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 epoxy, synthetic rubber or silicone. Touching bare LEDs using synthetic rubber or silicone can damage the delicate wire bonds from LED to package or the LED itself, so they may be protected by a plastic or glass cover, such as in the LED flash in smartphones. It is this YAG phosphor which causes white LEDs without diffusers (such as those used in LED lamps and bulbs) to look yellow when off. There are three main methods of mixing colors to produce white light from an LED: Because of metamerism, it is possible to have quite different spectra that appear white.