Question

How to choose a COB LED display?

Answer 1

When selecting a COB (Chip on Board) LED display, several key aspects need to be considered comprehensively to ensure that the chosen product meets specific needs and achieves the expected results. The following is a detailed introduction:

Display Effect

Resolution: Resolution determines the number of pixels the screen can display, directly affecting the clarity of images and videos. For scenarios requiring the display of detailed images, text, or video content, such as high-end commercial displays, advertising, and professional conferences, a high-resolution COB LED display should be selected to present a more delicate and realistic picture effect.

Contrast Ratio: Contrast ratio refers to the ratio of brightness between the brightest white and the darkest black displayed on the screen. High contrast ratio makes the colors of the image more vibrant, the layers more distinct, and enhances the visual impact. In low-light environments, such as cinemas and stage performances, a high-contrast COB LED display can provide a better viewing experience.

Refresh Rate: Refresh rate indicates the number of times the screen updates the image per second, measured in Hertz (Hz). A higher refresh rate reduces screen flicker and ghosting, making dynamic images smoother. For scenarios such as playing fast-moving videos, broadcasting live sports events, or playing video games, choosing a COB LED display with a higher refresh rate will result in a better visual experience.

Color Gamut Coverage: Color gamut refers to the range of colors a display screen can show. The wider the color gamut coverage, the richer and more vibrant the colors the display can present. For fields with high color reproduction requirements, such as art design, photography exhibitions, and film and television production, a COB LED display with a wide color gamut coverage should be selected to ensure accurate color reproduction of the original image.

Reliability and Stability

Heat Dissipation Performance: COB LED displays generate heat during operation. Poor heat dissipation will cause the LED chip temperature to rise, affecting its lifespan and performance. Therefore, it is important to choose a display with a good heat dissipation design, such as products using heat sinks, cooling fans, or liquid cooling technologies. You can check the product's heat dissipation structure, heat dissipation materials, and heat dissipation test reports to understand its heat dissipation performance.

Protection Rating: Depending on the usage environment, a COB LED display with an appropriate protection rating needs to be selected. The protection rating is usually indicated by an IP code, where the first digit indicates the dustproof rating and the second digit indicates the waterproof rating. For example, IP65 indicates that the product is completely dustproof and water-resistant, suitable for outdoor environments; while IP20 indicates that the product can only prevent the ingress of solid foreign objects with a diameter greater than 12.5mm, suitable for indoor dry environments.

Electromagnetic Interference Resistance: In some locations with complex electromagnetic environments, such as substations and communication base stations, COB LED displays need to have strong electromagnetic interference resistance to ensure their normal operation. You can check the product's relevant certifications and test reports to understand its electromagnetic interference resistance performance.

Installation and Maintenance

Installation Method: Choose the appropriate installation method based on the usage scenario and space layout. Common COB LED display installation methods include wall-mounted, ceiling-mounted, and floor-standing. Wall-mounted installations are suitable for wall mounting, saving space; ceiling-mounted installations are suitable for locations with high ceilings, such as conference rooms and auditoriums; floor-standing installations are suitable for scenarios requiring flexible movement or repositioning.

Modular Design: Choosing a COB LED display with a modular design allows for easy installation, disassembly, and replacement. Modular design simplifies and speeds up display maintenance. When a module malfunctions, only that module needs to be replaced, eliminating the need to disassemble and repair the entire display, significantly reducing maintenance costs and time.

Maintenance Convenience: Consider the ease of maintenance, such as ease of cleaning, inspection, and repair. Some COB LED displays employ special surface treatments, offering dustproof, waterproof, and easy-to-clean features, reducing daily maintenance workload. Simultaneously, the internal structure of the display should be rationally designed to facilitate inspection and repair by maintenance personnel.

Brand and After-Sales Service

Brand Reputation: Choosing a COB LED display manufacturer with a good brand reputation ensures product quality and performance. A brand's reputation can be assessed by reviewing its history, market share, and user reviews. Well-known brands typically have stricter quality control systems and more comprehensive after-sales service networks, providing users with more reliable products and services.

After-Sales Service: Comprehensive after-sales service is crucial for ensuring the long-term stable operation of COB LED displays. When selecting products, understand the manufacturer's after-sales service offerings, such as warranty period, repair response time, and technical support. Additionally, you can consult other users about their experiences and learn about the quality of the manufacturer's after-sales service.

Answer 2

Below is a practical and easy-to-understand COB LED display selection guide without tables.

1) First, consider the pixel pitch (P-value) – the core factor determining clarity.

Selection principle: Viewing distance ÷ 2.5 ≈ suitable pixel pitch.

Viewing distance 2–3 meters: Choose P0.9 ~ P1.2

Viewing distance 3–5 meters: Choose P1.2 ~ P1.5

Viewing distance 5–8 meters: Choose P1.5 ~ P1.8 The smaller the pixel pitch, the better the COB experience, as small pitch is its strength.

2) The higher the contrast ratio, the better (one of the core advantages of COB).

COB inherently has a large black area and low reflectivity, so the contrast ratio is usually higher.

Preferred: ≥ 5000:1 For XR, film, and studio use, the higher the better; 8000:1 or higher is even better.

3) Brightness should be selected based on the scenario, not necessarily the higher the better.

COB can be made high-brightness, but you should choose according to your intended use:

Indoor conferencing/monitoring: 400–600 nits

High-end commercial/exhibition halls: 600–800 nits

XR/film shooting: 800–1200 nits Excessive brightness can damage eyes, increase costs, and generate heat.

4) Refresh rate and scanning method – avoid flickering during shooting

This is crucial for taking photos or videos:

Standard displays: ≥ 1920Hz

XR/film shooting: ≥ 3840Hz (ideally 7680Hz) A higher refresh rate reduces the likelihood of "stripes" and "shadows".

5) Flatness and module consistency

COB packaging itself is very flat, but batch variations between different manufacturers can still affect image quality.

Inspection:

Is there any obvious seam at low viewing angles?

Is the reflection from the lamp surface uniform?

Is the brightness/color temperature consistency of multiple screens side-by-side consistent?

This is crucial if you are working on XR or in a showroom.

6) Protection Rating (Impact Resistance, Dust Resistance, Moisture Resistance)

COB offers significantly better protection than SMD, but specifications still differ:

General Indoor Use: Around IP50 is sufficient.

Public Places, Interactive Touchscreens: IP54–IP65 is safer.

Frequently Touched / Classroom / Showroom Interactive Walls: Choose "Surface Hardening" or "Nano Coating".

7) Choose a Mature Driver IC and Chassis Heat Dissipation Design

High brightness + high frequency refresh + small pitch will significantly increase heat generation.

Note:

Is the driver IC (e.g., MBI, Chipone Technology, etc.) a high-end version?

Does the cabinet have a rear aluminum heatsink?

Does it have automatic brightness adjustment (more energy-efficient)?

8) Color Accuracy and Calibration System

For applications with strict image quality requirements (XR, live streaming, exhibition halls), pay attention to:

Does the color gamut reach ≥ 90% P3?

Does it support 16-bit–18-bit grayscale?

Does it have a pixel-by-pixel calibration system (the more advanced, the more stable)?

9) Brand and After-Sales Service

COB has extremely high requirements for manufacturing processes; not all manufacturers can do it well.

Reasons for choosing a major manufacturer: better consistency, lower dead pixel rate, longer lifespan, and more stable after-sales service.

Common reliable brands in the industry include: Unilumin, Leyard, Leyard, Mairui, and Jingtai Solutions.