The VTT Technical Research Center of Finland has pulled the tarp off a new optical solution appropriate for thermal infrared applications for military, security, and mechanical inspection uses. The core is a monolithic lens element, which allows for a 360-degree panoramic view using just one lens. Previously, cameras like this required either several thermal cameras pointed in different directions or one camera that rotates. A rotating camera, though, cannot be fully panoramic because of the delay inherent as it turns.
“This concept enables the development of affordable and powerful products for the applications of broad horizontal thermal imaging. The optics design can be modified according to the desired vertical field of view or, for example, image sensor properties. This ensures the optimal image quality for the specific application,” said Kimmo Solehmainen, key account manager at VTT. Their solution will be introduced at the SPIE Photonics West exhibition in San Francisco on Jan. 30.
Thermal lenses detect infrared radiation and produce data on temperature variations.
In order to capture the 360-degree image in one shot, the lens element folds the panoramic field of view over one thermal sensor matrix. It takes a continuous thermal image on a horizontal plane.
Thermal visualizers can be used to detect elevated temperatures characteristic of people with the flu or similar symptoms. This example from 2014 created a 360-degree view through the use of a hyperbolic hot mirror pressed against the infrared camera. The camera itself does not view 360 degrees, but the mirror gathers the data needed to complete the circle. Other thermal scanners on the market today feature a rotating camera.