Custom Keyboards and Input Devices - INDUKEY - #12

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59 www.custom.indukey.com Technologies Lighting of Operating Surfaces Phone: +49 (0) 37468 - 650-0 | info@indukey.com LED keys With this method, the according lighting element is directly integrated into the key. In most cases, the lighting elements are LED’s which have a service life of approx. 50,000 hours. Those LED’s are available in various colours. Due to the transparency of the surface material of industrial keyboards, the keys can be illuminated effectively. As surface material, both foil and silicone can be backlighted due to their partial transparency. As illuminated keys, both short travel and long travel keys can be used. The advantage of this method is that no setup costs are arising, since the keys can be assembled onto the board in the conventional way and without additional efforts. Free LED In case of this technology, the LED’s are not constructionally linked to the key. They are either placed beneath or below the key, or they are position-independently placed as signal indicators (e.g. caps lock key). The latter function is the one which is more frequently used with regard to this technology. For the most part, here, On/Offmodes are visually realized. „Standalone- LED’s“ also can be used to indirectly illuminate keys without having to integrate them into the respective key. In case of silicone keyboards without mechanical switching elements, for example, the LED’s are positioned directly below the key. By using this method, also plated domes can be illuminated without having to integrate the LED’s constructionally. Here, the LED is fixed below the key. EL foils This interesting lighting method is based on the effect that energy is transformed into light when AC voltage is applied (electroluminescence). This way, the entire „EL foil“, which is located below the actual operating/decor foil, can be illuminated. All cut-outs on the foil are not illuminated. This allows for the manufacture of almost layout-independent lightings for operating surfaces. Here, compared to the usage of LED’s, non-recurring costs are arising due to the individual adjustment. However, the half life of the luminance is not as high as with the other technologies. After 10,000 hours, the luminance amounts to circa 50% of the original value. Plastic light ducts At first, in this case as well, an LED is used as light source. In contrast to other technologies, though, the light is emitted into light ducts made from plastic. Those light ducts have been abraded by means of chemical processes, so that the light is emitted there. This so called fiberlight-method is very versatile; due to the light scattering and the individual length of the light ducts, operating surfaces of all sizes are backlightable. Due to the respective specific odification, setup-costs are arising when this method is applied.