[Explained] Why Do Magnets Distort TV Screens?

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The interaction between the magnetic field and the flying electrons causes a force that causes the electrons to deviate from their intended path when a magnet is brought close to the picture tube. As a result of the electrons now striking the screen in unexpected locations, the image is now distorted.

Why Do Magnets Distort TV Screens

Magnets Distort TV Screens in Different Colour Signals

A stationary electron is not affected by a magnet. But if the electron moves, a force comes out of nothing. The electron’s charge, motion speed, and magnetic field intensity all influence this force in a linear fashion. In the television tube, electrons are shooting from the rear to the front of the tube, producing or painting the image as they do so.

When a magnet is placed close to a television, it causes the electrons to be diverted from their intended path, causing the incorrect phosphor spots to light up and produce the incorrect colors. Sometimes, if a magnet is left too long near a television, it can become magnetic and the colors will get distorted.

What Mechanism Works Here

A television first separates the audio (sound) and picture signals from a carrier wave when it receives a signal. To create sound, the audio is directly delivered to the speakers. Three components make up the visual signal: red, green, and blue

Three “electron guns”, one for each color are located at the back of a typical television. When you watch television while standing back from the screen, your eyes combine the dots and flicker to create a crisp image that appears to move. 

A magnet distorts the image by altering the path electrons take from the electron gun to the television’s screen. A magnet causes an alteration in the velocity of electrons since they are negatively charged particles.

1. Red Signal

One of these “guns” is fed the red signal. The strength of the red signal determines the intensity of the electron beam that the cannon emits. This beam is directed at the television. Magnetic fields are employed to “sweep” the electron beam, which originates at the top-left of the screen, across the screen in parallel horizontal lines.

Televisions in the UK (PAL) refresh the image 625 times per second, while those in the US (NTSC) update the image 525 times per second. Phosphor “dots” (pixels) cover the back of the television screen and glow when these electrons strike them. The red-signal electron beam is directed to impact red-glow phosphor dots, which release photons that the human eye can see.

2. Green and Blue Signal

The method is the same for green and blue; each color signal is sent to a specific electron gun, which only excites the dots of that color. The signal instructs the gun how powerful to fire, causing some dots to shine brighter than others.

Do Magnets Ruin TV Screens

Small voltages are applied to each pixel of LCDs to realign the liquid crystal and alter the electrical polarization. This involves very little magnetism and won’t damage the screen. Magnets also won’t affect plasma screens. Only older CRT displays are susceptible to magnetic fields.

Magnetic fields can have an impact on older televisions that use Cathode-Ray tubes. The display may become distorted if exposed to a powerful magnet. Avoid putting a magnet too close to the television. The screen may become permanently distorted, which means degaussing equipment cannot fix it.

Do Magnets Mess up Smart TV

LCDs are not damaged by magnets. The color or other display components of an LCD won’t be impacted by a magnet, even if it is put close to it. For instance, built-in speakers are a common feature of LCDs. 

Since these televisions don’t have coils either, the magnets that are frequently present in these speakers won’t damage or otherwise have an impact on the LCD. They merely employ a liquid pixel layer with a backlighting element.

Why Do Magnets Ruin Old TVs

However, cathode-ray tube (CRT) screens are not immune to magnets, whereas LCDs are. CRT technology was once utilized by the majority of televisions and other screens. The usage of an electron gun in CRT screens makes them unique. For their pixels, they use chemicals based on the phosphor. 

When activated, an electron cannon will fire electrons at these phosphor pixels, lighting them up. The direction of the electrons is controlled by a magnetic field in CRT screens. The electrons are guided by a magnetic field to the correct phosphor pixels. The magnetic field of a CRT will be disrupted if it is in contact with a magnet.

A CRT may suffer long-term harm from magnets. It will alter the electrons’ trajectory, causing optical distortion. A CRT may have a permanently bright or dark spot after being exposed to a magnet. The CRT may also be unable to create any color in the impacted area.

Conclusion

Holding a magnet too close to an older television could cause permanent harm; contemporary televisions typically go through a demagnetization process when you turn them on to prevent picture distortion. When you turn on some televisions, a degaussing coil inside of them resets the magnetism, restoring the colors to their proper state.

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