190 likes | 334 Views
Lecture 14. Topics on demand Digital cameras Security sensors. Digital cameras. Lenses - video. Source: www.jiscdigitalmedia.ac.uk. video. Digital cameras. Source: electronics.howstuffworks.com. video. video. Silicon image sensors.
E N D
Lecture 14 Topics on demand Digital cameras Security sensors
Digital cameras Lenses - video Source: www.jiscdigitalmedia.ac.uk video
Digital cameras Source: electronics.howstuffworks.com video video
Silicon image sensors • silicone release electrons when exposed to light – photoelectric effect (mathematically described by Einstein in 1905), first observed by H. Herz in 1887 animation video
Chip structure video Source: www.jaycar.com.au
Transfer from chip Source: www.astro.virginia.edu ; en.wikipedia.org
How to get color? Source: www.high-techdigital.com ; electronics.howstuffworks.com video
Actual chip structure Source: spiff.rit.edu
CCD image sensor charge coupled device (CCD) invented by Bell Laboratories in 1970 video A CCD image sensor (1024x1024) Source: astronomyonline.org 9 of 17
CMOS image sensor complementary metal oxide semiconductor (CMOS) video Source: electronics.howstuffworks.com A CMOS image sensor 10 of 17
CMOS vs. CCD CMOS • Lower power consumption • Low price • High noise CCD • Low noise • High price (requires a special manufacturing process) • High resolution • Higher image quality video
Problems • Blooming (pixel stores too many electrons, they can spill over resulting in a grossly over-exposed image) Source: astronomyonline.org
Security sensors • Smoke detector • Finger print sensor • PIR (passive infrared) – movement detection
Smoke sensor • Ionization • optical Source: extension.missouri.edu ; www.connectmidmissouri.com video
Fingerprint sensor Source: www.ehow.com ; www.ehow.com gkall.hobby.nl ; www.directindustry.com
Fingerprint sensor • Capacitive sensing Optical – video – with Arduino Source: computer.howstuffworks.com Fingerprint recognition video
PIR (passive infrared) – movement detection Source: www.ladyada.net
PIR (passive infrared) – movement detection • Fresnel lens Source: www.ladyada.net
PIR (passive infrared) – movement detection video Source: www.jablotron.cz Long and detailed teadown