Boss's asymmetrical clipping patent

[syzygy]

I've been playing with the diode placement on my recently built Chaos circuit, and got to thinking... Since Boss has the patent on asymmetrical clipping, does that mean that no one can legally create a commercial pedal with differing numbers/types of dioodes in the clipping section (read: anything but symmetrical style clipping)?

[filterazonatie]

What about Ibanez, Maxon, Fulltone, etc? They all have pedals with assymetrical clipping... That would be uber-weird. Then again, stranger things have happened I guess.

How the hell did they get that??

[mlabbee]

Do you have the patent number?  I'm curious to see what the patent really covers.

[vanhansen]

What about Ibanez, Maxon, Fulltone, etc? They all have pedals with assymetrical clipping... That would be uber-weird. Then again, stranger things have happened I guess.

How the hell did they get that??

Ibanez uses symmetrical clipping.  That's the main difference between the Boss SD-1 and Ibanez Tube Screamers.

[cd]

I've been playing with the diode placement on my recently built Chaos circuit, and got to thinking... Since Boss has the patent on asymmetrical clipping, does that mean that no one can legally create a commercial pedal with differing numbers/types of dioodes in the clipping section (read: anything but symmetrical style clipping)?

Don't worry about it.  The original OD-1 was introduced in the '70s.  Any patent has probably long expired.

[syzygy]

Ibanez uses symmetrical clipping.  That's the main difference between the Boss SD-1 and Ibanez Tube Screamers.

I also read that Ibanez said that Boss has a patent on asymmetrical clipping.    Read one reference here.. search for "patent".

So far, in non-Boss commercial schematics, I've only seen symmetrical clipping. (i.e., Marshall Blues Breaker, Proco Rat, MXR Distortion, Marshall Shred Master, Ibanez Tube Screamer, to name a few).

[syzygy]

Don't worry about it.  The original OD-1 was introduced in the '70s.  Any patent has probably long expired.

Interesting.  Well, I'm not personally worried about it, I'm just wondering why you don't see more asymmetrical clipping styles in schematics.  By now companies must have tried every combination of diode you can try -- so why don't you see as many out there?  But I haven't looked at too many modern commercial schematics.. I guess because they are too new to have their schematic floating around in public domain places like this

I guess my question should be.... does anyone know any commercial pedals with asymmetrical style clipping besides Boss pedals?

[cd]

[quote="syzygyI'm just wondering why you don't see more asymmetrical clipping styles in schematics.[/quote]

It's cheaper to use 2 diodes instead of 3.

[Greybeard]

Nobles DT-1 has asymmetrical clipping diodes, and symmetrical LED clipping both

[object88]

Can anyone actually find this supposed patent?  I just spent some time searching the USPTO (*), and the Roland Corp seems to have only 1 patent (which seems to have something to do with sampling).  I did a search for patents containing "asymmetric" and "clip" in the abstract, and got a few interesting results, including...

#5,032,796: held by St. Louis Music, Inc., granted in 1991, but specifically uses zener diodes and seems to relate to a bias shift.

#4,995,084: held by Eric K. Pritchard, granted in 1991, which the asymmetry is achieved an uneven bias and "limiting", and which has the clipping mechanism in a seperate part of the circuit.

#4,180,707: held by Norlin Industries (but invented by Bob Moog), granted in 1979, which talks about asymmetric clipping due to full-wave rectification.

Given this, I think that if there was a patent held by Roland / BOSS, it would have to detail a particular method, which means that the patent can probably be gotten around by avoiding that particular method.  I don't know if simply changing the number of diodes would work, but perhaps the type?

Oh yeah, BTW, I am not a lawyer.  

(*) admittedly, I only searched 1975-present full-text.

[puretube]

there are some other Japanese names behind the dozens of B*ss/K*rg/R*land patents...

[toneman]

there's the "Peavy" patent, i think, at GEO or AMZ.
uses twin-zeners in the feedback of an OA.

[R.G.]

It's worth noting that patents expire in 20 years.

[syzygy]

It's worth noting that patents expire in 20 years.

Interesting.. you mean all patents?  Would a company have to apply for another patent after the first one ends, or are they restricted from doing that?

[R.G.]

Interesting.. you mean all patents? Would a company have to apply for another patent after the first one ends, or are they restricted from doing that?

Actually, expiration is the whole point of patents from the government's point of view.  Well, at least it's the stated point. Patents are a barter agreement between governments and inventors.

Governments award patent protection - such as it is - in return for the inventor making the useful innovation public. The inventor was given a time of exclusivity to make money on their idea in return for telling everyone how to do it after the expiration date. That's why you have to provide enough detail in an application to show someone how to do it. The idea is that after the expiration, everyone is better off by having the useful knowledge be freely available.

USA law used to provide 17 years with a renewal process. If I remember correctly, it was changed to 20 years no renewal to be more in line with other countries' systems.

So patents expire. After expiration, you are welcome, in fact invited by your government to take the patent information and go make good stuff with it.

[syzygy]

Actually, expiration is the whole point of patents from the government's point of view.

Wow this is an eye opener, I never thought of that possibility.. I will never look at patents the same way.  Thanks RG

[ibanezts808]

I believe the patent laws have been changed down to seven years, because all of the sugar substitue companies, splenda, nutra sweet, etc. have expired after seven years if I recall correctly, I'll do some more research.

[puretube]

that`s trademarks...

[ibanezts808]

And The American Government Says:(drumroll)

How long does patent protection last?

--------------------------------------------------------------------------------

For applications filedon or after June 8, 1995, utility and plant patents are granted for a term which begins with the date of the grant and usually ends 20 years from the date you first applied for the patent subject to the payment of appropriate maintenance fees. Design patents last 14 years from the date you are granted the patent.  No maintenance fees are required for design patents.  

Note:  Patents in force on June 8, 1995 and patents issued thereafter on applications filed prior to June 8, 1995 automatically have a term that is the greater of the twenty year term discussed above or seventeen years from the patent grant.


Thank you for playing how the hell long does a patent last!

[ibanezts808]

that`s trademarks...

my mistake, I'm just glad that I didn't pick some random number that had no realtiona to anything in the ball park

you see, I'm not one of those "I must be in first place people"  I'm one of those, "I cannot come in last place people" call me a realist if you will. lol.  I only kid, or else I'd be out trying to buy my pedals right now.