When it comes to screen display quality, many friends may only focus on the difference between LCD and OLED panels, as well as luminous materials, resolution, refresh rate and color gamut. In fact, there are many factors that affect whether the "horizon" is wonderful or not.
Panel color depth distinguishes between native and dithery
The phone screen is made up of an infinite number of pixels, each of which forms the complete field of view we see by displaying a different color. So, how many colors can a screen display to be wonderful?
Each unit pixel has two states: light (white) and off (black), that is, 2 levels of color. However, when the pixels are quickly switched between one light and one off, the transition color between black and white is rendered - gray. Therefore, by adjusting the number of pixels to light and dark, you can control the depth of color, such as the number of light times can show light gray, the number of times to extinguish can show dark gray, by defining the number of pixels to light and dark the number of times and frequency can continue to enrich the number of color levels.
The parameter that determines the number of colors emitted in the screen panel is called "color depth", and its unit is "bit". If a pixel can display two colors, black and white, then it has 2 color scales, that is, a 1-bit color depth panel. If a pixel can display pure white, light gray, dark gray, pure black 4 colors, then it has 4 color levels, that is, 2bit color depth panel.
And so on, the calculation method of how many colors can be displayed by the x-bit color depth panel is "2 to the x power", and the 6bit, 8-bit and 10-bit color depth panels commonly found in the mobile phone field can display 64, 256 and 1024 color levels, respectively.
Whether LCD or OLED, three subpixels per RGB (three primary colors) make up a standard color unit. Taking the 10-bit color depth panel as an example, its RGB can display 1024 color levels per pixel, so the final number of colors that can be rendered is 1024× 1024×1024 total 1.07 billion colors. Similarly, the number of hair colors for the 6-bit and 8-bit panels is about 260,000 colors and 16.7 million colors, respectively.
The higher the color depth, the more color the panel produces, which means that the color transition is more natural without faults.
It should be noted that through pixel dithering technology (FRC, which is a compensation algorithm), it is possible to "6bit shake 8 bits" or "8 bits shake 10 bits".
However, this kind of "shaking" panel is definitely not as good as the "native panel" in terms of actual color scale, color number and transition effect. For example, compared to the native 10bit, 8+2bit will have a compensatory color mix, and the pseudo-color that should not appear in the raw cost will reflect the random small noise on the look and feel. Therefore, if you are particularly concerned about color quality, do not be intimidated by the so-called "10bit" panel, you need to look for "native 10bit" can be.
Color gamut standard Different display style
From the surface point of view, the color gamut and color depth are very similar, they will affect the breadth and richness of the color that the screen can display, the higher the indicator, the more vivid and full the picture, and the more natural the color transition. According to different application areas, the three major color gamut standards of NTSC, sRGB and DCI-P3 (there is also an Adobe RGB in the PC field), which overlap each other in color coverage and specialize in slightly different directions.
In general, 100% DCI-P3 color gamut > 100% sRGB> 72% NTSC.
However, they are all the same 8-bit and 10-bit panels, and whether they can get more than 100% sRGB or DCI-P3 color gamut often need to be matched with higher screen brightness to achieve. Many mobile phones in the display settings allow users to switch between different gamut standard modes, such as vivid mode is sRGB, standard mode is NTSC, movie mode is changed to DCI-P3, you can experience their own subtle differences in display style.
Differences in color accuracy test the skills of soft power
Do you think blue is blue? The color of the current display screen of the mobile phone screen is accurate, and everyone's feeling may be different. Therefore, in addition to color depth and color gamut, we also need to match a concept called "color accuracy" (also known as color aberration), whose standard is customized by professional display agencies, requiring panel or mobile phone manufacturers to spend more energy on color grading, calibrating the color displayed on the screen to infinitely close to the standard color, and achieving the ultimate goal of "what you see and get".
Color accuracy can be used "△E
Direct hit experience Refresh rate and sample rate
Higher refresh rates and sample rates have become the standard for today's mid-to-high-end phones. Their units are all "Hz", the higher the refresh rate means that the picture is displayed more smoothly, and the higher the sampling rate means that the operation is more followed, the former affects the visual experience, and the latter affects the operation feeling.
The standard refresh rate of mobile phone screens is 60Hz, and four high-resolution standards of 90Hz, 120Hz, 144Hz and 165Hz have gradually been derived. Among them, the smoothness brought by the upgrade from 60Hz to 90Hz is the most obvious, and it is difficult to observe with the naked eye beyond 90Hz. Increasing the refresh rate requires increasing the power supply to the screen circuit, and the higher this parameter, the greater the power consumption, so the vast majority of commercially available new products are capped at 120Hz. In order to achieve a super high refresh rate of 165Hz, the mobile phone represented by the Red Devil 6 has changed the video transmission interface from the traditional DHY to CPHY-DSI, and has been exclusively tuned with Qualcomm, the transmission rate has increased by 2 times, and its power consumption in 165Hz mode is even lower than that of Red Devil 5G's 120Hz mode screen display. In addition, the hardware-level variable refresh rate function of the emerging LTPO panel is also a good medicine to reduce the power consumption of high brush screens.
Some mobile phones will also have a special built-in unique chip, which can realize MEMC motion calculation and compensation technology, and can achieve higher frame rate screen output through intelligent interpolation without game manufacturer adaptation.
Screen sampling rate is for the sensitivity index of the mobile phone screen in touch operation, the higher this parameter means that the more "follow the hand" of the operation, the more "windy" the position, and the skill release "which to play".
Like the refresh rate, the standard sample rate for smartphone screens is 60Hz, and has evolved to 120Hz, 180Hz, 240Hz, 300Hz, 360Hz, and 480Hz, in addition to "instantaneous touch sampling rates" of more than 1000Hz. The level of screen sampling rate involves the quality of the touch chip, the working frequency, the firmware layer, the driver layer and the system layer and other software and hard level optimization, the higher the sampling rate, the more expensive the cost, the higher the power consumption. Gain above 240Hz perceptually will gradually decrease, and unless you're an esports enthusiast, there's no need to pursue the highest touch sample rate.
In addition to the refresh rate and sample rate, there is another technology that can further enhance the control experience, that is, "super-resolution touch technology". Take the early Redmi K40 series as an example, which used this technology to increase the touch partition of the screen from the original 2400×1080 to 19200×8640. More detailed touch partitioning means that the phone can recognize small movements of fingers, and the trajectory is smoother and more continuous when sliding the screen, and the touch operation is more precise at each step.