Controlling with photocells

[Mark Hammer]

I had the opportunity to use a device with expression-pedal control, and decided to substitute an LDR for the expression pedal.  I ran a cable from the expression pedal jack to a photocell mounted to the pickguard with some masking tape, in a location where I could hide/expose it with my picking hand as I played.  The photocell was not a perfect match for the expression pedal, but gave enough of a range of parameter change to get a sense of control.  Hand control has a decidedly different feel to it than foot control.

VERY neat!

I wonder what sort of market there might be for a custom cable optimized for this.  Imagine you had a 3-conductor cable, with moulded ends.   Hanging off the audio phone plug at one end was a thin-gauge cable with a flat photocell module that you could affix to the guitar surface with double-sided adhesive, and hanging off the other phone plug would be a secondary plug for the expression pedal jack.  That way, you could have hand remote control over the pedal, but without the nuisance and extra weight/risk of a second cable.

Seem appealing?

[R.G.]

Good idea.

I saw a device which did this at NAMM a few years ago. It was patented. Never saw it on the market or in use.

Neat idea. I think the environment may be a problem, depending as it does on ambient light to set up the photocell for conduction, and it's maybe somewhat directional, working different when you're facing the spotlights  than when you're facing the band or floor.

[Mark Hammer]

Which is part of the reasons to simply make it part of a cable that you can install and uninstall easily.  If the ambient conditions don't permit, then just opt for a normal cord and an expression pedal.  If it's one single cable, then it's no big whoop to switch.

I suppose the other thng is to have some sort of miniature thumbwheel pot on the photocell module to adjust resistance range as well as optimizing it for ambiant light conditions.

I bought a Lexicon MIDI floorboard from a buddy last year, and haven't really used it much since I bought it, but now I'm intrigued by the possibilities of using this with an expression-pedal input to control the MIDI-controllable rack units I have.

[soggybag]

Lovetone had a LDR controller that you could plug in. I think you bought a cord with the LDR in one end and just plugged it into the effect.

Wasn't there also some device that controlled effects by hand motions, where you wore this ring that was detected by the controller. Oh yea, and the Z Vex drip guitar with the built in wah  probe.

[R.G.]

Which is part of the reasons to simply make it part of a cable that you can install and uninstall easily.  If the ambient conditions don't permit, then just opt for a normal cord and an expression pedal.  If it's one single cable, then it's no big whoop to switch.

Yep. I think they built theirs into the plug body on a cord and were selling the cord. I was as polite as I could be trying to suggest things to them about their mechanical setup, but I fear that they just vanished. I've never seen one on a music store shelf or in a player's hands after seeing it at the show.

I believe they did the whole thing with an LDR in series with the signal line on the cable, which is different from your using it for the actual resistance in a pedal at the end of the cord, a little. Close enough to find a cheapo lawyer to sue if you didn't check it out carefully. On the other hand "they" (whomever they were) may no longer exist, so the patent issue could be firmly in limbo.

I suppose the other thng is to have some sort of miniature thumbwheel pot on the photocell module to adjust resistance range as well as optimizing it for ambiant light conditions.

Yeah. My approach to that was to suggest that they use an onboard LED that your finger interfered with, perhaps IR or UV to keep it from being noticeable to the eye. Actually, the version they had was so simple that I think it's a good adaptation to put on the pickguard of the guitar and just short out/around selectably. Make it part of the guitar controls, perhaps inside the pickguard or the center of the volume knob, something like that.

I bought a Lexicon MIDI floorboard from a buddy last year, and haven't really used it much since I bought it, but now I'm intrigued by the possibilities of using this with an expression-pedal input to control the MIDI-controllable rack units I have.

Yeah, using it for other than guitar by controlling an expression pedal is a little more elaborate; shouldn't be all that difficult to do. I'm still intrigued by putting it into the guitar itself, and using a stereo jack. Mono cord disables it, stereo cord carries it.

I think you ought to go do a patent search. By USA law, you have 1 year to file from first public disclosure. As it's well documented here, you could still file within the next year. "Their" patent may have been narrow enough to step around with the elaborations you've come up with.

[Gurner]

There are quite a few Infra Red LED controller circuit for robots that could be adapted as an expression controller  for guitar- the way around the ambient light being (eg spotlights) being addressed, is to send the infra red LED a 'carrier' signal (ie 30khz or so)  then extract the varying returned CV level (ie as picked up by a infra red detector as a hand moves over the sensor) ...aka AM demodulation.

[MoltenVoltage]

I think you ought to go do a patent search. By USA law, you have 1 year to file from first public disclosure. As it's well documented here, you could still file within the next year. "Their" patent may have been narrow enough to step around with the elaborations you've come up with.

2 points,

First, RG describes only American patent law.  By disclosing his ideas on the forum, Mark lost patent rights in many foreign countries.  From the USPTO:

"If the inventor describes the invention in a printed publication or uses the invention publicly, or places it on sale, he/she must apply for a patent before one year has gone by, otherwise any right to a patent will be lost. The inventor must file on the date of public use or disclosure, however, in order to preserve patent rights in many foreign countries."

Second, it's my understanding that making an improvement to another's invention does not give you the right to use the underlying invention.  You'd need to come up with a design that didn't use the original invention at all (which you may have done), or convince the patent holder to license it.

I saw this at NAMM a couple years ago too:
http://www.sourceaudio.net/products/hothand/

[Mark Hammer]

My own two points, I guess:

1) I'm not particularly interested in acquiring or defending any patents.  I can't think of a single idea I've ever had in my life that was anywhere as important as the legwork it took to bring the idea to implementation, and I don't have anywhere near the ambition it takes to bring things to implementation.  So, while I appreciate the sincerity of the advice, it's really somebody else's battle.

2) Regardless of who makes it, who makes profit from it, or how many manufacturers make it, the critical element is always going to come down to the pedal being compatible with such a thing in a manner that makes the pedal enjoyable and productive to work with.  Whether you've bought or made the cheapest cable that money can buy, or the priciest, you still have to plug it into something in order to get value from it.


As for the Hot Hand controller, I think it's a terrific idea and have been hoping to run into those pedals since they were released a couple of years ago.  Unfortunately, nobody in town carries them, and I don't get out much, so it's difficult to know if the controller is a great idea, or merely a great idea in principle.  The Hot Hand needs a specific brand of pedal to work.  My own musings about photocell controllers are basically with respect to an easily adaptable low-tech solution to a broad class of low-tech devices.  For instance, a person could easily pop a hole in a phaser pedal for a mini phone jack, and wire up a photocell to alter the sweep rate or resonance from the guitar in real-time.  In playing with it, as noted earlier, it seemed to me that the hand/palm control was decidedly different in feel than foot control.  It's also the case that there are some things you can do with your feet at the same time your hands are busy, so why not exploit the possibilities?

[R.G.]

First, RG describes only American patent law.  By disclosing his ideas on the forum, Mark lost patent rights in many foreign countries... The inventor must file on the date of public use or disclosure, however, in order to preserve patent rights in many foreign countries."

Yep. S'wat I said: By USA law, you have 1 year to file from first public disclosure.

Second, it's my understanding that making an improvement to another's invention does not give you the right to use the underlying invention.

Yep, that's true. Howsomever, it's my understanding that by patenting an improvement to another patent, you forever impede their ability to patent your improvement, and at the same time by disclosing it, you forever prevent them from filing and preventing YOU from using your improvement in a way that's not necessarily inherently built on their patent. We had to play this chess game a lot at my last employer. Sometimes we wrote contracts many layers deep into the game on the theory that it would be played out in courts if necessary; then we all agreed to cross license. 

You'd need to come up with a design that didn't use the original invention at all (which you may have done), or convince the patent holder to license it.

Maybe. As I noted:

"Their" patent may have been narrow enough to step around with the elaborations you've come up with.

Patent claims are interesting; lawyers exist who can split claims ever so finely based on things like where the commas are in a claim.  It's kind of like the medieval controversy over how many angels can dance on the head of a pin. I should say that I know **nothing** about the patented device we're discussing, other than it was there and they claimed a patent. I don't know that they even actually had one; never looked it up. Frankly, if I'd been the patent examiner, I'd have disallowed it based on the extensive prior art of LDRs in signal level controls of all kinds in the last century. But that's neither here nor there. I wasn't the examiner, and in my experience, "patent examiner" is not one of the huge draws of the finest technical talent, although there are some very good ones I've met.

If, for hypothetical discourse, they claimed only use of the device in a guitar cord, for controlling guitar volume, then their claims would be limited to that, and a hypothetical patentor of an LDR on a guitar body to control a remote expression pedal controlling something else other than the guitar's volume might be able to get the same loosey-goosey system that let a patent through on this widgie in the first place to issue a patent on all uses other than guitar volume when the LDR is in the cord. And then there is the issue that once the ink is dry on the patents, it's up to the patent owners to make them stick. They have the proverbial license to sue at their own expense, however much of that they think they can convince a jury (composed of "peers" who are too hapless to avoid jury duty) to award them.

Patents. Useful for clubbing others too poor to hire representation. 

[MoltenVoltage]

First, RG describes only American patent law.  By disclosing his ideas on the forum, Mark lost patent rights in many foreign countries... The inventor must file on the date of public use or disclosure, however, in order to preserve patent rights in many foreign countries."

Yep. S'wat I said: By USA law, you have 1 year to file from first public disclosure.

Mark is in Canada, and American law does not control patent law in other jurisdictions as your response implied.

I agree that the Patent system is far from perfect, but its better than nothing and levels the playing field to a pretty good extent for the garage tinkerer, assuming he/she can come up with a valuable idea and a few bucks to patent it.


Litigation: A machine which you go into as a pig and come out of as a sausage.
- Ambrose Bierce

and the lawyers make breakfast
- me

[deadastronaut]

done something very similar... but i had the ldr action reversed...so it opened a wah/volume/mod when dark....instead of lit..

i made one for a mate ages ago who wanted it in his mouth....the nutter.....   .it looked funny when he used it though!.

[MmmPedals]

http://www.sourceaudio.net/videos/post/introduction-to-hot-hand/

[R.G.]

Mark is in Canada, and American law does not control patent law in other jurisdictions as your response implied.

Yes, I know Mark is in Canada. And my statement did not say that USA law controls other countries; only that by USA law you have one year to file a patent. There is no implication there that USA law applies elsewhere.

Being in Canada does not prevent him from filing a USA patent. Patents may be filed in any country, and usually must be filed in most of the industrial countries to protect the idea to any degree that patents protect anything. Other countries will have other locally determined dance steps to be executed before being given a pretty certificate (the major value to an individual inventor).

I think you have to pay for the pretty certificate these days. I haven't checked recently, but the filing fees were on the order of $1k at one time, and if you hire a patent attorney to do the searches and other stuff associated with a filing, it'll be another few $K. Trivial to a company, but not trivial to an individual.

I agree that the Patent system is far from perfect, but its better than nothing and levels the playing field to a pretty good extent for the garage tinkerer, assuming he/she can come up with a valuable idea and a few bucks to patent it.

I disagree. The garage tinkerer coming up with a valuable idea which they patent and then make a zillion bucks on is little more than a pleasant myth as the world works today. If a patent is really valuable, it will be taken from the original patenter and used by whatever corporation wants it. There are case histories.

I've seen the patent system as it really works. It is better than nothing, but only marginally so. A patent is worth only the amount of money you can spend to defend it, compared to the amount of money that a major corporation can spend to break it. It's one of the clearest illustrations of the idea that you do not really own anything you can't defend.

Look up the history on the intermittent windshield wiper. The patent was filed in 1964, issued in 1969, and he got Ford to settle in 1990. The inventor's suit against Chrysler ended with a verdict in the inventor's favor in 1995, when he got $30M after spending over $10M in legal expenses. He *never* got a judgement against GM or other auto companies.

This case is most notable in that the inventor did finally win something. In almost all cases, the inventor can't spend several decades and millions of dollars defending an idea, and can't, as Kearns did, sell shares in the future winnings to finance legal action. The bottom line is that a patent's worth is determined by two things: (1) how good and commercially valuable the idea is and (2) how much justice you can afford to keep it. If the commercial value of a patent attracts a company who can spend millions on lawyers, the chances of an individual of keeping the idea and profiting from it are really very small. Notice that we're not even discussing whether major companies can enforce patents in places like China. That concept is in the news every few weeks. In some cases no amount of money will enforce your patent.

That is, the playing field is not leveled to any great degree. About all you can say is that it's made into a kind of lottery, where the original idea is a kind of lottery ticket.

So I respectfully disagree.

[Mark Hammer]

My experience with patents was vicarious, through my late father.  In the early 70's, he tried to get on the ground floor of temporary winter garages, and get a patent for a fastening system that would allow for easy installation of a plastic car shelter over a swaged tubular steel frame.  I worked just about every weekend on it with him, and he was making trips to Sears headquarters to line up orders, and attempting to secure a patent.  In the end, nothing came of it....for him, anyway, and today you can see those home-assembly garages in hardware store flyers everywhere that has winter.  I ended up having to give him my school loan to buy a 2nd hand car so he could get to his machine shop and do his regular work.  Could he have obtained a patent?  Quite possibly.  But his pockets were simply not deep enough to sustain the effort until the point of fruition.

And that is the take-home message from RG and myself: Patents are not obtained by walking in with a bright idea and a nice diagram that conforms to patent-office requirement, such that the person at the counter smacks their forehead and goes "Whoa, man, never seen anything like THAT before!".  They take a lot of hard slogging, and as the number of patents pile up over time, and globalization increases, it takes even longer to determine if what YOU are seeking patent protection for is distinct from everything else out there.  The Beatles were successful because they had the good fortune to come out in the early 60's.  As brilliant as they were, and as timeless as their music is, they would amount to a passing mention in the trade mags now, simply because they would not stick out against the sheer volume of all the other stuff out there.  Same is true with patents.

There's a show here, and in Great Britain, called "Dragon's Den" (there was also a show on US tv  last year with a couple of guys from the Canadian show as panelists; something with "shark" in the title).  The premise is that a panel of a half-dozen highly successful and moneyed entrepreneurs and investors listen to pitches from people who come on with what they believe are great business ideas.  The people with the ideas do a little dog and pony show, and indicate what sort of investment they are asking for, and for what percentage of the company.  If it is an object, or unique material or process, one of the first questions the investors usually ask is whether the developer has a patent on it, and where the patent is held.  If the product is uncomplicated to produce, and the developer is not able to say they hold Canadian, American and some form of European patent (and having PAF status does not count in their eyes), the investors quickly lose interest, because they know that someone else will likely copycat the product with cheap foreign labour in the blink of an eye.

[MoltenVoltage]

Here's how my grandfather did it - a true garage tinkerer.   He found a patent attorney willing to work for a piece of the action.

If you have a good great enough idea, there are patent attorneys out there that will work on contingency because they see licensing fees at the end of the rainbow.

Of course it's no simple matter to obtain, defend, and more importantly license a patent, but it happens all the time, every day, and there are thousands of success stories.

The example of Kearns, the intermittent wiper inventor, is not particularly telling since, according to Wikipedia, he waited 9 years to even file suit, and subsequently "decided to manage the Chrysler litigation on his own with his family. However, this strategy did not seem to work out well in subsequent litigation against GM, Mercedes, and Japanese companies as he missed deadlines for filing papers and his cases were dismissed."

As the old saying goes, the plaintiff who represents himself has a fool for a client.


As for success stories, here's one of my favorites, and its not just because Repo Man is one of my favorite movies:

http://en.wikipedia.org/wiki/Bette_Nesmith_Graham
http://www.women-inventors.com/Bette-Nesmith-Graham.asp

She is the mother of Michael Nesmith (of the Monkees, et al) and the inventor of liquid paper.


I agree that if your invention is not the next "liquid paper" you should save your money.

[amptramp]

I have an unusual patent story - I own one outright for work I did at a company that was sold before the patent issued.  The inventor must be paid the customary $1 for a patent by the company he is working for and my company did not do that.  Looking back, I imagine they may have been giving me the patent that I worked on at their expense (but they sold it to another company anyway - ethics was not their strong suit).  At another company I applied for that was familiar with my work, I was told that I owned the patent because the former company did not transfer ownership properly.  Some companies offer larger cash incentives for patents and file about 3 or 4 a week, but the company I was at was not like that.

So now I have a patent for deposition of column drivers on glass for LCD displays.  It was applied for in 1994 and issued in 2000.

I would agree that the patent system as it exists is priced out of reach of the average individual inventor and of many small corporations.  It is just a trading card for major corporations now.