Led tv how does it work

There is also a light diffuser between the two that helps to make the light coming to the screen more uniform. The liquid crystal display acts as some kind of filter.

It blocks light in each pixel by applying and controlling an electric field to each pixel. For black to be displayed , the light will be completely blocked while white means all the light will be let through. A portion of light will always find its way through the filter. One of the advantages of an LCD television over a plasma television is a lower energy cost. The energy consumed when applying an electric field to a pixel and illuminating the backlight is lower than the energy consumed in exciting the electrons in plasma.

The main disadvantage of LCDs is that some viewing angles do not work. CCFL stands for cold-cathode fluorescent lamp. CCFLS use thin light tubes unlike the fluorescent tubes used for regular lighting to light the liquid crystal display.

They are much smaller though. These televisions are far more energy efficient than their CCFL cousins and also a lot smaller. It is because of their relatively smaller size that LED televisions can afford to be so thin when compared to other types of televisions.

While LED televisions are often touted as a major innovation and a new kind of television, they are no more than a special kind of LCD television where the backlight is made of LEDs. This article explains how each TV technology displays an image and the differences between them. You can learn about it in more detail here. Plasma screens contain tiny pockets of gas that get excited when voltage is applied to them, turning them into a state of plasma.

In that state, the voltage then strikes electrons of mercury, turning them into ultraviolet UV light, which isn't visible to the human eye. The UV light then passes through phosphor cells; each pixel contains red, green, and blue phosphor cells. Thanks to these phosphor cells, the TV can turn the UV light into colors that are visible on the light spectrum. Essentially, plasma TVs don't require a light, and each pixel is self-emissive, so how one pixel displays itself is independent of the next pixel.

Since each pixel emits its own light, blacks are really deep. When the television wants to display black, it simply emits no light at all for the selected pixels. However, these aren't perfect blacks because each pixel retains a bit of voltage, leaving a bit of light to pass through.

Each pixel emits light in all directions, creating wide viewing angles , so the image remains accurate when viewing from the side. The pixels aren't excited continuously, but in short pulses, and some plasma TVs can pulse up to times every second.

The naked eye perceives this as flickering, and some people are very sensitive to this. There can also be some advantages to this; since each pixel holds a certain charge, it's ready to turn on and off as needed, resulting in minimal motion blur.

This means that fast-moving content, like in sports or video games, appears smooth. One of the downsides of plasmas was how they suffered from occasional image retention if they displayed the same image for a long period. So if you watched the news for about an hour, with all of its static displays, then switch channels, you'd still see the outline of the static elements. Eventually, they disappeared, but it could have been particularly annoying. Also, after several years in use, plasmas suffered from permanent burn-in.

This happened when the phosphor cells simply stayed stuck in one color and couldn't display any colors. Unfortunately, there was no way to avoid eventual burn-in, and almost every plasma TV suffered from it. OLED TVs have similar characteristics to plasmas with their infinite contrast ratio, wide viewing angles, near-instant response time, and to a lesser extent, the risk of permanent burn-in.

An LCD screen is composed of two parts: the actual liquid crystal display and a light source at the back of the screen called backlight. A light diffuser is placed between the backlight and the LCD screen to make the source of light uniform across the screen.

The LCD panel doesn't emit light by itself, and this is why it needs a backlight; it only acts as a filter to block the light on a per-pixel basis. The backlight is always on, and the pixels in the display rotate to allow light through, creating the colors needed for the image. Take a second to support Electrical e-Library on Patreon! Related Posts. The Jiuzhang 2. Artificial vision for blind people 21 de October de Laser types Part 2, diode lasers 14 de October de About Pedro Ney Stroski.

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.