The Amazing, Shrinking LED Pixel Pitch

Not many years ago, if you went out to buy an LED sign you could choose between a pixel pitch of 6 mm (for viewing at large distances) and a pixel pitch of 12 mm (for viewing at very large distances).

But over the the last few years, as seen at trade shows such as Infocomm and Digital Signage Expo (DSE), the minimum pixel pitch has been shrinking steadily. At the latest DSE, held March 11-12 in Las Vegas, Panasonic was showing signage modules with a pixel pitch of 1.1 mm and other leading manufacturers were not far behind. For perspective, when plasma television sets first came on the market they had this same pixel pitch: 1.1 mm. LED signs are now suitable for a widely expanded range of applications – and viewing distances far less than half the length of a football field.

Most manufacturers build up signs from seamless or near-seamless modules measuring between 12 and 24 inches on a side, although they are not necessarily square. Depending on size, pixel pitch and manufacturer, modules cost between $2000 and $6000 each. These are expensive signs, but all of the manufacturers I spoke to at DSE said there is substantial early demand from high-end retailers.

As shown at DSE 2015, this large Planar LED display was made up of the company’s seamless DirectLight modules with 240 x 180 pixels at a 1.6mm pitch. (Photo: Ken Werner)

As attractive as the current products are, it’s clear that lower cost and/or even smaller pixel pitches would greatly increase market size. Is this possible? LED chip-maker Osram Opto Semiconductors thinks so. Osram Opto has just announced it will be co-ordinating the new InteGreat Project, whose other participants are Osram GmbH, Fraunhofer-Gesellschaft, LayTecAG, Würth Elektronik GmbH and Mühlbauer GmbH. The project is supported by the German Ministry for Education and Research.

The project’s objective is to develop new production processes for high-efficiency LEDs that “remove the boundaries between the individual value-added stages….” Project co-ordinator Jürgen Moosburger said, “We will be researching completely new concepts for LED production and questioning the traditional paradigms of the manufacturing process. …With new production concepts, we expect to be in a position to develop both low-cost miniturized LEDs and highly integrated modules”.

Those are goals that seem to include micro-LED displays as well as more conventional signage and lighting applications.

I hereby make a very safe prediction: LED pixel pitches will continue to amaze us and will continue to shrink. – Ken Werner