Analysis of high brightness and high energy saving applications of LED display

I believe that more and more people in the industry are well aware of how LED displays save energy. They are implemented from the aspects of high-brightness LED lights, driver ICs, switching power supplies , product power consumption design, intelligent energy-saving system design and structural energy-saving design. Of course, finding the best balance among these aspects will achieve the best energy-saving effect of LED displays.

But since when and for what reason, perhaps due to the intentional or unintentional promotion of some manufacturers, the concept of high energy saving has been quietly blurred or even replaced by "high brightness": under the same cost premise, the higher the brightness of the display, the more "energy-saving" and the more value-for-money! And it has gradually become the value-for-money "cost-effective" advantage they feed back to customers.

In fact, in order to achieve a good energy-saving goal, excessive pursuit of high brightness is contrary to energy saving. Next, let's analyze the potential relationship between "high brightness" and "high energy saving".

At present, the popular 12000cd/m2 high-brightness LED lamps in China basically use large-size LED chips. This large-size LED chip is widely adopted by most LED display manufacturers as the mainstream of the market, and there is no core technology to speak of. As we all know, the brightness of the LED screen is proportional to the driving current of the LED lamp. The brightness of 12000cd/m2 is nothing more than increasing the driving current of the LED lamp. However, the physical characteristics of LED lamps will be inevitable: high-brightness LED lamps are inevitably accompanied by high attenuation and low stability. High attenuation is not only not conducive to the long-term use requirements of LED display screens, but also becomes a congenital defect of excessive pursuit of high brightness, and this congenital defect will damage the life and picture effect of LED display screens all the time like a multiplier effect.

Taking the high-brightness PH16mm display screen as an example, the technical parameters of this high-brightness LED lamp show that the brightness of 12000cd/m2 will seriously decay to 8000cd/m2 within 1.5-2 years, and its annual decay rate is more than 20%. Some irresponsible manufacturers claim that the brightness is still above 10000cd/m2 after 2 years in their publicity. Consumers who buy this kind of screen will have no way to complain even if it decays quickly after 2 years because the contract has been fulfilled. In fact, consumers can verify it in a very simple way, that is, to see the effect of several high-brightness display screens that have been running for more than 2 years and used for more than 12 hours a day. What's more serious is that after the brightness has dropped from 12000cd/m2 to 8000cd/m2, its high working current has not changed, which will further multiply the speed of its brightness decay, causing the later decay speed to accelerate several times, becoming a high-decay display screen. Moreover, it exists in a vicious cycle of brightness decay and cannot meet the requirements of long-term use at all.

In order to avoid light pollution and comply with environmental regulations, the brightness standards for LED display screens during the day and at night are different. As we all know, reducing the brightness will more or less cause grayscale loss. The greater the brightness adjustment, the greater the grayscale loss. Therefore, if the initial brightness value of the LED display screen is set to 12000cd/m2 during the day, when it is lowered to 800cd/m2 at night, either the grayscale is extremely lost, making the night picture quality very poor; or the brightness cannot be adjusted to the standard requirements for night use, resulting in severe light pollution.

From this point of view, the excessive emphasis on high brightness in the market does not mean technological leadership in terms of LED display manufacturing technology, but rather a high current and high brightness at the expense of the life of the display. On the contrary, it is inevitable that people will suspect that it is flashy and inadequate.