Several concepts related to the brightness and lumen value of side emitting surface mount LEDs - Tengjie Optoelectronics
Publish：Shenzhen Teng Jie Optoelectronics Technology Co., Ltd. Time：2024-12-09
The brightness of side emitting patch LED is closely related to the angle of LED emission. The smaller the angle of LED, the higher its brightness. The manufacturing process is different, and there are differences in lifespan. The luminous intensity of white light at an angle of 180 degrees from a 5MM LED is only a few hundred MCD, while the intensity at a 15 degree angle is around 10000 to 20000 MCD. When using high-power LEDs outdoors, the brightness is even higher, with individual powers including IW, 3W, 5W, and some combining multiple high-power LEDs to form a high-power LED with a power of several hundred W.
Color temperature and brightness are not related, while brightness and lumen value are related. Let‘s take a look at a few related concepts:
(1) Brightness
Brightness refers to the intensity of light emitted by an object seen by the eyes from a certain direction. The unit is candela/square meter [cd/m2], with the symbol L indicating the luminous flux per unit solid angle unit area in a specific direction. It is equal to the luminous intensity of 1 candela emitted on a surface of 1 square meter.
(2) Side emitting patch LED luminous intensity
Luminous flux refers to the total amount of light energy emitted by a light source into the surrounding space. The distribution of light flux emitted by different light sources in space is different. The unit of luminous intensity is Candela, with the symbol cd, which represents the luminous flux emitted by a light source within a unit of spherical solid angle (the angle formed by the surface of the object with respect to a point light source). 1cd=1lm/lsr (unit of sphericity for s body angle)
(3) Luminous flux
Due to the varying sensitivity of the human eye to electromagnetic waves of different wavelengths, we cannot directly measure light energy using the radiation power or flux of a light source. Instead, we must use the unit of light flux, which is based on the human eye‘s perception of light, to measure light energy. The luminous flux is represented by the symbol 0 and is measured in lumens (| m).
(4) Color rendering of side emitting surface mount LED
In principle, artificial light should be the same as natural light, so that the human eye can correctly distinguish the color of things, of course, this depends on the position and purpose of the lighting. The degree to which a light source presents the color of an object is called color rendering. It is usually called "color rendering index" (Ra). Color rendering refers to the relationship between the true color of an object (its own color) and the color displayed under a standard light source. The determination of Ra value is to compare the 8 test colors defined in DIN6169 standard under the standard light source and the tested light source. The smaller the color difference, the better the color rendering of the tested light source.
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