What's the difference between digital camera sensor CMOS and CCD?

The image sensor is equivalent to the film used by the film camera. Of course, for camera shooting, it can be imagined as the film used when shooting film movies. The image sensor is composed of semiconductor integrated electronic components, and its main function is to convert the collected light into electrical signals in the image sensor. At present, the image sensors used in digital cameras are generally divided into two types: one is CCD (Electronic Coupler) and the other is CMOS (Complementary Metal Oxide Semiconductor). Let's take a look at the differences between the two image sensors.

CCD image sensor

Although CCD imaging quality is good, its cost is high, and it also consumes electricity in use. In the past, in the era when the camera was standard definition, the CCD image sensor used by the camera was usually based on100000 pixels. For example, a 400000-pixel CCD was basically 720*576 standard definition. With the popularity of high-definition digital cameras, the number of pixels of CCD began to increase, but when not many models of CCD reached one million pixels, new CMOS image sensors began to occupy the field of image sensors on a large scale.

The main material of CCD is silicon semiconductor, and its basic principle is similar to that of solar cells on Casio computers. Through the photoelectric effect, the light of the light source is induced by the surface of the photosensitive element and converted into the ability to store charge. According to the principle of camera, simply put, when the CCD plane receives the light from the shutter, the lens will convert the energy of the light into charge when it comes in. The stronger the light, the more charges there are, and these charges will become the basis for judging the intensity of light. There are channel lines on CCD elements. By transmitting these charges to the amplification and decoding original, all the signals generated by the photosensitive elements on the CCD can be restored to form a complete picture. Compared with a digital camera, an electronic shutter is added, and the continuous picture is decomposed into 25, 30, 60 or more pictures per second according to the recording format or special purpose.

cmos image sensor

Compared with CCD, CMOS has the characteristics of low cost and power saving. With the continuous improvement of imaging quality, it is widely used in household, professional and even broadcast cameras. CMOS, like CCD, is a semiconductor that records light changes in digital devices, and its appearance is almost indistinguishable. The manufacturing process of CMOS is different from CCD, and it is closer to the general computer chip. CMOS has developed rapidly, and the number of pixels has also increased rapidly. At present, many high-end CMOS used in the camera field have reached the full HD resolution of 1080* 1920. The number of CMOS pixels of some household digital cameras has also reached nearly 6.5438+million.

The confrontation between CMOS and CCD

Compared with CCD, CMOS has the advantages of low cost, low power consumption and easy manufacture, and can be on the same chip as the image processing circuit. With the continuous improvement of CMOS manufacturing technology, it used to exist only in economical digital equipment, but now it occupies almost the whole digital camera field and most of the digital camera fields. Judging from the current market situation, CMOS image sensor is likely to replace or even completely replace CCD image sensor in the field of professional and household photographic equipment.