The idea for the wind scanner was born in Ikea's accessories department.
While he and his wife were hunting for blinds for their son’s room, Professor Torben Mikkelsen noticed a small night light, the bulb in which could be turned in all directions. This give him the idea for the now patented invention with the trademark ‘WindScanner’.
Torben Mikkelsen and his colleagues were wrestling with a problem at the time. They had developed an effective method for measuring wind in front of a wind turbine. Using laser light, they were able to measure the wind speed in the direction of the laser beam, but only at a single point at a time. They wanted to be able to scan the entire wind field, and exploit the fast laser-based measuring method.
"We could rotate the whole light cannon or add mirrors, so it could scan a large area. But due to the major optical requirements, the mirrors would be too big and clumsy. So we thought of bending the beam of light instead using two prisms placed on top of each other. The only problem was that the image would become distorted if the beams didn’t pass symmetrically through both prisms at the same time—i.e. if the angle of entry and angle of departure were not always identical in both prisms, regardless of their orientation,” recalls Torben Mikkelsen.
“So I was pondering how to position the prisms in order to get sharply focused laser beams. And then I noticed the small night light and got the idea that if the two prisms were mounted in the light, they could be rotated independently of each other, while upholding the requirement for symmetrical beam paths. Once I realised this, I just wanted to get the shopping done as quickly as possible so I could hurry home and draw a sketch.”