Privacy Filter
One of the less-known 3M products include privacy filters for notebooks, tablets and other electronic devices. 3M uses the "microlouver technology" within the film structure to reduce the horizontal viewing area of the LCD screen to 60 degrees.

The film functions like a vertical window blind restricting the path of light through the filter. Persons directly in front of the display would have unobstructed views of the displayed information. However, from either sides of the display beyond approximately 60 degrees, observers would see a dark, blank screen. The privacy film technology also helps to shield out unwanted ambient light, incrementally increasing the effectiveness of glare reduction and contrast enhancement.

How it works

The privacy screen consists of a number of closely-spaced partitions or louvers, which selectively block the transmission of light depending upon the angle at which light strikes the film surface.
The louvers are angled perpendicular to the surface of the film. Thus, maximum transmission occurs in the perpendicular direction. The louvers are composed of agglomerates of small particles of optically-limiting material which may be made up of substantial opaque particles to block light transmission.

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The louvered film is coated with a solventless composition of an oligomer, a monomer, and a photo-initiator, which polymerises to a clear, hard layer upon exposure to certain types of radiation, forming a louvered plastic film.

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