What is LED Display?
LED means Light Emitting Diode: Light emitting diodes emit visible light when electricity is applied. Traditionally LEDs are created from two semiconductors. By running current in one direction across the semiconductor the LED emits light of a particular frequency (i.e. of a particular colour) depending on the physical characteristics of the semiconductor used. The semiconductor is covered with a piece of plastic that focuses the light and increases its brightness. These semiconductors are very durable, they contain no filament, require little power, are very bright and have a long life.
What is a programmable LED display sign?
Programmable LED displays are connected to a computer by cable, modem or via Ethernet. It is also possible to program an LED display sign by means of its own programming keyboard. ALPHA LED displays normally have both options. It is generally simpler and more efficient to program by means of a computer. Software designed especially for programming ALPHA LED displays is available. Most LED Displays are equipped with backup batteries to protect the data in the event of a power outage.
What is the difference between a full matrix and character matrix sign?
On a full matrix sign, there are no spaces between the individual LED cubes. Each cube is directly adjacent to the cubes around it. This makes the sign look like a solid wall of LED pixels, which allows both text and graphics to be displayed. On a character matrix sign, spaces exist between the individual LED cubes, so only text can be displayed.
What is the difference between an indoor and an outdoor sign?
Indoor signs have smaller characters than outdoor signs, because the viewing distance is much shorter. Indoor signs do not have to be as bright as outdoor signs, because they do not have to be viewed in bright daylight. Outdoor signs are manufactured to withstand outdoor conditions of direct sunlight, and large temperature variations, rain, snow and dust.
What size characters are recommended?
It depends on the speed of traffic and the size of the characters. Below is a handy chart to help you determine which display is right for your application.
Someone traveling
in a car at... |
Needs this
MRLD |
Then select a sign with |
MPH |
Ft./sec. |
Ft./sec. |
Character Size(in) |
Lateral offset(ft) |
75
70
65
60
55
50
45
40
35
30
25 |
110
103
95
88
81
73
66
59
51
44
37 |
605
565
524
484
444
403
363
323
282
242
202 |
20
19
17
16
15
13
12
11
9
8
7 |
0-53
0-50
0-46
0-43
0-39
0-35
0-32
0-28
0-25
0-21
0-18 |
NOTE: MRLD (Minimum Required Legibility Distance) is the min. distance required for a sign to be readable. This is based on the Legibility Index (LI). In this table an LI=30 is used. This means that for each 1-in of character ht, a sign can be read up to 30-ft. For example, with LI=30, a 10-in character is readable up to 300-ft (30 x 10). Until recently an LI=50 was the "gold standard". However, this is based on someone having 20/20 vision. Today, due to an ageing population, a more realistic value would be LI=30 which is based on someone with 20/40 vision. |
A detailed explanation can be found in the brochure "Understanding Outdoor Electronic LED Signs"
and a detailed fact sheets in "Outdoor LED Sign Fact Sheets"
CALL MAGEN ELECTRONIC DISPLAY TODAY and we are here to help you. |
