Heat Meters are one kind of meters measuring the heat
consumption. In order to save the energy and decrease the environment
pollution, the heat meters are more and more popular for the modern buildings.
Heat meters can realize centralized heating supply. Now with the rapid
technology development, the heat meters also experience a fast way of growing
up. Now the government of the world starts to pay much attention to the
building remolding and new buildings heat meter installation. As the new type
of energy calculation, the heat meters have the advantages of higher accuracy,
energy saving and easy installation.
Heat Meters Heat Meters,Mechanical Heat Meters,Ultrasonic Heat Meters,M-Bus Heat Meter,Digital Heat Meter Berggruen Technology Co.,Ltd , http://www.meter-technology.com
The effect of temperature on the led display has the following five points:
First, the temperature is too high will lead to the complete destruction of led display (1) led display operating temperature exceeds the chip's carrying temperature will make the led display's luminous efficiency is rapidly reduced, resulting in significant light failure, and cause damage;
(2) The LED display is mostly made of transparent epoxy resin. If the junction temperature exceeds the solid phase transition temperature (usually 125°C), the encapsulating material will change to a rubbery shape and the thermal expansion coefficient will suddenly rise, resulting in the open and failure of the LED display. .
Second, the temperature will shorten the life of the led display The life of the led display as its light decline, that is, a long time, the brightness is getting lower and lower until the last extinguished. Usually defines the LED display light flux decay time 30 for its life.
The reason that led to the led display light fades usually has the following aspects:
(1) The defects existing in the LED display screen chip material will quickly proliferate and multiply at a high temperature until invading the light emitting area, forming a large number of non-radiation recombination centers, and seriously reducing the luminous efficiency of the led display screen. In addition, under high temperature conditions, the micro-defects in the material and the fast-spreading impurities from the interface and the plate will also be introduced into the light-emitting region to form a large number of deep levels, which will also accelerate the light decay of the LED display device.
(2) The transparent epoxy resin will be denatured and yellowed at high temperatures, affecting its light transmission performance. The higher the operating temperature, the faster the process will proceed. This is another major reason for the decline of the LED display.
(3) The light decay of the phosphor is also a major factor affecting the light fade of the LED display, because the attenuation of the phosphor at high temperatures is very serious.
Therefore, the high temperature is the cause of led display failure, shortening the main source of led display life.
Different brands of LED display light decline is different, usually led display manufacturers will give a set of standard light decay curve. LED display luminous flux attenuation caused by high temperature is irreversible, led display screen does not occur before the irreversible light attenuation of light flux, called the led display "initial luminous flux."
Third, the increase in temperature will reduce the luminous efficiency of the led display The temperature affects the led display luminous efficiency reasons include the following aspects:
(1) As the temperature increases, the concentration of electrons and holes increases, the band gap decreases, and the electron mobility decreases.
(2) When the temperature rises, the probability of radiative recombination of electrons and holes in the potential well decreases, resulting in non-radiative recombination (heat generation), thereby reducing the internal quantum efficiency of the led display.
(3) Temperature rise causes the blue light wave peak of the chip to shift toward the long wave direction, which makes the emission wavelength of the chip and the excitation wavelength of the phosphor unmatched, and also causes the reduction of the external light extraction efficiency of the white light led display screen.
(4) As the temperature rises, the quantum efficiency of the phosphor decreases and the light emission decreases, and the external light extraction efficiency of the led display screen decreases.
(5) The performance of silica gel is greatly affected by the ambient temperature. As the temperature rises, the thermal stress inside the silica gel increases, resulting in a decrease in the refractive index of the silica gel, thereby affecting the light efficiency of the led display.
Fourth, the temperature on the led display light-emitting wavelength (light color) The led display light emission wavelength can generally be divided into the peak wavelength and the main wavelength. The peak wavelength is the wavelength with the largest light intensity, and the dominant wavelength can be determined by the X, Y color coordinates, reflecting the color perceived by human eyes. Obviously, the change in the light emitting wavelength of the led display caused by the junction temperature will directly cause the human eye to feel differently about the light color of the led display. For a led display device, the bandgap value of the light emitting region material directly determines the wavelength or color of the device's light emission. As the temperature rises, the bandgap of the material will decrease, resulting in longer device emission wavelengths and red-shifted colors.
Fifth, the temperature is too high will limit the maximum input current of the led display The above points are the temperature of the introduction of the led display, through the above description that the temperature increase on the led display is a very large impact. So the right and proper temperature is the focus of the led display.
From the functions of the different types of heat meters, there are mechanical
heat meters, Digital Heat Meter,Ultrasonic Heat Meters, M-bus Heat Meters and also wireless heat
meters. Our company, Berggruen Technology Co.,Ltd never stops the steps for
further higher technology research and development. We are devoted to study the
new technology in the world to make better quality heat meters.
How temperature affects the LED display
Led displays have great potential due to their energy saving, environmental protection, and long life. But the temperature is very important for the led display, the temperature of the led display: relates to the led display life, light efficiency, color and so on. So the right temperature is very important for the led display.