A Complete Guide to LED Displays

There are numerous LED display panel types on offer. Some of the more common configurations include segmented displays, dot matrices, alphanumeric and light bar versions.

The sections below provide a closer look at the differences between these types of LED screens and outline when a particular model or style might prove more useful or economical.

LED dot matrix displays can be considered as the next logical step up from 16-segment alphanumeric arrangements. In a typical dot matrix LED display, the clustering of individual diodes is dense, while the dots (LEDs) are typically arranged in a rectangular grid that is wider than it is tall.

The basic operating principle of an LED matrix display is straightforward. By turning individual lights on or off in programmable sequences, full alphanumeric displays can be rendered as a matrix in reasonable detail. The precise level of detail achievable will depend on the density of the LED array and the resolution of the dot matrix. This may also impact the digit height.

Standard resolutions for many LED matrix displays include:

• 128x16 (two-lined)
• 128x32 (four-lined)
• 128x64 (eight-lined)
• 92x31 (four or three-lined)

An LED dot matrix display is commonly used with all manner of billboards, hoardings, signage, and video walls. They can leverage additional detail and clarity over segmented number LEDs to show more complex information. They are often found in city centres and commercial areas, particularly with outdoor 3D LED displays for advertising or information purposes, and are easily programmed to display:

• Simple images and symbols
• Prices
• Temperatures
• Times and dates
• Seamless scrolling news ticker updates and messages

An LED 7-segment display is one in which any numeral can be laid out using an arrangement of seven separate LED segments. The individual diodes in a 7-segment display are arranged in a rough figure-eight system so that each LED segment can be individually illuminated (or left unlit), allowing the grouping to display any digit from 0-9.

Seven-segment display arrangements are sometimes abbreviated to SSDs and can also be referred to as seven-segment indicators. They are among the most common LED display configurations used for providing simple numerical readouts on a broad range of device types.

Seven-segment displays are generally limited to showing numerals. They are not considered especially suitable for lettering, as the minimal number of segments in each LED display makes it difficult to render sufficiently readable characters.

A 14-segment LED display takes much the same basic format as the 7-segment version but uses double the number of diodes. They are arranged in the familiar figure-eight shape, but with the addition of diagonal diodes crossing through the centre point. This configuration is also known as a Union Jack or starburst LED display.

The increased LED count allows for a significantly more detailed display, meaning that full alphanumeric readouts become much more feasible. However, even with fourteen segment displays, some letters in the alphabet remain difficult to render with great clarity.

In the mid-1980s, pinball machines and other arcade games were among the first everyday devices to help popularise the LED 14-segment display. In some design applications, the format is still used to achieve a stylised retro aesthetic. 14-segment displays remain a popular option for many device types.

As with 7-segment and 14-segment displays, a 16-segment LED display also conforms to the same basic figure-eight module arrangement. However, an additional pair of diodes are added by splitting both the upper and lower horizontal segments into two.

This allows for yet more detail in the graphical rendering of numbers and letters. It is generally deemed sufficient for reasonably full alphanumeric LED display readouts on devices where a more intricate dot matrix LED display is impractical or unnecessary.