Understanding How LED Display Works


In this day and age, you can find LED displays just about anywhere, from advertisements along the streets to billboards atop skyscrapers. But, do you ever wonder how they work? In this blog, we’ll find out about the inner workings of LED displays, from their basic components to the technology behind them.

What is LED?

LED or Light-Emitting Diode is a type of diode made up of semiconducting materials. Once electricity passes through, these materials react and produce light. The materials inside the LED will dictate what the color of the light will be. LEDs come in only three colors: red, green, and blue. The first generation of LEDs could only emit red or yellow lights.

LEDs were invented by Russian scientist Oleg Rosev in 1927 using silicon carbide. In the 1980s, the blue LED was invented by Japanese scientist Shuji Nakamura. With further developments in LED technology, it was found to be an efficient lighting source for liquid crystal displays (LCD), giving birth to the present-day LED displays we know today.

How LEDs Compare to Other Light Sources

  1. Energy Efficiency: LEDs produce their own light by using electric current that flows through them. This process is much more energy efficient than heating a filament or gas to emit light like incandescent bulbs do.
  2. Lifespan: LEDs can last up to 100,000 operational hours or about 10 years. In comparison, fluorescent lights used in LCDs only last for 15,000 hours, while incandescent bulbs last for 1,000 hours.
  3. Durability: LEDs are typically made from gallium arsenide, which gives them a crystal-like appearance. These tiny bulb-like semiconductors don’t have moving parts, making them more resistant.
  4. Instantaneous Lighting: LEDs react to electricity fast, so they light up instantly once an electric current is applied.
  5. Directional Light: LEDs light up in only one direction, so they can distribute light more accurately. In comparison, traditional bulbs light in different directions, so they aren’t able to control light distribution.

How Does an LED Screen Work?

What’s Inside an LED display

  • LED Pixels: Pixels are the basic unit of an LED display. An LED display has thousands to millions of pixels, depending on its size. Each pixel contains LEDs. These LEDs produce red, green, and blue light. When mixed, they form millions of other colors.
  • Driver Chips: Driver chips control the voltage and current in LEDs. They are crucial in adjusting the brightness level of each LED, which enables the display to show color-accurate and detailed images.

Working Principle of LED Display

  1. When electricity passes through the LED, the semiconductor materials inside them are energized.
  2. The electrons in the semiconductor materials react by releasing energy in the form of light.
  3. The color of the light will depend on the materials inside the LED. The driver chips adjust each LED’s brightness accordingly, mixing the red, green, and blue colors in varying brightness to form other colors.

What are LED Displays?

LED displays use thousands of light-emitting diodes as a light source. These LEDs produce red, green, and blue light. These three primary colors are combined to produce millions of other colors. Once electricity passes through, the LEDs emit light. The created content is converted to signals by a processor and the LED display interprets the content.

Types of LED displays

  • Indoor LED Displaystypically used in indoor installations at close viewing angles such as in malls, concert halls, and transport hubs
  • Outdoor LED Displays: built from durable materials that can withstand harsh environments. These have high brightness levels that make them suitable for billboards and stadium screens.
  • Fixed LED Displays: used for permanent installations in high-traffic areas both indoors and outdoors such as in front of buildings, activity centers, welcome banners, and even as decorative details in buildings.
  • Rental LED Displays: these are also known as mobile LEDs because they are easy to assemble and disassemble. They are typically used for one-time events such as concerts that need to transport the screens from one location to another in a short period.

Uses of LED displays

  • Entertainment: Aside from TV sets, LED screens are popular for stage designs in concerts, music events, and theatres. They are used as backdrops to enhance the mood and stage lighting.
  • Advertising: One of the most common uses of LED displays is advertising products and services. Because they have high brightness levels and colors, they are effective in capturing the attention of potential customers.
  • Transportation: Every transportation hub, terminal, or airport has large LED screens that show trip schedules, announcements, and route maps.

What Does RGB Mean?

RGB are the three primary colors red, green, and blue. These three can be combined to produce millions of other colors. The intensity value can range from 0 to 225, producing different colors with every adjustment. For instance, setting the intensity of the three primary colors to 225 will result in white, and setting them to 0 will result in black.

Does RGB Affect How An LED Screen Works

LED displays have thousands of red, green, and blue LEDs that illuminate the screen to create images. The brightness level of each LED can be controlled individually, allowing them to produce millions of color combinations. LEDs’ consistency in color reproduction enabled LED displays to show accurate and detailed images across the screen at any viewing angle.

What is Pixel Pitch and Resolution?

Pixel pitch refers to how far a pixel is from its closest neighbor. This dictates the pixel density or how closely packed the pixels are in an LED display. It also affects how sharp and detailed the images will be displayed across the screen. The smaller the pitch, the higher the image quality, and vice versa.

Resolution, typically shown as length x width, is the total number of pixels across the screen. For instance, 4K (3840 x 2160) resolution TV. This means the TV has 3840 pixels from left to right and 2160 pixels up and down. To get the resolution, multiply the length and width to get 8,294,400 pixels. A higher resolution means a clearer picture.

How Pixel Pitch and Resolution Affect Image Quality

Pixel pitch and resolution significantly affect image quality. As mentioned above, the value of the pixel pitch affects resolution, and resolution, in turn, affects the overall picture quality.

If the display has a large pixel pitch, it results in a grainy and pixelated image. This is more suitable for close-distance viewing as the image will eventually lose quality as it is placed further away from the viewer. On the other hand, LED displays with small pixel pitch are excellent for long-distance viewing such as in billboards as image quality won’t diminish even when viewed from a distance.

LED Display Lifespan

According to studies, LED displays can last up to 100,000 operating hours or about 10 years. This is significantly longer than the 6-year average time an American household keeps their LED TVs. The lifespan of LEDs is measured in half-life or when their brightness levels have diminished by 50% of the original. If you have a high-quality LED display, you can expect a longer lifespan.

Factors Affecting LED Lifespan

  • Operating Conditions: The installation location of LED displays can significantly affect their lifespan. Exposure to elements, extreme temperatures, and everyday wear and tear could shorten their operational life.
  • Power Cycling: Power cycling of the repeated turning off and on of the display may contribute to the degradation of its internal components.
  • Quality of Components: Not all LED displays are made equal and you can see it in the quality of the materials used. More expensive LED screens are typically made with higher-quality materials that can last longer.

Maintenance Tips

  • Regular Cleaning: Regularly clean the surface of LED screens using a gentle cloth and products without harmful chemicals.
  • Monitor Conditions: Keep the LED display in ideal operating conditions. If possible, control the temperature and ventilation in the location.
  • Regular Inspections: Regularly inspect the display for any damages to its components and immediately replace or repair it to avoid bigger damage.
  • Follow Manufacturer Guidelines: Stick to the operating guidelines set by the display’s manufacturer as these have been tested to help your display last longer.
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