Guide to Computer Keyboard Key Switch Mechanisms

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This page is a guide of computer keyboard key switch mechanisms.

Rubber Dome Switch

Most keyboard key mechanism today use rubber dome. ⁖ basically all laptop keyboard and Microsoft Keyboard Gallery. Rubber dome type is cheap to make, but is not as good as other mechanisms that use spring, because the tactile feedback is not precise, kinda wobbly. Usually what made it worse is the cheap key housing that goes with it. (ever had squeaky keys that make ugly noises and sometimes stuck midway due to friction?)

keyboard construction
Laptop keyboard construction. img src
keyboard rubber dome
Rubber dome switch. img src

Scissor Switch

laptop keyboard scissor-switch mechanism laptop keyboard scissor-switch mechanism 2-2
Scissor switch on laptop. The middle is your rubber dome. img src

Scissor-switch is found in laptop computers, starting around ≈2002. It is still rubber dome, but is enhanced by a scissor-like mechanism above the rubber membrance.

Buckling-spring Switch

This is most famous as used by IBM Model M keyboard, and loved by many programing geeks.

model M keyboard
IBM Model M keyboard
keyboard buckling spring
buckling spring mechanism.

You press the key, the spring compresses, then at some point, it can't take it anymore, then CLICK, it buckles, crumpling and gave up all resistance!

This tech is old. If you want the tactile feel of the click, you can get from keyboards that use “Cherry MX Blue” switch. 〔☛ List of Keyboards with Mechanical Switches〕 But if you really want buckling-spring, you can buy it from Unicomp. See: IBM Model M keyboard, Unicomp.

Cherry MX Switches

Cherry Corporation of Germany makes mechanical switches called Cherry MX. It is the most popular mechanical switch. There are several different models of Cherry MX, with different properties of feel. These models are color coded. They are:

Linear Action

animation cherry mx red
Cherry MX Red. Smooth linear action. Popular in gaming keyboards. Example: Corsair K60 keyboard.

Cherry MX Black is same as Red, except more force is required. I don't like MX Black one at all. For example of Cherry MX Black, see SteelSeries 6Gv2 keyboard.

Tactile

The Brown & Blue types are good for writers or programers. When you press down, after certain point, there's a bump feel, then after that the pressure is reduced. This lets you know precisely when a key is activated.

animation cherry mx brown
Cherry MX Brown Switch mechanism. Tactile but no audible click. Most popular.
animation cherry mx blue
Cherry MX Blue Switch mechanism. Tactile with audible click.

The primary difference between Brown & Blue is that Blue has a audible “click” at the bump point, and Blue is lighter. For many people, the major complaints about Blue is that it's noisy.

There are few others, but less common. Here's a summary.

Cherry MXbrown blue green red black
Key FeelTactile BumpTactile ClickTactile ClickSmooth (Linear)Smooth (Linear)
ResistanceMedium-LowLowFirmVery LowFirm
Cherry MX Brown keyswitch
Cherry MX Brown keyswitch
Max Keyboard Premium PCB mount Cherry MX Switch, O-Ring and Keycap Sampler Kit

Cherry MX Key Switch Sound Comparison

Here's a video that compare the noises they make.

Cherry MX Red, Black, Blue and Brown Switch Comparison

the keyboards are:

Note: the only one that intentionally makes a sound, is the MX Blue, which makes a click sound.

All the others, do not make any noise if you press the key slowly. The sound came from the key hitting bottom. Also, they don't sound as loud as in the video. In the video, the wooden desk and recording makes it louder.

Except the Blue MX, these Cherry MX keys do not make more noise than average full-sized key rubber dome keyboards, unless when compared to laptop style shallow scissor-switch keys, which are basically silent.

Also, some keyboard makers claim to have some sort of silencer, but i haven't tried them.

Another way to reduce noise is to buy those rubber ring switch damperners.

cherry rubber o ring switch dampeners
Cherry Rubber O Ring Switch Dampeners

here's me typing on the Truly Ergonomic Keyboard:

Truly Ergonomic Keyboard (Cherry MX Brown), typing starts at 5:40

You can visit a local store to test out different switches. (if you are in San Francisco Bay Area, California, USA, you can visit Fry's Electronics.) Or, you can buy a switch testing kit.

QWER mechnical key switch testing kit
Key switch testing kit from http://www.qwerkeys.co.uk. (photo by Moritz Ulrich)

Capacitive Switch: Topre Switch

Another type of expensive switch is by capacitance. In particular, one made by Topre Corporation, of Japan.

Topre key switch
Topre key switch. US patent 4584444

Topre key switch as famously used in:

White Alps Strongman Switch

don't know how this switch works, but i have used one for a couple of years. It's excellent. See: Keyboard: Matias Mini Tactile Pro. This keyboard has strong presence in Mac community.

Does Mechanical Keys Matter?

Yes. See: Keyboard: Effect of Mechanical Key Switch on You.

List of Keyboards with Mechanical Switches

List of Keyboards with Mechanical Switches

Key Ghosting & n-key Rollover

Another issue commonly discussed with key mechanism is key ghosting and n-key rollover. Basically, it means how many keys can be pressed simultaneously. See: Keyboard Ghosting; How Many Keys Your Keyboard Can Take?.

References

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