LCD-TFTs – in pursuit of non-standard shapes

Most of the LCD-TFTs surrounding us are rectangles in standard 16:9 aspect ratio. We are familiar with this common format. It works well for most applications. In recent years, however, there has been a growing demand for digital signage solutions with unusual display shapes and sizes. This has led to adding stretched, square and round shapes to industrial grade displays. This trend is directly related to the need to efficiently use the space available for information visualization. Especially when there is no space for a standard display.

Imagine when a customer asks about a stretch display for use in transport. In transportation, designers are often faced with real-life limitations how to fit displays for information visualization. For example, on a train or in a metro, there is available only a narrow space between the door or window and the roof.

Note that passenger information is a crucial part of any journey. Especially, if this data is being updated in real time. This generates an increasing demand for dynamic information visualisation solutions. The challenge, therefore, is to position messages intended for passengers in such a way that they are clear, accessible and useful, but from the passenger’s point of view. This means that in the case of limited available space to put a readable display, as in the example of a train or metro above, solutions must be well optimized to fit in. Sometimes it may not be possible to match a suitable LCD-TFTs from among the standard models. Hence the pursuit for solutions that, in this article, we refer to as ‘non-standard’.

Conventional cutting of the LCD-TFTs

One method of manufacturing LCD-TFTs with non-standard shapes is to simply cut it out.

In order to produce a stretched display, the final format has to be literally cut out of a standard LCD-TFT panel, which usually comes in 16:9 format. The cut area is then sealed to avoid damage to the liquid crystals. The edges are further protected against the ingress of dust or moisture. The advantage of this solution is the availability of LCD-TFT panels ready for cutting, because the factories specializing in the production of liquid crystal arrays are optimized to produce them in large quantities. With the appropriate protecting measures in place, this is a proven and cost-effective way of manufacturing non-standard display shapes.

However, the catch is that with LCD-TFT conventional cutting technology not all shapes and sizes are available, so certain design limitations must be accepted within this technology. What’s more, the cut-off remains must be disposed of, which makes this process not environmental friendly, unless it can be used to produce further displays.

AUO TARTAN technology

Researching non-invasive solutions for LCD-TFTs in non-standard formats, AUO has developed the TARTAN technology, which uses native photomask manufacturing process. A photomask is a sort of template for TFT glass, which is then copied onto subsequent matrices (called open-cell panels).

How does the TARTAN technology work? The process involves obscuring parts of a bigger photomask to obtain the target shape or size of the LCD matrix. TARTAN technology uses a base a photomask up to 65 inches in either UHD or FHD. If as a designer you are looking for the optimum solution for a display that fits within these parameters, then TARTAN technology can save time and reduce costs, as there is no need to manufacture a completely new photomask. As a result you get a customized display in size and format. And it’s available even in relatively low quantity runs.

The most important advantage of the technology TARTAN is the ability to create liquid crystal matrixes in various shapes and sizes – tailored to the customer’s requirements, without the need for unnecessary interventions in the LCD-TFT material already produced. This means that the final format of the display is manufactured at an earlier production stage than in the case of mechanical cutting of the already produced LCD-TFT panels.

Moreover, TARTAN technology is characterized by industrial quality. As AUO points out, the high-brightness solutions are relatively energy-efficient thanks to the new cell design. Displays with a brightness of 2500 cd/m² consume less energy than the previous 1500 cd/m² versions. TARTANs are suitable for operation in wide temperature ranges from -40 to 110°C, as well as in continuous 24/7 mode. They also use hiTNI technology, which prevents the liquid crystals from being damaged by exposure to sunlight, allowing for implementation in sunny locations.

Summary

For a long time, application designers only had a rectangular LCD-TFTs at their disposal for information visualization. As a diversification, it was possible to make some combos on the existing product – like placing the screens in portrait orientation or grouping them together as a videowall. The main downside was that the final design had to be adapted to the available shapes and sizes of the LCD-TFT displays, regardless of its final application. In extremely demanding places, there may have been situations where the use of a standard display was rejected altogether because there was physically not enough space for it.

With the advent of conventional LCD-TFTs cutting technology, it became possible to manufacture more flexible formats and bring the displays into almost all potential application locations. The TARTAN technology developed by AUO is another step towards optimizing the space available for information visualization.

What’s more, the non-standard formats in displays are eye-catching. For this reason, those displays are increasingly being used in other areas, such as gastronomy as square menus, in gaming as arcade machines or in retail as unusual media for advertising.

Jacek Marcinkowski,
Head of Solution Department