dotdotdot writes:
An extremely tiny lensless camera (PDF), developed by Rambus, has been slowly making waves over the past year. Researchers for the company, David Stork and Patrick Gill won a Best Paper award at last year's Sencomm 2013 for describing what the company has created.
We describe a new class of lensless, ultra-miniature computational imagers and image sensors employing special optical phase gratings integrated with CMOS photodetector matrices. Because such imagers have no lens, they are ultraminiature (~100 µm), have large effective depth of field (1 mm to infinity), and are very inexpensive (a few Euro cents). The grating acts as a two-dimensional visual 'chirp' and preserves image power throughout the Fourier plane (and hence preserves image information); the final digital image is not captured as in a traditional camera but instead computed from raw photodetector signals. The novel representation at the photodetectors demands that algorithms such as deconvolution, Bayesian estimation, or matrix inversion with Tikhonov regularization be used to compute the image, each having different bandwidth, space and computational complexities for a given image fidelity.
Such imaging architectures can also be tailored to extract application-specific information or compute decisions (rather than compute an image) based on the optical signal. In most cases, both the phase grating and the signal processing can be optimized for the information in the visual field and the task at hand. Our sensor design methodology relies on modular parallel and computationally efficient software tools for simulating optical diffraction, for CAD design and layout of gratings themselves, and for sensor signal processing. These sensors are so small they should find use in endoscopy, medical sensing, machine inspection, surveillance and the Internet of Things, and are so inexpensive that they should find use in distributed network applications and in a number of single-use scenarios, for instance in military theaters and hazardous natural and industrial conditions.
(Score: 3, Interesting) by anubi on Saturday March 29 2014, @12:52AM
I am particularly intrigued by the depth of field as well as its small size.
I would *love* to have a little wand I could poke into places I cannot see. I have a microscope, but it is big and bulky. The little USB microscope I have has serious depth of field issues, resulting in me being able to only see things "in focus" at any particular setting.
Now, if I could get something like a "test probe" that can see at the end, and let me wear one of those little displays on my glasses so I can see what my little probe is seeing, it would sure make a lot of my work a helluva lot easier.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 2) by carguy on Saturday March 29 2014, @11:57AM
> Now, if I could get something like a "test probe" that can see at the end, ...
Hi tech replacement for an inspection mirror--sounds pretty useful. Mechanics and dentists use little mirrors, but there is always the problem of getting light on the subject. The next patent might be combining this camera with tiny white LEDs.
This could also vastly reduce the cost of (low-res?) IR cameras. My understanding is that a good part of the cost is in the fancy lens material that can pass IR (regular glass blocks longer wavelengths)--much smaller lens = lower cost.
(Score: 2) by umafuckitt on Saturday March 29 2014, @01:13PM
At what wavelengths does regular glass block IR? Is it far IR? I use regular, cheap, lenses at work for a 950 nm laser and there are no issues. My lenses are just coated for those wavelengths, but that's not expensive. Thor sell achromatic doublets rated to 1620 nm [thorlabs.com] for only about 45 bucks. Seems to be the same price [thorlabs.com] for visible wavelengths.
(Score: 1) by cosurgi on Saturday March 29 2014, @01:37PM
yeah, I concur. Actually the problem is on the other end of the spectrum. It is difficult to find glass that is transparent for wavelengths shorter than 300nm.
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