The important aspects of the optical parameters of LED are: luminous flux, luminous efficiency, luminous intensity, luminous intensity distribution, and wavelength.

Luminous efficiency and luminous flux

Luminous efficiency is the ratio of luminous flux to electric power, and the unit is generally lm/W. Luminous efficiency represents the energy-saving characteristics of light sources, which is an important indicator to measure the performance of modern light sources.

Luminous Intensity and Luminous Intensity Distribution

The luminous intensity of LED is to characterize its luminous intensity in a certain direction. Since the luminous intensity of LEDs varies a lot in different spatial angles, we have studied the luminous intensity distribution characteristics of LEDs. This parameter is of great practical significance and directly affects the minimum viewing angle of the LED display device. For example, in a large-scale LED color display in a stadium, if the selected LED single tube has a narrow distribution range, the audience facing the display at a large angle will see a distorted image. And traffic lights also require a wider range of people to recognize.

wavelength

For the spectral characteristics of LED, we mainly see whether its monochromaticity is excellent, and we should pay attention to whether the main colors such as red, yellow, blue, green, and white LEDs are pure. Because in many occasions, such as traffic lights, the color requirements are relatively strict. However, according to the observation of some LED lights in my country, the green is blue, and the red is dark red. From this phenomenon, we conduct special research on the spectral characteristics of LEDs. Very necessary and meaningful.