SCANNING FREQUENCY
In CRT (Cathode Ray Tube) technology, scanning frequency refers to the rate at which the electron beam scans and refreshes the display on a CRT monitor or television. It encompasses both the horizontal scanning frequency and the vertical scanning frequency.
Horizontal Scanning Frequency: This refers to the rate at which the electron beam moves horizontally across the screen, scanning one line at a time from left to right. It is measured in kilohertz (kHz) and is commonly known as the horizontal scan rate. The horizontal scanning frequency determines the number of horizontal lines that can be displayed per second. It directly affects the resolution, clarity, and stability of the image. Higher horizontal scanning frequencies result in sharper and more detailed images, reducing the visibility of scan lines.
Vertical Scanning Frequency: The vertical scanning frequency, also called the vertical refresh rate, represents the rate at which the electron beam moves vertically, scanning from the top of the screen to the bottom and then returning to the top for the next frame. It is measured in hertz (Hz) and indicates the number of complete frames that can be displayed per second. The vertical scanning frequency affects the smoothness of motion and the perception of flicker in the displayed image. Higher vertical scanning frequencies result in smoother motion and reduce the perceived flickering effect.
The combination of the horizontal and vertical scanning frequencies determines the overall refresh rate of the CRT display. For example, a CRT monitor with a horizontal scanning frequency of 31.5 kHz and a vertical scanning frequency of 60 Hz would have a refresh rate of 60 Hz.
Scanning frequency is an important factor to consider when selecting a CRT display or ensuring compatibility with video sources. It is particularly relevant in applications that involve fast motion, such as gaming and video playback, where higher scanning frequencies contribute to smoother visuals and a more immersive experience. Additionally, matching the scanning frequencies of the CRT display with the output frequencies of the video source helps ensure optimal image quality and stability.
