Researchers from Cornell University have a design for an image sensor has been developed in which the pixels in the direction of the incident rays of light can determine. With this lightfield sensor, the focal length can subsequently be determined.
The research team led by Alyosha Molnar of the Cornell University has an image sensor have been developed that it is possible to, not only the intensity, but also the angle of the incident light on the pixels to register.
The so-called angle-sensitive pixels are created with a standard 130nm cmos process and have a structure with two stacked layers with tiny slits above a photodiode. The first tralielaag produces a particular diffraction pattern, while the second layer is the light in more or to a lesser extent, blocks or allows to pass through.
With the help of a fourier transform is then the distance to an object to calculate. Also is this hindsight the focal point in the picture to determine. The idea is similar to that of the Lytro, but that last lightfieldcamera makes use of a tralielaag and a matrix of micro-lenses to a 3d image.
Also think Molnar that his method is better than the Lytro technology, because the angle of the light beams simpler and less computationally irreducible. Especially for video would be the solution of Molnar better.
The test unit of the cmos image sensor of Molnar has about 150.000 asp-pixels and have a size of 7µm. Although the resolution is still relatively low, this can be increased by the chip to make it larger.
