Technical Description

Introduction

A TV screen is part of a television that is used to display video. It is part of the TV that is used to process television signals which are usually transmitted via cable or satellite. TV screens use a wide array of technologies such as liquid crystal displays (LCDs), Light Emitting Diodes (LEDs), Organic light-emitting diodes(OLEDs), Plasma, and more. Over time these technologies have been getting better and better, which allows for higher-quality images and higher resolutions, but today we will be talking about the grandfather of them all, the Cathode Ray Tube (CRT).CRTs, being the oldest of the three, is the grandfather of all displays today. While not currently used anymore, it paved the way for these incredible displays we have today. “A cathode-ray tube (CRT) is a specialized vacuum tube in which images are produced when an electron beam strikes a phosphorescent surface” (Tech Target Contributor, 2021). CRTs consist of three simple parts, an electron source often called an electron gun, an electromagnetic deflection system, and a phosphorescent screen (Edwards, 2021). The screen glows when an electron strikes it. Due to this action happening so fast, our eyes don’t view each beam of light separately, but as a bunch of beams that create an image. Now just one beam creates a black-and-white image. To have colored images and videos you would use three beams, a green, red, and blue beam.

Components of A Cathode Ray Tube CRT

 

There are many components to a Cathode Ray Tube. The main components are the electron gun, focusing and deflecting systems, and the screen itself. The electron gun itself consists of three parts, the first cathode. When the cathodes are heated to 1700+ degrees Fahrenheit, it produces electrons which are then accelerated by the second part of the electron gun which is the anode. Once the electrons pass the anode, they pass through a small hole into the cathode ray tube(TechTarget Contributor, 2021). The second part of the CRT, the focusing and deflecting systems, works by taking the beam of electrons from the electron gun and focusing them down to a single point which then hits the screen. The electrons are focused using an electromagnetic field, similar to how a lens can focus on a beam of light. This allows the TV to produce accurate images by focusing the electron beam where it needs to be going. As for focusing the system has to deflect the beam as well to the exact spots where it needs to go. This is also done with magnetic fields. (See Figure 1)

Figure 1

 

 

(Google, n.d.)

 

The last component of the Cathode Ray Tube is well obviously the screen. The screen is a flat piece of glass that is covered with phosphor in the back. A phosphor is a chemical that lights up when it comes in contact with a source of electrical energy. In this case, the electrical energy here is electrons. When the electrons hit the phosphor layer, it creates a quick light where that electron hits. This happens fast enough that our eyes can see the full picture rather than each little beam of light. (See Figure 2)

Figure 2

Conclusion

 

The Cathode Ray Tube(CRT) was an extraordinary invention that changed the entertainment industry forever. From what was low quality, to the ultra-HD displays today. None of that would be possible if it wasn’t for the CRT. The first tv screen, the pioneer of LEDs, OLEDs, LCDs, TFT, AMOLED, and more. We all should thank the CRT for making way for our beautiful displays today. So next time you sit in front of your TV or monitor remember where it all started.

 

Work Cited

Contributor, T. (2021, December 3). cathode ray tube (CRT). WhatIs.com. https://www.techtarget.com/whatis/definition/cathode-ray-tube-CRTEdwards, B. (2021, August 24). What Is a CRT, and Why Don’t We Use Them Anymore? How-To Geek. https://www.howtogeek.com/722863/what-is-a-crt-and-why-dont-we-use-them-anymore/Cathode ray tube | Encyclopedia.com. (n.d.). https://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/cathode-ray-tubeComputer Graphics Cathode Ray Tube | CRT – javatpoint. (n.d.). www.javatpoint.com. https://www.javatpoint.com/computer-graphics-cathode-ray-tube[Electron Gun diagram]. Retrieved February 27, 2023, from https://circuitglobe.com/electron-gun.html[Phosphor screen diagram]. Retrieved February 27, 2023, from https://www.inf.ed.ac.uk/teaching/courses/cg/Web/intro_graphics/hw.html

Skip to toolbar