Function introduction:
1. CMOS: generally refers to the photosensitive components of digital cameras, which are widely used in mobile phones and low-end digital SLR cameras (do not be confused with CMOS chips on the motherboard of the computer).
2. CCD: image sensor (charge coupled element) a semiconductor device that converts optical signals into electrical signals and then converts them into digital signal transmission. Mainly used in cameras, high-end SLR cameras.
The relationship between COMS and CCD:
1. The main difference is that CCD is integrated on semiconductor single crystal materials, and CMOS is integrated in metal oxide semiconductor materials. The working principle of the two is basically the same: both use photodiode (photodiode) for photoelectric conversion and convert images into digital data, among which, the main difference is that the way of digital data transmission is different.
2. Signal transmission mode: the charge data of each pixel in each line of CCD sensor will be transmitted to the next pixel, which will be released by the bottom part of the sensor and amplified by the amplifier at the edge of the sensor.
In the CMOS sensor, each pixel will be adjacent to an amplifier and A/D conversion circuit, and the data will be output in a manner similar to the memory circuit.
3. Imaging performance: because each pixel of CMOS sensor is composed of four transistors and one photodiode (including amplifier and A/D conversion circuit). The photosensitive region of each pixel is much smaller than the surface area of pixel itself, so the sensitivity of CMOS sensor is lower than that of CCD sensor when the pixel size is the same.
4. CCD manufacturing process is more complex, and the manufacturing cost is high, so the price is expensive. COMS manufacturing process is slightly simpler than CCD, the manufacturing cost higher, but the price is lower than CCD.