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LCD VS OLED -- Who Is The Final Winner?

From the accidental death of artist Gao Yixiang in a variety show, to the mid-life crisis where economic and physical conditions are frequent, the fast-paced modern life with increasing speed and pressure, and our own irregular habits, are slowly destroying our bodies. Today, Energy Jun wants to talk to you about health.


Since we are a technology media, we must talk about health and technology together. Here, we're going to start with the mobile phones that you almost never leave behind and talk about the differences between these two popular screens from an eye health perspective.

Of the three iPhones released by Apple this year, only the iPhone 11 uses an LCD screen, while the remaining two Pro models use OLED screens. Not only the iPhone, but also many Chinese mobile phone manufacturers have used OLED screens in their flagships this year, and as far as we can see, OLED basically rules the mid- to high-end mobile phone market.

Many LCD party shouted "OLED blind screen, LCD will never be a slave", which attracted the attention of the Energy Jun, searched the Internet, for Apple's first product with OLED screen, the iPhone X in the online evaluation of the general not very good.
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The culprit for why OLED is called a blind screen is strobe, or more precisely, the fact that its dimming method is fundamentally different from that of LCD.

Strobe is very common in life, mobile phone strobe, LED lamp strobe, monitor strobe, etc. Occasional strobe is not harmful to the human eye, but if you are in this environment every day, the long-term damage to the eyes is very big.

So what is the damage of strobe to the eyes?

The retina of an organism is capable of distinguishing and responding to light at frequencies of 100-160Hz, and in some cases up to 200Hz. The damage it can do to the human body can produce headaches, migraines, fatigue, increased eye pressure, reduced visual efficacy of the eyes, visual fatigue, distraction and neurological problems, and can also cause brain damage.

In the alternating current 50Hz frequency, domestic general lamps and lanterns strobe frequency of 100Hz, measuring lamps and lanterns strobe percentage below 3.2%, is no strobe hazard limit range; of course, as long as the strobe percentage in 8% of the low risk range, lamps and lanterns strobe is a safe range, if higher than 8%, the lighting products can be regarded as unsafe.

Current mobile phone screens with PWM dimming have a flicker frequency of around 200-300Hz, which is too far from the pass mark.

OLED strobe is caused by PWM dimming, while LCD is DC dimming. DC dimming is based on the principle of continuous lighting, which improves the screen brightness by increasing or decreasing the power, so changing the voltage or current will improve the screen brightness. Therefore, DC dimming is strobe-free.

PWM, on the other hand, relies on the screen alternating between light and off to improve the screen, and as long as the alternation is fast enough, the naked eye thinks the screen is always on.

So can you make OLED screens without PWM dimming?

Many domestic manufacturers have also seen the damage caused by PWM dimming to the human eye, so the OLED DC dimming function was introduced, but unfortunately, these can only be referred to as DC dimming, and not true DC dimming, only to a certain extent to alleviate the damage caused by strobe, treating the symptoms rather than the root cause.

Don't scold the mobile phone manufacturers for not giving a damn, this pot is mainly caused by the immaturity of the upstream screen manufacturers OLED technology, because the rapid screen flicker will significantly shorten the life of the mobile phone screen, leading to screen burn, and make the power consumption greatly increased.

So is a DC-dimmable LCD less harmful to the eyes?

For those who insist on LCD, don't immediately feel that LCD has "turned over a new leaf", you may need to wear a pair of powerful anti-blue light glasses when using the phone, because the amount of blue light on LCD screens is higher than OLED, but as long as your anti-blue light glasses are powerful enough, the damage to your eyes can be reduced to a great extent.

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