There are significant differences between CCD and CMOS in terms of construction, operating principle, manufacturing cost, room for pixel improvement, and power consumption. Here are the characteristics of each of them:
Construction: The CCD sensor is similar in construction to a memory, with each imaging point containing a photodiode, a charge-voltage conversion unit, a resetting and selector transistor, and an amplifier. Covering the entire sensor are metal interconnectors (for timing applications and reading signals) as well as longitudinally arranged output signal interconnects, which can read signals with a simple x-y addressing technique. CMOS sensors, on the other hand, are relatively simple to construct.
Working principle: The CCD charge coupler needs to output information one by one in the behavioral unit under the control of the synchronous clock, which is slow. In contrast, CMOS photoelectric sensors can take out electrical signals at the same time as collecting optical signals, and can also process the image information of each unit at the same time, which is much faster than CCD charge couplers.
Manufacturing cost: Due to the complex manufacturing process, only a few manufacturers such as Sony, Panasonic, etc. have mastered this technology, resulting in the high manufacturing cost of CCD, especially large CCD, which is very high. Comparatively speaking, the manufacturing process of CMOS is relatively simple and relatively low.
Pixel improvement space: CCD started from 300,000 pixels and has grown to 6 million now, and the improvement of pixels has reached a limit. At the same resolution, CMOS** is cheaper than CCD, but CMOS devices produce lower image quality than CCD.
Power consumption: One of the advantages of CMOS image sensors is that the power consumption is lower than that of CCDs. This is because in the process of charge transfer, CCDs have to pay the price of high power consumption in order to make charge transfer smooth and noise reduced. In contrast, a CMOS image sensor converts the charge of each pixel into a voltage, which is amplified before it is read, and uses 3It can be driven with a 3V power supply, and the power consumption is lower than that of CCD.
Overall, CCD and CMOS have their own advantages and disadvantages. The choice of image sensor depends primarily on the specific equipment application needs and budget considerations.