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CMOS image sensors are widely used in digital cameras to capture images. Their competitors are the CCD, making the same operation. We analyze the advantages and disadvantages of both options.
Architecture of CMOS Image Sensor with Active-pixel CCD devices differ in that each pixel is not only the photo-sensitive process the incoming photons (light) into electrons, but also a detection circuit such costs generated by a tense econversion. This is the main difference between the CCD and CMOS image sensors, and from there the rest of the architecture differs accordingly.
We can see from this simple fact, what are the advantages and disadvantages of one solution over another. To begin, the opaque circuit does not allow detection of photons to reach the photoactive substrate, in which electrons are generated. Therefore, given a pixel size CMOS sensor is inherently less sensitive to light and require more lightscenes.
Another difference is that the charge voltage amplifier is just one in a CCD sensor and a per pixel in a CMOS. Therefore, the CCD provides a more uniform, as it is influenced by the process of propagation (millions of transistors statistically may not have the same electrical characteristics).
Unlike CCDs, CMOS sensors for converting analog-digital chip. The circuit current in each pixel provides an analog signal that is sent to an analogDigital Converter (ADC). This is another glaring difference between the CCD and CMOS: CMOS sensors are more tracks to do their design and higher dimensions, but allow a simple circuit off-chip.
Another difference is that CMOS sensors require much less power and operate at lower voltages, resulting in longer battery life for handheld applications.
Finally, an advantage over CCD CMOS sensors is that they require lessdedicated process, thus reducing costs.
Although all the differences mentioned above are real, the CCD and CMOS image sensors have become increasingly closer in their characteristics and performance. Therefore, the two technologies coexist again. Moreover, their strengths and weaknesses are exploited in different applications.
