimately it is much the same thing.



This simple example shows how easy it is to search for previously uncited prior art that can be used to help invalidate a patent. These searches can be based on the number of the patent being invalidated, and rather than relying on your own assumptions about keywords, you can instead can draw upon the collective wisdom of all of the prior art reports in this area to do the work for you.

And does it work? In the words of our users:

We would like to mention how great we think the AmberScope search tool performs. We had the opportunity to test it now already for a case we are working on and it performs brilliantly.” – Dr. Patrick Daum, M.Sc., B.Sc, European Patent Attorney

I represent [X] in their case against [Y].  I was thoroughly impressed by your analysis of the [Y] patents”  – US patent attorney

I was looking for a prior art patent to invalidate a granted patent that was blocking a client’s product coming to market. I had tried a conventional patent search, and even a conventional citation search, but without luck. So I ran the search in AmberScope – and by exploring the visual links was able to find a prior art patent that essentially discloses the blocking patent. My client is now in a much better position to bring a product to market. Once again, AmberScope has found prior art missed by other searching techniques.” Gennaro Simonetta – Patent attorney, IP consultant – Griffith Hack

I recently used AmberScope for a novelty search and got a knock-out hit in less than half an hour. Even though, we generally use other platforms for searches I have to admit once you use Amberscope, you can’t go back to anything else. Keep up the good work!” –  A.M, Australian patent attorney


Want to try this for yourself?

Please contact us about a personal demonstration and free trial. We also offer free trial searches (we do the work for you, to prove that it works) for patent litigators. 

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