How do televisions work?

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Televisions are pretty amazing inventions. There aren’t tiny actors inside our TV sets performing for us, but by watching TV, we can see the images of actors, sports, cartoons, and much more right in our own homes!

TVs actually work by tricking our eyes and our brains! The screens show us many still images, like pictures. They change very quickly, often 30 times every second! That’s so fast that you’ll really miss some if you blink your eyes. With pictures moving so fast, and each picture being just a little bit different, our eyes are tricked into thinking we’re actually seeing something moving. Really we’re just seeing pictures changing really fast!

The picture isn’t made with paints, or ink, or anything in your art supplies. It’s actually made with light! Thousands of tiny dots or stripes of light are used to make a full picture on our TV screens. There are usually three primary colors of light that are used: red, green, and blue. By using those three colors in different combinations, our TVs can make any color we can think of!

How does a TV know which colors to display? A video signal comes into the TV from antennas, satellite dishes, cable or other TV services. It’s an electrical signal that tells the TV’s speakers what sounds to make, and it tells the screen which colors of light it should show. Many TVs use what’s called a cathode-ray tube, which actually shoots beams of energy (electrons) at the backs of our TV screens. These beams are so precise that they can hit just one tiny red, green, or blue point on the screen. When they hit, a small part of the TV screen shines as one of those colors! The rays of energy zigzag across the screen, lighting up different colors faster than our brains can notice. We just see a full picture on the TV!

Other televisions, like plasma TVs, work in a similar way. Plasma screens don’t use a cathode ray tube. There’s no room because they are so skinny! Instead they use tiny compartments filled with gas. Electricity charges the gas, which creates energy that lights up red, green, or blue spots on the screen!

Getting to the Point

There is a type of painting called Pointillism where, instead of using long paintbrush strokes, an entire painting is done just by using tiny points or spots of different colors. It’s a little bit like how a TV works, except a TV uses light instead of paint!

If you have paint, you can try to make a painting out of tiny spots of colors. You can use grid or graph paper and markers or crayons to do this too. On the graph paper, try to make a picture, but only use one color in every box on the sheet.

Up close, your painting or drawing may be hard to figure out, but if you step away from it, your eyes and brain will work together to see the image!