Last Updated On July 27, 2020 / Written By Lauren Christiansen

What is LED? A Guide into Everything There is to Know About LED Signs

The utilization of images and videos are powerful ways to attract an audience and convey information. In fact, a message that contains visuals is processed by the human brain at a 60,000 times higher rate than text alone.



LED signs provide versatile opportunities for businesses to advertise their brand. Here's a guide into everything there is to know about this LED technology and how to use it to your business's advantage.

Vocab and Definitions

In order to fully understand the capabilities of LED signs are and how they operate, it's important to become familiar with the technical terms and descriptions, which include-

1. LED Display
A flat panel display that utilizes an arrangement of light-emitting diodes (LEDs) to display images, content, and videos. Displays vary in size, can be one or double-sided, and are monochrome or complex.

2. Pixel
A point of light that is the tiniest controllable element of a picture represented on a screen. LED displays are made up of many different pixels, each acting as a source of light. The pixels combine together to form text, videos, and content on the LED panel. A single pixel can be as small as one LED, or it can contain a group of LEDs that act together as a unit to display visuals.

3. MatrixThe total number of pixels displayed vertically and horizontally. For example, if a sign has a matrix of 36 by 84, this means that it has 36 pixels from top to bottom and 84 pixels from left to right. It can also be referred to as the resolution, or the number of distinct pixels in each dimension that are displayed. The resolution affects the visibility of the display.

4. Full Color
A display that utilizes a combination of red, green, and blue LEDs to create a multitude of colors.

5. Millicandela
A standard unit of measurement for the brightness of an LED. One millicandela is equivalent to 1/1000 candela, which is the unit of luminosity from the position the display is seen.

6. Pixel PitchThe density of pixels, typically measured in millimeters. Pixel pitch is the distance between the center of one pixel to the center of the pixel adjacent to it. The smaller the pixel pitch, the higher the pixel density and resolution of the display is.

7. Nit
A unit of measurement that describes how bright a type of display is over one square meter. In other words, it is the candela per square meter. Businesses should take the nit level into consideration when deciding which LED sign to purchase. The higher the nit level is, the more resolute the display is.

8. Viewing Angle & Viewing ConeThe maximum number of angles and directions that images and text can be viewed without becoming distorted. If the angle is too narrow, the text and images will disappear because the viewer has moved too far away from the sign. A viewing cone is double the amount of the viewing angle.

9. Parent/Parent and Child/Parent Two-sided displays are LED signs that operate on both sides of the screen. The displays on each side can either be different or the same, depending on the configuration. In a parent/parent configuration, the two sides can show the same message or different messages simultaneously. In a child/parent configuration, one side of the sign sends a message to the other, resulting in both sides projecting the same image simultaneously.


10. Grayscale
A monochrome display that shows different shades of one color, typically red.

Components

There are a number of different components that combine to make up an LED sign as one whole a unit, including-

1. LED
A light-emitting diode, or two-terminal (di) electronic component that moves a current in a specific direction. When the current passes through the component, light is emitted. It's a semiconductor device or electronic component that relies on certain materials in order to function. LEDs last longer and utilize less energy than standard light bulbs.

2. Controller
The brain of the LED, which varies in its messaging capabilities. Some controllers can only display simple messages, while others are capable of more features.

3. LED Module
A board that contains rows and columns of pixels, along with the components that control those pixels.

4. LED Cabinet
The metal enclosure that contains all of the sensitive electronic components of LEDs. The cabinet protects the components from weather damage or vandalism.

5. Power Supply
A device that converts incoming current that changes directions (AC power), to the correct amount of DC power, or current that flows in one direction. This power is then distributed to the different electrical components within the LED sign in order to make it function.

6. Light Sensor
A device that adjusts the brightness of the LED display. It prevents the sign from being too dim when exposed to sunshine, or too bright in the nighttime.


7. Sender Card
This device takes input from the controller, or brain of the LED sign, and converts it to a signal that is sent to another device (receiving card), in order to project a portion of the display.


8. Receiver Card
The component that receives the signal sent by the sender card and then transmits it to the LED modules in order to create a portion of the display.

Common Questions & Answers

1. Does Brightness Matter?
The level of brightness projected by an LED sign affects the visibility of the message. Signs that are too dim, especially during the daytime, can be difficult to see. Conversely, signs that are overly bright at night can be straining to the viewer's eye. Though LEDs utilize less energy than standard lights, they can still burn out and grow dimmer over a period of time. If the purchaser chooses a sign that has a stronger brightness capacity to begin with, it will last for a longer period of time.


2. What Size Should I Choose?
Before deciding which size of LED electronic messaging center (EMC) to purchase, it is important to consider where it will be placed, how far away the viewing audience will be, what angle will it be viewed from, and how it will be used. All of these factors can affect which type of size the sign should be.


Pixel pitch, or the distance between one pixel to the adjacent pixel, is utilized to determine the EMC's minimum viewing distance. If the EMC is viewed at distances less than the minimum pixel pitch, the message might be readable, but pixelated. Therefore, it's necessary to choose a size that is greater than the minimum pixel pitch, but not bigger than 10 times the size of the sign's square footage. Any sign that is too big will have a decreased readability.

Optimizing Graphics

There are four approaches to consider in order to make an image more easily viewable to an audience-

1. Resizing
This is the least desirable option because multiple pixels have to be combined into one, which causes the image to lose much of its detail. Larger pictures that are resized tend to cause the picture to lose much of its original value, and the image will appear blurry. The image will also look stretched out because much of the height has to be reduced more than the width in order to make the original image fit.

2. Cropping
This approach is more acceptable because cropped images won't combine multiple pixels into one, causing it to lose its detail and quality. However, less of the original image will show up, which is a downside for those who want to incorporate the entire image onto their display instead of a partial portion.

3. Combination
This is the best approach when optimizing graphics to fit an LED sign. First, the image is resized to something larger than the display, and then cropped. It includes more of the original image than a cropped version, but also reduces the amount of detail so the new image can fit appropriately.



4. Choose the Right Image
Picture subjects should be simple and have a smooth gradation of color and shades. Overly detailed photos have too many adjacent pixels that have to be combined into one when cropped and resized. This will make the image appear pixelated and blurry.