CBS Interactive is being sued by Blue Spike Inc, a company based in Florida and who have started similar actions against a range of other companies. And in fact, a review of this matter on the US Patent Pair website suggest 39 different companies are being sued by Blue Spike, including NEC Corporation, Fujitsu, Nielsen, Yahoo, Google, and Shazam.
Blue Spike are alleging that CBS (and these other companies) are infringing several patents, the first listed patent being US7346472. This patent claims a method of monitoring 'signals' such as broadcasts, songs, videos, and potentially any media work, including when the signal is sent through the internet. It is claimed to be an advance over prior art methods that monitor similar signals using added digital watermarks, but where the added watermarks can get lost during broadcasting, or may need special software to read.
At the risk of oversimplfying a complex patent, claim 1 of this patent can be understood to be read as something along the following lines:
- Receiving a signal;
- Creating an summary ('abstract') of this signal in some way, where the summary is based on the signal itself, and where the summary still retains a 'perceptual relationship' to the signal;
- Storing the signal in a database;
- Analysing a query signal in the same way, and comparing this to the stored summary in the database.
The 'perceptual relationship' term in this claim is likely to be important, and as defined in the body of the patent:
may either mathematically discernible or a result of market based needs....The purpose is to afford a more consistent means for classifying signals than proprietory related text-based approaches. A simply analogy is the way that in which a forensic investigator uses a sketch artist to assist in determining the identify of a human
Later on in the patent, the applicant refers to an embodiment including data reduction techniques that led to a:
significantly data-reduced that is not likely to reflect the human perceptual quality of the signal
So there appears to be no limitation that the relationship be human perceptual, i.e. being mathematically discernible is sufficient.
This Blue Spike patent has a filing year of 2000, and claims a series of priority dates, with the earliest claimed priority date being July 1996.
But is this patent novel and inventive? Because if it wasn't novel and inventive over the prior art, any claim by Blue Spike Inc against CBS and any other companies that it has alleged infringement of this patent against would disappear.
This is the sort of question that is ideally suited for our new patent search tool AmberScope, which searches for patents through citation relationships to known patents in the same field to find patents that may be disclosure similar inventions.
In this case study, we started by entering US7346472 into the AmberScope search box, producing the following image. This shows US7346472 as a dot in the centre of a network of other dots, each dot which represents either a patent that is a backward or forward citation to this central patent. There are also some 'ghost patents' shown, which are selected patents that are connected to either forward or backward citations, and which AmberScope suggests might be relevant to the patent in the centre of the network.
Note there are mostly backward citations, as indicated by the blue lines (showing backward citations). The green lines show forward citations.
In the above picture, the 'Title Box' of the BlueSpike patent is shown. The Title Box of other patents can be shown within AmberScope by moving a mouse over these other patents. Pressing the Details button found in each title box opens up either a Google Patents or Espacenet webpage providing further details of the patent.
One option to simplify this network is use the filing year Filter to remove all patents later than 1997, since 1997 was the priority year of the BlueSpike patent. But in this particular case, there are still plenty of patents to have to go through.
Another trick when looking at a crowded patent network is to use the 'Next button' (bottom left hand corner of the screen) to systematically work your way through every patent in the map - it need not take long. The patent Title Boxes are then displayed in the order of their AmberScore value, which is a measure of patent connectiveness that is shown in every patent box. For example, the patent box for the BlueSpike patent shows an AmberScore value of 2.9 (in the orange coloured triangle) - where 2.9 means that this patent is 2.9 times as connected as the average US granted patent filed in the last 20 years.
By using the Next button in this way, we ended up opening up US5606609 to Scientific Atlanta, which was highly rated (AmberScore value of 30) and seems a little promising as it referred to 'an identifier for invoking the processing of the security information'. This is not quite what we were looking for, but a step in the right direction.
US5606609 has 411 forward and backward connections, and any one of these patents could be what we are looking for. So we 'refocused' the patent network onto this patent, using the 'more' button found in its patent box.
After the patent network has been refocussed this way, we can start exploring its connection in the same way as before, i.e. by filtering out patents filed later than 1997, and then using the Next button to systematically work our way from the highest ranked patent downwards. Although the diagram below looks a little crowded, in practice using the Next button makes navigating this patent network very manageable in practice.
This in turn leads us to US5259025 to Audio DigitalImaging, which discloses the concept of using biometric data such finger prints in a compressed form as an identifier.
Is biometric data a 'signal'?
We will leave this to the lawyers to argue this one. But they may not need to, because the real value in US5259025 is what happens when the network is refocused on this patent, and again the patents are year filtered and the Next button is used to work our way through the patent network.
This shows a couple of patents that are very close to what we are looking for, including
- US4230990 to Lert et al – creates a broadcast signature which is used to compare documents, and so appears to quite similar to the Blue Spike patent, and was filed in 1979.
- US4993068 to Motorola – use of a biometric characteristic in a compressed form as and identifier, and the use of this for verification. This patent was filed in 1989.
The Lert patent discloses an invention very similar to the Blue Spike patent by itself, but why stop when we are on a roll? So the network is refocussed one last time to be centered on US4230990, which has 377 further connections and an AmberScore value of 51, suggested that it is a very important patent.
Using the Next button and the filing year quickly brings up two more patents of likely relevance to the Blue Spike patent:
- US4697209 to AC Nielsen– uses intrinsic parameters as a signature/abstract, and which are compared to other signatures, and was filed in 1984.
- US4843562 to Broadcast Data Systems – waveforms are used as an 'spectagram' (similar to abstract) , and compared to other waveforms in a library, and was filed in 1987.
And we could keep going, but we have made our point by now. A number of these patents are a lot closer to the Blue Spike patent than the main patent discussed by the examiner in the file wrapper (US6088455 to Logan, published in 2000), and could potentially be of great interest to the lawyers defending companies such as CBS against charges of patent infringement.
This further confirms the ability of AmberScope, based purely on citation connections, to find highly relevant prior art missed by patent examiners and patent applicants.
While some of these patents are in different technical fields, they do disclose inventions that are similar in concept. And this case, we started with a patent that referring to sending signals, moved on to some patents that referred to biometric data, but then found these patents linked us to patents that were in a very similar technical field to what we started with.
Please note the overall searching techniques we need used in this search:
- Start with the patent we trying to invalidate
- Apply a filing year filters to make the search more manageable
- Use the 'Next' button to work our way from the patent with the highest AmberScore value downwards, looking for patents of potential relevance.
- Refocus the network on patents of potential interest, even if imperfect matches to what we are looking for
- Repeat this process a number of times, working our towards patents of greater and greater relevance.
- Do not worry about keywords or IPC codes, as these may be misleading and limit the patents that you find.
This overall search strategy is shown below.
Interested in trying AmberScope for yourself? Simply go to www.amberscope.com and register your details to use AmberScope as part of our free beta trial.
March 2013 update - some of the images shown above feature quite crowded patent landscapes. Thanks to an update in AmberScope introduced in February 2013, the same search would show a less crowded landscape which would be easier to navigate and faster to load - but still produce the same outcomes.