By Richard Moss @ gizmag.com
Researchers at Rice University’s Laboratory for Nanophotonics (LANP) have developed a new image sensor that mimics the way we see color by integrating light amplifiers and color filters directly onto the pixels. The new design enables smaller, less complex, and more organic designs for CMOS (complementary metal-oxide semiconductor) sensors and other photodetectors used in cameras.
Conventional image sensors work by first converting light into electrical signals, then combining that information with the red, green, and blue color data determined by separate filters (or, especially in low-end cameras, a single filter array that uses a mosaic pattern to interpret colors). But this approach adds bulk to the sensor, and the filters gradually degrade under exposure to sunlight.
Nature inspires color-sensitive, CMOS-compatible photodetector – [Link]
Raj from Embedded Lab informed us about his new Easy Pulse release (Version 1.1) that has improved performance over its predecessor. The new version uses a more robust sensor based on transmission PPG principle where an IR LED illuminates a finger tip from one side and a photodetector receives the transmitted light from other side. The photodetector output is filtered and amplified to obtain a nice and clean PPG waveform, which can be further processed by a microcontroller to obtain vital information about the cardiovascular system. The Easy Pulse is also available for purchase on Tindie.
Easy Pulse PPG sensor for measuring pulse rate – [Links]
Conventional CMOS image sensors, which are the preferred choice for digital photography in both professional and consumer devices thanks to their low cost and low power consumption, are not suitable for low-light applications such as X-ray or astronomical photography because the large pixel cells necessary to compensate for low light levels do not allow high readout speeds. A new, patented optoelectronic component developed by researchers at the Fraunhofer Institute for Microelectronics eliminates this problem.
Conventional CMOS image sensors use pinned photodiodes (PPDs) to convert the light into electrical signals. However, with pixels above a certain size they cannot support the readout speeds typically needed in low-light applications. To solve this problem, the Fraunhofer researchers developed a new optoelectronic device called a lateral drift field photodetector (LDPD), in which charge carriers are driven to the collection electrode by an electric field at speeds up to 100 times the diffusion rate of charge carriers in PPDs. [via]
High-speed CMOS sensors yield better images – [Link]