Detailed comparison of LED display and LCD display

The upgrading speed of the display market in recent years has completely exceeded the previous ones. Just when people are still struggling with which size display to choose, and are hesitant to buy 16:9 or 16:10, another new technology Displays began to appear on the market, and this is the LED-backlit liquid crystal display. What are the advantages of LED displays? How about the price of LED display? Compared with traditional LCD monitors, what is the difference?

LCD liquid crystal market fight fiercely

The current LCD market can be described as chaotic. Products of various specifications coexist in the market. Only 16:10 widescreen has 19, 22, 24 and even larger sizes. The sudden emergence of 16:9 widescreen has made this The situation is even more chaotic. The prices of products of various specifications in the two series are staggered. The price difference between 19, 22 and even 28 inches is only a few hundred yuan, or even tens of yuan. The quality is also uneven. In order to control the cost, some large-screen displays are suspected of being shoddy from the core components to the shell design. Obviously, the previous practice of determining what product to buy based on size alone is no longer applicable.

LED LCD “spoiler” display market

The addition of LED-backlit liquid crystals makes consumers even more confused. LED-backlit liquid crystal is only based on the traditional liquid crystal, changing the backlight system from fluorescent to LED, but both in terms of display effect and lifespan, there has been great progress. More importantly, this kind of display has been developed for nearly a year. The price has dropped from thousands of yuan at the beginning to about 2,000 yuan at present, which is in the same price range as traditional LCD.

What should consumers do when faced with so many choices? How good is the display effect of LED LCD? Is it worth paying for it? As a new technology, what are the performance advantages of LED backlight? Can the ultra-long lifespan and low power consumption of LED liquid crystals offset the price difference with traditional liquid crystals? In order to answer these questions, we have collected several representative LED LCD products this time, hoping that through testing and analyzing them, consumers can choose more suitable products for themselves in the foggy LCD market. .

The low-priced LED displays currently on the market are designed with a white backlight

Since LED backlight is still a relatively new technology, major manufacturers are applying it to high-end products. For example, the XL20/ XL24/ XL30 products launched by Samsung are all positioned at the professional market and are expensive. However, this type of product uses RGB three-color LED backlight, that is, each LED light source point can emit three colors of red, green, and blue at the same time, so its color expression can reach a very high level.

Of course, not all manufacturers have positioned LED backlight LCDs so high. For example, ViewSonic’s VLED221wm also has LED backlights, but the price is much gentler, at 3,999 yuan. The price of V19/V22 launched by AOC is 1699 yuan and 1999 yuan respectively. Although the price of this kind of product is low, it uses another kind of backlight: white light LED, that is, the LED in the backlight only emits white light. So what are the advantages of this product, and whether it is worth buying at this stage, now we will answer you in detail.

From fluorescent tubes to LEDs

In the past, the backlight used in liquid crystal displays was called CCFL, which can be simply understood as a very small fluorescent tube. And LED is a kind of light-emitting diode. In our daily life, we see more LED flashlights, which have the advantages of high brightness, long life, and small size. LED LCD only changes the backlight from traditional CCFL to LED, and there is no change in the panel type.

LED white backlight

Advantages Have five advantages

★Richer colors ★Brightness is more uniform

★Smear and dynamic contrast ★More power saving

★Lighter and thinner

Contrast 1. Richer colors, LED color gamut as high as 100%~130%

At present, the color of LCD monitors is still not satisfactory. In the eyes of many users, the color of LCD monitors is still not comparable to that of CRT monitors at its peak. However, at the current stage when the panel manufacturing technology cannot achieve a major breakthrough, only through the improvement of the backlight technology can the color of the liquid crystal display be improved.

LED display color gamut range up to 100%~130%

The current mainstream CCFL (cold cathode backlight) emits white light that cannot be decomposed into more colored light due to its own spectrum limitation, and the color gamut range is only about 70% of NTSC. The use of LEDs as the backlight source is different. The light emitted by LEDs covers a wider color spectrum, and its color gamut can reach 100%-130%, without the 30% color loss like traditional CCFL backlights.

Therefore, the color displayed by the LED backlight display should be fuller, and the details of the picture should be clearer, and the color transition should be more natural. For users, this also means better picture quality when gaming or watching high-definition movies.

Now let’s compare AOC V22 with a common 22-inch widescreen to see if LED LCD is as good as theoretically inferred compared to traditional LCD.

Contrast test: the display effect on LED LCD is more natural

LED liquid crystals have unparalleled advantages in terms of color purity and transitional naturalness. Take a picture of fallen leaves as an example. On an ordinary LCD monitor, the colors on the leaves are very messy. On the middle leaf, there is a very obvious dividing line between red and green. On the LED-backlit LCD, although the leaves in the middle have various colors such as green, red, purple, orange, etc., the transition between colors is extremely soft. The most amazing thing is that on the CCFL liquid crystal, a leaf is displayed in green, but on the LED backlight display, we can see that the leaf is actually light yellow, and it is obvious that the appearance displayed on the LED liquid crystal is more nature. This is very important for users who like to watch blockbuster movies.

Tips: What is the NTSC color gamut

NTSC color gamut: the sum of colors under the NTSC standard. NTSC is a set of protocols for television broadcast transmission and reception formulated by the National Television Standards Committee of the United States. The color bit depth is set at 24 bits (about 16.7 million different colors), which has exceeded the number of colors that the human eye can distinguish (12 million-14 million), so it is also called true color.

Summary: LED has a perfect performance in color, and the transition is more natural

Previous CCFL backlit liquid crystals have been deceiving our eyes. LED liquid crystals have extremely powerful color transition capabilities, and thanks to this, the details in the picture are more clearly presented to us.

Contrast 2. The brightness of liquid crystal is higher, and the uniformity of brightness is better

Insufficient brightness and uneven brightness on the screen, these two problems are especially obvious on large-size LCD monitors, which will make some places on the screen bright and some places dark, and also cause color deviations.

Traditional LCD is generally 300-500 lumens, while LED brightness can reach thousands of lumens

The brightness of traditional LCD monitors cannot be too high, generally between 300-500 lumens. The brightness of LEDs can theoretically be increased infinitely. Therefore, the brightness of the display with LED backlight can even reach thousands of lumens to meet the needs of various users.

In addition to brightness, the biggest benefit of LED backlight is better brightness uniformity. Traditional CCFL backlit monitors have elongated light tubes. No matter how they are arranged, the brightness of every point on the screen cannot be made the same. The brightness difference between the center and the periphery of the screen may reach about 100 lumens. The LED backlight is illuminated by a collection of point light sources, and many small LEDs are evenly distributed, which enables the brightness difference of each point on the screen to be controlled, and as the number of LEDs increases, this difference can continue. reduce.

For users who like high-definition movies or need to do graphics processing, the higher brightness will make the details on the screen clearer. And better brightness uniformity will also make it impossible for some places to be bright and some places to be dark on the screen.

The brightness difference of each point of LED is about 15 lumens, while that of LCD is about 80 lumens

The test of brightness still uses an illuminance meter, while the test of brightness uniformity is to take 9 test points on the screen display. After testing the brightness of each point, use the point in the center of the screen as the standard to calculate the difference between other points and this point. The difference between points, the smaller the value, the better.

In terms of brightness uniformity, the performance of LED liquid crystals is very good. The brightness difference between the surrounding 8 test points and the central reference point is only about 15 lumens, while this data is about 80 lumens on CCFL liquid crystals. It is obvious that the brightness uniformity of LED liquid crystals has reached a relatively high level.

Summary: The brightness of LED liquid crystal is average, and the uniformity of brightness is excellent

The brightness uniformity of LED liquid crystal is very good. But why is there a situation where the difference value at a certain point is particularly large? The only reason can only be that there may be problems with the brightness value of the LEDs below this point. And with so many LEDs in the LED backlight system, how can we completely ensure that their brightness is the same? This is not unfounded, LED backlight integrates more LEDs, which also means that there is a greater chance of problems.