Braille that fits in your pocket
Tetragon, a TU Wien spin-off, has invented a completely new kind of Braille display, which is user-friendly, cost-effective and extremely portable.
Braille has proven to be a very effective writing system for many decades. However, it has still not yet fully entered the digital age. Braille displays are expensive, complicated and unwieldy. This could be set to change though, with the Austrian start-up Tetragon, a spin-off of the TU Wien, which is developing a completely new concept. The Tetragon display consists of a ring, inside which letters are displayed in Braille for the user to feel. The ring is relatively straightforward in technical terms – it fits into any jacket pocket and is projected to be far more affordable than similar products that are already on the market.
Different ideas with different disadvantages
For many years, Prof. Wolfgang Zagler has been working on technologies intended to help older people or those with physical disabilities. “For decades, we have been aware that the problem of creating the perfect Braille display is still yet to be fully solved,” says Prof. Zagler. “Different approaches have been tried time and again – movable pins controlled electromagnetically, solutions using piezoelectric elements and products based on various other technologies – but all of these approaches had drawbacks.” Some displays have high power consumption or a very limited shelf life; they are at best suitable for office use but they are not truly portable. As a result, they are also technically complex and, in most cases, very expensive.
“Of course, today we have voice output software that can read out text for you – but that’s not an adequate replacement,” asserts Prof. Zagler. “Ultimately, reading is a key cultural component; it is essential that blind people continue to know how to use Braille in the future. We want to help Braille totally make the leap into the mobile computer age.”
The solution: a movable ring
Together with Michael Treml and Dominik Busse, two of his former students, Prof. Zagler has developed a completely new approach: Braille will no longer be displayed on a fixed, flat line. Instead, users will be able to read the text on the inside of a rotating ring. “You can manoeuvre the ring like a computer mouse and move it across the top of your desk,” explains Prof. Zagler. “Your index finger is located inside the ring and can feel the letters, which are newly formed each time the ring is turned. So when you’re reading, this gives you the impression of one seemingly endless line.”
The six tactile dots, which form each letter in Braille, have been divided into three horizontal pairs. “There are four options for each pair: two dots, one dot on the left, one dot on the right, or no dots at all,” explains Prof. Zagler. “These four possibilities are placed on the four sides of a cuboid. While the cuboids move in a circle on the inside of the ring, they can be rotated as required, so that the relevant letter, comprised of three cuboids, is displayed for the next reading operation.”
This simple approach – the rotation of cuboids – is much easier to implement than displaying Braille characters using movable pins. It ensures that the display is robust while producing a very low error rate. The ring-shaped structure makes possible a compact design, so the device is easy for users to carry.
“The concept has already been patented and we are currently working on setting up a company,” says Prof. Zagler, who retired in 2016 after 45 years at TU Wien, although retirement clearly hasn’t dampened his enthusiasm for research. “We still need to clarify a few key issues, such as what materials would be most suitable, how actuators with the lowest possible power consumption can be used, and what ergonomic and haptic properties are the most comfortable. However, we are expecting to resolve all of these issues in the next few months.”
The price of the finished device has not yet been set, but it is anticipated that the Tetragon display will be significantly less expensive than products currently available on the market: “We want to offer the display for around the same price as a good smartphone – and we’re very confident we’ll be able to do so,” says Prof. Zagler.
Prof. Wolfgang Zagler
Institut für Gestaltungs- und Wirkungsforschung
Technische Universität Wien