Glossary

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Display System Glossary / Terminology

Resolution

Resolution is the ability of a display to show the fine details in an image. Just as with digital cameras, computer monitors and similar imaging devices the higher the resolution of your display, the clearer the image will be. In the same way as computer monitors resolution is stated in terms of pixels wide and pixels high. The resolution required for your LED display depends on the messages or content that you intend to show.

Pixel pitch or dot pitch

Pixel pitch is the distance from the center of one pixel to the center of an adjacent pixel. The smaller the pitch the closer the pixels are together. Pixel pitch is important because as the pitch increases so does the minimum viewing distance. Small pitch displays (6-10mm) are ideal for interior viewing. Intermediate pitch displays (30-40mm) are popular for businesses located on city streets. Large pitch displays (127mm) are intended to reach motorists travelling at high speeds on motorways and inter-urban roads.

Character Height

Character height is the minimum physical height of a letter on the display. Electronic displays require a minimum of seven pixels to create the standard alphabet. Therefore, the way to calculate character height is multiply the pixel pitch by seven.

Although seven pixels high is the minimum vertical resolution to form a character, you should use more than seven pixels to increase the viewing distance. Your audience can read larger character heights from longer distances.

Viewing Angle

Viewing angle measures readability in typical conditions. Beyond the specified viewing angle, you lose readability.

A display appears the brightest when the viewer is perpendicular to the display face and diminishes as he or she moves from side to side or up and down. For example, a display with 90 degrees horizontal and 40 degrees vertical viewing angle can be read from 45 degrees left to 45 degrees right, to 20 degrees above and below the display.

So why not choose a sign with the widest possible viewing angle? Wider viewing angles typically dilute the brightness of your image. Conversely, narrow viewing angles concentrate the image’s brightness. When choosing a sign, wide viewing angles are important for stationary audiences dispersed over a wide venue such as pedestrians or slow-moving traffic. Narrower viewing angles are generally appropriate for faster-moving traffic.

Viewing Exposure

Traffic speed, display size, viewing angle and pixel pitch all influence the amount of time a viewer can see your electronic display. For example, a sign located near faster traffic must be larger to attain optimal exposure time.