What makes tvs work

Some apps come preloaded, and you can download more to add to the TV's app library. Exactly how you navigate through the smart TV menu and manage your apps varies with the brand and model. TV brands incorporate one or more platforms through which they offer apps. This integrated platform is what makes a TV smart. Also, some smart TVs provide web browsing, gaming, and access to compatible media content stored on your computer.

In addition to internet streaming, some smart TVs provide more capabilities, such as Miracast and Screen Sharing, which allow users to view content from compatible smartphones and tablets on a TV screen.

Some smart TVs are even able to do the reverse: send content from the TV to a compatible smartphone. After sending, the user can continue to view that content on the smartphone, away from the TV.

The hype surrounding smart TVs is compelling, but there are some cost considerations and limitations to consider. Using a smart TV may result in privacy issues. For example, every time you log into Netflix, the menu shows what you've watched recently, as well as updated suggestions for related movies or programs that you might like based on your 'watched recently' list. You might think that this type of tracking is a good thing because it cuts search time for movies or programs to watch, but a smart TV might be doing more than just track your viewing habits.

Also, any credit card purchases you make using your TV might be trackable by third parties. If your voice control or webcam is on, don't say or do anything that you wouldn't do or say in public—and be cautious with your online credit card purchases.

If you recently purchased, or currently have, a TV without smart features or an older smart TV with limited options, you don't need to buy a new smart TV if your TV still works well and satisfies your picture-quality needs. You can add smart features to your current TV viewing experience at minimal cost. Media Streamers. Blu-ray Disc Players. If you want to add TV, movie, music streaming, and other smart features to your home entertainment experience but don't know if you need a smart TV, here are some guidelines:.

A smart TV is just one way to add internet streaming and related features to your TV viewing experience. Use the guidelines above to decide if it's the best choice for you. That said, you can still connect game consoles and DVD players, although you don't need a smart TV to use those devices.

Yes, most of the time. Look for "Wi-Fi-enabled" in the product description to be sure. To connect your smart TV to Wi-Fi , go to the TV's welcome screen, search for available wireless networks, select your network, and enter the password.

The steps for adding apps to your smart TV depend on the brand, but most models have an option to search for apps on the home screen. You can download apps for free, but you may need to set up an account to use some streaming services. Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content. Create a personalised content profile.

By putting together 15 or more subtly different frames per second, the brain integrates them into a moving scene. Fifteen per second is about the minimum possible -- any fewer than that and it looks jerky. When you download and watch the MPEG file offered at the beginning of this section, you see both of these processes at work simultaneously. Your brain is fusing the dots of each image together to form still images and then fusing the separate still images together into a moving scene.

Without these two capabilities, TV as we know it would not be possible. A few TVs in use today rely on a device known as the cathode ray tube , or CRT , to display their images. LCDs and plasma displays are other common technologies.

It is even possible to make a television screen out of thousands of ordinary watt light bulbs! You may have seen something like this at an outdoor event like a football game. Let's start with the CRT, however. The terms anode and cathode are used in electronics as synonyms for positive and negative terminals. For example, you could refer to the positive terminal of a battery as the anode and the negative terminal as the cathode.

In a cathode ray tube, 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.

Electrons are negative. The anode is positive, so it attracts the electrons pouring off the cathode. In a TV's cathode ray tube, the stream of electrons is focused by a focusing anode into a tight beam and then accelerated by an accelerating anode.

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. There is a cathode and a pair or more of anodes. There is the phosphor-coated screen. There is a conductive coating inside the tube to soak up the electrons that pile up at the screen-end of the tube. However, in this diagram you can see no way to "steer" the beam -- the beam will always land in a tiny dot right in the center of the screen.

That's why, if you look inside any TV set, you will find that the tube is wrapped in coils of wires. On the next page, you'll get a good view of steering coils. The steering coils are simply copper windings see How Electromagnets Work for details on coils. These coils are able to create magnetic fields inside the tube, and 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. A phosphor is any material that, when exposed to radiation, emits visible light.

The radiation might be ultraviolet light or a beam of electrons. Any fluorescent color is really a phosphor -- fluorescent colors absorb invisible ultraviolet light and emit visible light at a characteristic color. In a CRT, phosphor coats the inside of the screen. When the electron beam strikes the phosphor, it makes the screen glow. In a black-and-white screen, there is one phosphor that glows white when struck. In a color screen, there are three phosphors arranged as dots or stripes that emit red, green and blue light.

There are also three electron beams to illuminate the three different colors together. There are thousands of different phosphors that have been formulated. They are characterized by their emission color and the length of time emission lasts after they are excited.

In a black-and-white TV, the screen is coated with white phosphor and the electron beam "paints" an image onto the screen by moving the electron beam across the phosphor a line at a time. To "paint" the entire screen, electronic circuits inside the TV use the magnetic coils to move the electron beam in a " raster scan " pattern across and down the screen. The beam paints one line across the screen from left to right.

It then quickly flies back to the left side, moves down slightly and paints another horizontal line, and so on down the screen. In this figure, the blue lines represent lines that the electron beam is "painting" on the screen from left to right, while the red dashed lines represent the beam flying back to the left.

When the beam reaches the right side of the bottom line, it has to move back to the upper left corner of the screen, as represented by the green line in the figure. When the beam is "painting," it is on, and when it is flying back, it is off so that it does not leave a trail on the screen. The term horizontal retrace is used to refer to the beam moving back to the left at the end of each line, while the term vertical retrace refers to its movement from bottom to top. As the beam paints each line from left to right, the intensity of the beam is changed to create different shades of black, gray and white across the screen.

Because the lines are spaced very closely together, your brain integrates them into a single image. A TV screen normally has about lines visible from top to bottom. In the next section, you'll find out how the TV "paints" these lines on the screen. Standard TVs use an interlacing technique when painting the screen.

In this technique, the screen is painted 60 times per second but only half of the lines are painted per frame. The beam paints every other line as it moves down the screen -- for example, every odd-numbered line. Then, the next time it moves down the screen it paints the even-numbered lines, alternating back and forth between even-numbered and odd-numbered lines on each pass.

The entire screen, in two passes, is painted 30 times every second. The alternative to interlacing is called progressive scanning , which paints every line on the screen 60 times per second. Most computer monitors use progressive scanning because it significantly reduces flicker. Because the electron beam is painting all lines 30 times per second, it paints a total of 15, lines per second. Some people can actually hear this frequency as a very high-pitched sound emitted when the television is on.

When a television station wants to broadcast a signal to your TV, or when your VCR wants to display the movie on a video tape on your TV, the signal needs to mesh with the electronics controlling the beam so that the TV can accurately paint the picture that the TV station or VCR sends. A signal that contains all three of these components -- intensity information, horizontal-retrace signals, and vertical-retrace signals -- is called a composite video signal.

One line of a typical composite video signal looks something like the image on this page. The horizontal-retrace signals are 5-microsecond abbreviated as "us" in the figure pulses at zero volts. Electronics inside the TV can detect these pulses and use them to trigger the beam's horizontal retrace. When we turn on our TV, these diodes gets electrically charged and produce light. This light then passes through liquid crystals layer and a RGB colour filter.

Some of us may have this question — if we are talking about an LED TV, why does it have a liquid crystal panel in it? This confusion is because of the terms used to describe these technologies.

As of now, there are three main types of backlit technologies — an edge-lit technology which is used in most of the LED TVs, PC monitors and phones, while the most premium among them is the full-array technology, which is used in high-end full HD TVs.

A LED panel requires a dedicated backlighting setup to produce light. However, an OLED panel can produce its own light.