Eight effects of LED lamp beads on LED display

Time:2018-10-18 Views:328

1, the Angle of view

The perspective of LED display depends on the perspective of LED lamp bead.To date, most outdoor display screen choose horizontal Angle 100 °;50 ° and vertical perspective;Elliptical LED, indoor display, choose level is 120 ° from vertical;The patch LED.Display on the highway 30 ° is generally selected due to its particularity;Round leds for viewing angles are enough.Some tall buildings have screens that require a higher vertical Angle of view.Viewing angles and brightness contradict each other, big viewing angles will inevitably reduce brightness.The choice of perspective needs to be determined according to specific purposes.

2, brightness

LED brightness is an important determinant of display brightness.The higher the LED brightness, the larger the current margin, which is good for saving power and maintaining LED stability.Leds have different Angle values. The smaller the Angle, the brighter the LED, but the smaller the screen Angle.In general, 100 degrees of LED should be selected to ensure that the display screen has sufficient viewing Angle.For screens with different spacing and different viewing distances, a balance should be found in brightness, Angle and price.

3. Inefficiency

As full-color display is composed of pixels composed of thousands or even hundreds of thousands of red, green and blue leds, the failure of any color LED will affect the overall visual effect of the display.Generally speaking, according to industry experience, the failure rate before the LED display assembly starts to aging 72 hours before shipment should be no more than three parts per million (refers to the failure caused by LED beads themselves).

4. Anti-static ability

LED is a semiconductor device, which is sensitive to static electricity and easily leads to the failure of static electricity. Therefore, the anti-static ability is crucial to the life of the display screen.In general, the LED human electrostatic mode test failure voltage should not be less than 2000V.

5, life

The theoretical life of LED device is 100,000 hours, which is much longer than the working life of other parts of LED display screen. Therefore, as long as the quality of LED device is guaranteed, the working current is appropriate, PCB heat dissipation design is reasonable and the production process of the display screen is rigorous, LED device will be one of the most durable parts in the whole display screen machine.

LED devices account for 70% of the price of LED display, so LED devices can determine the quality of LED display.China is not only a major producer of LED devices, but also a gathering place for LED display.High technology requirements for LED display screens are the future development trend. High quality requirements for LED display screens are not only about the trend of LED display screen manufacturers, but also about the development of LED display device manufacturers.From the control of LED devices, we will promote the transformation of China from a major manufacturer of LED displays to a major manufacturer of LED displays.

6. Attenuation characteristics

After a long time of working, LED display screen will show a decrease in brightness and color inconsistency, which is mainly caused by the brightness attenuation of LED devices.The attenuation of LED brightness will reduce the brightness of the whole screen.The inconsistency of the brightness attenuation of red, green and blue LED will cause the inconsistency of the color of LED display, which is the phenomenon that we often say the display screen is spent.High quality LED device can control brightness attenuation well.According to the standard of lighting 20mA at 1000 hours room temperature, red attenuation should be less than 2%, and blue and green attenuation should be less than 10%. Therefore, blue and green LED should not use 20mA current as much as possible in the display design, and it is better to use only 70% to 80% of the rated current.

Attenuation characteristics are not only related to the characteristics of red, green and blue leds, but also affected by the use of current, PCB plate cooling design, and the ambient temperature of the display screen.

7, size

The size of the LED device affects the pixel distance of the LED display, that is, the resolution.The 5mm oval lamp is mainly used for outdoor screens above P16, the 3mm oval lamp is mainly used for outdoor screens of P12.5, P12 and P10, the 3528 patch LED is mainly used for indoor screens of P6 and P8, and the 2020 patch LED is mainly used for indoor screens like P2 and P3.On the premise that the point spacing remains unchanged, the size of LED device increases, which can increase the display area and reduce the sense of particle. However, as the black area decreases, the contrast is reduced.In contrast, the LED size decreases, reducing the display area, increasing the particle sense, increasing the black area and increasing the contrast.

8. Consistency

Full-color display is made up of numerous red, green and blue leds. The brightness and wavelength consistency of each color LED determines the brightness consistency, white balance consistency and chromaticity consistency of the whole display.Generally, the display manufacturer requires the device supplier to provide leds with a wavelength range of 5nm and a brightness range of 1:1.3. These indicators can be classified by the device supplier through the spectroscope.Voltage consistency is generally not required.

Since leds are angled, full-color LED displays also have angular orientation, that is, when viewed from different angles, their brightness will increase or decrease.In this way, the Angle consistency of red, green and blue leds will seriously affect the consistency of white balance in different angles, directly affecting the fidelity of video color on the display screen.To achieve the matching consistency of the brightness changes of red, green and blue leds at different angles, the packaging lens design and raw material selection need to be strictly scientific designed, which depends on the technical level of the packaging suppliers.The normal white balance is good. If the Angle consistency of LED is not good, the white balance effect of different Angle on the whole screen will be bad.The Angle consistency characteristic of LED lamp bead can be measured by LED Angle comprehensive tester, which is especially important for medium and high grade display screens.