Another common backlighting solution is fiber optic weave. Similar to light guide film, it takes LED light and distributes it across a larger area. In fact, it usually only requires a single LED to backlight an entire assembly. It should be noted that the LED used is a bullet LED, which requires a PCB as a base because we cannot place bullet LEDs onto our printed membranes. Using only a single LED, this leads to one if its greatest drawbacks; it isn’t very bright and may not be a good solution if the device will primarily be used in ambient light.
There are other important considerations as well. First, the fiber optic weave and fiber optic bundle are quite large and need to be accommodated in the design. In addition, the thick construction diminishes the tactile feedback of buttons. Combined with the weak light, there are few projects to which this backlighting technology is suited. While we see this option to continue in existing models, we anticipate that this solution will soon give way to thinner backlighting solutions as devices become smaller and lighter.
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