The Invisible Technology behind Gaming Mice

Greg Thaddeus Jones, World Executives Digest | Find out how the optical sensor of your gaming mouse can improve sensitivity, reduce acceleration and make you a more accurate gamer.

Despite being constantly put to new and novel uses every year, infrared technology is nothing new – it’s been turning your TV on and off for years. It’s been used to solve crimes, to fly drones and give tactical snipers an edge with ‘night vision’ thermal imaging.

Back to school: What is Infrared?

Although called ‘infrared light’ it’s actually invisible. Infrared lies towards the long-wave end of the portion of light we can see on the Electromagnetic Spectrum, known as ‘visible light’. Infrared encompasses a wavelength range of 700nm to 1mm at a frequency of 430THz to 300GHz.

From the minutely accurate IR sensors, like RS Components’ range, used to monitor nanoelectronic boards, to the behemoth spectroscopy systems used to determine grain maturity in the agricultural industry, IR is an invaluable piece of tech.

And the gaming industry has taken note.

If you’re a PC gamer, the chances are you’ve typed optical versus laser at some point to determine which gaming mouse is more responsive. You’ll also have heard of acceleration, DPI and CPI rates, which are barometers of how good a mouse is. In general gaming terms, acceleration is when you move your mouse across the pad and then move it back to the same physical position; the cursor should be in an identical position. If it is not, then you have added acceleration, which is very frustrating when you overshoot your target in an intense FPS shooter. However, in terms of IR technology, what’s going on?

Firstly, it’s useful to clarify the actual mechanisms of ‘acceleration’ and exactly what is going on with your gaming mouse. Optical and laser mice using optical sensors both rely on IR sensor technology to interpret the relationship between mouse and user movement and in-game movement, processed by a Digital Signal Processor (DSP). This can be called resolution, in terms of the ratio of movement. Ideally, you would want a 1:1 for your movement versus in-game movement. Acceleration therefore, is when the mouse erroneously responds to a minute movement unintended by the user.

An IR light-emitting diode reflects light off the surface of the mouse pad and a CMOS sensor, or complementary metal-oxide-semiconductor, relays the pattern to the DSP. The DSP compares this new pattern to the previous pattern transmitted a fraction of a second ago. With this comparison, the DSP can ‘track’ the mouse movement accurately and translate the coordinates onto the screen.

In effect, what we are seeing here are 1000s of images being taken every second, the images analyzed and the DSP moving the cursor accordingly. Acceleration, or more accurately, resolution error versus speed, occurs when too much of the surface is picked up. Laser-illuminated sensors specifically struggle with this, as the images they relay are so accurate they pick out not only the surface of the mouse pad but the fibres just below the surface, which, although highly accurate, is not great for gaming, as you only care about measuring distance across the pad. Therefore, the optical IR sensor only scans the surface or, if you take a microscopic view of a mouse pad, the peaks of the fibrous material. In this way, the optical IR sensor can relay seamless and efficient information relating to distance and not, as with laser, the material itself.

The Future of IR in gaming

The Wii (remember the Wii?) was the first to use IR sensors to capture player motion and translate in-game, whilst Xbox kinect took it to a new level. Sony has been developing and improving its camera that essentially works in the same way as the optical sensor on a mouse. It is able to pick up player motions, track eye movement et cetera, and relay the coordinates onto the screen. With improvements in receptacle accuracy and IR-beam depth, you may begin to see eerily accurate user motion in-game.

For gamers everywhere, this is particularly exciting when coupled with the rise of VR, for the ultimate immersive gameplay.