IT168 evaluation With the increasingly fierce competition in the mobile phone industry, the mobile phone market has already passed the era of hardware configuration competition. eight nuclear processor and large memory have also become very common in the thousand yuan mobile phone. It can be said that the current thousand yuan mobile phone can meet the needs of ordinary users in terms of configuration and experience. However, apart from the hardware configuration and software experience, as the second feeling of the user to the whole mobile phone, the attention of the screen is not as high as that of the hardware mentioned before, and with the gradual increase of the resolution of the screen, the attention of the user to the screen is gradually decreasing, so is the screen time really incomparable? Today, Xiaobian will give you an analysis of those things between screens.

according to xiaobian's survey, the main reason why many users pay less attention to mobile phone screens is that most thousand-yuan-class mobile phones have already used 18P screens, while the mid-range mobile phones and even flagship mobile phones of the same brand also use the same resolution screens, and boasting about screen technology makes consumers dazzled but can't be compared intuitively. Therefore, users often give priority to comparing the internal parameters between different price points of the same brand, while the screen does not pay much attention. However, as a small series that has read countless "machines", there is not only a gap in internal configuration between different price points of the same brand, but also a huge gap between its mobile phone screens. Therefore, in order to let you see the real side between their screens, Xiaobian today compares the screens of four brands of mobile phones with different price points, so that you can see what gaps exist between the screens except the resolution in the same brand mobile phones with different price points.

Before the comparison began, Xiaobian reorganized the mainstream screen materials and technologies on the market, so that you can intuitively understand what mainstream screen materials and technologies are on the market now before the comparison began.

▲ Standard three primary colors

Principle: The three primary colors of R (red), G (green) and B (blue) are needed for the mobile phone screen to display the words and images we see. Each pixel in the screen has a complete arrangement of three RGB sub-pixels, and each color on the screen can be recorded and expressed by a set of RGB values, and the RGB component of each pixel is within the range of -255 intensity values. Only by mixing the three colors of red, green and blue in different proportions can we present all the colors we see.

Analysis of relevant liquid crystal materials (technologies) mentioned in this paper

TFT material

▲TFT principle

is the abbreviation of thin film transistor. Compared with other screen materials, it is not particularly accurate to summarize TFT as a screen material. Rather, TFT is actually a core component in LCD screen. Its function is to provide a semiconductor switch for each pixel, and its processing technology is similar to that of large-scale integrated circuits. Because each pixel can be directly controlled by point pulse, each node is relatively independent and can be continuously controlled. This design not only improves the response speed of the display screen, but also accurately controls the display gray level, so the color of TFT liquid crystal is more realistic. Therefore, both high-end and low-end LCD screens are inseparable from TFT, so TFT itself is not synonymous with low-end.

TN panel

▲TN panel principle

The full name is Twisted Nematic panel, which is mainly used for the screen display of entry-level and mid-range mobile phones because of its low price. It is a common type of LCD panel in the market at present. Its biggest disadvantage is color and viewing angle. Relatively speaking, TN color is pale and not gorgeous enough, and the viewing angle is small. If it is off-center, there will be obvious color cast and brightness difference.

However, with the maturity of TN screen technology, most of the TN panels we see at present are improved TN+film, which is the compensation film, to make up for the lack of viewing angle of TN panels. At present, the viewing angle of improved TN panels is above 15. It also performs very well in all aspects. The improved TN screen has a light transmittance of more than 8%, a viewing angle of 15, a brightness of 2-35 cd/m2, a contrast ratio of 5:1 and a color saturation of 4%, which is obviously more perfect than the earlier slightly greasy ordinary display screen, and is also an absolute advantage compared with the wide-angle panel in terms of price. (representative models: most low-end mobile phones)

IPS technology

▲IPS can provide brighter colors and wider viewing angles

IPS is the abbreviation of English In-Plane Switching (transverse electric field effect display technology), which is a liquid crystal panel technology introduced by Hitachi in 21, commonly known as "Super TFT". As we can see from the name, IPS screen is actually a technology based on TFT, and its essence is TFT screen. It can effectively improve the color difference problem and narrow field of vision in TN screen when the viewing angle is poor. The electrodes of IPS liquid crystal are in the same plane with the liquid crystal, and the viewing angle of 178 degrees can be obtained, which greatly improves the problems existing in TN screen. But at the same time, IPS screen is not as flawless as we thought. The power consumption of IPS screen is high, there is no obvious improvement in other aspects except the viewing angle, and the response speed is slow, so it can be regarded as both advantages and disadvantages. (representative models: iphone series mobile phones and LG series mobile phones)

AMOLED

▲ Schematic diagram of AMOLED (1)

Also known as "Magic Screen", the full name is Active Matrix/Organic Light Emitting Diode, which can be translated as an active matrix organic light emitting diode panel. Originated from OLED display technology, that is, organic light-emitting diode, it has the characteristics of self-luminescence, using very thin organic material coating and glass substrate, when there is current passing through, these organic materials will emit light. AMOLED is based on organic light emitters. Thousands of light sources that can only emit one of the three colors of red, green or blue are placed on the substrate of the screen in a specific form. These light emitters will emit red, green or blue when applied with voltage. The voltage conversion also depends on TFT, and only after adjusting the proportion of the three primary colors can they emit various colors.

▲ schematic diagram of AMOLED (2)

In terms of display efficiency, AMOLED has the characteristics of faster response speed, higher contrast and wider viewing angle, which are the advantages that amoled is naturally superior to TFT LCD. In addition, AMOLED has the characteristics of self-luminescence, so it can be made thinner than TFT, and the thickness of AMOLED without backlight can be saved by 3-4%, which is positive for the thinness of mobile phones. And the cost paid by the backlight module can be saved.

in addition, many different versions of AMOLED have been derived in the development process, such as AMOLED, SuperAMOLED, SuperAMOLED Plus, SuperAMOLED Advanced and so on. (representative model: Samsung series mobile phones)

LTPS (low temperature polysilicon technology)

▲ low temperature polysilicon technology LTPS

low temperature polysilicon technology ltps (low temperature poly-silicon) is also an improved display technology based on LCD. As early as the mid-199s, this technology began to enter the trial stage. It was originally developed by Japanese and North American technology companies to reduce the energy consumption of Note-PC display and make Note-PC appear thinner and lighter. Low temperature polysilicon (LTPS) belongs to polysilicon products. Compared with ordinary TFT, the molecular structure of polysilicon is arranged in a Grain in a neat and directional state, so the electron mobility is 2-3 times faster than that of amorphous silicon. In terms of display performance, LTPS-TFT LCD liquid crystal display has the advantages of high resolution, high color saturation and low cost, so it has high hopes. (representative model: charm blue note3)

Nega negative liquid crystal technology

▲ negative liquid crystal panel principle

negative liquid crystal technology, whose liquid crystal particle deflection principle is just the opposite of positive liquid crystal technology (this is also the name of negative liquid crystal). The liquid crystal particles of negative liquid crystal technology are in a horizontal state when no electricity is applied, which brings a great advantage. For example, when displaying a completely black picture, the backlight system is still working and there is still light entering the liquid crystal layer. In positive liquid crystal technology, because the liquid crystal particles are vertical, a large amount of light will pass through the two ends of the liquid crystal particles, resulting in "graying" of the screen display. However, in negative liquid crystal technology, because the horizontal liquid crystal particles block most of the light, the screen appears darker and closer to black.

▲ Negative LCD can reduce the black area of the screen

. When the liquid crystal molecules are energized, more light passes through because of its vertical deflection, so the details of the bright part of the image become more prominent. The combination of the two brings about an overall improvement in brightness and contrast and even color gamut. At the same time, negative LCD technology also makes the overall voltage level of the screen more stable, which is of great benefit to the screen life. Moreover, because there is no need for high-power backlight, the heating and power consumption of the screen can be effectively reduced. (representative models: 36 mobile phone flagship edition, Glory 7, etc.)

NTSC standard color gamut

▲ Common color gamut range

Simply put, color gamut is a method of encoding a color, and it also refers to the sum of colors that a technical system can produce. In computer graphics processing, color gamut is a complete subset of colors. The most common application of color subsets is to accurately represent a given situation. Such as a given color space or a color range of an output device.

▲ The higher the color gamut, the more accurate the color will be.

The p>NTSC standard comes from the National Television Standards Committee, which is responsible for developing a set of American standard television broadcast transmission and reception protocols. The NTSC standard uses a depth of 24 bits, which can represent about 16.7 million different colors. Because ordinary people's eyes can only distinguish between about 12 million and 14 million different shades and tones, 24-bit colors are also called color or true color. And the 24-bit color channel allocates 8-bit data for each color, that is, red, green and blue, and each of these three primary colors can have 256 variations. Therefore, theoretically, the higher the NTSC color gamut of the screen, the larger the displayed color range, which means more colors can be displayed.

Meizu PRO 5 VS charm blue note3

▲ Meizu PRO 5

Meizu PRO 5 adopts a 5.7-inch screen and Samsung AMOLED technology, with a resolution of 192×18 and a PPI of 387. It has an ultra-high contrast ratio of 1:1 and an NTSC color gamut of up to 1%, with bright colors and the highest brightness of 35cd/m2. And because of the self-luminous characteristics of AMOLED, the screen of Meizu PRO 5 is very power-saving, so that the mobile phone can provide longer battery life.

▲ Charm Blue note3

Charm Blue note3 uses a 5.5-inch screen and LTPS technology, with a resolution of 192×18 and a PPI of 43. It has a contrast ratio of 1:1 and an NTSC color gamut of 87%, with the highest brightness of 45cd/m2. In order to make the color reproduction of Charm Blue note3 more realistic, Meizu specially built in the advanced MiraVision? 2. screen display function.

▲ Solid color contrast (left: Meizu PRO 5；; Right: Charm Blue note3)

In the comparison of solid color screen above, we can see that Meizu PRO 5 with Samsung AMOLED screen has very accurate color reproduction in solid color, and the actual displayed color is not far from the standard RGB. The screen of Charm Blue note3 has different degrees of color cast. Thanks to the black and non-luminous characteristics of OLED screen, Meizu PRO 5 has exactly the same effect as closing the screen when displaying pure black pictures. Charm Blue note3 shows obvious graying when it is displayed in pure black. From the contrast of pure white, Meizu PRO 5 is more pleasing to the eye and Charm Blue note3 is slightly stiff.

▲ Comparison of actual picture effects (left: Meizu PRO 5；; Right: Charm Blue note3)

In the comparison of actual picture effects, the difference between NTSC color gamut appears. Obviously, Meizu PRO 5 has a bright picture impression, while Charm Blue note3 is slightly dull. And Meizu PRO 5 is much better than Charm Blue note3 in color reproduction, and the extremely high contrast also makes Meizu PRO 5 more vivid in the layering of light and dark.

Summary: It can be seen that apart from the gap in configuration, the gap between Meizu PRO 5 and Charm Blue note3 is also huge. Thanks to the blessing of Samsung AMOLED screen, Meizu PRO 5 has a huge gap in color performance, screen level and screen brightness. Charm Blue note3 shows different degrees of color cast, and the maximum brightness is higher than Meizu PRO 5, but the actual brightness is not quite satisfactory.

36 mobile phone flagship VS 36 mobile phone N4

▲36 mobile phone flagship

36 mobile phone flagship uses a 6-inch screen from Sharp, and adopts a new generation of Nega negative LCD technology with a resolution of 192×18 and a PPI of 368. It has a contrast ratio of 14:1 and an NTSC color gamut of up to 95%.

▲36 mobile phone N4

36 mobile phone N4 uses a 5.5-inch TFT screen with a resolution of 192×18 and a PPI of 43. The contrast ratio is 14:1 and the NTSC color gamut is 85%. The unique intelligent dynamic adjustment technology is adopted, which can adjust the brightness and contrast of the screen in real time.

▲ solid color contrast (left: 36 mobile phone ultimate edition; Right: 36 mobile phone N4)

As a thousand yuan mobile phone with the highest cost performance, the screen performance of 36 mobile phone N4 is equivalent to that of its own flagship version of 36 mobile phone, and there is no big difference in the comparison of three primary colors or black and white. However, in the pure black background, we can see that there is still a little light leakage in the upper right corner of the 36 mobile phone N4.

▲ Comparison of actual picture effects (left: 36 mobile phone flagship edition; Right: 36 mobile phone N4)

But in the actual picture display effect, we can still see some gaps between them. From the picture, we can see that the flagship version of 36 mobile phone is a little better in brightness than that of 36 mobile phone N4, and the color gamut of 36 mobile phone flagship version is as high as 95%, which makes the color expression more intense. In addition, there is no more performance on the screen.