CCTV Cameras-2.pdf - Sofab.net

CCD and CMOS Image Sensors
The Technology Difference between Images Sensors : CCD vs CMOS in Analog Cameras.
The image sensor of the camera : is responsible for transforming light into electrical signals . When building a
camera , there are two possible technologies for the cameras image sensor: CCD (Charged Coupled Device ) and CMOS
( Complementary Metal Oxide Semiconductor ).The CMOS sensors do not exhibit the bright light blooming problem
that is seen in CCD sensors. CCD sensors r`equire auto– iris for minimizing the blooming . In General ,the non auto—
iris lens CMOS are far superior lens in quality to auto-iris lens CCD.
CCD Technology
CCD sensors have been used in cameras for more than 35 years .CCD sensors are more expensive as they are made in a
non– standard process and more complex to incorporate in to a camera. In addition with there is a very bright object in
the scene ( such as a lamp or direct sunlight ), the CCD may bleed, causing vertical stripes below and above the object.
This phenomenon is called a smear .CCD sensors require auto-iris for minimizing the blooming .CCD sensors are produced
using a technology developed specifically for the camera industry.
CMOS Technology
Recently advances in CMOS sensors bring them not only closer to their CCD counterparts in terms of image quality ,
but make them much better then CCD in terms of sensitivity , noise performance ,readout speed ,power consumption.
CMOS sensors provide a lower total cost for the cameras since they contain all the logics needed to built cameras
around them . They make possible to produce smaller– sized cameras. Large sized sensors are now available . These
CMOS sensors do not exhibit the bright light blooming problem that is seen in CCD sensors . In General, the non autoiris
lens are far superior lens in quality to auto –iris lens are far superior lens in quality to auto-iris lens. CMOS sensors
are based on standard technology already extensively used in memory chips, Inside
PC’s for example.
Sample Image
Camera with a CCD Image Sensor
Sample Image
Camera with a CMOS Image Sensor
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