How to Choose an Image Sensor for Night Vision Camera
One of the core technologies of surveillance camera realm is infrared imaging. Infrared imaging usually falls into two types: active and passive. Active infrared imaging uses image chips and invisible active LED infrared source to illuminate the scene. LEDs that are used in infrared cameras degrade over time. The older it gets, the lower the luminous efficiency of the infrared LED gets. The lower the luminous efficiency of the infrared LED gets, the worse the night vision results.
To tackle this issue, SONY developed the STAVIS chip. The STARVIS is back-illuminated pixel technology used in CMOS image sensors for surveillance camera applications. Its quantum efficiency is high in visible and near infrared band. STARVIS sensitivity goes as low as 0.0001 lux and provides magnificent infrared imaging in the dark. Please see the comparison of STARVIS imaging and a conventional chip below:
Picture 1 Photo Credit: Sony Website.
Using Sony CIS sensor’s back-illuminated pixel technology results in higher quantum efficiency and better image quality up to twice.
Full Spectrum Quantum Efficiency and Surveillance Infrared Camera Sensor Chip
Full spectrum quantum efficiency is one of the indicators when choosing an infrared camera. We learn the sensor’s sensitivity and performance through its quantum efficiency curve. Picture 3 demonstrate that back-illuminated pixel technology used in CMOS image sensors brings its quantum efficiency in visible band (450nm ~ 650nm) up to 80%, infrared band (800nm) to 25% and 10% at 900nm. It should be evident why Sony STARVIS surveillance camera is popular and reflects Sony’s preeminent back illumination technology.
(The World’s Best QE Testing Solution Provider : Enli Tech) (The World Best QE Testing Solution Provider ~ Enli Tech)
Enli Technology is dedicated to full spectrum quantum efficiency analysis technology. There more than 1000 cited SCI papers adopt Enli in their research, ranging from CCM (CMOS Camera Module), CIS wafer, CIS module, photodiode, photodetector, photo-receiver to solar cell. Spectrum ranges from UV, VIS, NIR, SWIR to MWIR…etc.
For more information about CIS quantum efficiency measurement, please see the link MVIS-SYSTEM
Picture 2 ENLI MVIS can be used to measure camera’s quantum efficiency and other performance parameter, including CIS quantum efficiency.
Picture 3 SONY IMX178 installed in Basler acA3088-16gm camera. Using MVIS EMVA 1288 to measure full spectrum quantum efficiency.