Lensless Smart Sensors
For buildings and homes to become ‘smarter’ and more adaptive, new sensing technology must be capable of detecting, counting and tracking occupants regardless of motion. While next-generation sensor technology offers a glimpse of an exciting future in which buildings adapt and learn, real-world privacy issues will almost certainly have to be addressed before mainstream adoption is achieved.
Although focused cameras may adequately address sensing requirements, they also present a range of legal, privacy and hacking risks. These legal and technical issues, coupled with public distrust of lenses, will likely result in a limited deployment of focused cameras for room occupancy sensing tasks in offices and residences. And while defocused cameras offer certain limited advantages over their focused counterparts, images produced by such devices may be easily refocused.
In contrast, Rambus’ lensless smart sensor (LSS) technology reduces occupancy sensing privacy concerns by capturing the raw data of a scene with a diffractive grating, rather than a recognizable image with a lens. Put simply, LSS does not capture focused images or purposely de-focused images. Instead, the technology creates what is called the ‘blob’ domain, which is a series of point spread functions (PSF) of light. This unique ability makes LSS an ideal choice for widespread deployment in smart buildings.
Note: LSS is no longer being marketed as a product, though Rambus maintains ownership of the IP created in the LSS program.
Imaging and smart sensors are essential for the Internet of Things to become a reality. In order for the objects and machines around us to adapt and anticipate our changing needs, they must be able to gather and act upon relevant data from their surroundings quickly and cost-effectively.
We have pioneered a new class of computational imagers ideally suited for ubiquitous sensing with our ultra-miniature Lensless Smart Sensors (LSS). LSS take a novel approach to reduce the size, cost and power consumption for sensing and imaging by replacing the lens with a low-cost diffraction grating attached directly to the image sensor array. Each grating has a unique design that creates a predictable and pattern on the sensor that is used to capture data-rich images and information about its surroundings.
The gratings and sensors are combined with computational algorithms optimized for specific applications. The net result is a smart sensor with a smaller form factor, better power efficiency, greater precision, and lower cost compared to a traditional image sensor with computer vision. LSS can be used for a broad range of tasks including point tracking, gesture recognition, change detection, motion flow and range finding.