Thinner lightguides

Livingston, Scotland-based Design LED Products has developed a means to make thin printed lightguides with embedded light-emitting diodes that can be formed into complex 3D curves.


In the manufacturing process, side-emitting LEDs are first attached to transparent flexible substrates. A light-scattering pattern is then printed onto the substrate that controls the location and uniformity of the emitted light.


The lightguide material can either printed, or placed, onto the substrate, which optically connects the LEDs to the light-scattering areas.


Light-blocking features can also be added to give a high optical isolation and good contrast between segments.


A top graphic or diffusing material can be added and conductive pads or tracking for capacitive and other switch technologies can be printed within the lightguide structure.


In addition, the passive segmented lightguide components can be produced to interface to LEDs mounted on conventional PCBs.


The company says that since the process steps are similar to those used in the manufacture of membrane keypads and other printed electronic products, it is inexpensive and easily scalable to high volume.


The resulting lightguides are thin, typically less than 1mm including the flexible circuit, lightguide and outer graphic, and are an alternative to injection-moulded lightguides and electroluminescent displays.


The company also claims that they have a higher optical efficiency than an LED combined with an injection-moulded lightguide.


The company is aiming its display technology at the automotive, medical, consumer and industrial markets.