Keyboard technology has remained pretty static now for the better part of several decades.
The only real innovations have been minor ones – like the availability of the far more affordable membrane or rubber-dome keyboards.
So we were long overdue a leap forward in how we get information from your fingertips to our screens.
Optical keyboards are a perfect example of this.
Let’s look at how they work.
But first.
What is an optical keyboard?
A membrane keyboard uses a rubber membrane suspended over a printed circuit – when you press a key the rubber “dome” makes contact with a sensor and sends a signal to your computer to print that letter or character onscreen.
A mechanical keyboard, as the name suggests, uses an individual spring-mounted mechanical switch under each key. When this switch is depressed a signal is sent to your computer to print whatever letter or character onscreen.
An optical keyboard uses a light beam instead of a physical switch.
How do optical keyboards work?
The term “optical keyboard” might make you think you’ll be typing on some kind of laser-projected keyboard on a flat surface.
While that sounds nicely futuristic, it’s not actually what happens.
Optical keyboards are actually opto-mechanical keyboards instead.
They still use physical keys but it’s what happens during actuation (when the key is pressed) that sets them apart from either membrane or membrane keyboards.
With an optical keyboard, when the key is depressed, it breaks the light sensor present under each individual key.
Membrane or mechanical keyboards rely on physical contact being made with either a rubber membrane or a metal contact.
So the actual mechanism is almost identical to a mechanical keyboard i.e. there’s a spring and physical key.
But it’s the “switching” mechanism that’s different – the signal from your keyboard actuation is sent at literally the speed of light to your computer’s I/O processor.
This means you get faster response times when typing.
That might not make a huge difference if you’re just typing a document, but could give gamers a competitive edge.
But are there any other reasons for using an opto-mechanical over a mechanical keyboard?
Optical keyboards last longer
Traditional keyboards rely on a physical switch making contact with something else.
This can only ever result in one thing – wear and tear.
So your favorite keyboard will eventually stop working.
If you don’t wear out the lettering on the keys first – which is my personal pet hate.
But I can always replace the keycaps if I really want to.
The neat thing about optical keyboards is that they don’t need to make contact with a surface to produce a typed character.
Each key only needs to interrupt a beam of light, so your keyboard should last longer.
An average opto-mechanical keyboard is good for more than 110 million key pressed.
The question is – How much longer?
To illustrate this let’s take a look at traditional keyboards first:
Membrane keyboards – 5 million presses before failure
Mechanical keyboards – 50 million presses before failure
So that means mechanical keyboards last 10x as long as membranes.
But that figure also pales in comparison to photo-optical keyboards.
Faster response times
Light travels faster than electricity.
In fact, electricity travels at about 1/100th the speed of light.
Although it never feels like that when you accidentally electrocute yourself – something I’ve experienced several times.
When you depress a key on a regular membrane or mechanical keyboard, it completes a circuit which then triggers a signal to be sent to your computer via a wire or over an RF (Radio Frequency) signal.
This all happens in the blink of an eye, but there’s still a built-in delay because of the mechanical nature of the action you took.
Optical keyboards don’t require that circuit to be completed.
Instead, you’re simply breaking a beam of light, and once broken your computer registers that a key has been pressed.
That signal still needs to travel through a wire or via RF signal to your computer.
But it does so 100x faster than it normally would.
The problem is that the difference in response times is measured in Milliseconds (ms) and that’s far too small for human beings to even recognize.
More comfortable typing experience
You might not realize it but the energy you put into depressing a key as it strikes a surface also puts wear on something else that’s really important.
Your hands.
It’s like working out on a heavy bag for 20 years without using wraps or gloves – you’re going to cause permanent damage.
I should know.
40 years of typing on keyboards has given me some nice early arthritic pain to worry about.
So there’s a physical benefit to not having to push a key down far enough to make contact with something else.
Although some optical-keyboard users say they find the keyboards a bit too “squishy” for their liking – especially the linear models.
But they do always have the option of simply using a “clicky” optical keyboard instead.
Do they cost more than other keyboards?
Not really.
A typical optical keyboard retails for between $50 for a regular models and around $200 for a high-end model.
Which is roughly the same as a branded mechanical keyboard.
So you potentially get a lot more bang for your buck.
Are there any downsides to optical keyboards?
The more moving parts anything has the higher the likelihood there is that it will break down sooner rather than later.
Membrane keyboards are so cheap to buy that you’re probably better off replacing one than trying to repair it.
But you can repair yours, if you want to try.
Mechanical keyboards have more moving parts than a membrane keyboard, but each of these parts is replaceable.
They’re what we called “field serviceable” – you can fix them at home without relying on the manufacturer.
Optical keyboards are a slightly different beast though because although they share many of the same internal components, there’s also light sensors to factor in.
Are these easy to replace?
Where can you get spare parts?
Sure, they might last forever, but what happens when they don’t?
Does having one sticky/stuck key on your keyboard render it useless.
It’s something to consider before you go spending your hard-earned cash.
Cover image source: Razer.
