As more and more mobile phones begin to adopt OLED screens, what is the difference between OLED screens and LCD screens in mobile phones?
In this article, I am going to talk about the differences between OLED and LCD and what are the merits and demerits of both displays.
To know the difference between OLED screen and LCD screen, you first need to understand their display principles.
LCD Backlight
The light-emitting principle of LCD mainly relies on the backlight layer. This part is usually composed of a large number of LED backlights. It has only one function, which is to display white light, but white light cannot form an image, so add a layer of color on this white backlight layer.
After the white backlight penetrates the colored film, the color can be displayed, but the ratio of red, green, and blue needs to be adjusted. The light cannot be directly penetrated through the red, green, and blue, but the liquid crystal layer changes it. The size of the two-pole voltage controls the arrangement of the liquid crystal molecules so that the large opening and closing will emit more light, and the small opening and closing will emit less light. This way, the amount of white light can be controlled, so that the red, green, and blue can be adjusted. Matched.
OLED self-luminous
OLED does not require a backlight layer like an LCD screen, nor a liquid crystal layer that controls the amount of light. OLED can emit light by itself, so OLED is like a screen with countless small color light bulbs.
Disadvantages of the LCD screen
LCD currently has a fatal problem, that is, the liquid crystal layer cannot be completely closed, so if the LCD displays black, part of the light will pass through the color layer, and the black of the LCD is actually gray mixed with white and black. While looking at it, it is actually gray with a sharply decreasing brightness, not pure black.
In addition, due to the existence of the backlight layer, the LCD display still has a light leakage phenomenon, and it is impossible for the LCD to completely avoid the light leakage phenomenon.
The OLED is different. When the OLED displays black, the pixels in the black area can be directly turned off to achieve an almost pure black effect.
Advantages of OLED screens
Thickness:
LCD is much thicker than OLED due to the existence of backlight layer and liquid crystal layer, so OLED screens are very easy to make mobile phones or displays thinner, which is a great improvement for mobile phones, and thinner screens allow you Insert more components to enhance the experience of other parts.
Flexibility
Because of the existence of the liquid crystal layer and the backlight layer, the LCD screen cannot be bent significantly, and the OLED can be folded almost like origami. Samsung’s curved screen is supported by OLED technology. It should be noted that this is about large bending. The curved screens of desktop computers are still LCDs. You can find that the degree of bending is not large. OLEDs can be folded in half like paper.
Color
Contrast refers to the ratio of white to black. The higher the contrast, the darker the picture. Because LCD has a backlight layer, black is not pure black, so the contrast is difficult to increase. OLED black does not emit light, so you can directly turn off the black area. Pixels, so that it is basically infinitely close to black.
Separate lighting
When LCD is turned on, the entire backlight layer is turned on, so LCD is either fully turned on or fully turned off, and each pixel of OLED is independent, so OLED can individually light up certain pixels, so that you can Screen reminders (aways on display), which can greatly reduce the number of times the screen is turned on and indirectly save power.
Power consumption
Since OLED pixels work independently, they should be bright, dark and dark, and off, no matter what color the LCD displays, the backlight is fully turned on, so LCD is destined to consume power.
Response time
The color of the screen is displayed by pixels, and it takes time to change the color of pixels. This time is called gray-scale response time. If the gray-scale response time is too long, afterimages will appear. Smear will appear visually, which greatly affects the visual perception. There is almost no procrastination on the OLED screen, while the smear is still a smear on the LCD screen.
Disadvantages of OLED screens
Burn-in
The defects of OLED are also obvious and fatal. LCD screens are inorganic materials, and their aging speed is much slower than that of organic OLEDs. Therefore, the lifespan of OLED organic materials is not as good as that of LCDs, and it is more deadly.
Since each pixel of OLED is self-luminous, instead of the entire block as in LCD, it will cause the working time of each pixel of OLED to be different. Some pixels display blue for a long time, so it’s blue The color attenuation will be more than that of other pixels, and the blue will become lighter and lighter in the future, so a phenomenon that OLED is very prone to as burn-in.
But screen burning is a very long process. Generally speaking, as long as you control the brightness of the mobile phone under 60% in daily use, and ensure that the mobile phone screen does not display a screen for a long time, the burned screen that is visible to the naked eye can appear after 3 years. And the mobile phone will basically be replaced by that time.
Therefore, some people who use OLED at low brightness will feel obvious discomfort. Therefore, before choosing an OLED screen, it is best to make sure that you can accept low-brightness PWM strobe before making a decision. It should be noted that, in fact, many low-end LCD screens are also PWM dimming. Don’t think that LCD is all DC dimming.
Low pixel density:
The more pixels there are on the same screen area, the clearer the screen. However, the arrangement of the OLED screen pixels will cause the two mobile phones to have the same resolution, but the screen resolution will be less than 1/3.
Therefore, in the case of the same resolution, the OLED screen is not as clear as the LCD, but the current mobile phone screen is quite clear, even the 1K resolution OLED is difficult to see the pixels, but if you need to take the root for the horizontal contrast The number is down 2/3.
To Sum Up
The screen is composed of pixels, and each pixel is composed of three sub-pixels of red, green, and blue. The color is developed by adjusting the ratio of red, green, and blue of the sub-pixels; the imaging principle of LCD is to rely on the white backlight to penetrate the color film to develop color; The imaging principle relies on self-luminescence, so each pixel can work independently.
LCD inorganic materials, OLED organic materials, so OLED life is not as good as LCD. Because OLED is an organic material and the pixels work independently, burn-in occurs. The essence of burn-in is uneven screen aging. The color of OLED is much better than that of LCD. OLED is oil painting and LCD is watercolor strokes.
The OLED screen has almost no smear and has a fast response speed. OLED screen adopts PWM dimming, and strobe under low brightness will make some people feel uncomfortable. OLED pixel density is not as good as LCD under the same resolution. OLED is more power-efficient than LCD screens, thinner, and can be greatly bent.
