In February last year, we sharply evaluated the strobe situation of some mainstream manufacturers, although high-frequency PWM dimming had basically become the standard configuration of mobile phones at that time, but the experience between them was quite different, and it was more clear that with high-frequency PWM dimming, it could not be equal to mobile phone eye protection.
In 2024, the quality, parameters, and functions of domestic mobile phone screens have made great progress. With the change of screen function, the previous relative strobe scheme has changed significantly, and the strobe scheme of mobile phones at different prices is also different.
The correct way to open the strobe
If you are sensitive to strobe, you should avoid using your phone when walking, running, taking the bus, or other scenarios that make your body shake.
Because in this scenario, the screen shake will make you unconsciously increase the speed of eye movements, forcing yourself to see the screen clearly, just like a mobile phone focusing, but the more you focus on the content on the mobile phone screen, the more it will aggravate the negative effects of stroboscopy.
In addition, when looking at mobile phones, such as playing games, reading e-books, chatting, or processing some text content on mobile phones, it is recommended to maintain appropriate screen brightness and ambient brightness, because the strobe of domestic mobile phone screens in medium and high brightness is very small to human eyes, which is why it is often seen that some people suggest turning on a desk lamp when looking at mobile phones at night. Of course, high-frequency PWM dimming is generally used at low brightness, and the damage to the human eye is relatively small.
But this suggestion is not useful every time, if you use a mobile phone is full brightness low-frequency PWM dimming, such as iPhone, SamsungS24, S23 series, even if the screen and ambient brightness are very high, its strobe is still more harmful, unless you change the phone, otherwise it makes no sense to turn on more lights when watching at night.
So according to the current strobe pattern of smart phones, what are the strobe strategies, and which strategy is the least harmful to the human eye?
There are many solutions to the strobe
At present, the more common practice of flagship machines is three-pulse DC dimming. Before talking about this dimming scheme, we must first understand 8T LTPO, which appears at the same time most of the time.
Perhaps it is the poor energy efficiency performance of the Snapdragon 888 and the first-generation Snapdragon 8 that has largely overshadowed the advantages of LTPO, and has become synonymous with unprotective and unsmooth eyes in our eyes, which has also affected the reputation of today's 8T LTPO. In fact, as a new generation of LTPO, it is not the product of some compromise.
8T LTPO refers to the "8T" refers to the 8T1C drive pixel circuit design, compared with the past use of 7T circuit, it is equivalent to the entire screen circuit completely opened, and the electrical performance has been further improved.
The screen driver will be reset three times periodically, with a reset frequency of 360Hz, so as to achieve the effect of smoother screen switching and lower screen shake of flagship phones. In addition, the 8T LTPO improves brightness fluctuations and display abnormalities caused by switching frequencies at low brightness.
At present, most flagship mobile phones on the market, such as Huawei Mate60 Pro, Honor Magic6 Pro, OPPO Find X7 Ultra, OnePlus 12, etc., use LTPO models, and use this LTPO circuit scheme.
In order to give full play to the full performance of 8T, the best way is to do more fine frequency conversion through multi-pulse and more frequency modulation gears brought by it, and at the same time pay attention to the eye protection effect, which is implemented into the product is three-pulse DC dimming. For mobile phones with 8T LTPO, this is a solution that can take into account smoothness, power saving, and eye protection, which fills the shortcomings of Apple's and Samsung's LTPO solutions.
However, some users use a high-shutter camera to shoot this dimming scheme, and they will find that it has a lot of black bars, and it is even a bit similar to low-frequency PWM dimming, which has a psychological effect. Or the body feeling is indeed not as comfortable as the previous single-pulse DC dimming, and problems such as eye soreness and eye swelling begin to appear, and then the conclusion of "eye protection effect regression" is drawn.
In fact, the current mainstream 240Hz/360Hz three-pulse DC dimming scheme is not the root cause of poor strobe performance, if you also encounter similar problems, the main reason is that the actual duty cycle and fluctuation depth of the screen are not good.
Take OnePlus 12 as an example, it uses 8T LTPO, medium and high brightness is three-pulse DC dimming, and the duty cycle can be close to 93%, which is a very high level. Because the duty cycle is larger, the depth of fluctuations at lower brightness is also lower, and the strobe performance is therefore better, for example, at ultra-low brightness of 6 nits, the SVM value enters 0.4 for the first time (no flicker hazard), and 80nit is only about 0.21, and then slowly decreases as the brightness increases.
At present, the mobile phones on the market that use three-pulse DC dimming can basically achieve a duty cycle of 92% to 93%, which is obviously much better than the previous generation, which is generally lower than 85%.
Starting from the perception, because they all belong to the three-pulse DC dimming, and the difference in value between each other can only be recognized by the machine, if you think that the look and feel of a certain three-pulse DC dimming mobile phone is good, or you don't feel it, then look at other brands of the same plan mobile phone The feeling is similar, and the naked eye can not see the difference.
But if you start from the technical principle, then there are still some differences between the three-pulse DC dimming, such as OPPO, OnePlus, and realme's flagship mobile phones, which are 120Hz Reset + 2 additional EM pulses combined to form a three-pulse DC, and most of the other brands are 360 Reset.
This is also why, only a few models such as OPPO Find X7 Ultra, OnePlus 12, and Realme GT5 Pro can provide a single-pulse DC dimming option, but the expression is different, such as OnePlus 12 with bright eyes and eye protection turned off, which is a single-pulse DC. On other brands of mobile phones, consumers have to choose between three-pulse and single-pulse DC dimming schemes.
Therefore, 360Hz three-pulse DC dimming and 8T LTPO are not equal to blindness, nor is it a regression of eye protection, it is currently a solution that takes into account LTPO smoothness, power saving and eye protection, and the disadvantage is that the cost is high, the yield is low, and most of them appear on flagship mobile phones.
But it should also be noted that some users are not so comfortable looking at such a screen, this is because the 360Hz three-pulse DC dimming is compared with the previous 120Hz-like DC, and the latter's ultra-high altitude proportion is indeed relatively more friendly to the human eye. If you prefer the latter, there are also flagship phones currently using this solution, such as the Xiaomi 14 series.
左:小米14 Ultra 右:小米13 Ultra
Xiaomi Mi 14 Ultra continues to be tuned on the basis of the Xiaomi Mi 14 Pro 120Hz single-pulse DC dimming scheme to achieve a higher empty ratio, and the eye protection effect is better than that of Xiaomi Mi 14 Pro and Xiaomi Mi 13 Ultra, and the empty ratio has been significantly improved. Therefore, it has a clear strobe advantage when comparing three-pulse DC mobile phones. And because it is a flagship machine, the software and hardware are optimized in place, so some shortcomings of single-pulse DC, such as the dynamic refresh rate change is not smooth enough, etc., are not obvious in it.
If the mobile phone does not use LTPO, then it is generally 120Hz single-pulse DC dimming, which is also DC-like dimming in consumer perception. However, now there is another solution that is beginning to be used by more and more mobile phones, that is, full high-frequency PWM dimming.
Before, we talked about high-frequency PWM, which generally refers to the cut-off point of the mobile phone's brightness of about 80nit, and the downward part is high-frequency PWM dimming, while high brightness is not. From this point of view, it is probably understandable why some mobile phones advertised high-frequency PWM dimming last year, and the medium and high brightness turned out to be low-frequency PWM dimming that hurts the eyes.
Full high-frequency PWM dimming refers to the lowest brightness of the screen to the highest manual brightness, all high-frequency PWM dimming, on behalf of the earlier OPPO Find X6 Pro, which has now updated the function of iQOO Neo9 series, iQOO 12 series, vivo X100 series, and the inner screen of the vivo X Fold 3 series is also expected to be realized in the future.
Medium and high brightness is still high-frequency PWM dimming
It is worth noting that full-high frequency PWM dimming does not rule out the possibility that it will become the best solution for most 8T LTPO mobile phones in the future.
As mentioned above, the current OLED mobile phones on the market generally have high-frequency PWM dimming for low brightness, and DC-like dimming for medium and high brightness, which involves the problem of screen debugging strategy switching, and even users need to re-adapt to the screen state under different brightness.
Full high-frequency PWM dimming does not have this problem, no matter what brightness and strobe conditions are the same strobe scheme, a debugging strategy.
Secondly, a series of features such as dynamic refresh rate adjustment, refresh rate switching, improvement of low-brightness display and brightness fluctuation of 8T LTPO can be retained under the condition of full high-frequency PWM dimming, and the relevant adjustment strategy does not need to be changed, and the possibility of switching strategy BUG is much smaller.
Finally, when the high-frequency PWM dimming frequency is high to a certain extent, such as 2160Hz, the SVM value can be within 0.1, which is much lower than the single-pulse DC dimming favored by many strobe-sensitive people. Generally speaking, it is best to control SVM within 0.4, and it is best to keep it within 0.2 for people who are sensitive to strobe.
It is precisely because of this advantage that full-high frequency PWM dimming is a promising strobe scheme. But then the question arises, since it's so good, why not use it earlier?
The main reason is the high power consumption. In the first two years, the energy efficiency of the processor used by the domestic camp was not ideal, and the full high-frequency PWM dimming on the brainless will only amplify the problem of high power consumption. But now the situation has changed, and domestic mobile phones can use energy-efficient processors such as the second-generation Snapdragon 8, third-generation Snapdragon 8, and Dimensity 9300, and at the same time, they can also be stuffed with ultra-large-capacity batteries in a limited body, creating a good prerequisite for its use.
Secondly, under full high-frequency PWM dimming, it is impossible to give a single-pulse DC dimming option, but now that the former has made a better eye protection effect than the latter, it is not so meaningful.
If you are more sensitive to strobe, 120Hz single-pulse DC and full high-frequency PWM dimming are relatively good choices, but the latter is not yet a lot of mobile phones, but with the deepening of research, there will be more and more mobile phones with such strategies as sampling.
Compared with the previous few years of "mobile phone strobe is metaphysics", now strobe has become a non-negligible quantifiable parameter affecting visual fatigue, and the progress of related technology and cognition is not insignificant, which is really good for our users.
How to choose an "eye protection mobile phone"?
To be clear, whether you're sensitive to strobe or you're not sure if you're susceptible to strobe, I recommend choosing a phone with better strobe performance.
Recommended Xiaomi 14 series (especially Xiaomi 14 Ultra), Xiaomi 13 Ultra, Redmi K60 series, Redmi K70 series, Xiaomi Civi 4 Pro, Redmi Note 13 Pro series, OPPO Find X7 Ultra, Huawei P60 series, Huawei nova12 Pro/Ultra, Huawei Mate X5 (12GB version), Huawei Mate X3, OnePlus Ace 3V, iQOO 12 series, iQOO Neo9 series, vivo X100 series, OnePlus Ace3, etc.
Basically, the current main models of domestic brands are excellent in terms of strobe, and some mobile phones that use three-pulse DC dimming, such as Honor Magic6 series, Huawei Mate60 series, etc., it is recommended to go to the store to actually experience it and confirm whether you can accept it.
OPPO Find X7 Ultra, OnePlus 12, and Realme GT5 Pro are also three-pulse DC, but because they provide a single-pulse DC dimming option, while vivo X100 series, iQOO 12 series, and iQOO Neo9 series push a full-frequency PWM dimming option, remember to turn it on in developer mode after updating, so don't worry about the strobe problem caused by LTPO.
A good screen is always the next piece
No!
There are many strobe schemes of domestic manufacturers, and the realm of vitality and competition of all things is still in front of you, with 360Hz three-pulse DC, 120 single-pulse DC, and full-high-frequency PWM dimming...... These refinements have not yet had a crushing advantage, and there are still variables between them, which means that there is still room for improvement.
Just like will one day, LTPO will become synonymous with "eye protection", although the strobe scheme it matches is not good enough, but it is much better than the first generation of LTPO, and the strobe performance will continue to improve after that.
I think there is no so-called end to the progress of screen eye protection technology,There may be more demand in the future,And based on this,Constantly push back technological progress,So for screen manufacturers,Mobile phone manufacturers,And consumers who use mobile phones every day,A good screen is always the next piece。