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LUMIX Digital Camera Know-Hows
CMOS Image Sensors
Many people consider the quality and sensitivity of CCD image sensors to be superior to those of CMOS image sensors, and since both of these factors have a large impact on an image's expression, CCD image sensors are often used in professional-level equipment. CMOS image sensors, on the other hand, have the advantages of high-speed signal readout and low power consumption. Also, since CMOS image sensors and their peripheral circuits can be designed to fit onto a single chip, they are used primarily for small-sized, low-cost products, e.g., mobile phones and toy cameras.

CCD and CMOS Image Sensor Comparison
  CCD CMOS
Sensitivity *  
Image quality *  
Compact, single-chip design   *
High-speed readout   *
 
CMOS Structure
Normally, two types of transistors are used: P-type and N-type. These two types are combined into one semiconductor, called a CMOS (Complementary Metal-Oxide Semiconductor). Mounting both P-channel MOS-FET and N-channel MOS-FET on the same semiconductor substrate reduces power consumption and speeds up operation.
 
CCD and CMOS Image Sensor Differences
CCD
 
CMOS
 
CCD image sensors apply a voltage to each electrode, then use a relay system to transfer the charge and amplify the signal.
 
In a CMOS image sensor, each pixel consists of a photodiode and a switch that employs a CMOS transistor. The signal from each pixel is amplified. Another switch is mounted to each of the photodiodes, which are arranged in a lattice pattern, and the successive operation of these switches allows each pixel to be directly read and its data to be transferred at high speed.
 

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