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high dynamic range display

HDR displays, High Dynamic Range (HDR), use special techniques to increase the limited dynamic range of normal displays. In LCD displays, the brightness values are increased via the backlight. The display is not illuminated from behind with the same brightness over the entire surface, but is partially illuminated brighter and darker via an LED array.

With uniform backlighting, the brightest white valuewould become brighter, but at the same time the darkest black would also become brighter. This would only result in a shift, but not in an improvement of the dynamic range. Therefore, in HDR technology, the hue and its brightness are controlled depending on the image content.

Background illumination in the HDR display

Background illumination in the HDR display

The backlight is brighter in places with bright image content and darker in darker places. This extends the dynamic range to the entire available contrast, which is the result of the brightest and darkest values of a display. HDR displays and HDR televisions work with a brightness resolution of 10 bits, HDR10, and can reproduce 1,024 brightness levels. They can display brighter whites and darker blacks than conventional displays.

The SMPTE has specified the luminance levels for the darkest black and the brightest white under ST.2084. According to this, the black level must be below 0.0005 nits for certification. The brightest luminance is 10,000 nits. In device practice, values between 0.01 and 4,000 candela per square meter( cd/m2) are already achieved, which corresponds to a dynamic range of 400,000:1.

Englisch: high dynamic range display
Updated at: 17.02.2018
#Words: 235
Links: high dynamic range (HDR), dynamic range, indium (In), lost calls delayed (LCD), brightness
Translations: DE

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