Wearable Displays Sport Classic Designs

There was a time when watches seemed to go out of fashion. Everyone knew the time by looking at their mobile phone screen. In the last couple of years, “connected watches” have become a wearable part of the mobile ecosystem, as their design has approached that of classic wristwatches. The intuitive round-faced hand dial watch user interface has pulled through, once again.

JDI Memory-in-Pixel reflective connected watch display. (Photos by Jyrki Kimmel.)

How has this development come about? Weren’t we satisfied with the function of the square-screen Android devices that appeared on the market about 5 years ago? Apparently not.

The wearables offering on the exhibition show floor featured many round-faced watch-sized displays. The Withings activity monitor, for instance, was featured in the E Ink booth. It sported a reflective e-paper display, in a round design.

Withings Go activity monitor with 1.1-in. circular, segmented e-paper screen.

Assuming that customer demand drives the adoption of consumer devices, once the technology to realize these is available, we can infer from the exhibits shown that there is a demand to minimize the bezel and dead space in a watch form factor display. Companies are striving to provide a bezelless design similar to what has become possible in mobile phone displays. This is much more difficult using a round shape. AUO showed in two symposium presentations how this can be done using a plastic substrate display. Instead of placing the driver chip on the face of the display, in a ledge, or using a TAB lead, they bend the flexible substrate itself to place the driver at the backside of the display. This way a bezel of 2.2 mm can be achieved, with clever gate driver placement and bringing the power lines into the active area from the opposite side of the display face.

Another direction in the development of wearables is to introduce a band form factor display that wraps around the user’s wrist. Canatu, the Finnish touch panel maker, had an E Ink based display device from Wove on its stand. 

Wove wrist device with Canatu integrated touch system.

The touch panel was assembled in an “on-screen” touch fashion to make a complete, integral structure without any separate outside encapsulation. The whole module thickness is only 0.162 mm, according to the press release.

So, it seems like the technical capabilities in displays are coming to terms to satisfy user needs in wearable devices. With the round-faced and band-shaped form factors making it possible to wear a watch again, the “Internet of Designs” can begin. –Jyrki Kimmel for Information Display