Keyboards play a fundamental role in the way in which computers and electronic devices work. When a device requires “input” from a human operator, it typically used a peripheral or touchscreen interface. For the former, keyboards are used for their versatility and convenience. However, there are several different types of keyboards, each of which has its own unique characteristics. Today, we’re going to take a closer look at optical keyboards, revealing how they work and what makes them unique.

Also known a photo-optical keyboards, optical keyboards use light to detect keypresses. They are typically equipped with light-emitting devices as well as photo sensors. The light-emitting devices project light across a surface, while the photo sensors detect interruption in this light. The light is projected horizontally across the keyboard’s interior. And the only time it can be blocked is by pressing a key. Thus, when you press a key, it blocks the light while subsequently allowing the keyboard to determine which key you pressed.

Most optical keyboards use two or more beams of light, including a vertical and horizontal beam. However, there are also optical keyboards that feature a special key format that blocks light in a specific pattern, allowing only a single beam of light for each row of keys.

There are several benefits associated with optical keyboard technology, one of which is longevity. Because the technology identifies keypresses using light-emitting devices and photo sensors, they tend to last longer than traditional mechanical keyboards. With mechanical keyboards, each keypress adds stress and wear to the keys. Over time, this can result in failure of the keyboard. While optical keyboards also have a finite lifespan, they tend to last longer than other types of keyboards, including mechanical keyboards.

There are also projection keyboards, which differ from optical keyboards in a few ways. A projection keyboard, for instance, uses a laser to project a digital image of a keyboard onto a flat surface. Additionally, it features a camera or various sensors to determine when and where keypresses occur. The sensors actually work by monitoring the user’s hand movements. And when it sees the user touch a key, it responds with the appropriate key command. Projection keyboards such as this can simulate a variety of different size keyboards, ranging from small projector keyboards to full-size keyboards. The downside to using projection keyboards, however, is the simple fact that they lack tactile feedback.