Input Devices & Their Functions

By Milton Kazmeyer

Computer input is a constantly evolving field. The venerable mouse and keyboard system is still dominant in the desktop PC world, but touch screens have dominated mobile computing and other alternative input systems have found their way into specialty niches. These alternate input devices can offer new ways to control your applications, and they can be a boon to disabled users as well.

Voice Recognition Software

Voice recognition software uses a microphone to capture voice commands, a sound analyzer to identify the spoken words, and a parser to determine the meaning of the command. These systems are suitable for dictation as well as direct software control, and can be very useful for users with arthritis or other conditions that make it difficult to type for extended periods. While voice recognition software continues to evolve and become more skilled at recognizing words, these programs often take some time to train to your particular speaking style for maximum accuracy. Dragon Naturally Speaking is one example of voice recognition software, and features specialized editions for legal and business work as well as consumer voice tasks.

Digital Pens and Tablets

In the 1980s, the "light pen" offered the ability to "draw" directly on a CRT monitor, using the electron beam inside the cathode ray tube as a guide. Modern LCDs have rendered this technology obsolete, but styluses and digital pens still offer the ability to input natural handwriting and drawing gestures. Pen tablets are touch pads that accept input from the associated stylus, allowing artists fine control over line weight and thickness by varying the pressure. Digital pens and tablets like the Wacom systems use motion detection technology in a writing instrument to digitally capture your writing strokes, and often include audio technology to record voice notes as well.

Motion Sensors and Cameras

Web cameras and infrared motion sensors offer users the ability to command computers with gestures and body movements. Microsoft's Kinect is one popular motion input device, using multiple sensors to track user movements, map facial features, and record voice commands. These devices can even recognize individual users, tailoring system preferences to whoever is using the device at any given time. Cluttered backgrounds, inconsistent distances, and background movement can confuse these systems, however, making for a frustrating experience.

Biometric Sensors

Biometric input devices offer increased computer security. The most common biometric input device is a scanner that images a user's fingerprint, using it to verify identity before unlocking the system. Other methods include facial recognition, voiceprint analysis, retinal imaging and even mapping blood vessels under the skin. Paired with a traditional password or PIN system, these technologies can make it extremely difficult for unauthorized users to gain access to protected computer systems. Apple integrated a fingerprint scanner into the operating system of the iPhone 5S, and the Eyelock Myris is one of the first consumer-level retinal scanners, debuting in 2014.