The most fatal shortcoming of iPhone 13
To talk about the hottest digital news recently, it must be about the unboxing and review video of iPhone 13 series. Although every year everyone says how small the iPhone upgrade, but after each release is said to be a crazy rush again and again, this year’s iPhone 13 is no exception.
This year’s iPhone 13 brings smaller bangs, 120Hz adaptive refresh rate screen, powerful A15 processor and imaging system, etc. Many digital bloggers have also praised it.
But many users found a fatal drawback of iPhone 13 after receiving the goods to use, that is, full brightness PWM dimming, what is the impact? Simply put, it is easy to hurt your eyes. Here are a few aspects of this matter.
Why do you say iPhone 13 is PWM dimming?
Because in the video published by the netizens, it is obvious to see that no matter what brightness, the iPhone 13 screen will have a vertical stripe (camera shot, the naked eye can not be observed), this screen dimming method is often said to be PWM dimming.
What is PWM dimming?
At present, the main types of dimming for cell phone screens are: DC dimming and PWM dimming.
The principle of DC dimming is simple, it is to change the brightness of the screen by increasing or decreasing the power of the circuit. Power = Voltage x Current, so changing the voltage or current can change the screen brightness. This means that regardless of low or high brightness, your screen is always on.
And PWM dimming is different, it is through the pulse backlight on the light to adjust the screen brightness, some people will ask, the backlight off a little not to see, because the human eye has a visual temporary effect, as long as the switch speed quickly our naked eye can not see.
The difference between DC and PWM?
Say a simple example, when you look at a flashlight, DC dimming is equivalent to the flashlight is always on, while PWM dimming is someone else has been switching, so is it easy to distinguish. Only on the phone screen, the switch is fast, our naked eye can not detect.
What are the dangers of PWM?
Know the difference between the two, then in the end which is better? The answer is better DC, PWM dimming will cause damage to the eyes, simply put, is the frequent flicker, will cause eye fatigue, resulting in the attenuation of vision, serious headaches and other problems may arise. And DC dimming will not have this problem.