Light Guide Film

Light guide films typically have a thickness of 0.05” or more, and are made from polymers such as acrylic or polycarbonate. Side view LED’s are attached to the edge of the film. Cutouts can be made in the film to place side view LEDs at the appropriate location. Several technologies exist to extract the light through optical features including laser microdots, half-tone printed inks, and mechanically pressed shapes.

The light rays from the side view LED travel through the film and are refracted upwards towards the surface of the overlay once it hits these optical features, producing an illumination effect. Uniformity of this effect can be controlled through patterns and materials. A back reflector is utilized to further capture any light that is transmitted downward from the light emitting surface. Opaque materials can be utilized to block light in undesired areas.

Understanding How Light Guide Film Works & When to Use It

Light guide films use thin sheets of optically clear material coupled to an illumination source (like an LED) to spread light across a surface. Light is selectively extracted from the film through printed, raised, or embossed features. This technology is highly adaptable requiring no tooling or special handling.

Light guide film is best used to illuminate larger surface areas when keeping a low profile is important, making it well suited for applications like the following: 

• Membrane Switches/Keypads
• Badges
• Accent Lighting
• Automotive Lighting Interior/Exterior
• Commercial Vehicle Lighting
• Control Consoles
• PRNDLs
• LCDs
• Human Machine Interface
• Aerospace Lighting
• Personal Protective Equipment
• Keyboards
• Medical Device Panels