Flexible lens array enables wrap-around camera
Researchers at Columbia University in the USA have developed a flexible camera that can be wrapped around objects.
The team, led by Shree K. Nayar, T.C. Chang Professor of Computer Science at Columbia Engineering, designed and fabricated a flexible lens array that adapts its optical properties when the sheet camera is bent.
The optical adaptation enables the sheet camera to produce high quality images over a wide range of sheet deformations. Research engineer Daniel Sims will present the work at the International Conference on Computational Photography (ICCP) at Northwestern University in Evanston, IL, from 13 to 15 May.
‘Cameras today capture the world from essentially a single point in space,’ said Nayar. ‘While the camera industry has made remarkable progress in shrinking the camera to a tiny device with ever increasing imaging quality, we are exploring a radically different approach to imaging. We believe there are numerous applications for cameras that are large in format but very thin and highly flexible.’
If such an imaging system could be manufactured cheaply, like a roll of plastic or fabric, it could be wrapped around all kinds of things, from street poles to furniture, cars, and even people’s clothing, to capture wide, seamless images with unusual fields of view. This design could also lead to cameras the size of a credit card that a photographer could simply flex to control its field of view.
The flex-cam requires two technologies: a flexible detector array and a thin optical system that can project a high quality image on the array.
The adaptive lens array is made of elastic material that enables the focal length of each lens in the sheet camera to vary with local curvature in a way that mitigates aliasing in the captured images. This inherent optical adaptation of the lens is passive, avoiding the use of complex mechanical or electrical mechanisms to control each lens of the array.
The lens array was fabricated from silicone and the scientists have demonstrated its ability to produce high image quality over a wide range of deformations of the sheet camera. The research was conducted in Nayar’s Computer Vision Laboratory and was funded by the Office of Naval Research.
‘The adaptive lens array we have developed is an important step towards making the concept of flexible sheet cameras viable,’ Nayar said. ‘The next step will be to develop large-format detector arrays to go with the deformable lens array. The amalgamation of the two technologies will lay the foundation for a new class of cameras that expand the range of applications that benefit from imaging.’