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T-rex

Quetzalcoatlus

Gorgonops

something else

I ain't scared of no pterodactyl

purplemonkey dishwasher

[notStanley]

https://en.wikipedia.org/wiki/Laser_turntable

A few of today's search hits tried to imply it was "not digital", that is just market speak.  The optical interface will not be analogue.

[hedgie]

My turntable isn't contactless, unfortunately, but *does* have a USB output.  So, whenever I buy a new LP, the first thing I do is record a playthrough and encode it as flac.  Of course, I am lazy and have several acquisitions that I haven't played yet because chopping up the resulting stream into discrete tracks is annoying.

[Thrudd]

https://en.wikipedia.org/wiki/Laser_turntable

A few of today's search hits tried to imply it was "not digital", that is just market speak.  The optical interface will not be analogue.

You can blame the whole mess on today's modern patent jungle that has stymied any real developments of a commercial product outside of the rarefied atmosphere of audiophiles with more money than sense.

If I was designing such a system to day I would start by using a cellphone camera module through a short focus lens since it is pretty much off the shelf except for the lens, small and lightweight.
Physical tracking would be linear to match the mechanism they used to cut the original track for the die press so you avoid the tonearm tracking distortion you would normally get.
The software for this is a straight off the shelf industrial vision system.

As for the reading of the track data 100% digital may give you too much detail and you would have to get creative with your filtering algorithms but the reproduction would be 100% accurate.
Mind the electronics to do all this would have to be using the processing power equivalent to a modern video card and not a few hundred kilohertz used in most consumer goods.

[Tova]

Which specific whole mess are you referring to in your post? There are so many to choose from. 

I'd be curious to know what patents on this technology, if any, remain unexpired. The fundamental patent would have expired by now.

I suspect that the devil is in the implementation detail, as is the case with a lot of these kinds of ideas. But if it's as even half as straightforward as you say, why not go ahead and build one?

[Wingy]

Our late cat would bury her face in anything that smelled like sweaty feet.

One of our late cats was the same.  If I came in all hot and sweaty from doing outside chores, the Best. Possible. Thing. for that cat to do was come over to where I was lying on the floor and roll in my left armpit.  The wetter and nastier it was, the louder she'd purr.  My right armpit wasn't nearly as interesting; go figure.  And if I made the mistake of taking my Tshirt off, she'd groom my armpit hairs (which you can imagine what a cats tongue feels like on unprotected armpit skin). 

Truly a strange beast.  Yes, I have pictures.

[Thrudd]

Which specific whole mess are you referring to in your post? There are so many to choose from. 

I'd be curious to know what patents on this technology, if any, remain unexpired. The fundamental patent would have expired by now.

I suspect that the devil is in the implementation detail, as is the case with a lot of these kinds of ideas. But if it's as even half as straightforward as you say, why not go ahead and build one?

From my limited experience, reading on the subjects and discussions with those on the law end of things all those patents and copyrights and trademarks just don't effectively expire unless someone forgot to renew them [see LEGO and the law office that lost a whole list of major clients for that screw-up - they forgot to file the paperwork in time]

Patents get renewed, refreshed by minor tweaks to a formula [pharmaceuticals] or design modifications [yes changing one spec in a patent makes it "new"], or abandoned due to being encircled by similar patents that prevent any modification to the original.

Copyright is the latest tool to lock down technology through copyrighting code and the anti-hacking laws making third party service highly illegal.
Copyright is also death+70 years or some such crazy corporate shite since if it wasn't like that the creators would not be able create more work. [they're dead Jim]
The biggest instigator for that little gem is Disney so that they can keep the mouse in the house.
The Copyright office is a bastion of dysfunction where the rule is "if it wasn't in our files as yet it can be patented" and we end up with patents being issued on centuries old technology or the transfer of an everyday common work routine onto an automated system and patenting the work routine itself because it is done on a computer [mind they don't even bother detailing the how, just the what].

When it comes to this specific application, each and every component or system I mentioned is available off the shelf.
The issue does not come from assembling everything into a working system but to be able to sell the resulting product at a commercial scale without going broke and-or crazy.
Each part comes with it's own licensing and sub licensing, patents and copyright fees.
You would have to find each and every copyright and patent holder and make a deal with them and pray they do not say no or charge some ridiculous amount and that there is some obscure stupid patent that you missed that will extort huge sums from you.
This is easier for mega-corps since they have portfolios of patents and lawyers at their beck and call yet even they fall prey to patent trolls who extort moneys for nonsensical patents that were issued because fighting them is costlier than paying them off - well unless they really piss the corp off and then they hunt down and ravage the trolls patent portfolio into non-existance.

Too bad it is damn near impossible to get rid of a troll unless they are the epitome of chutzpah, stupid and crooked - see Prenda Law for a rare example of this - it is a fun read.

[Is it cold in here?]

I got called in for a deposition in a patent lawsuit against a former employer. It was over a pretty obvious technique that my former employer had not used. One lawyer said that progress in that particular field had come to a halt because of patent litigation.

[Mr_Rose]

The biggest instigator for that little gem is Disney so that they can keep the mouse in the house.

They won’t ever lose Mickey; trademarks can be refreshed indefinitely.
What they don’t want is people publishing certain, ah, how shall we say, early works of a controversial nature? Yes, those, from being published on YouTube or whatever without any legal means to remove them, because copyright extends exclusively to individual works, not bodies of work or parts of a work like a character.

This is wholly separate to the patent issue and I agree, the USPTO is messed up right now, but considering they’ve issued patents for perpetual motion machines for at least the last century I’m not sure it’s that new a phenomenon.

[Tova]

Patents get renewed, refreshed by minor tweaks to a formula [pharmaceuticals] or design modifications [yes changing one spec in a patent makes it "new"], or abandoned due to being encircled by similar patents that prevent any modification to the original.

Copyright is the latest tool to lock down technology through copyrighting code and the anti-hacking laws making third party service highly illegal.
Copyright is also death+70 years or some such crazy corporate shite since if it wasn't like that the creators would not be able create more work. [they're dead Jim]

I used to work for one of the world's most prolific patent writers, so I'm somewhat familiar with this topic.

And yes, in case you're wondering, I am extremely frustrated with the patent system, and particularly in relation to software patents, which is a can of worms all on its own.

It is absolutely true that patents often get renewed through the addition of minor tweaks that are somehow justified as novel. Here is the thing about the patent system in general. The patent office gets ludicrous numbers of applications and the barrier to justifying a patent application as novel and inventive is somewhat lower than it really ought to be. Essentially, just because a patent application is successful, that doesn't mean that the patent is truly valid. That is particularly true of the kinds of refreshes you are talking about. Their attitude is that if it passes some low barriers, then it will be granted, and if you don't like it, you can test it in court.

There are lots of "perpetual motion patents" as Mr_Rose puts it, and the like, which I wouldn't regard as valid, but as they haven't been tested in court, there they sit.

Because challenging a patent in court is a costly and lengthy exercise pretty much reserved for people who can afford expensive lawyers, this is a bullshit system. It's the reason so many trolls are successful, as I'm sure you're aware. They generally rely on you not having the funds or the patience to test their claims in court, and in fact, even large companies like the one I used to work for would rather settle than go to the trouble of challenging much of the time. It's cheaper.

And yes, that's the reason you see so many perpetual motion patents.

The only real bright side from my experience is that I have some ability to read patentese now.

Patents are meant to be a trade between the inventor and the state. The inventor discloses to the state how to make the thing they have invented. The state grants the inventor a monopoly over that invention for a period of time. In theory, everyone ought to benefit from such a trade. We all know that's mostly not the case. We need to change this.

Also, since you mention it, yes I agree that 70 years for copyright is BS as well. 20 years ought to be ample time.

Back to the contactless turntable you're talking about. You are implying that the reason these are not commonplace is because of patent issues. However, it's possible that the real reason is that getting these things to work reliably and well is rifer with difficulty than you are imagining. When you look at the various reviews, they talk about them not being able to play coloured vinyl and being highly sensitive to dust and impurities.

While it is possible that they "refreshed" the patent by patenting some new technique or tweak, it should be possible to avoid such patents by avoiding these new techniques, possibly by coming up with your own innovations to solve the problems those patents are addressing, or maybe even just ignoring them. The fundamental patent has expired, so there is nothing stopping you from implementing it.

P.S. I am not a lawyer, just an engineer, so my word on patents is far from gospel.

[Thrudd]

P.S. I am not a lawyer, just an engineer, so my word on patents is far from gospel.

Then you know a darn sight more than the Lawyers and all but maybe one or two judges.

Now onto the more fun engineering issues you mentioned.

(click to show/hide)

/Begin Geek

Dust:
Since we are avoiding direct physical contact and will be using a rigid head tracking system my suggestion is put everything into a glass faced box [cool factor]
Lets run it like a first generation HDD [I mean the DEC Pizza Boxes] by having the case under partial pressure with clean filtered air.
We could even have an airstream / vacuum set up to clear the tracks in front of the read head.

Reading:
Lasers have had the issues of tracking accuracy on the groves. Their solution was to use several to triangulate over the variable surface terrain.
Silly things like LPs are just not flat enough.

My original thought was ultrasonic to avoid the colour issue but the resolution is the equivalent of a Mack truck on a bicycle path.

My next idea is to use modern industrial optical software with high speed auto-focus and scanning using a cellphone camera module or cluster.
This is not unlike terrain following radar except we only have to stay focused one one thin track as the disk spins below the read head.
Add to that multiple light sources of various wavelengths [LEDs are awesome] to automatically select the correct colour for a viable optical response.
An added bonus with looking at a large enough area is that you can keep track through damaged areas like scratches and such.

Once we get the tracking mechanism to actually track then we can zoom in and focus on the track itself and use image analysis tools to convert that into an audio stream.
This is where your sample rates come into play
 - how many overlapping images from different angles are spliced together to determine the true contour
 - Scratch and pop elimination algorithms come into play here as well
 - Then there is the filtering and frequency response adjustment that could simulate the response of an electromagnetic head and vacuum tubes

Now the kicker is we need to do all this in real time and that would be some serious computing power.
Mind if you are just concerned with encoding and conversion to an electronic format then you don't have to run the system as fast and crunch everything at a much slower pace.

/End Geek

[Tova]

I'll just throw in the complication that there are actually two contours to work out, not just one, for stereo albums.

[Thrudd]

I had to look that up - stereo on a record - sheeesh - I don't remember any of the records or players I have ever owned being stereo capable.
- just checked my record accumulation and dang it, I do have some stereo LPs
- all of them are orchestral and operatic collections I picked up at various bazaars and yard sales over the years.

Fortunately that would only require a tad more work on the software side treating the left and right sides of the grove as separate data streams

[pwhodges]

I had to look that up - stereo on a record - sheeesh - I don't remember any of the records or players I have ever owned being stereo capable.

Hardly new; the mono LP was only around for ten years before stereo ones became available, and separate mono pressings died out barely ten years after that.  Nearly all LPs are stereo.

Funny story.  In 1957 there was an international meeting to agree the means by which stereo would be put into a record groove.  The preferred way was agreed, and then the Bell Labs representative told the meeting that they had patents on that method, so everyone would have to pay them royalties.  The British representative then, without a word, put a copy of an expired patent on the table.  It was Blumlein's 1931 patent for the exact same thing, which Bell Labs were not even aware of! (Blumlein was one of the true technical geniuses of that time, and worked for EMI just outside London; he did pioneering work in sound reproduction, television and radar.)

[Tova]

I had to look that up - stereo on a record - sheeesh - I don't remember any of the records or players I have ever owned being stereo capable.
- just checked my record accumulation and dang it, I do have some stereo LPs
- all of them are orchestral and operatic collections I picked up at various bazaars and yard sales over the years.

Fortunately that would only require a tad more work on the software side treating the left and right sides of the grove as separate data streams

If I recall correctly, it's something more along the lines of left and right movement of the stylus being left + right, and vertical movement of the stylus being left - right. Maybe not exactly, but something along those lines.

The reason for that is that you want your albums to have mono compatibility. So if it's a mono player and only looks at the horizontal movement, then you get the sum of the two channels which is a basically mono-compatible mix. But stereo players can also calculate the left and right signals by adding half the difference channel to get the left and subtracting to get right.

The ability to play albums on mono and stereo equipment was a big deal.

I think my parents may have had a handful of mono albums, but the vast majority were in stereo. Some of them made a very big deal of being stereo and mono-compatible on the front of the cardboard sleeve.

[Tova]

Funny story.  In 1957 there was an international meeting to agree the means by which stereo would be put into a record groove.  The preferred way was agreed, and then the Bell Labs representative told the meeting that they had patents on that method, so everyone would have to pay them royalties.  The British representative then, without a word, put a copy of an expired patent on the table.  It was Blumlein's 1931 patent for the exact same thing, which Bell Labs were not even aware of! (Blumlein was one of the true technical geniuses of that time, and worked for EMI just outside London; he did pioneering work in sound reproduction, television and radar.)

This is why you have to be so careful in searching for prior art before lodging a patent claim. The risk of being granted, and paying for, a worthless patent is very real.

[pwhodges]

"Mono-compatible" on a stereo LP simply meant that the LF components of the difference signal were attenuated so that a pickup not designed to track the vertical movement wouldn't get thrown out of the groove.

Although there have been pickups that sensed the horizontal and vertical movements and matrixed them (in the sensor coils, or a separate transformer) to generate left and right outputs, most pickups are actually mechanically arranged so that the two 45° movements actuate separate sensors so that no matrixing is necessary.

[Tova]

I see! Thanks for that bit of info.