subject: Why Optical Filters Are Used In Electronic Displays [print this page] Optical filters are used to selectively block certain wavelengths of light, while allowing others to pass through freely. People think of optical filters purely in terms of photography. However, in this context the word light means far more than just the wavelengths that we can all see.
Visible light is just one small area of the much larger electromagnetic spectrum, which includes all forms of radiation, from microwaves to radio signals. People often use the term optical filter as a generic catch-all term that includes infra-red, ultra-violet and radio frequency interference (Rfi) shields. In general terms, however, an optical filter allows visible light to pass through, while blocking infra red radiation. This can be clarified to transmit visible light of only certain wavelengths. The end result is low glare, low electrical resistance and high colour density.
Optical shields are used in photography, astronomy, window glass, movie projectors and, increasingly, electronic displays. These filters are typically made of scratch-resistant acrylic plastic, and contain linear polarisers to cut down reflections and glare. Polarising optical filters confine light to a single plane, and will block or transmit light according to their polarising effect - sunglasses work in the same way.
With the majority of electronic displays today being of the flatscreen/LCD type, optical filters have a major part to play in, for example, defence, financial, educational and medical institutions, as well as for business and home use.
We at Instrument Plastics supply optical filters, including Optolite polarizing filters, for use in electronic displays of all sizes.
