Camera prototype is thinner than a US dime coin
05 December 2015
A patented prototype called FlatCam is little more than a thin sensor chip with a mask that replaces a traditional camera lens - plus some clever algorithms.
Traditional cameras are shrinking, driven by their widespread adoption in smartphones. But they all require lenses, and the post-fabrication assembly required to integrate lenses into cameras raises their cost, according to the researchers.
FlatCam does away with those issues in a camera that is also thin and flexible enough for applications that traditional devices cannot serve. FlatCams can be fabricated like microchips, with the precision, speed, and the associated reduction in costs, says Ashok Veeraraghavan, assistant professor of electrical and computer engineering at Rice University. Without lenses, the most recent prototype is thinner than a US dime coin.
“As traditional cameras get smaller, their sensors also get smaller, and this means they collect very little light,” says Veeraraghavan. “The low-light performance of a camera is tied to the surface area of the sensor. Unfortunately, since all camera designs are basically cubes, surface area is tied to thickness. Our design decouples the two parameters, providing the ability to utilize the enhanced light-collection abilities of large sensors with a really thin device.”
FlatCam shares its heritage with lens-less pinhole cameras, but instead of a single hole, it features a grid-like coded mask positioned very close to the sensor. Each aperture allows a slightly different set of light data to reach the sensor. Raw data sent to the back-end processor (currently a desktop computer) are sorted into an image. Like much larger light field cameras, the picture can be focused to different depths after the data is collected.
The hand-built prototypes use off-the-shelf sensors and produce 512-by-512 images in seconds, but the researchers expect that resolution will improve as more advanced manufacturing techniques and reconstruction algorithms are developed.