Bespoke LED solutions for thin, flexible, segmented backlights and backlit switches

Technology

Design LED Products have developed and patented device structures and manufacturing process used to make thin printed lightguides with embedded LEDs.

The major process steps are:

  1. Side emitting LEDs are attached onto transparent flexible substrates with electrical tracking.

  2. A light scattering pattern is printed onto the substrate. This controls the location and uniformity of the emitted light.

  3. The light guide material is either printed or placed onto the substrate, optically connecting the LEDs to the light scattering areas.

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

  5. A top graphic or diffusing material can be added.

  6. Conductive pads or tracking for Capacitive and other switch technologies can be printed within the lightguide structure.

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

 

The process steps are similar to those used in the manufacture of membrane keypads and other printed electronic products.

This is an established printing process, is readily available, inexpensive, has high repeatability, easily scales to high volume and used standard equipment sets.

Features.

  • Thin, typically <1 mm including flex circuit, lightguide & outer graphic.

  • 70%+ uniformity. The human eye will not detect any variation.

  • Wide gamut of colours available - red, green, blue, white.

  • Simple animation, colour fading & secret until lit effects. Independent illumination of segmented areas.

  • Alternative to injection moulded lightguides & ElectroLuminescent displays.

  • Low design & prototyping costs. No hard tooling costs. Based on a standard & widely available manufacturing process.

  • Higher optical efficiency than LED + injection moulded lightguide.

  • Displays can be flexible or can be formed into complex 3D curves.

  • Solid state, robust products, 10 year+ operating lifetime.

  • Low power, low voltage, intrinsically safe. Can be incorporated with mechanical & capacitive switches into keypads.

  • Design freedom. Put light where ever you want it