AR Anti-reflective film- AR coated film lamination - specular and diffused
Air Gap approach to contrast enhancement
There are applications that require contrast enhancements but the cover glass or touch screen must remain independent and separated from the display. These applications cannot accept optical bonding where the cover glass and display are bonded as a single unit. Despite the requirement for keeping the display and window separate, in order to achieve low reflective loss, each surface; front and back of the cover glass and the front of the LCD, must be corrected with AR coatings.
For these applications, the Air-Gap film lamination approach to index matching is ideal. In this approach, the cover glass is pre-coated with AR coatings and the display receives its AR coating in the form of a film lamination that has the AR coating applied to the top surface of the film. As the film is laminated to front polarizer of the display, the front surface becomes a very low reflecting surface; improving contrast.
AR film lamination lowers surface reflections to below .8%. This, coupled with a double sided AR window, will make any display system requiring the separation of the display and window daylight readable for displays that are less than 500 nits. For displays running at 800 nits or more, they will be completely sunlight readable.
AR film sample showing increased contrast
High transmissivity AR coating on hard-coated PET film substrate
Low, wide-band reflectivity with neutral blue cast
Superior clarity and uniformity
Hardcoat for excellent scratch and chemical resistance
Anti-finger print and smudge topcoat
Other benefits of the AR film used by GDS is that the film twice as durable as the front polarizer of the display. This surface will be much less prone to scratches and digs into the surface. Additionally, the film surface has anti-smudge and anti-finger print capabilities. Lastly, the surface has a much stronger resistance to chemical damage compared to the surface polarizer of the display.
AR film lamination from GDS is available in two front surface treatments- Clear and Diffused. Clear has a shiny surface with zero diffusion. Clear is the ideal surface for an AR lamination if it is going to be placed behind a cover glass or touch screen. It is never recommended that an internal surface in an optical stack be diffused. Diffused has a slight haze or dullness to the front surface to the AR film lamination. This surface will scatter the small amount of reflected light and obscure mirror-like reflections on the top surface. Diffused AR is ideal when there is no cover window in front of the display and the AR surface is front-most surface. The diffused AR comes in a 110 gloss rated surface so the amount of diffusion is very light. Once the AR film is laminated to the display, GDS can supply a wide selection of double-sided AR coated cover windows. These cover windows can be fabricated from glass in various thicknesses, strengthened glass, laminated safety glass, and acrylic and polycarbonate plastic windows. Additionally, AR film can be laminated to rear of touch screens. This will make the touch screen have the lowest amount of reflective loss possible. Though it is possible, it is not recommended that the front of any touch screen be laminated with AR film. AR film will reduce the reflective loss from the front surface of the touch, but there are issues. The oil from a finger print is naturally non-anti-reflective and the finger print will reflect light. This phenomena causes the finger print to reflect alone and essentially light up with reflected light. AR coating on a touch screen is consider to be "user unfriendly".
