How TV Works

1. How TV Works

2. Through devices you are able to receive entertainment shows, educational shows and informative shows.

3. Human Brain

4. Pixels • Pixels are small dots of colour placed next to each other. • Our brain takes these dots and reassembles them into a recognisable image. • If you are close up to the dots they are too large for your brain to link them together as an image, however the smaller the dots are the easier this is as the dots are almost unnoticeable to the human brain.

5. Motion TV if you divide a moving image into bunch of still images and show them in rapid concession the human brain reassembles them into a moving image.

6. Analogue TV How it works

7. Opposites Attract

8. Cathode - Ray - Anode + • The cathode is a heated filament (not unlike the filament in a normal light bulb). The heated filament is in a vacuum created inside a glass "tube.“ • The ray is a stream of electrons that naturally pour off a heated cathode into the vacuum. • The anode is positive, so it attracts the electrons pouring off the cathode.

9. Cathode Ray Tube

10. This tight, high-speed beam of electrons flies through the vacuum in the tube and hits the flat screen at the other end of the tube. This screen is coated with phosphor, which glows when struck by the beam. • The phosphor dots are arranged in small groups of red, green and blue. By combining these three primary colours any colour can be created.

11. How are they electrons aimed at the screen? There are copper coils which are able to create magnetic fields. The electron beam responds to the fields. One set of coils creates a magnetic field that moves the electron beam vertically, while another set moves the beam horizontally. By controlling the voltages in the coils, you can position the electron beam at any point on the screen.

12. What Is Phosphor? • A phosphor is any material that, when exposed to radiation, emits visible light. • Any fluorescent colour is really a phosphor. • In a black-and-white screen, there is one phosphor that glows white when struck. In a colour screen, there are three phosphors arranged as dots or stripes that emit red, green and blue light.

13. Digital TV How It Works

14. Digital TV is a wireless system for delivering television programming directly to a viewer's house. • Programming is transmitted via a radio signal.

15. How is digital different? • Digital TVs, work under an entirely different concept. Digital signals are sent in a series of short bursts, each identical in size and length. • The process creates a binary code--a series of 1s and 0s, which can be used to send information much the same way a computer does. Binary coding 1000111000011110001010111011001010100011

16. True Digital • True digital TV is completely digital and involves: • Digital cameras working at a much higher resolution than analogue cameras • Digital transmission • Digital display at a much higher resolution

17. Digital Vs Analogue • There are several good reasons to go digital, including: how much data it can transmit, how consistent the data stays over distance, and what type of data the signal can carry. For the same amount of bandwidth, you can stuff a lot more information into a digital signal than an analogue signal.

18. Digital Vs Analogue

19. Digital Vs Analogue Digital Picture Analogue Picture

20. Digital Signal with Analogue TV? • The set-top box receives a digital signal from the satellite or cable; the box then converts that signal to an analogue signal and sends it to your analogue TV. That's why if you're a digital cable or satellite TV subscriber, your provider probably told you that the June 2009 DTV transition wouldn't require you to buy new equipment.