Here is the list of useful terms related to LED Video Wall.
Table of Contents
It’s a technology that allows to elaborate videos without reducing the quality in a perceptible way. After this elaboration (called Gamma Correction) it is possible to visualize 65.000 color’s levels for each of the three primary colors. So, this means that you can be visualize 60.000 x 65.000 x 65.000 = 280 billions colors.
Candela measures how much light is produced as measured at the light source. See also CDM.
The cathode ray tube or CRT, invented by Karl Ferdinand Braun, is the display device that was traditionally used in most computer displays, video monitors, televisions and oscilloscopes. The CRT developed from Philo Farnsworth’s work was used in all television sets until the late 20th century and the advent of plasma screens, LCDs, DLP displays, and other technologies.
As a result of this technology, television continues to be referred to as “The Tube” well into the 21st century, even when referring to non-CRT sets.
However, digital billboards and CRT monitors are totally different, both for functioning principle and type of application.
CDM is the acronym of Candela per Square Meter (cd/m2), the Standard unit of luminance (also called Nits in the USA, from latin “nitere” = “to shine”). 1 Candela is equal to 1 NIT.
Are the shades of color touches that every color can have. In the LED visualization field are considered the color’s levels of Red, Green and Blue, the three primary colors. Moreover, it is obvious that higher is the number of possible touches, higher is the quality and the naturalness of the visualized image.
It’s a measure of reference defined by CIE (International Commission for Illumination) and it is measured in Kelvin degrees (°K). In addition, the color’s temperature needed to get the Pure White is around 6000 °K.
It’s the difference between the light emitted by the electronic billboard and the environmental light reflected by the screen’s surface. Minor is the light reflected, higher is the contrast and therefore the cleanliness and naturalness of the images.
It is a PC that manage the LED Video Wall, to which is directly linked. Hence, it can be installed internally (embedded PC) or within a few meters from the display.
Is the number of horizontal and vertical LEDs on the screen. Basically the Resolution is referred to the single module of 1 m2 , while the Definition is referred to the whole display (once all the modules have been assembled).
Is the acronym of Digital Visual Interface and it is a standard interface created by the Digital Display Working Group. The DVI standard was created to allow the transfer of big quantity of video data in digital format, regardless of the type of monitor utilized.
It is a image management system indispensable when it is needed to visualize high quality images on every kind of monitor, from the television to the PC monitor and the LED screen. Gamma correction controls and manages the brightness and cleanliness of the images.
It is the degree of protection against dust and humidity. It is identified as IP acronym of “Ingress Protection”.
Is the acronym of Light Emitting Diode. The LED is a semiconductor that emits light when electricity pass through it. The color of the light emitted can be of different colors (red, Green, Blue, Amber, White…).
Is a unit of measurement of the amount of brightness that comes from a light source. The standard lumen rating of a data projector is the average of photometer readings at several points on a full white image on the screen.
Technically, lumens measure “luminous flux.” A wax candle generates 13 lumens; a 100 watt bulb generates 1,200. The lumen rating is a critical specification when choosing a data projector. In a darkened room, 500 lumens may be ample; however, in a conference room with normal lighting, 1,000 lumens would be better. In a room with bright daylight, 2,000 lumens is preferred.
Luminance (also called luminosity) is a photometric measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. It is measured in candela per square meter (cdm).
The mCd is the acronym of millicandela (or mCd = CD/1000). 1000 millicandela equals 1 candela (CD). It is the unit of measure commonly used to describe LED brightness. Candela measures how much light is produced as measured at the light source.
Please also see CDM (candela per square meter)
As a measure of light emitted per unit area, this unit is frequently used to specify the brightness of a display device. See aòso CDM.
It the distance between the pixels, expressed in millimetres. It is a fundamental measure as it defines the image’s quality, the digital billboards minimum viewing distance and besides it affect significantly the final cost of the LED screen.
It’s the luminous dot typical of every LED visualization device. It can be composed by one or more LEDs (in some model the pixel is composed by 36 LEDs).
The basic idea of a plasma display is to illuminate tiny colored fluorescent lights to form an image. Here, each pixel contains three fluorescent lights — a red light, a green light and a blue light. In addition, just like a CRT television, the plasma display varies the intensities of the different lights to produce a full range of colors.
The central element in a fluorescent light is a plasma, a gas made up of free-flowing ions (electrically charged atoms) and electrons (negatively charged particles). Hence, under normal conditions, a gas mainly comprises of uncharged particles. Therefore, if you introduce many free electrons into the gas by establishing an electrical voltage across it, the situation changes very quickly.
Hence, by varying the pulses of current flowing through the different cells, the control system can increase or decrease the intensity of each subpixel color. In this way, it create hundreds of different combinations of red, green and blue. In this way, the control system can produce colors across the entire spectrum.
The “Plug and Play” technology is a capability developed by Microsoft that gives users the ability to plug a device into a computer and have the computer recognize that the device is there. The user doesn’t have to tell the computer. In many earlier computer systems, the user needed to explicitly tell the operating system when a he adds a new device .
It’s the maximum distance within the images visualized on the electronic billboard are readable, therefore clearly recognizable.
The refresh rate identify the number of times that the image is “refreshed” every second. When using led screens for TV shows or other uses where the ledwall needs to be recorded on videos is mandaory the choice of a high refresh rate to prevent bands in recordings.
It is a second PC linked to the Control PC: it is utilized in every situation in which the position of the LED billboard doesn’t allow the access to the Control PC (for example a large height installation). This Remote PC communicate directly with the Control PC and it manage the settings to be transmitted to the display.
This kind of screens is ideal for temporary applications like live concerts, sports events, TV shows, fashion shows, open air events exhibitions and conventions. Euro Display’s LED video wall have a specific design that guarantee lightness and portability of the modules. Moreover, it also strength and solidity of a structure which undergoes frequent assembling stress.
It’s the number of LEDs mounted on every m2. Obviously higher is the number of LEDs, better is the image’s quality. In addition, it is important to note that smaller is the pitch, higher is the resolution.
Is the acronym of Red, Green, Blue. Hence, every color perceptible by the human eye is generated by a proportionate mix of these three primary colors.
The SMD technology is electronics’ new frontier: a real revolution it brought in the graphic visualization field, is the miniaturization of all the electronic components, LEDs included. Moreover, all the SMD (“Surface Mounting Device”) components are mounted on the surface of the electronic board, without passing through it.
The stand-alone displays function as a screen connected to a VCR that shows everything is pre-recorded on the videotape. Moreover, once the sequence of images to be visualized has been memorized, there is no need for a Control PC to keep functioning. For this reason stand-alone displays are not able to forecast live videos which is a feature of the modular.
It is the first time when you install and turn on the digital billboard. Hence, in this occasion an technician take care that all the links between the modules are proper and proceed switching on the maxi-screen.
A electronic billboard’s viewing angle is the angle within which the brightness of the display is less than 50% of the frontal luminosity. For example, a screen with a frontal brightness of 6000 NIT (NIT = millicandels for m2) has a viewing angle equal to the angulation’s in which its brightness is less than 3000 NIT.
The virtual pixel is a image management technology that allows to visualize images with a definition higher than the physical definition of the LED billboard. Thanks to a technique called “pixel interpolation”.
It’s the maximum distance within the LED video wall is able to capture human’s eye’s attention, even if the images are not perfectly recognizable. The visibility of a maxi-display is usually equal to the double of the readability.