Crestron Trolling Again

[MorbidFractal]

Recent effort to patent known technology.


US20160373076A1 - Average current-mode feedback control of multi-channel class-d audio amplifier


US20160373076A1 - Average current-mode feedback control of multi-channel class-d audio amplifier
- Google Patents


Generally falls foul of Melanson/Dixon. Dixon is/was the Unitrode Application notes Dude.


EPO Global Dossier


European Patent Register


The examiner, in part, uses Dixon to trash the claims made by Crestron. However it looks like the USPTO is going to allow the Patent coz...


Crestron modified Claim 1) to suggest the current sense resistor location is special.


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[jan.didden]

I don't understand why people are so hung up on patents. What does he want to gain by it? Does he think people will actually going to pay him for the privilege to build and sell an amp like that??
Bragging rights?
Or does he think the rest of the world will suddenly want to have one of those amps??

Jan

 

[MorbidFractal]

In some respects I understand the value of patents. There are or may be virtues in implementing current mode control, average or otherwise, in a Class D amplifier in that it could simplify post filter feedback. From my perspective the patent even as amended in Claim 1) is completely invalidated by prior art and if it is granted by the USPTO and Crestron try to file via the EPO I will submit third party observations under EPC 115 and get it kicked. If the PCT properly applies then it will die in the US as well.

 

[jan.didden]

Even if the patent is sensible, there are so many ways around it or just 'almost' like it, don't for a second believe that all of a sudden the sound is incredible.
Every $ they spend on that patent is money down the drain.

It's all emotional.

Jan

 

[scott wurcer]

The examiner, in part, uses Dixon to trash the claims made by Crestron. However it looks like the USPTO is going to allow the Patent coz...


Crestron modified Claim 1) to suggest the current sense resistor location is special.


...

It's known as narrowing the claims which seriously weakens the value. I have seen patents where claims were narrowed down to small ranges of capacitor and resistor values so in effect the basic general idea had no protection.

My vote for the worst offender US5103188A. The USPTO granted the current feedback amplifier again with claims that read directly on material published almost 10yr. before. If you read there was litigation in 2006, 100's of hours of my time wasted.

 

[MorbidFractal]

In respect of sensible then yes it possibly, definitely, is. I've spent lots of time trying to optimise something similar using average current mode control and have no doubts others have done so based on what is already known. It does work.

In respect of ways around it and/or narrowing the claims once filed you are not allowed to introduce new subject matter and this will be why Crestron have re-worded Claim 1) in the manner that they have.

The problem is that anyone 'skilled in the art' seeking to control filter inductor current would look for branches in the circuit to do so and, if appropriate, select that particular location. Crestron only noticed after the initial rejection event.

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[MorbidFractal]

Third party observations filed...


United States Patent & Trademark Office


Argued on the basis of Lloyd Dixon Unitrode application note U140.


http://www.ti.com/litv/pdf/slua079



The examiner used the same to discount the applicants previous claims.


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