What is the screen refresh rate

In the days of CRT monitors and televisions (cathode ray tube), everyone had to have at least a general idea of what the refresh rate of a screen is. If, of course, it was important for him to keep

Vision, not to experience a headache and accompanying discomfort when working at a computer or watching TV programs. We can say that the refresh rate of the screen was indirectly related to health. In our time, the situation has changed radically. Devices for displaying graphic information were created, using completely different operating principles than CRT technology. Although the LCD screen in TV and monitors is not yet perfect enough to talk about complete harmlessness: the effect on vision has dropped significantly, but has not completely disappeared.

To answer the question about what the frequency of the screen refresh is equal to, it's the easiest way for owners of computer monitors. In the case of using the latest version of Windows operating system, you need to bring up the menu in any free space on the desktop by clicking the right mouse button and select "Screen Resolution" in the list that appears. Then you need to proceed to the "Advanced Options". Here, by opening the tab "Monitor", you can see the line "Update screen frequency".

In modern monitors based on liquid crystals, 59 and 60 hertz are usually available - this is for budget models; In more expensive you can also set 75 and 100 Hz. The LCD screen refresh rate is the legacy of the CRT era. In liquid crystal models "by eye" it is impossible to distinguish between 60 and 100 Hz. The only thing that is influenced by this parameter is the smooth movement of the mouse cursor and the possibility of using 3D glasses (100 Hz is needed for them).

But in the era of CRT it was different. The inner surface of the screen (tube) was covered with a layer of a special substance (phosphor), capable of glowing a few milliseconds after the electrons hit it. Three electrodes (guns) emitted radiation particles streams, the motion of which was corrected by the magnetic field. It deflected the rays from a straight line so that the upper-left corner of the screen would begin to glow first, then the flow would cause a glow along the horizontal line to

Right upper corner. Then the beam was shifted one line down and everything was repeated. When he reached the lower right corner, he returned to the beginning and everything repeated. The number of such screens per second is just the refresh rate.

In the LCD controller is able to selectively change the passage of light through the elements of the matrix of liquid crystals - you can simultaneously light or extinguish the screen. The flicker of the backlight lamp itself is the last flaw that is actively eliminated in new monitor models. The phosphor on the screen was still glowing, creating the illusion of a holistic image. The eye just did not have time to notice the flicker caused by the constant updating of the picture. However, it was present, and at refresh rates less than 75 Hz it was noticeably sidelined. To eliminate this effect, manufacturers offered monitors with frequencies even over 120 Hz. Of course, the described scheme is simplified for understanding - we do not consider the formation of color and the picture itself.