deskthority

Hello there!
I am Luxanna, and while I am not quite active here (or should I say I am not active here at all) I have been into mechanical keyboards for some while now and maybe it's because I come from audiophile community (which obviously is known for having it's own terminology for basically everything) or maybe it's because I am a perfectionist who gets triggered on the inside every time somebody calls rubber dome a "membrane keyboard", but I think there should be a more advanced and clearer division system of mechanical keyboards.

I guess we all can agree that there are 2 very basic systems of dividing mechanical keyboards right now:
1. Mechanical keyboards and membrane keyboards
2. Mechanical keyboards and rubber dome keyboards
The first one is obviously wrong, but it's the more popular one (because it's easier to remember I guess) and the second one is also wrong because it doesn't cover like 50% of the key-switch types out there, and while for exampe you could just say that topre is a rubber dome (yeah, let's use the most radical example) it doesn't really do the justice because it's not "just" a rubber dome and it's just an example!

I think I came up with a better idea of dividing the types of keyboards and here is what it looks like
1. Rubber dome keyboards (this is quite simple and I don't think there should be any need to explain this category and
what should be in it, because if you look at the rest of the system it will become almost self explanatory)

1.1 Rubber dome based switches - Rubber dome based switches would be the ones which use rubber dome to register
the key press but they aren't "just" a dome (most of the dome with slider switches, alps integrated domes, fujistu
peerless and scissor switches)

2. Rubber dome feel mechanical switch - this is quite simple. It's a switch which uses rubber sleeve / dome / whatever
for tactility and/or return force but it doesn't use it to register the key press resulting in different, a lot of the times
much more refined key feel (Topreh, Fujitsu Libretouch or tactile foam and foil).

3. Mechanical switches (and now I have to define what a mechanical switch is... Well, according to what I just said a
mechanical switch is a switches which doesn't use a rubber dome to register the key press)

And now you might be asking yourselves... But what's the point? Well, I always say that it's not about the type of a keyboard, but it's all about it's quality, however I know how hard it may seem for an average person to get into our hobby and I think it would help a lot if we had some simple and easy to understand division system people could start with. Obviously this system doesn't cover everything (mainly because I am too lazy and there are too many switches out there), however I think it's a good core which we could expand so it could become one of the best starting points for new keyboard fans.

Well I think the most accurate way to explain a keyboard would be by how switches are activated (capacitance, hall-effect, cross-point contact, reed, membrane) along with how switch resistance is created (spring (default), buckling spring, rubber dome, plate spring). This can be complicated with some edge cases but if the person knows about the edge cases then they understand what you are talking about by just saying the model number of the keyboard or key switch.

Example of what I am talking about,
Membrane Buckling Spring Switches (Model M)
Membrane Rubber Dome Switches (Most modern keyboards)
Membrane Scissor Switches (Most Laptop Keyboards)
Crosspoint Switches (Cherry MX) < default assumption is resistance is applied by a spring
Hall Effect Switches (Xmit keyboard) < default assumption is resistance is applied by a spring

Oh, you will never find consensus of what "mechanical switch"/"keyboard" means ...
1) has moving parts (everything but a touchscreen or laser keyboard basically)
2) mechanical linkage (inclined plane, hinge, etc.) in the switch
3) mechanical linkage (inclined plane, hinge, etc.) is used for actuation within the switch
4) has a coiled spring
5) is in an "enthusiast grade" keyboard
6) has properties of typical mechanical switches, such as actuation before bottoming out, distinct bottom etc...
7) has a slider over the rubber dome :rolleyes:
... etc
Personally, I would go with (3).

A "membrane keyboard" is technically one that does not have anything on top of the membrane (ZX81, Atari 400).
I would say that Wikipedia is correct on this (but confusing), and our wiki is even worse, as ours lumps together membrane keyboards and keyboards that use a membrane as only a part of the actuation mechanism.

Many people, however seem to think that "membrane" refers to the domes being connected in a rubber sheet, or refer to the rubber dome itself as a membrane (because they don't know that it is not thin all over), or believe that domes in all rubber dome keyboards are backed with membranes -- all of which are wrong.

None of these are right or wrong. The term "mechanical" has been put to use 100% arbitrarily by the mk community. Any definition you come up with is just as wrong as the others you've described :p .

I've been recording under [wiki]Mechanical keyboard[/wiki] all manufacturers who use the term "mechanical" in patents or literature. The consensus from the data so far is that "mechanical" means metal switch contacts.

The general classifications from manufacturers are: membrane, mechanical, solid-state.

Yes, membrane here means keyboards where the membrane circuit traces are are closed via a mechanism (slider over dome, spring over dome etc). This is not your microwave keypad, but rather, where all or half of the matrix circuit is printed onto a membrane. You can have one, two or three membrane sheets depending on design. (You can have half of the matrix circuit on a PCB instead.)

Solid state covers anything where no physical circuit is operated. It doesn't mean touch-screen, it means that the sensing element is solid state. This is everything from Hall effect to foam and foil. Calling foam and foil "solid state" seems far fetched to me, but you'll have to take that up with the likes of the former Cherry Electrical Products USA.

Mechanical covers designs with metal switch contacts.

As for the wiki, the classification is more fine grained. You can get an idea from [wiki]Category:Keyboard switches by design[/wiki]. That category may be better off split into implementation, keycap mount etc. At the moment, capacitive is not classed as electromagnetic — maybe that is also not a meaningful split. In general though, the categories are more specific that those that manufacturers use.

Also, a switch can be in multiple categories if needed, so Alps integrated dome could be in both "rubber dome switches" and "discrete switches", while rubber dome over membrane designs could be in "rubber dome switches" and "membrane switches". There's no need for either-or classification in the wiki.