Manufacturers of LED edge-lit displays are facing an increasingly important problem in the design of monitors, TVs, and digital signage. The fact that LEDs are point light sources and have poor light spreading in lightguide-based displays forces device designers to incorporate bezels (to shield areas in which light is poorly mixed); it also limits their ability to reduce the number of LEDs in a display and makes these systems highly sensitive to LED variations in color and brightness.
Insufficient light mixing in current edge-lit LED backlights has prevented the continuous reduction of LED count that would be expected from the steady increase in LED efficacy. This is critically important since reducing the number of lamps is a traditional cost reduction path for displays.
3M proposes to mitigate this barrier to low-cost systems by introducing a light-mixing tape—3M™ Uniformity Tape—that can be applied directly to the injection edge of a lightguide. This simple solution delivers improved design flexibility, enables a 50 percent reduction in LED count and opens new paths toward entitlement backlights with respect to cost and performance.