Dicolor Led Display-The dialectical relationship between the brightness, lifetime and energy consumption

The dialectical relationship between the brightness, lifetime and energy consumption

5.1 Analysis of 13500nits brightness

For mainland China's natural environment, the outdoor full color LED display screen brightness only need to reach 5000nits ( CD/m2) above, thus it can meet the market demands, this is because of mainland China's outdoor sun light intensity are not the strongest. If a piece of outdoor full color LED display screen needed to be installed near the equator, then the brightness of the display must reach 10000nits above, and that would be more appropriate, because the strong sun light at the earth equator requires the brightness of the display to achieve so high!

5.2 brightness higher than 10000nits means high energy consumption and short life

The LED luminous tube is what we commonly known as the LED lamp; the brightness of the LED lamp depends on the magnitude of the current supplied to the LED lamp. With the same LED lamp, the higher current applied in it, the higher brightness it gives out, Rated current of LED lamp is 20 MA, some irresponsible display manufacturers use poor quality and low brightness LED lamp but also hope to produce the display with a high brightness, the most direct way is increase the supply of current to the LED even more than20 MA in production, But this result in the high energy consumptions of the LED lamp. At the same time, because of the large current leads to high work load, these LED lamps appears to light attenuation faster, the entire screen life can be shorten. It seems like a person running at the speed of 100 meters of sprint running, within just a few seconds this man won’t be able to continue running, but if he runs slowly, he could run for several hours.

5.3an inaccurate or wrong concept

Many people know that, through the operation of LED display of the broadcast control software, we can set the entire screen brightness value. So some people will say, I produced the display with a brightness of the entire screen up to 10000nits above, but the daily use of the brightness of the entire screen down to 6000nits use, until a year later I put up the brightness of the entire screen, so in order to save energy and extend the life of the screen.

The above statement is inaccurate, even in a sense is the wrong approach! Not practical! Below we give a simple example to prove it:

Suppose now use a LED lamp to produce a LED display screen, when supplying LED light with a current of 8 Ma, a lamp can give out 7500nits of the brightness of the entire screen, this fully meet the requirements of outdoor. But now when increasing current value from 8Ma to 20 MA, the brightness of the entire screen can be extended from 7500up to 13500nits!

The current value of the brightness of the entire screen size and the relationship between the levels is such! The next step is to decide, the display of the brightness of the entire screen, want the7500nits or 13500nits? The answer to this question is determined, display manufacturers before mass-production, through repeated testing power supply circuit using resistor values, and thus change the current value, finally realize the predetermined value of the brightness of the entire screen!

Simple explaining: the production of a13500nits brightness of the display screen, every moment the screen is powered on bright, LED lamp are supplied with a current value which is identified as a numerical value, such as20 MA. If the same LED lamp produces a 7500nits brightness of the display, so every moment the screen is powered on bright, LED lamp are supplied with a current value is determined by the 8 ma.

At that time some people will ask: 13500nits brightness, when using it we will adjust the brightness to 7500nit, can this reduce the current and power saving?

The above statement is inaccurate! Through broadcast control software, we decrease the brightness of the display from the 13500nits is reduced to 7500nits, and it does not decrease current value, the current value is not changed! When the screen was powered on in the brightest moment, LED lamps are supplied with a current value as huge as 20 MA! The above operation just change the running time of display between High brightness and low brightness. That is to say when the13500nits is reduced to 7500nits, just the high brightness time of screen is short, and the time of low brightness is long! Here is the "on" and" off" is frequently appear alternately, they switch between frequency, has exceeded the eyes' recognition level, so we see the screen is working, the brightness is down, but in fact every time the screen power on there is a short time of brightness reach to13500nits, just it is very short!

The above approach we said that it is not good! Why is it not good? Let take the example of people running: suppose there is a running game, the rules of the game are: requires running speed not slower than 10 kilometers per hour, let’s see who ran a longer time? Then someone have two choices:

(1) the first choice is: using uniform speeds of 12 kilometers per hour, managed to keep it up;

(2) Second choices: 60kilometers per hour speed rush, just punch1 second and then stop, and then repeat the step again and again.

Through this example, we can understand which person that race more appropriate? The same, a LED lamp needs only a very small current can reach 7500nits brightness, why supply it with large current to 13500nits brightness, but when in using, just keep at 7500nits? Why is this?

In the example above, we want to prove that: when using high brightness LED lamp to produce outdoor full-color display, as long as the brightness of the entire screen reach the outdoor requirements, then it is already enough, only by this can we ensure to supply the minimum current to the LED lamp! While the low current is the science method of reducing of light losing and extending screen life!

5.4 low brightness energy-saving schemes is the key

Dicolor Optoelectonics recommends energy saving scheme of low brightness! Products made by step from the LED luminous tube selection, selection of drive IC, PCB circuit design, switching power supply selection, selection of heat dissipating scheme for control system, and these are the six major aspects where we apply energy saving scheme with matched design.

Product of Energy saving scheme, its default full screen brightness value can reach 13500nits, and meanwhile LED luminous tube are supplied with a current value less than the rated current of 20mA! But when we are developing the energy saving scheme for the screen, we will set the default brightness of the screen from 13500nits to 7000nits, this is because: first, 7000nits completely meet the needs of mainland China Daily outdoor brightness demand, and then, decrease the default current value of LED lamp when working, and set the LED lamp which should have been able to give out 13500nits brightness with a replacement of 7000nits brightness, this can significantly improve the LED luminous tube service life, and can greatly reduce the consuming electricity needed daily during work, thus this makes energy saving scheme Dicolor Led Display’s rated power is less than 500W per square meter, the average power consumption is only about 100W!

General speaking,

LED display manufacturers should have the spirit of integrity, responsible attitude to research product and develop market!

Must not be arrogant, not to play tricks! Not to destruct the market just in order to win over the masses’ attention, or just a gimmick, simply because the customers do not know this kind of industrial product. To pursue the so-called conceptual product mirage with over 10000nits brightness! This product is not either energy saving nor environmentally friendly, not to comply with the world trend! And daily use of electricity is very high! This approach not only can not extend the display’s life, it will also shorten the life time of the display! It is a bad product!

Dicolor Optoelectric,  2012-04-28