LED TV - Clouding

The problem of uneven lighting is usually called "clouding". This is because the light distribution gives the image cloud-like, bright areas. Unfortunately, the problem is not something that can be fixed, but you can minimize the experience of it by changing the TV's picture settings.

The clouding problem is most evident in dark scenes, which can make it difficult to notice at a demonstration at a major electronics store (without any dedicated and authentically illuminated home theater). We therefore recommend that all TV buyers read several reviews about an intended TV before the purchase!

How tangible the clouding problem is can also vary between different copies of the same TV model. It is also usually not considered to be a fault covered by the warranty. People who are sensitive to this type of problem should therefore carefully check the TV retailer's terms of open purchase.

Simulated example of "clouding". The example is exaggerated for the sake of clarity!

LED TV - Led lighting

The LEDs that illuminate the LCD panel of an LED TV can be placed in several different ways. The most common thing today is that they are located along the edges of the TV (called "edge-lit"). The light they generate is controlled behind the LCD panel and evenly distributed behind it. One of the biggest advantages of this technology is that the TV sets can be made incredibly thin.

Today, the LEDs are usually placed along the edges of the TV.

The other solution is to place the LEDs directly behind the LCD panel (called "back-lit"). This solution is used in some of the cheapest and some of the most expensive TV models. The solution makes the TV somewhat thicker, but can also provide a great advantage for the contrast (explained later in this chapter).

The LEDs can also be placed directly behind the LCD panel.

It is not possible to say that one lighting technique is better than the other. The problems with uneven lighting that edge-lit TVs suffered from initially have less impact over time. Now the image quality is rather determined by how well worked the lighting is. An edge-lit TV from the premium segment may well have a more even lighting than a back-lit TV from the budget segment.

What is the difference between an LCD TV and an LED TV?

The LCD panel consists of millions of liquid crystals, and it is from there it got its name, Liquid Crystal Display. The panel sends electrical charges to the crystals. Depending on the current, which can be varied for each individual crystal, the crystal permits different amounts of light. If no light is passed through, the crystal is perceived as black. As mentioned, an LCD screen does not generate its own light, but must in some way be illuminated from behind. This is where LED comes into the picture, literally.

Color without filters

The big difference between LCD TV and LED TV is how to illuminate the screen so that the different colors of the pixels are visible. An ordinary LCD TV uses Cold CathodeFlourescentLamps, a type of fluorescent lamp, such as a light source, CCFL. CCFL sits behind the LCD panel. They cannot be made as small as possible, giving the screen some thickness. In addition, several environmentally hazardous materials are included in the production, which you want to avoid as much as possible. An LED TV uses light emitting diodes.
LEDs are a type of semiconductor LED that emits light when current is passed through them. They can be manufactured in different colors without the use of filters or color, by using different materials for the light generation itself, which is an advantage.

LEDs provide benefits

LEDs often replace light bulbs in e.g. traffic lights, bicycle lights and flashlights, indicator lights and also in remote controls and vehicle lights. By using LEDs as a light source in an LED TV, you gain many advantages. For example, the LEDs draw less power and do not contain harmful substances that the cold-cathode lamps do. The LEDs can also be made very small and last very long, emit very little heat and can easily be turned on or off, or dimmed, to create very high contrasts in the TV picture. Samsung has already used LEDs to backlight LCD TVs, but with the LED TV series it takes it to a whole new level. In all Samsung LED TVs, the LEDs are placed around the screen, and the light is advanced in an advanced way behind the screen to illuminate the pixels. In this way, the TV can be made extremely thin.