Light-emitting diode of their major uses until their price drops low enough to make signaling and illumination uses more economically feasible. Barcode scanners are the most common example of machine vision applications, and many of those scanners use low-cost products red LEDs instead of laser-based LEDs. Optical computer mice are an example of LEDs in machine vision, as it is used to provide an even light source on the surface for the miniature camera within the mouse. LEDs constitute a nearly ideal light source for machine vision systems for several reasons: The light from LEDs can be modulated very quickly so they
Light-emitting diode use of LEDs to promote health for astronauts. Light can be used to transmit data and analog signals. For example, lighting white LEDs can be used in systems assisting people to navigate in closed spaces while searching necessary rooms or objects. Assistive listening devices in many theaters and similar spaces use arrays of infrared LEDs to send sound to listeners' receivers. Light-emitting diodes (as well as semiconductor lasers) are used to send data over many types of fiber optic cable, from digital audio over TOSLINK cables to the very high bandwidth fiber links that form the Internet backbone. For some