In the official introduction of iPhone 12, the word XDR is quite eye-catching. Many people are curious about its meaning and the screen parameters it represents. Some people think that XDR is a new screen material, but the whole iPhone 12 series is equipped with OLED screen as standard. How to explain this? < / P > < p > XDR is not screen material, it is the synonym of ultra clear retinal screen, and HDR is the same type, representing the overall quality of the screen. HDR focuses on the display resolution of 1080p, while XDR is more than 2K or higher; if 1080p is called ultra clear, HDR should be described as extremely clear. At present, XDR technology is mostly Apple based products. Since iPhone x, subsequent mobile phone screens have supported this technology, including Apple’s XDR professional display with super high price before. < p > < p > take the iPhone 12pro as an example, which supports HDR display, 2532 * 1170 pseudo 2K resolution, 460ppi; the typical contrast value is 2000000:1, the maximum brightness is 800 nit, and the HDR mode is 1200nit, and it also supports P3 wide color gamut. With such screen parameters, no wonder Apple dares to put the XDR label on the iPhone 12. < / P > < p > XDR not only represents high resolution, but also maintains PPI above 450 due to the size of the screen, which can give users a more delicate look and feel. In a sense, PPI is more important than resolution. If a screen is 4K resolution, but the size is more than tens of inches, it will produce a strong grainy sense, and the display effect is very poor, which is far lower than the 4.7 inch mobile phone screen with a resolution of 720p. < / P > < p > in addition, high dynamic range and high contrast are also the advantages of XDR screen. High contrast can make the color display more clear, the higher the contrast, the more obvious the sense of hierarchy of color. High dynamic range is also called HDR, also known as HDRI to avoid ambiguity. It highlights the details of the image through the exposure principle, especially in the dark. In short, high dynamic range can make the image more realistic. < / P > < p > this year’s iPhone 12 XDR screen also has a flaw, that is, it doesn’t have a high refresh rate. Although high refresh rate can not make the color of the screen more beautiful, but the smoothness of UI switching is incomparable to ordinary 60Hz. Once you use the high refresh rate screen, it is difficult to return to the previous. It’s a pity that the iPhone 12, as an expensive flagship model, does not have this feature. In other words, XDR is not directly related to OLED. The former is the screen technology, the latter is the screen material, the former is the embodiment of the latter’s display quality, and the latter is the hardware foundation of the former. The iPhone 12 combines XDR and OLED, and the display effect is naturally excellent. Continue ReadingAmerican companies begin to give up R & D: who should pay for corporate research?