The matrix is the basis of any photo or video device. It determines the quality and size of the resulting image. To date, two different technological principles are used in the manufacture of matrices - CCD and CMOS. You can often hear the question: “Which matrix to choose: CCD or CMOS?” Among the lovers of photo and video equipment there is heated debate. In this article, we will review these two types and try to figure out which matrix is better - CCD or CMOS.
general information
Matrices are designed to digitize the parameters of light rays on their surface. Talking about the clear advantage of one of the technologies is not possible. You can make comparisons on specific parameters and identify a leader in one aspect or another. As for the preferences of users, often for them the main criterion is the cost of the product, even if it will be inferior in quality or technical characteristics to its competitor.
So, let's figure out what both types of devices are. CCD-matrix is a microcircuit that consists of photosensitive photodiodes; It is created on a silicon basis. The peculiarity of its work lies in the principle of operation of a charge-coupled device. CMOS-matrix is a device created on the basis of semiconductor field-effect transistors having an insulated gate with channels of different conductivity.
Principle of operation
Let's move on to identifying the differences that will help determine the choice: what is better - a CMOS or CCD matrix? The main difference between these two technologies is the principle of their work. CCD-devices convert the charge from the pixels into an electric potential, which is amplified outside of the photosensitive sensors. The result is an image in analog form. After that, the entire image is digitized in the ADC. That is, the device consists of two parts - the matrix itself and the converter. CMOS technology is characterized by the fact that it digitizes each pixel individually. The output is a ready-made digital picture. That is, the electric charge in the pixel of the matrix is accumulated in the capacitor, from which the electric potential is removed. It is transmitted to an analog amplifier (built directly into the pixel), after which it is digitized in the converter.
What to choose: CCD or CMOS?
One of the important parameters that determine the choice between these technologies is the number of matrix amplifiers. CMOS devices have a larger number of these devices (at each point), so when the signal passes, the picture quality slightly decreases. Therefore, CCD matrices are used to create images with a high degree of detail, for example, for medical, research, industrial purposes. But CMOS technologies are mainly used in household appliances: webcams, smartphones, tablets, laptops, etc.
The next parameter that determines which type is better - CCD or CMOS - is the density of the photodiodes. The higher it is, the fewer photons “will be idle,” respectively, the image will be better. In this parameter, CCD matrices bypass their competitors, as they offer a layout that does not have such gaps, while they are present on CMOS (transistors are located in them).
Nevertheless, when the user faces a choice: what type of matrix - CMOS or CCD - to purchase, the main parameter pops up - the price of the device. CCD technology is much more expensive than its competitor and energy-consuming. Therefore, installing them where there is enough medium quality image is impractical.