Can the luminous intensity mcd and the luminous flux lmΦ of the LED be converted into each other?
First, we have to figure out some basic definitions
Let us understand the definition of a luminous flux Φ: a point light source with a light intensity of 1cd in all directions, the luminous flux radiated by it is 4 πlm. That is to say, when a point light source is assumed to be on the center of the sphere, if its radiant luminous flux is 4 πlm (≈12.56lm), the luminous purpose of any point on the sphere is 1cd. From this point, we can In the case of switching between the two.
Let's use another example to illustrate. If it is known that the luminous intensity IV of an LED is 5cd and its emission angle is 60°, what is its equivalent luminous flux? Since the LED is not a real point light source after being made into a device, the light it emits has a certain light distribution range, here is 60°, that is, the light-emitting cone angle is 60°, which is only 1/6 of the spherical surface. The equivalent luminous flux can be expressed as: Φ= (4 π×60°/360 °) lm ×5cd=10lm. Under the same luminous intensity, the larger the LED emission angle, the greater the equivalent luminous flux. When the IV is the same, Φ increases with the increase of θ.
Secondly, to be simpler, it is almost 3.5 times the relationship.
