LED (Light Emitting Diode) Tour

The term "Pixel" derives from the words "Picture Element." A pixel is one point in a character pattern. It is a point of light on an lighted programmable sign. It is a moving element on a mechanical programmable sign. The size of a pixel is stated by the diameter of the pixel. A pixel can be as small as a single .1" diameter LED, and can be made up of one or more LED's. A discrete LED has one individual diode. LED blocks and clusters are multiple LED's installed as a single unit.

For a single stroke character, it takes 7 pixels high and 5 pixels wide, plus the spaces between characters and lines.

Pixel diameter and center to center spacing (distance from the center of one pixel to the center of the next adjacent pixel) define the resolution or density of the character being displayed. The closer the pixels are to each other, the higher the resolution or density of the character. Low resolution characters are designed for distance viewing.

An LED sign is made up of an array of dots or pixels. The array is described by the number of dots vertically and the number of dots horizontally. For example, 16 X 80 means that the sign has 16 dots vertically and 80 dots horizontally. The characters and graphics of a message are formed by turning on or activating specific patterns of pixels within the display array. A sign is defined by its display array--the number of rows and columns of pixels. A sign with a 7x80 display array has 560 pixels.

The number of characters on a line of a sign is determined by the number of pixels across the sign and by the size of the character. A normal character is 5 pixels wide. One pixel space is used to separate characters. Thus, an 80-column sign will display 13 characters (80/6= 13.3). As you plan out your sign requirements, write down the messages that you intend to display on the sign. Count the characters in the words that you use most often. How many words do you want to see at once? This determines the number of characters per line required by your application. If a word won’t fit on the line, the word displays, one character at a time, or it starts a new line, depending on the display mode being used.