Brightness is eye-catching. "Illuminance" is the light density of the illuminated area, and "brightness" is the light density of the luminous area. Physical luminance is essentially an indicator of energy. If the power of light is the same, the less energy divergence or transmission area the light source has in a certain direction, the brighter (i.e. the more intensive) it will be, especially in mobile display luminance measurement
. The emphasis is not on the size of "total amount", but on the degree of intensity.
For soft light sources, in order to increase brightness, besides increasing power, divergence angle and condensed luminous area can also be reduced. While watching, because the eyes will converge the scattered light, the small area of light source convergence surface sharp, small divergence angle light source energy is more concentrated, just like the sting in the retina. So intuitively, the brighter the more dazzling. Like a computer screen, although it can illuminate a room, it is not as dazzling as a cell phone. This is also one of the reasons why people are often warned not to play with their mobile phones in bed. In order to cope with daytime sunshine, mobile display luminance measurement shows that the brightness of mobile phones is usually very high.
And "illumination" is the degree to which a surface is illuminated - that is, the "pressure of light". Like the "illumination" used to measure indoor light and shade. For example, it is stipulated that the illumination on the desktop should not be less than 500 lux. This means that there is a "500 lumen per square meter" luminous flux on the desk. In this case, the light requirement for eye comfort can be generated. Therefore, mobile display luminance measurement requires special attention to this parameter.