LCD, LED, QLED, OLED, and future quantum dot OLED, who is the good display screen?

2019-08-29 10:57:51 hongling

LCD, LED, QLED, OLED, and future quantum dot OLED, who is the good display screen?

"LCD", "LED", "QLED", "OLED" and "quantum dot OLED": What is a good display for users? But at present, quantum dot OLED is still in the experimental stage of research and development, there is no real large-scale production, and large-scale production equipment is also in the research and development. According to relevant reports, Samsung Display is expected to start trial production of "QD-OLED" displays in the second half of 2019. The main reason is that Samsung and Canon, Kateeva and other joint efforts to develop production equipment, several greatly shortened the equipment development time.

For mass consumers: from LCD, LED to QLED, OLED, one after another, the new display technology makes users a little dazzled, do not know what kind of large screen display device to choose to achieve good display effect, and now a "quantum dot OLED" has emerged, making users more confused.

However, for a large number of user groups: they do not know what these nouns stand for, they are only concerned about the numerous display devices, which display device has better display effect. For this purpose, the following classifications and summaries are made for your reference:

Firstly, the following LCD and LCD LCD screens usually include the following price parts:

First, each LCD splicing unit has an independent backlight system. At the beginning, the backlight of LCD is fluorescent lamp and other devices. Now, the LCD splicing unit uses LED backlight. LED is light emitting diode, which can also be understood as "lamp tube", but compared with the traditional one. The lamp has low power consumption and obvious advantages in service life, so many types of lamp on the market are LED.

Secondly, LCD splicing unit needs a light guide besides a backlight. Its main function is to distribute the light generated by the backlight evenly into a plane and form a luminous plane.

Third, in addition to the need for light guide plate to form a plane, but also need a liquid crystal layer, because the light guide plate formed by the light wall is monochrome light, can not form an image. But the characteristic of liquid crystal is that the voltage applied to it is different, and the law of its movement will be different, so that the light blocked is different, thus forming the gray level of light and shade, which is often called the LCD splicing screen. The more types of applied voltage, the greater the gray value, and the more types of light it will display.

Fourth, although LCD can display many kinds of light through voltage, they are all gray screen, and can not show other colors. So it needs a color filter. If you use a magnifying glass to observe the LCD splicing unit, you will see red, blue and green dots, that is, the color filter. Usually the colours seen on LCD mosaic large screen are formed through this.


Limitations of LCD and OLED, QLED:

From the principle of liquid crystal display, we can see that the light emitted by liquid crystal is actually emitted by the back lamp. So there are two problems.

First, liquid crystal molecules have a limit to shield light, not all of them can be blocked. The so-called pure black is actually a kind of gray, because light can penetrate it. When the brightness of the screen is higher, the brightness of its LED backlight will be higher. The more light thrown through the LCD screen, the more impure the black will be. And black impurity will lead to weak contrast of the screen, and the color of the screen will not be distinct after the contrast is limited.

Second, the problem of color region

Scientifically speaking, the color that the human eye can distinguish belongs to the spectra of visible light, and the display equipment can only display part of it. For the standard, there are some RGB, NTSC, NTSC and other standards: about 72% of the early LCD, and then with the progress of filter technology, it gradually reaches 80% and 90%. But it's still a long way from what the human eye sees in the real world.

Because of the existence of both LCD and LED, the later OLED appeared. In fact, OLED has a long history, which can be traced back to Kodak Laboratory decades ago, but for mass production, it is in recent years. Compared with LCD, OLED has certain advantages. First, OLED is active luminescence, does not need any backlight. Second, it can achieve very small size. Today's mobile phones basically use OLED as a display screen. Another point is that its color can be very realistic, can reach a high color area. That's why mobile phones look better than LCDs and LEDs. In addition, the response time of OLED is much faster than that of LCD: it does not need liquid crystal layer, slow liquid crystal molecule movement, so that the dynamic picture can be displayed much better without shadow or hysteresis.

But this does not mean that OLED is a good display device, for example, pure OLED: it should be red, green, blue three colors of OLED. Three kinds of light are mixed together to display, and that's what early Sanxing OLED did. But TV and mobile phones are different, TV is a few hours, every day, and red, green, blue OLED life is different, as the use of time increases, red attenuation 50%, green attenuation 20%, blue attenuation 30% after the TV bias ah! So Samsung didn't play that way for years.

And LG came up with a way to use white OLED, or the light source of each point can turn off and display pure black, but the color depends on red, blue, green tricolor.