我想你一切關於iPhone X等手機低頻PWM傷眼的疑問在本文都會得到解答……

03-25

如今關於低頻PWM的科普文章並不少，但我希望本文可以更直觀，更系統的介紹這一內容，我本身也曾有關於它的許多疑問，所以我會站在一個普通小白的角度從更實用的角度去介紹。

首先我相信有一定的消費者希望了解低頻PWM等的原因是以此考量是否購買iPhone X/Xs/XsMax等採用OLED屏幕的手機。

所以我想把iPhone X的屏幕優勢亮出來，我想這強大的吸引力很可能讓人們淡化低頻PWM導致的對這塊屏幕的不喜。

1.解析度2436x1125 458PPI 在智能手機中算較高的解析度和PPI，日常使用極其清晰

2. 5.8寸圓角全面屏，用白話說有三個重點

一是沒有下巴，二是邊框較窄，三是圓角弧度完美貼合邊框。

3.HDR顯示

4.原彩顯示，觀看舒適

5.相對LCD更低的屏幕藍光

6.黑色像素不顯示，黑色更深邃，整體更節能

7.P3廣色域

是不是很誘人，但我們還是要言歸正傳

這裡是Notebook check給出的關於PWM低頻調光的彙報節選

我將從中選取對消費者最直觀的核心內容摘取

The PWM brightness regulation is another typical characteristic of an OLED panel, and this is the case for the iPhone X as well. We can measure a comparatively low frequency of 240 Hz as soon as the luminance is at 50% or below. Sensitive users should get the iPhone 8 / 8 Plus with an LC display, where we did not determine PWM. In addition to the 240 Hz PWM, we can also measure a slight flickering at 60 Hz (see screenshots below) at higher brightness levels (even at the maximum).

這段話總結的核心是

「當亮度在50%或更低時，可測得頻率240 Hz」

Screen Flickering / PWM (Pulse-Width Modulation)
To dim the screen, some notebooks will simply cycle the backlight on and off in rapid succession - a method called Pulse Width Modulation (PWM) . This cycling frequency should ideally be undetectable to the human eye. If said frequency is too low, users with sensitive eyes may experience strain or headaches or even notice the flickering altogether.

這段話有兩個重點

一是理想情況下，這種循環頻率應該是人眼無法察覺的。也就是PWM並不是應該一棒子打死，不要看到PWM就立馬臉黑，只是目前240hz不夠高。

二是如果頻率過低，眼睛敏感的用戶可能會感到緊張或頭痛，甚至會完全注意到閃爍。這點直接表明了PWM低頻調光的壞處。

Screen flickering / PWM detected 240 Hz ≤ 100 % brightness setting
The display backlight flickers at 240 Hz (Likely utilizing PWM) Flickering detected at a brightness setting of 100 % and below. There should be no flickering or PWM above this brightness setting.
The frequency of 240 Hz is relatively low, so sensitive users will likely notice flickering and experience eyestrain at the stated brightness setting and below.
In comparison: 52 % of all tested devices do not use PWM to dim the display. If PWM was detected, an average of 9330 (minimum: 43 - maximum: 142900) Hz was measured.

Fast response times are another advantage of the OLED technology. The changes between grayscale and black values are faster than 2 ms, so there is no tearing or other effects on the display.
Display Response Times
Display response times show how fast the screen is able to change from one color to the next. Slow response times can lead to afterimages and can cause moving objects to appear blurry (ghosting). Gamers of fast-paced 3D titles should pay special attention to fast response times.

我之前有一個疑問

也是我在內外網多方面搜尋的一個主要目標

」既然X是低亮度時低頻，那麼多少亮度對應多少頻率呢？「

我希望有個表格幫我確定我應該在什麼亮度我的頻率是我的眼睛可以接受的，

答案是

頻閃一直是240hz

也就是跟多少亮度無關，只是低亮度人眼/手機更易察覺！

所以解決方案只能是這一種

TAG:PWM | iPhoneX | OLED |

我想你一切關於iPhone X等手機低頻PWM傷眼的疑問在本文都會得到解答……

5.這樣240Hz永遠都是滿的！