When researching lighting options for a keypad or membrane switch, you may come across light guide films. They are used to distribute the light across the device’s interface. You can order a keypad or membrane switch with or without a light guide film. With a light guide film, the light produced by the keypad’s or switch’s backlighting will be evenly distributed. Here are five facts about light guide films.
#1) Prevents Dark and Bright Spots
Light guide films are designed to prevent dark and bright spots. Some keypads and membrane switches may suffer from uneven brightness. Some areas of the interface may look brighter or darker than other areas of the interface. If you’re worried about uneven brightness such as this, you should choose a keypad or membrane switch with a light guide film. It will distribute the light evenly across the interface so that dark and bright spots don’t occur.
#2) Used With Edge-Lit LEDs
Light guide films are commonly used with edge-lit light-emitting diodes (LEDs). Keypads and membrane switches may feature a perimeter of LEDs. Known as edge-lit LEDs, they point inward toward the center of the device. A light guide film will help to guide the LEDs’ light.
#3) Available as Standalone or Integrated Layers
Light guide films are available as standalone or integrated layers. Standalone layers means the light guide films feature their own substate. Integrated layers, in comparison, means the light guide films use an existing substrate. Regardless, you can choose light guide films as either standalone or integrated layers.
#4) Incredibly Thin
To say light guide films are thin would be an understatement. While some of them are thicker than others, they can be designed with a thickness of just 0.2 millimeters. A typical strand of human hair is about 12 millimeters thick. Therefore, light guide films are a little less than twice as thick as human hair. They are incredibly thin, low-profile components that take up very little space in keypads and membrane switches.
#5) Extends Battery Life
You might be surprised to learn that light guide films can extend the battery life of the devices with which they are used. Portable devices may feature a rechargeable battery. A light guide film won’t eliminate the need for a portable battery. It may, however, extend the battery’s life. The portable device may require fewer LEDs if it features a light guide film. With fewer LEDs, it will consume less energy during use, thereby extending the life of the battery.