Real Pixels Converted Into LED Screen That Can Generate Virtual Pixels

Companies that trade LED screens, to promote their products in a highly competitive market, declare that they use the technology of "Virtual Pixel" that can duplicate or even quadruple the effective resolution of a screen. For example, a graphic definiton of "real" 320x240 pixels, in fact, is it converted into an LED screen that can generate "virtual" definition of 640x480 pixels (or a 20 mm pitch screen with normally 2500 pixels per square metre can reach 10000 virtual pixels per square metre).

All the leading manufacturers of LED screens are now focusing on new models with higher resolution based on "Real Pixel" technology. This has also been made possible by latest developments in Surface Mount Technology (see related FAQ). "Virtual Pixel" technology is still used quite often, particularly in some specific applications like rental & staging, but it will probably be given up in years to come.

Why are the leading developers and manufacturers of LED Screens making this choice? Let's try to analyze the situation and determine, where and when it makes sense to use the technology of "Virtual Pixel" and when instead it is better to use the technology of "Real Pixel".

In traditional fullcolor production, each pixel is composed by a cluster of LEDs with three basic colours (Red, Green, Blue: RGB). Their positioning on printed circuit boards is “gathered”, or rather electronically driven as if it was a unique inseparable unit, “pixel to pixel” (Fig. 1).

In the “Virtual Pixel” technology – “Square Pixel”, so called by Tecnovision - the mounting arrangement is like a “carpet”; diodes are the same distance from one another, placed in an alternate and crossed way, and are electronically controlled “LED to LED”. In traditional system each pixel of the image to visualise corresponds to a precise LED grouped cluster on the display. In “Square Pixel” system, thanks to the special configuration of individual LEDs and evolved electronic management characterised by very high refresh rate (500 frames per second), correspondence is not one-to-one any longer but now pixels are created also by using LEDs from adjacent pixels.
Let’s take into consideration, for instance, the pixel composed by 4 LEDs (BRRG) in the central panel highlighted in (Fig. 2); you will see that the two adjacent LEDs on the right hand side (BR), connected through signal to the two LEDs (RG) belonging to the central panel itself, allow obtaining another completed pixel (RGBR).

By horizontally linking LEDs together through electronic system, the number of visualised horizontal LEDs will be doubled; the same will happen vertically (Fig. 3).

Therefore, a "Virtual Pixel" contains information of the 4 pixels of the initial image. This often leads people to think that the screen definition is doubled or resolution quadrupled. Which is not exactly true. Indeed, one pixel on the screen cannot hold and display all the information coming from the initial four pixels.

Does “Virtual Pixel” technology have advantages? In general, we can say yes, it does. In several circumstances, the overall quality of the pictures is improved, getting crisper and smoother. This technology gives very good results in terms of color shades, on fragmentary pictures and particularly with live video.

However “Real Pixel” technology has clear advantages in some other applications like perimetral signage and advertising when animation is displayed. The quality of text is definitely superior. At an equal minimum viewing distance, a better picture quality is perceived. Morevoer this technology has a lower manufacturing cost, therefore, it can generally offer a better value for money.
Each project of installation of LED screens must be carefully assessed with an expert to choose the most appropriate technology, taking into consideration the final product use and the exact location.