Mechanical switches are now to be found almost everywhere and have become the choice of both gamers and people who type a lot. Mechanical switches are somewhat old technology being developed in the 1980s, but now variants and improvements are coming to marketing in recent years. One of those improvements is optical-mechanical switches, that use light for actuation instead of mechanical connection.
First, what are mechanical switches?
Keyboards use two main technologies. First are “regular” rubber dome, that uses rubber sheet for resistance and registering keypress. Second, are mechanical keyboards that use individual key switches and metal springs. Mechanical keys are easily recognized by stronger feedback with a bump on point of actuation and audible clicks, depending on the type of switches used in the keyboard. Mechanical switches provide a smoother and more accurate feeling while typing and gaming and areas such regarded as a premium choice. Mechanical keyboards are far more durable and can withstand years of heavy use.
How are optical+mechanical switches different?
As we mentioned in recent years we witness the rise of mechanical switches in all segments and new types are emerging, the newest one are optical + mechanical switches. They still have moving mechanical components just like a standard mechanical switch. You press on the keycap, a stem moves within a shaft, and a spring pushes the switch back to its reset position after your press is released.
The difference is in how the input is received and transmitted. Optical switch registers your input when stem blocks the light instead of the metal point of the key making contact with the inner part.
Benefits of optical+mechanical switch
There are several positive effects of removing metal contacts. First is eliminating the chance of performance degradation due to the oxidization and wear of the metal contact points. Because of that optical+mechanical switches can withstand more presses then regular mechanical keyboards.
Second is the faster response of a few milliseconds thanks to no debounce. In ordinary mechanical switch, a metal point comes in contact with an inner metal sheet, and while to user contact feels instant, in reality, they can bounce from each other several times before registering the contact.
Lastly, the design of optical+mechanical switches removes the need for soldering switches to a PCB and eliminates a potential point of failure.
Switches have a horizontal infrared light beam shooting across the inside of the switch shaft. The stem of the switch blocks the light beam, but when you press a key, you push down the stem, allowing the light to make a connection across the shaft and actuate the command.
Switches actuate at 1.5mm–this, as opposed to the 2.0-2.2mm actuation of most standard mechanical switches–and A4tech said that the switch resets faster than most, too. The company claimed that the Switch could “respond” as fast as 0.2ms.
It also claimed that its Key Response PK Software could demonstrate this speed. Regarding such a claim: First of all, one should always be wary of a test that favors the entity that created both the test procedure and the testing software. Second, we have seen this test and the software in action, and although it’s certainly a great way to show off the switches’ capabilities on a tradeshow floor, it’s by no means scientific.
The test is set up with a small piece of plastic, about the size and shape of a spacebar, straddling two keyboards–one a Bloody keyboard with Switches and the other an unknown model with regular mechanical switches. To perform the test, the demonstrator presses down on the plastic bar, pushing down a key on each of the two keyboards simultaneously, and the software spits out the actuation data.
In-person, I noticed that the plastic bar was pressing down on a regular-sized key on the Bloody keyboard and a larger key on the no-name keyboard. The performance of those two differently-sized keys, even if they were using the same switch on the same keyboard, will always be slightly different. Then, of course, there’s the fact that the actuation points of the two switches were certainly different–remember, the Switch actuates at least 0.5mm sooner than a normal mechanical switch, so you’ll always get disparate data if you press them at the same time.
This is not to say that A4tech is a shady company with a snake-oil product. Simply, the claims A4tech makes seem grandiose and not exactly scientific, but the concept, design, and execution of the Switches all appear excellent–just not as over-the-top excellent as A4tech would make it seem.