LED vs. LCD Part 1: The competitive landscape of visualization technologies
By Gary Feather, CTO, NanoLumens
InfoComm 2016 was again a demonstration in innovation and an implementation of "firsts" in the LED display market. It is these push-and-pull factors that are driving future change.
The innovations this year were unique and seminal for the LED digital signage industry. For example, this was the first time displays were seen for near-to-the-viewer — or less than 2 meters of viewing distance — performance (i.e. tightest pixel pitch) as well as large-area seamless displays, which could be found across all of the major suppliers in the industry. We have demonstrated the ability to prepare displays for the exhibition of 4K and even 8K in a single continuous display over 55 meters squared. It can be said that with LED anything is now possible in resolution and size.
We have seen that pixel pitch has pushed ahead rapidly in order to allow HD resolution into ever smaller screen sizes. For example, high definition (2K HD) displays at 2.5-mm pixel pitch last year occupied 13.8 meters squared in surface area; whereas 1.25-mm pixel pitch displays were prominent throughout InfoComm this year.
This ongoing revolution in innovation has allowed a significant 4X improvement in pixel fill factor PPM2 (pixels per meters squared). These tighter pitch solutions have reduced the surface area to only 3.45 meters squared. And to challenge the possibilities of imagination, there were a few examples of 0.9-mm pixel pitch, allowing a 2K HD display surface area of 1.68 meters squared, or only about twice the area of a 60-inch 2K HD LCD.
With regard to resolutions, initial thinking might suggest that competitive LED digital signage solutions must track LCD and get down to 0.7-mm or even 0.35-mm pixel pitches in order to be a viable replacement. However, this is not true.
Based upon size requirements where multiple equivalent LCD panels are the entry point for fine pitch, seamless tiled LED displays with pixel pitches of 1.25 millimeters down to 1.0 millimeter can and will quickly begin to replace needed digital signage requirements of resolutions for tiled LCD panel displays. This includes 2x2 (four panels) and 3x3 (nine panels) or larger.
When factoring in digital signage sizes, the implied viewing distance and the ability of the eye to discern the pixels and notice pixelation, a viewing distance of 1.25 to 2 meters can be expected. The digital signage system objective is one that the user's content resolution will match the perception of resolution of the viewer's eye, which is based upon the fovea of the eye and the distance to the screen, to the created resolution of the LED display.
The sweet spot for LED seamless tiled displays should focus on the 1.25-mm displays starting next year and sustaining that pixel pitch for the next three to four years. There will be many opportunities in the 1.5-mm and 1.875-mm pixel pitch space, but those wider pixel pitches will be new solutions for larger size and further viewing distance requirements not directly aligned to LCD replacements.
In the second part of this series, we will discuss the other factors affecting the future of the digital signage industry such as efficacy and image quality. Keep in mind that pixel pitch is on a path to get tighter. Along the way opportunities will grow for the 2.5-mm, 1.8-mm and 1.5-mm pixel pitches as the industry focuses on achieving a full-value solution in the 1.25mm pixel pitch.
Anything is possible with LED in today's market, and we are ready for the exciting innovations ahead.