A projection keyboard is a form of computer input device whereby the image of a virtual keyboard is projected onto a surface: when a user touches the surface covered by an image of a key, the device records the corresponding keystroke. A laser or beamer projects visible virtual keyboard onto level surface. A sensor or camera in the projector picks up finger movements Software converts the coordinates to identify actions or characters.
Some devices project a second (invisible infrared) beam above the virtual keyboard. The user's finger makes a keystroke on the virtual keyboard. This breaks the infrared beam and reflects light back to the projector. The reflected beam passes through an infrared filter to the camera. The camera photographs the angle of incoming infrared light. The sensor chip determines where infrared beam was broken. Software determines the action or character to be generated.
The projection is realized in four main steps and via three modules: projection module, sensor module and illumination module. The main devices and technologies used to project the image are a diffractive optical element, red laser diode, CMOS sensor chip and an infrared (IR) laser diode.
Price: US $169.99
