What are the benefits of LED display brightness? As a medium of publicity, LED display screens frequently appear in our lives, and the demand for maintenance identification information relative to LED display screens has also increased. Let’s discuss how to identify the brightness of the LED display.
First of all, let’s understand what is the brightness of the LED display:
The brightness of the LED light-emitting tube refers to the intensity of the light emitted by the luminous body, called light intensity, expressed in MCD. The luminous brightness of the LED display is a comprehensive index, which refers to the comprehensive index of the total luminous flux (luminous flux) of all LED modules per unit volume and the illuminance at a certain distance.
LED display brightness: In a given direction, the luminous intensity per unit area. The unit of brightness is cd/m2.
The brightness is proportional to the number of LEDs per unit area and the brightness of the LED itself. The brightness of an LED is directly proportional to its drive current, but its lifetime is inversely proportional to the square of its current, so the drive current cannot be excessively increased in pursuit of brightness. At the same point density, the brightness of the LED display depends on the material, packaging and size of the LED chip used. The larger the chip, the higher the brightness; conversely, the lower the brightness.
So what are the brightness requirements of the ambient brightness for the screen?
The general brightness requirements are as follows:
(1) Indoor LED display: >800CD/M2
(2) Semi-indoor LED display: >2000CD/M2
(3) Outdoor LED display (sit south and face north): >4000CD/M2
(4) Outdoor LED display (sit north and face south): >8000CD/M2
The quality of LED luminous tubes sold in the market is uneven, and most of the brightness cannot be guaranteed. Consumers are deceived by the phenomenon of shoddy. Most people do not have the ability to distinguish the brightness of LED luminous tubes. Therefore, merchants say that the brightness is the same as the brightness. And it’s difficult to distinguish it by naked eyes, so how to identify it?
1. How to identify the brightness of the LED display
1. Make a 3V DC power supply that is easy to connect to the light-emitting diode by yourself. It is best to use a battery to make it. You can use two button batteries, put them in a small plastic tube and lead out two probes as positive and negative outputs. The tail end is directly made into a switch with shrapnel. When in use, the positive and negative probes correspond to the positive and negative contacts of the light-emitting diode. On the negative pin, press and hold the switch at the end, and the luminous tube will emit light.
2. Secondly, combine a photoresistor and a digital multimeter to form a simple light metering device. Lead the photoresistor with two thin wires and connect them directly to the two pens of the digital multimeter. The multimeter is placed at the 20K position (depending on the photoresistor, Try to make the reading as accurate as possible). Note that the measured value is actually the resistance value of the photoresistor. Therefore, the brighter the light, the smaller the value.
3. Take an LED light-emitting diode and use the above 3V direct current to light it. The light-emitting head is facing and close to the photosensitive surface of the connected photoresistor. At this time, the multimeter reads to distinguish the brightness of the LED.
2. The brightness discrimination level refers to the brightness level of an image that can be distinguished by the human eye from the darkest to the whitest.
The gray level of LED display screen is very high, which can reach 256 or even 1024. However, due to the limited sensitivity of human eyes to brightness, these gray levels cannot be fully recognized. In other words, it is possible that many adjacent levels of gray scale human eyes look the same. Moreover, the distinguishing ability of eyes varies from person to person. For LED display screens, the higher the level of human eye recognition, the better, because the displayed image is for people to see after all. The more brightness levels the human eye can distinguish, the larger the color space of the LED display, and the greater the potential for displaying rich colors. The brightness discrimination level can be tested with special software. Generally, the display screen can reach a level of 20 or more, even if it is a good level.
3. Requirements for brightness and viewing angle:
The brightness of the indoor LED display must be above 800cd/m2, and the brightness of the outdoor full-color display must be above 1500cd/m2 to ensure the normal operation of the LED display, otherwise the displayed image will not be clear because the brightness is too low. The brightness is mainly determined by the quality of the LED die. The size of the viewing angle directly determines the audience of the LED display, so the larger the better. The viewing angle is mainly determined by the die package.