Purpose and Application of led screen

Before you buy an outdoor LED screen, you need to know what you want to use it for and where you want to install it. Different uses and locations have different requirements for the screen’s features and performance. Here are some questions you should ask yourself to help you choose the right outdoor LED screen for your needs:

• What is the main function of the screen? Do you want to use it for advertising, information, or entertainment?
• How far away will the viewers be from the screen? Do you need a high-resolution screen that can show clear images and text even from a close distance, or a low-resolution screen that can cover a large area and be seen from far away?
• How wide is the viewing angle? Will the viewers see the screen from one direction or from different angles?
• What are the weather conditions? Will the screen face direct sunlight, rain, wind, or extreme temperatures? Do you need a waterproof, dustproof, and heat-resistant screen that can withstand harsh environments?
• How much can you afford to spend? What is your budget limit for buying and maintaining the screen?

Pixel Pitch and Resolution

Pixel pitch and resolution are two key factors that affect the quality and clarity of an outdoor LED display. Pixel pitch is the distance between each pixel on the screen, while resolution is the number of pixels that make up the screen. Pixel pitch and resolution are inversely related: the smaller the pixel pitch, the higher the resolution and vice versa.

The best pixel pitch and resolution for an outdoor LED display depend on how far away the viewers will be from the screen and how clear and detailed the image needs to be.

For instance, if you want to show a large image that can be seen from more than 10 meters away, you may choose a pixel pitch of 10mm or more. This will give you a low-resolution screen that can cover a wide area. But if you want to show a small image that can be seen from less than 10 meters away, you may choose a pixel pitch of 5mm or less. This will give you a high-resolution screen that can display sharp and crisp images.

• The light attenuation of LED display

  The light attenuation reflects the life of the LED display. That is to say, as time goes on, the brightness will be increasingly lower until it dies out. High temperature is the main cause of the light attenuation and the shortening life of LED displays. The light attenuation varies among different brands of LED displays. Usually, LED display manufacturers will give a set of standard light attenuation curves. The luminous flux attenuation of LED displays caused by high temperature is irreversible.

• Outdoor high brightness LED Display Screen Catch fire

  Poor quality power cables/Lan cable/flat cable, Improper wiring or connection could burn under high temperature, incompatible power supply can cause an overloading, short circuit, or sparks

How to Choose the Appropriate outdoor led display

• Refresh rate

  The refresh rate of an LED screen is the number of times per second that it updates the image on the display. The higher the refresh rate, the smoother and clearer the motion on the screen. A high refresh rate screen can reduce flickering and ghosting effects, which can cause eye strain and fatigue. You should look for a screen with a high refresh rate, preferably above 2880 Hz if the led screen is going to be taken video by the audience.

• Contrast ratio

  The contrast ratio of an LED screen is the ratio between the brightest white and the darkest black that it can display. The higher the contrast ratio, the better the image quality and depth perception of the screen. A high contrast ratio screen can show more details and nuances in both bright and dark areas than a low contrast ratio screen. You should look for a screen with a high contrast ratio, preferably above 3000:1. However, you should also check for local dimming performance, as some screens may have a high contrast ratio but poor local dimming control.

• Color gamut

  The color gamut of an LED screen refers to the range of colors that it can display. The wider the color gamut, the more colors and shades that the screen can reproduce. A wide-color gamut screen can show more realistic and natural colors than a narrow-color gamut screen. You should look for a screen with a wide color gamut, preferably covering at least 85% of the DCI-P3 color space. However, you should also check for color accuracy, as some screens may have a wide color gamut but poor color calibration.

VISIONPI High Brightness Outdoor Series

Outdoor high brightness LED Display Screen

• High-quality gold wire LED and big currency driving IC  and components that can withstand high temperatures without blackening or degrading.
• Effective aluminum heat sink design, such as 4 layer pcb board creates more space for the circuit and an external ventilation fan inside the control box to help the led screen dissipate the heat quickly.
• Calibrating and adjusting the brightness of the electronic product according to the ambient light and time of day using software tools or lighting sensors.
• High-temperature solder paster ensures the strength of the soldering work.
• Common cathode energy-saving technology decreases power consumption and heat.

Unlocking the Secrets of LED Display Refresh Rate

In the realm of LED displays, the refresh rate stands as a pivotal aspect that significantly impacts the visual experience. This comprehensive guide delves into the nuances of LED display refresh rates, frame rates, and the optimal settings for various applications. Whether you’re engaging with LED displays for professional video production, broadcasting, or XR (extended reality) filmmaking, understanding these concepts can dramatically enhance the quality of your visual output.

What is Refresh Rate?

The refresh rate of an LED display is the frequency at which the content on the screen is updated per second, measured in Hertz (Hz). A higher refresh rate means that the content is updated more frequently.

To put it simply, the LED display can be compared to a flipbook, where each page represents a frame on the display. The refresh rate determines how quickly the pages are flipped through in one second. Increasing the refresh rate results in smoother motion for displayed animations or videos.

Why Refresh Rate Matters?

In the context of LED displays, a higher refresh rate is particularly important for:

Reducing Flicker: At lower refresh rates, the human eye can perceive flickering, which can be uncomfortable or even cause eye strain over time. A higher refresh rate minimizes this flickering, producing a more stable image that’s easier on the eyes.

Improving Image Quality: For dynamic content, such as videos or animations, a higher refresh rate ensures smoother motion. This is crucial for maintaining clarity during fast-moving scenes and enhances the viewer’s experience.

Enhanced Performance in Captured Video: When recording video of an LED display (such as during televised events or with smartphones), a high refresh rate helps to prevent the appearance of rolling bands or flickering in the captured footage. This is vital for broadcasters and content creators who demand the highest quality in their productions.

How to increase the refresh rate of an LED display?

1. Evaluate Hardware and Driver IC Compatibility: First, check if the hardware or driver integrated circuit (IC) of your LED screen supports a higher refresh rate. If the current hardware or driver IC does not support the desired refresh rate, consider replacing them with models that do. Look for driver ICs that are known for supporting higher refresh rates.

2. Modify PCB Design or Change Scan Mode: Assess the printed circuit board (PCB) design and consider changing the scan mode to accommodate a higher refresh rate. Another option is to increase the number of driver ICs on the device. This can enhance the device’s processing capability and support for advanced functions, enabling a higher refresh rate.

3. Use High-Quality Driver ICs: Opt for premium and reliable driver ICs, such as ICN2153 and MBI5252, which are known for their performance and capability to support higher refresh rates. It’s crucial to have a good understanding of how these components work or to seek assistance from a professional or the product provider to install them correctly, as improper installation can damage the device.

4. Software Configuration: The software used with the LED screen can significantly impact its refresh rate. Some software may offer limited features and options, restricting the device’s potential for higher performance. Explore software options that allow for adjustments to the refresh rate or provide more advanced control over the display settings.

What is the Best Recommended Refresh Rate for led displays?

Choosing the right refresh rate for your LED display depends on the application and the intended use. Here, we break down the best recommended refresh rates for different scenarios:

– 1920Hz for General Viewing and Non-Camera Interactions: A refresh rate of 1920Hz is ideal for applications where the display is primarily viewed directly without through-the-lens recording. This rate ensures smooth motion for general content, including presentations, digital signage, and other similar applications where camera capture isn’t involved.

– 3840Hz for Video Taking and Broadcasting: For scenarios involving camera capture, such as broadcasting or live streaming, a higher refresh rate of 3840Hz is recommended. This rate significantly reduces the risk of flicker and banding when the display is viewed through a camera lens, ensuring that the captured video appears as smooth and clear as the direct visual experience.

– 7680Hz for XR Filmmaking and High-End Applications: At the pinnacle of refresh rate requirements, 7680Hz is suited for XR filmmaking and other high-end applications. This ultra-high refresh rate is crucial for eliminating motion blur and maintaining the illusion of reality in virtual and augmented reality environments. It ensures that even the fastest movements are captured with unparalleled clarity, making it indispensable for creating immersive experiences in XR films.

Comparision between LED Display Frame Rate and Fresh Rate.

The relationship and difference between the refresh rate and frame rate in the context of LED displays are important concepts in understanding how images are displayed and perceived.

How to increase the led display Frame rate to 120hz/240hz 

 To increase the frame rate of an LED display, you need to focus on improving several key configurations:

1. Processing Power of the Control Card: The control card is the core component of an LED display, responsible for processing signals and driving the pixels on the screen. Enhancing the processing speed and efficiency of the control card’s CPU can accelerate data processing and signal transmission, thereby increasing the frame rate.

2. Memory Capacity and Speed: The capacity and speed of memory on the control card directly impact the volume of data that can be quickly read and written, which is crucial for high frame rate displays. Enhancing the memory’s read-write speed and expanding its capacity can effectively increase the frame rate.

3. Data Transmission Interface: The speed of data transmission is another key factor in increasing frame rate. Utilizing high-speed data interfaces (such as HDMI 2.1, DP 1.4, etc.) can speed up the transmission of data from the source to the display, which is especially important for achieving high frame rates at high resolutions.

4. Parallel Processing Capability: Increasing the control card’s capability for parallel processing, i.e., the ability to process multiple signals or tasks simultaneously, can significantly increase the frame rate. This can be achieved by using multi-core processors or deploying multiple control cards in the system, which can distribute processing pressure and enhance overall processing speed.

5. Software and Algorithm Optimization: Optimization at the software level is also crucial, including but not limited to more efficient encoding/decoding algorithms, faster image processing algorithms, etc. Optimizing control software and driver programs can reduce processing delays and increase frame rate.

6. Display’s Own Refresh Rate: Although this is not directly related to the control card’s configuration, the physical refresh rate limit of the display itself also determines the upper limit of the frame rate. Even if the control card and other system configurations support a higher frame rate, the display’s own refresh capability must also keep up.

The key to increasing the frame rate of an LED display lies in the optimization of the overall system design, including hardware configuration upgrades and software-level optimizations. In practical applications, these factors should be balanced according to specific display requirements and budget to achieve the best display effects.

Conclusion

Understanding and selecting the appropriate refresh rate for your LED display can make a profound difference in the visual quality of your content. From general viewing to professional filmmaking, tailoring the refresh rate to match the specific demands of your application ensures optimal performance and viewer satisfaction. By considering the explained guidelines, you can elevate your visual projects to new heights, ensuring they captivate and engage your audience with unmatched clarity and smoothness.

Static: A single-driver IC has 16 pins and can drive a maximum of 16 LED chips. In static drive mode, all LEDs on the LED module can be driven by the IC simultaneously, as illustrated in the following image.

1/2 Scan: In 1/2 scan mode, the IC drives a set of 1/2 LEDs on the module at a time, and subsequently switches to another set of 1/2 LEDs.

1/4 scan: 1/4 of LEDs on the module are driven by IC at one time, and next time there are other 1/4 LEDs that are driven.

Module size:300×168.75mm; pixel resolution: 160×90=14,400 dots.

Each LED contains 3 color chips(1R1G1B), so there is a total of 14,400×3=43,200 colors in one led module.

with 1/45 scan driving mode. only 43,200/45 =960 colors are required to be lit up each time.

Since each Driving IC has 16 pins. so the total amount of Driving ICs required for one module is 960/16 = 60 pcs (2o pcs for Red color;20 pcs for Green Color;20 pcs for Blue color)

Why is Dynamic driving mode essential? 

A static driver design (P1.875) would require  2700 16-channel driver ICs and current setting resistors. That will lead to an increased number of PCB layers and costs, on the other hand, the brightness is much higher but the current is also too high. 

A dynamic driving mode design utilizes a single driver IC to activate more LEDs, conserving space on the PCB board and optimizing the budget and driver IC’s layout. However, when aiming for high image quality, there is a trade-off between high grayscale and high scan rate. As a result, a smaller pitch necessitates more time-multiplexing in the design. Typically, P2.5 displays implement a 1:16 time-multiplexing design, whereas displays with a pitch of 2 mm and below require time-multiplexing above 1:16.

Scan Mode,brightness,refresh rate and grey level

• Power Consumption 

  Increasing the scan rate results in higher power consumption. A simple formula accurately reflects this correlation: for instance, a 1/8 scan consumes twice as much power as a 1/16 scan. The current is also a limiting factor. In the future, factories may reduce current, thereby diminishing both power consumption and brightness. commom cathode technolgy can reduce the power consumption without sacrifce the brightness.

• Refresh Rate

  The refresh rate of a screen is indicated in hertz (Hz) and signifies how frequently the image is updated per second. When the number of scan lines is doubled, the time required to illuminate all LEDs will increase twofold, and the refresh rate will be halved. Thus, increasing the number of time-multiplexing in a design makes it more challenging to achieve a high refresh rate. Decreasing the scan rate will reduce the refresh rate and vice versa. However, the PCB design and type of driver IC also influence the refresh rate. Incorporating a driver IC with an embedded SRAM can enhance the refresh rate by decreasing the time required to transmit grayscale data. If the driver IC supports GCLK multiplier technology, the refresh rate must be doubled.

Choosing a scan mode for LED display is a crucial decision that depends on various factors, such as brightness, power, refresh rate and cost. A higher scan mode is not always better, nor is a lower one. The goal is to design an optimal LED screen that meets the desired specifications.

Best COB LED Display Manufacturers:

Cedar Electronic

Cedar, established in 2001, is a global leader in providing LED display and lighting products with Flip-chip COB fine pitch technology. We belong to the Changchun Institute of Optics, Fine Mechanics, and Physics (CIOMP), which is part of the Chinese Academy of Sciences. We operate five branches in Beijing, Shanghai, Shenzhen, U.S.A., and Germany, and three factories in Changchun, Hangzhou, and Foshan.

Visionpi Display

Visionpi specializes in R&D, and production, and provides OEM Service of Micro&Mini LED  display modules and LED Display Screen.Guided by its core values, Visionpi’s expert R&D team continually enhances its R&D and production technology and equipment, innovates high-quality products, and maintains strict quality control, advancing in the new high-tech display field with a customer-centric service principle.

Fire hazards are a serious concern for LED displays, which are widely used in various fields. To prevent fire accidents and protect people and property, this article proposes five strategies for fire protection of LED displays:

LED Screen Fire Analysis

• Wire rods: The wire rods used for LED displays should conform to the national standard, as they need to withstand high power consumption and ensure electrification stability. Low-quality wire rods can cause overheating and short circuits.
• Power supply: The power supply products for LED displays should be certified by UL, as they have a scientific conversion rate and can work under hot external environments. Inferior power supply products can cause voltage fluctuations and fire hazards.
• Protective materials: The protective materials for outdoor LED displays should be resistant to aging, rain, and high temperatures. Aluminum-plastic plates are prone to crack and let moisture penetrate into the screens, resulting in short circuits and fire accidents.
• Plastic housing : The plastic kit for LED displays should be inflaming retarding and durable, as it can prevent deformation and brittleness under high and low temperatures. It should also be combined with glue with fine sealing performance, as it can prevent rain from entering the interior and causing short circuits and fire accidents.

How to prevent fire accidents

• Power supply: The power supply products should have safety certification and a high conversion rate. They should be able to work under high-temperature environments and prevent harmonic currents from causing fires. Large-scale LED displays should have a built-in PLC circuit switch to control the power load.

• Protective materials: The protective materials for outdoor LED displays should be fire-resistant and durable. They should not crack or age under different temperatures and rainy environments. They should prevent rain or moisture from penetrating into the screens and causing short circuits and fire accidents.

• Plastic protection kit: The plastic protection kit for LED modules should be made of flame-retardant PC glass fiber material. It should resist fire and various temperatures for a long time. It should not deform or embrittle. It should also be bonded with glue to prevent rainwater from entering the interior and causing short trouble and fire disaster

UL 94 is a plastics flammability standard released by the Underwriters Laboratories (USA). The standard classifies plastics according to how they burn in various orientations and part thicknesses from the lowest flame-retardant to the most flame-retardant in six different classifications.

Thermal and Ventilation Design

Outdoor LED displays generate a lot of heat, which can be dissipated by two common methods: fan or air conditioner. The choice depends on the maximum heat dissipation. Moreover, a scientific thermal balance design is important for the whole heat dissipation solution, which is sometimes neglected or underestimated. Thermal balance design aims to distribute the heat of the whole system evenly, so as to reduce the risk of fire disaster caused by excessive heat accumulation.

Fire-proof LED Display 

The impact of  led display working in low temperature

Outdoor LED displays in cold climates face the problem of different thermal expansion coefficients and uneven changes in the physical dimensions of their materials, such as masks, PCBs, module kits, and cabinet frames

• Crack between module and module, cabinet and cabinet.
• The shrinkage and breakage of the led modules’housing kits and cabinet frame.
• The uneven shrinkage between the LED lamp and the mask, causing the LED lamp to loosen and display failure;
• The potential dangers of water intrusion caused by the shrinkage of the waterproof rubber ring of the cabinet in low temperature.
• The Power supply cease to work.
• the protective(PVC) layer of the cable is easily broken, which will cause serious problems such as short circuit or even fire.
  

Selection of Low Temperature Resistant Raw Materials.

Adopt low-temperature resistant raw materials and devices, such as cold-resistant masks and bottom shell kits, low-temperature resistant waterproof glue, low-temperature power supply(meanwell) (can be started in an environment of -40℃; -25℃); Adopt low-temperature resistant cabinets, low-temperature resistant electronic devices and connectors.

Extra high protection ability

As outdoor fixed LED display works in outdoor environment for a long time, the PCB, power supply, soldering joints, etc. have high requirements for high and low temperature resistance, water resistance and corrosion resistance ability. It is recommended to carry out the coating and cold-proof treatment for PCB, components and parts, solder joints, etc., to protect the circuits from damage under the environments containing chemical substances (such as: fuel, coolant, etc.), vibration, moisture, salt spray, humidity and high temperature, low temperature conditions, thereby prolonging their service life.

Strong LED cabinets

The use of low-temperature resistant LED Cabinets: when the temperature reaches minus thirty degrees or even lower, the box of the LED display will shrink and deform, which will cause the gap between the box and the box to become larger, and even cause the peer lamps are not in the same straight line.

Heating Devices

Installing heating devices or fans inside the cabinets to keep the temperature within a reasonable range.

Daily Maintenance in extrem cold weather.

To prevent damage to your led screen in very cold conditions, follow these tips:

• The best option is to keep your led screen on all the time
• If you can’t do that, at least use the stand-by mode when you are not using it
• If you have to turn it off and it doesn’t turn on easily, then you may need to heat up the led screen gently

VISIONPI Low Temperature resistant Outdoor led display

• High-quality gold wire LED and big currency driving IC  and components that can withstand high temperatures without blackening or degrading.
• Effective aluminum heat sink design, such as 4 layer pcb board creates more space for the circuit and an external ventilation fan inside the control box to help the led screen dissipate the heat quickly.
• Calibrating and adjusting the brightness of the electronic product according to the ambient light and time of day using software tools or lighting sensors.
• High-temperature solder paster ensures the strength of the soldering work.
• Common cathode energy-saving technology decreases power consumption and heat.