- What is a “dot pitch”?
The pitch of a LED display expresses, in millimeters, the distance between pixels. This measure is fundamental to determine the characteristics
and performance of a LED display. To know a display’s pitch is very important since this measure marks the minimum viewing distance, the
module’s definition and therefore the total LEDs density present on the display, which means the resolution. It is important to highlight
that by reducing the pixel pitch, the LED density increases exponentially: for example, reducing the pitch by 50%, you can have 4 times
the number of pixels on the same surface.
- Which is the difference between SMD and DIP LEDs?
SMD is the acronym of Surface Mounting Device and it is the new frontier of the electronic technology: the revolution brought by the SMD
technology into the sector is represented by the miniaturization of all the electronic components, including LEDs. The SMD components are
mounted on the surface of the electronic board, without “passing through it” as any other electronic component utilizing the former technology
(called PHT, acronym of “Plating Through Holes”). The SMD LED is also placed on the external part of the board without both filaments
(anode and cathode) having to pass through it, as described on the image below (proportions are real): LEDs utilizing SMD technology are
different from common PHT LEDs for another very important characteristic: thanks to the miniaturization it is possible, in fact, to place
3 LEDs of different colors within the same case (as in the picture on the top right), resulting in a three colors LED. The possibility
to visualize three colors at the same time (Red, Green and Blue) on a single LED allow to create maxiscreens with a very reduced pitch
(distance between pixels) and therefore to get a much higher quality image.
- What is the RESOLUTION of a display?
The resolution is nothing else but the number of pixels present on each m2. The resolution is therefore opposite proportional to the pixel
pitch: smaller is the distance between two pixels, higher is the resolution (because the surface of the screen will have a higher number of LEDs).
For example a 20mm pitch screen has a resolution of 2304 pixels: this measure is obtained by dividing the total length of a single module
(975 mm) by the pixel pitch (in this case 20mm) resulting in the number of pixels on a single line: 975:20 = 48 pixels. By multiplying
the number of pixels present on a single line by the total number of lines, you get as a result the total number of pixels present on
the screen’s surface, which is called resolution. In our example, 48 x 48= 2304 pixels in total. Given this formula, we find out that a
30mm pitch screen has a resolution of 1024 pixels per module, and a 10mm pitch one has a resolution of 9216 pixels per module. It is
important to notice that reducing the pixel pitch by only a few millimeters, the LED number increase exponentially and therefore the resolution.
- What is the COLOR TEMPERATURE and why is it important?
As an international convention defined by the CIE (International Commission of Illumination) states, while evaluating the properties of any
source of light, it is used a measure that takes into account their chromatic content. Such measure is called “color temperature”
and it is expressed in Kelvin degrees (°K). Low levels of color temperature correspond to color tones closer to red, while high levels
correspond to color tones closer to blue. In LED screen, it is fundamental to keep constant these values to visualize high quality
images. Our company’s screens have an electronic system of colors’ equalization that deals with these parameters automatically,
depending on the environmental lighting, in order to obtain always a constant color temperature during both day and night performances.
- What is the REFRESH RATE and why is it important?
The refresh rate indicates the number of times that the image refreshes every second. For example, a PC monitor has a “refresh rate”
of 72 Hertz (Hz) and therefore it refreshes all the pixels of the screen, from top to bottom, 72 times every second. The refresh rate
is fundamental since it determines the image’s quality: if it is too low, the human eye can see a flicker that causes headache and
damage to our eyes. To provide a comparison, most of the TV monitors have a refresh rate of 50Hz and only a few last generation
televisions have a 100Hz refresh rate. Led Lite Vision’s screens have a 240Hz refresh rate, which is almost three times higher
regarding the most advanced cathode tube technologies. This feature is another prove showing Led Lite Vision’ quality and the
state-of-the-art technology, result of many years researching and testing in situ.
- Do LEDs really have a lifespan of 100,000 hours (or 11 years)?
To guarantee a 100,000 hours lifetime, LED producers state clearly two fundamental conditions that must be respected, the internal
temperature and the power intensity. These measures have different values depending on the LED type and the manufacturer, but to provide
a limit of comparison we can say that:
1 – the LED internal temperature must be below 120 °C (measured in a 25°C environment)
2 – the power on which the LED works must be below 20mA. If both conditions are maintained, the LED producer guarantees that after 100,000
hours (about 11 years always turned on) the LED brightness will be reduced by 50% regarding the initial value. Keeping in mind the
importance of these parameters, Led Lite Vision has invested in technological solutions able to manage these values correctly and
automatically, and keep them constant during the whole device life. Led Lite Vision products are also able to verify them with a
series of related devices and controls as: 1 a special forced ventilation electronic system electronically controlled, 2 a specific
chip that manages every single LED and on which a certain power phase is defined, 3 a special heat dissipation system.
- What are the differences between INDOOR and OUTDOOR screens?
From a general point of view the difference between indoor and outdoor screens are the following:
1 – lower resolution: as the outdoor displays are usually watched from longer distances, they do not need a very high resolution. The cost
for a big screen is therefore compensated by the lower resolution needed to provide a good image quality.
2 – protection against weather (IP 65 protection grade) and cooling system: screens are treated with a particular “tropicalization” technique
that guarantees an excellent resistance to water, salty air and corrosive intrusions typical of outdoor installations. Moreover a special forced-ventilation system guarantees that the temperature inside the screen remains constant and never passes the critical levels.
3 – against-sun and against-vandalism protection system: outdoor screens have a special protection system that has the double function of protecting the screens from the
sun (increasing the contrast levels and obtaining a better image) and from vandalism acts.
4 – higher brightness: the outdoor use requires high brightness LED components in order to be visible from longer distances and most of all
able to contrast the direct sunlight.