What Is a Display Glare Measuring Device?
A display glare measuring device assesses the degree of glare on the screens of TVs, smartphones, and other devices. This glare, seen as fine bright spots flickering on a display, results from surface irregularities acting as lenses, causing variations in brightness and color. Factors like dirt, sebum, and fine pixel density can exacerbate glare, making accurate quantitative evaluation increasingly important.
Uses of Display Glare Measuring Devices
These devices evaluate glare and resolution characteristics of various displays, including 8K/4K TVs, monitors, projectors, smartphones, tablets, large displays, and in-vehicle systems. They are essential for assessing anti-glare films applied to PCs and smartphone screens, which can also contribute to glare due to surface irregularities affecting light emission.
Principle of Display Glare Measuring Devices
Display glare measuring devices use cameras to photograph the display surface. They measure luminance non-uniformity, calculating a glare rating value based on the glare pattern’s frequency distribution. A lower glare rating indicates less luminance variation and reduced glare. The process involves photographing the display with a CCD camera, then dividing the standard deviation of the luminance distribution by the mean value from the image, displayed as a percentage. The measurement accuracy is influenced by the position of the camera lens aperture and the measurement surface on the display.
Countermeasure Against Display Glare
To mitigate glare, anti-glare films are applied to display surfaces. These films reduce glare from lighting and enhance image contrast. Low glare AG films, suitable for high-definition displays like smartphones, offer smooth touch panel operation and fingerprint resistance, effectively reducing glare even on OLED displays.
Display Glare Measurement Standards
The International Organization for Standardization (ISO) has initiated standardization for display glare contrast measurement.
Manufacturers of Display Glare Measuring Devices
Few manufacturers specialize in display glare measuring devices.
DM&S, a German company, offers the SMS-1000 system, which measures glare and evaluates sharpness, anti-glare, and transmission characteristics, adhering to IEC and ASTM standards. The system is recognized globally for its accuracy and ease of use. Topcon Technohouse Corporation’s SR-5100 2D spectroradiometer spectrally analyzes images and quantitatively evaluates glare and glare contrast, expressing the glare contrast value as a coefficient of variation.