lamp are indispensable and important items in people’s daily life now. Since humans know how to control flames, they know how to get light in the dark. From bonfires, candles, tungsten lamps, incandescent lamps, fluorescent lamps, tungsten-halogen lamps, high-pressure sodium lamps to LED lamps, people’s research on lamps has never stopped.
And the requirements are increasing, both in terms of appearance and optical parameters.
A good design creates a pleasing appearance, meanwhile a good light distribution endows the soul
(E-Lite Festa Series Urban Lighting)
In this article, we take a closer&deeper look at light distribution curves. Id like to call it the sketch of light’s soul.
What is light distribution curves?
The method of scientifically and accurately describing the distribution of light. It clearly describe the shape, intensity, direction and other information of light through graphics&diagram.
Five typical expression methods of light distribution
1. Cone chart
Usually it used for ceiling spotlights.
As shown in the first line of the picture, it means that the spot diameter d=25 cm at a distance of h=1 meter, the average illuminance Em=16160lx, and the maximum illuminance Emax=24000lx.
The left side is the data.Meanwhile the right side is the intuitive diagram with stimulated light spots. All the data is showing in it, we only need to understand the meaning of the letters to get the information.
2. equiangular light intensity curve
(E-Lite Phantom Series LED Street Light)
The light of street light is often distributed very widely, so it is often described by an equiangular light intensity curve. At the same time, it is also intuitive to use curves of different colors to represent different illuminance.
3. equiluminous curve
It generally uses for street light, garden light
The 0.0 indicates the location of the lamp, and the 1st circle indicates that the illuminance is 50 lx . For example, we also can get (0.6,0.6) meters from the lamp,the illuminance is 50 lx at the red flag position.
The above diagram is very intuitive, and the designer does not need to do any calculations and can directly get the data from it and use it for the lighting design&layout
4. Polar coordinate light distribution curve/Polar Curve
To really understand it, Let look at a mathematical idea- polar coordinates firstly.
A polar coordinate system consisting of angles and circles representing distances from the origin point.
Since most of the lights are directed downwards, the polar coordinate light distribution curve generally takes the bottom as the starting point of 0°
Now, lets look at an example of ants pulling a rubber band~
1st ,ants with different strength dragged their rubber bands to climb to different directions. Those with more strength climb far, while those with less strength can only climb closer.
2nd,draw the lines to connect the points where ants stopped
Finally, We will have the strength distribution curve of ants.
From the diagram ,we can get that the ants strength in the 0° direction is 3, and the ant power in the 30° direction is about 2
Likewise, light has strength—light intensity
Connect the description points of light intensity in different directions to get—the “intensity distribution” curve of light.
The light is different from the ants.The light will never stop, but the intensity of the light can be measured.
The light intensity is represented by the distance from the origin of the curve, meanwhile the direction of light is represented by the angles in polar coordinates.
Now lets really take a look at street lights polar coordinate light distribution curve as below:
(E-Lite New Edge Series Modular LED Street Light)
This time we share 5 common expression methods of light.
Next time, Lets take a closer look into it together. What information can we get from them?
Lisa Qing
International Business Engineer
Email: sales18@elitesemicon.com
Mobile/ WhatsApp: +86 15921514109
E-Lite Semiconductor Co.,Ltd
Web: www.elitesemicon.com
Tel: +86 2865490324
Add: No.507,4th Gang Bei Road, Modern Industrial Park North,Chengdu 611731 China.
Post time: Mar-21-2023
