The aim of incorporating anti-reflection technology to the range of BeoVision models currently available is to provide high-quality visual experiences, irrespective of lighting conditions.
Direct reflections caused by lamps and windows are eliminated and the reflection of diffuse light is reduced to a minimum. The result is an improved overall contrast, providing a picture rendition of very high quality even during daylight hours.
|The coating process consists of applying three layers of a solvent-mixture to
a large glass panel. Each layer must be applied with an depth accuracy of 3 - 4%,
equalling a measure of just 3 - 4 nanometres (3 - 411000 millimetres).
To remove the reflection of a specific colour, a layer at the thickness of exactly 25% of the wavelength needs to be applied. The reflection is then in anti-phase; it is said to 'overlap'.
|Reflections from lamps and windows are drastically reduced by the
anti-reflection coating. Also the diffuse light emission of lit-up surfaces such
as walls, carpets and floors are reduced, providing a high contrast picture.
Anti-reflection coating is therefore especially beneficial also for watching TV
during daylight hours.
|A normal un-coated glass
surface reflects about 5% of ambient light, sufficient for detailed
mirroring of lit-up objects and surfaces
|Applying anti-reflection coating reduces the amount of reflections by a factor of 10, equalling a total reflection of just over 0,5%. The benefit is a clear picture with improved contrast||A triple layer coating is used
to widen the range of wavelengths removed, so that the colours most visible
to the human eye are eliminated. The only colour which remains as visible
reflection is a vague violet tinge.
|Graph showing the effect of the three-layer coating to different colours/ wavelengths. The
layers are designed to match the colours most sensitive to the human eye. The
majority of visible colours are reduced to a reflection below 5%.
|The amount of light reflected by the coated surface is reduced to 0,6%,
compared to the 5,2% for an uncoated glass surface.
Reducing reflections by a factor of 10 drastically reduce the annoyance caused by reflected lamps and windows. However, the most important effect is the improved contrast, as the light from the picture tube does not have to compete with the ambient light in the room.
The anti-reflection coating combined with the contrast screen is especially
beneficial when television is viewed by daylight or in illuminated surroundings.
< Characteristic links of the video chain
Note, that after cleaning an antireflection coated surface, all traces of cleansing agent must be removed entirely, as they in principle would influence the thickness of the coating layers, causing the coating to loose its effect.
Development of VisionClear Processing
The picture quality elements of VisionClear are as follows:
The above are the electrical elements of
VisionClear. The last and very important elements are mechanical: the
contrast glass and the coatings, improving daylight viewing even further (see
further details on Contrast Screen Coatings)
Over the years, Bang & Olufsen has improved on these analogue picture improvement technologies to an advanced level in order to deliver the unsurpassed picture quality of their TV sets of today. Furthermore the technologies are the platform for future picture quality, influenced by digital technologies, and will not be made obsolete by this.
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