IT Home February 20 news, according to IT Home netizens contributed, recently one plus 8 Pro and one plus 8T ushered in the ColorOS 12 beta version update, the main content is the addition of low brightness no stroboscopic eye protection (DC dimming) function.
IT home learned that the original DC dimming one plus 8T update Color OS 12 after the DC dimming function is missing, the official did not explain the reason.
It is reported that the current mainstream PWM dimming and DC dimming are a way to adjust the brightness of the screen. PWM dimming is to change the brightness of the screen by alternating between light and off of the screen. Why is it that when the screen brightness is adjusted, the mobile phone is always on? That's because the alternation of light and extinguish is fast enough, beyond the range of human eye perception. The longer the off-screen state lasts, the lower the screen brightness; conversely, the longer the screen time, the screen will become brighter, which is often referred to as stroboscopic. However, the sensitivity of different people's eyes to the screen alternately illuminated and extinguished is different, some people are more sensitive, encounter low-frequency PMW dimming screen, there will be eye discomfort, serious may be dizzy, nausea.
DC dimming is to change the screen brightness by increasing or reducing the circuit power, power = voltage x current, so changing the voltage or current changes the screen brightness, and the dimming process is softer. Although DC dimming can alleviate the fatigue caused by the human eye looking at the mobile phone for a long time, it is more friendly to users who are more sensitive to low-frequency PWM dimming, but this scheme is not 100% perfect, DC dimming is easy to appear in low brightness Color uneven "rag screen" phenomenon, very low brightness loss of dynamic range and resulting in poor color uniformity.
OnePlus Technology Zhang Xuan (Weibo ID: Acid Digital) once said on Weibo that after the DC dimming was turned on, it brought many new problems to the manufacturer's screen after-sales and quality reputation, which is an important reason why the manufacturer has removed this switch and no longer supports it.
According to OPPO ColorOS engineers previously introduced, OPPO's DC dimming is different from other manufacturers, which adopts the method of "mask dimming" + "dither smoothing", by calling the Internal Qualcomm Snapdragon Platform - Snapdragon Display Engine Layer Mixer function, plus Dim Layer and other layers for transparent mixing processing, and finally the content brightness of the entire picture has been effectively reduced, and similar DC has been retained The effect of dimming mode. In addition, OPPO also continued to explore the backlight system, and finally came up with three optimal value coefficients, which finally solved the problems of color inaccuracy, flashing white light, and unstable brightness values. While protecting the eyes, it maximizes the display effect of the screen.
