| LED |
LED or "Light Emitting
Diode" is a semi-conductor made of a combination of substrates to emit light when
charged with a low DC current, typically at 20 milli amp (mA). This drive current spec is
important, because "driving" the LED above 20mA to achieve a greater brightness
shortens the life of the LED dramatically. |
| LED Life |
LED life is typically rated for
100,000 hours by most LED suppliers. In outdoor applications its "actual life"
greatly depends on the design of the overall system, type of substrate materials, LED
grade, drive current, and manufacturing technology used by the display manufacturer. |
| Candela (cd) |
Candela is a unit of brightness
used specifically for LED's. The measurement is made at the 0° axis. Its rating varies
with the half-intensity viewing angle of LED. The unit of milli candela is also used
interchangeably, for which 1 cd = 1,000 mcd. |
| Half Intensity Angle |
Half Intensity refers to the
viewing angle rating as specified by the LED manufacturer, such as Hewlett Packard or
Nichia. This simply states that at X degrees the LED intensity will be ½ as intense as it
would be at 0 degrees. Our high-brightness & high-contrast design allows the actual
visible angle to be much larger than the ½ intensity angle. |
| Max. Viewing Angle |
The maximum viewing angle as
specified by various sign manufacturers could be quite misleading. This measurement is
ambiguous and varies greatly with ambient light conditions. To truly compare signs of
different manufacturers, one should use the ½ intensity angle. |
| Constant Current |
Constant current design and
constant voltage design refer to the way LED’s are "driven". To ensure
consistent LED brightness, constant current design is used by us. This technology is more
expensive, but produces a high quality display. Constant voltage design allows the
LED’s to exceed their 20mA current rating, thereby shortening the life of the display
and producing non-uniform color. |
| NIT |
NIT is a measurement of
brightness used to rate LED displays. NIT is expressed in "candela per square
meter". While NIT is the measurement of brightness being emitted from the LED
display, be aware that contrast plays a key role in determining the legibility of an LED
display. |
| Contrast |
The contrast between the
LED’s and their surroundings can influence the legibility of the display. Our
supplier has addressed this issue by developing a proprietary, patented design that
eliminates the glare and thereby provides the best legibility for the display. |
| Pixel |
A pixel is a single point of
light, capable of producing all of the colors of the display. This differs from
incandescent displays that produce a single color per lamp, which is not a true
pixel. |
| Full Matrix |
A full matrix display allows the
user to combine the entire display’s pixels to produce larger characters and
graphics. This feature, as offered by us, allows greater flexibility and creativity. |
| UL |
Underwriters Laboratory
certification is a critical factor for installation in most US cities. Our outdoor
displays are all certified by UL. Our suppliers product quality is further guaranteed with
a prestigious ISO9000 compliant certificate. |
