US Patent 6175636 - Electrostatic Speaker With Moveable Diaphragm Edges

[User211]

This is not light reading, but I thought I'd post it because it looks interesting. To be honest, I haven't read it all yet, but I will do soon.

Here's the link: http://www.patentstorm.us/patents/6175636/description.html

Any comments that would help laymen to understanbd what this patent is about would be cool - a basic summary so to speak.

I have often thought an obvious limitation of the ESL is the fact that the diaphrams are anchored - maybe this will improve matters.

If this has been discussed before please let me know - it is a 7 year old patent, after all. Searching MLOC for the patent gave no references.

Looks like you have to register to download the PDF with the useful diagrams in. But it is free.

 

[MiTT]

Justin, if you try this link you should be able to see the associated diagrams...

http://www.google.com/patents?id=F-cFAAAAEBAJ&dq=patent:6175636&as_drrb_ap=q&as_minm_ap=1&as_miny_ap=2008&as_maxm_ap=1&as_maxy_ap=2008&as_drrb_is=q&as_minm_is=1&as_miny_is=2008&as_maxm_is=1&as_maxy_is=2008

Looks very interesting!

 

[User211]

Thanks Tim.

Well, that certainly helps from a brief glimpse... however, tonights TV viewing is sorted

It's been around so long surely ML have had a play with the ideas...

 

[User211]

Well, not much interest shown so far, but I have just had a good read and understood as much as I can - not being an ELS speaker designer probably doesn't help too much.

Basically, figures 2 & 5 show the configuration required. It isn't rocket science - in fact it is very simple. I am not saying it won't be hard to implement well, but the concept is simple. Just tension the diaphragm in the Y plane, don't support the vertical edges, and let the whole surface move back and forth. That way you can get more air displacement as the sides aren't fixed.

Surely this is a good idea, as Fig 4b shows you'll get more air displacement over the conventionally adopted 4a pattern. The bigger displacement for a given size means it must be a better bet for low frequencies.

This is pretty obvious stuff - what's wrong with it, I wonder? An ideas? Why hasn't anyone adopted it? Triple stator dual force seems like hard work in comparison.

Point of uncertainty - in fig 5, how are the diaphragms driven - in other words, at any given time, are the diaphragms moving in the same, or the opposite direction? I'd guess the later, since the gap between them isn't sealed. But you don't need the dual diaphragm - a single diaphragm will do - just don't support it at the edges.

This patent begs the question, why did they ever support the diaphragm on all sides? Surely this is the most obvious way to get good results. Bit puzzled by that, to be honest.

Thinking caps on, please! Comments most welcome... Roger Sanders - what do you think?