The difference between CCD and CMOS in photoelectric switch

Both CCD and CMOS are two important categories of photoelectric switches. Both use photodiodes for photoelectric conversion. The main difference lies in the way of digital data transmission. CMOS is mainly a semiconductor made of two elements of silicon and germanium, making it coexist with N (negatively charged) and P (positively charged) semiconductors on the CMOS. The current generated by these two complementary effects passes through The image can be obtained after processing.

Because the image changes rapidly and the current follows the change, the CMOS in the early photoelectric switches is prone to noise. CMOS is cheap, and the image quality is not as good as CCD. It is mainly used for camera imaging. With the development of science and technology, the current CMOS image sensor converts the charge converted from each image into a voltage, then amplifies it and drives it with a 3.3V power supply. It can be seen that the power consumption is lower than that of a CCD. Another advantage of CMOS is that the signal can be processed well in the sensor, and the sensitivity and noise control are also well improved.

At present, a large number of SLR cameras also use CMOS. CCD is also a charge-coupled device image sensor, which is composed of many photosensitive units, most of which are currently in megapixels. When its surface is irradiated by light, it converts the light into electric charges, and then undergoes analog-to-digital conversion to obtain a digital signal. The digital signal can be saved by the internal memory card. The memory card is connected to the computer, and the image can be processed. The advantage of CCD lies in its good imaging quality. Because the manufacturing process is responsible, domestic manufacturers have little control. In the past few years, most of them relied on imports, so they were expensive. There is another obvious feature of CCD. Everyone should be able to feel that the camera we often take pictures will not last long after being used. This is because CCD uses high-voltage differential transmission to make charge transfer smoothly and reduce noise. Power consumption.