Shulou(Shulou.com)12/24 Report--

CTOnews.com news on December 14, Wang Teng, general manager of Redmi Market and spokesman for the Redmi brand, posted on Weibo that popular science "screen SVM":

SVM is "the certified value of the Lighting Association". Below 1 is in line with the eye protection specification, which is an index tested by the lighting industry, not an authoritative indicator in the screen field.

At present, there is no recognized test standard for screen SVM testing, which can not represent the true feeling of human eyes. At present, the values advertised by various companies are taken from their own laboratory data.

In view of the fact that competitors have been trumpeting this indicator, we announce that the OTA upgrade will be officially launched tomorrow! Keep the SVM value of K70 within 0.1! End this numbers game!

▲ CTOnews.com Picture Review: Redmi K70 Pro [chat screen SVM]

1. What is SVM

SVM is the certified value of the Lighting Association, and below 1 is in line with the eye protection specification. In the past, the lighting equipment will have the problem of frequency flicker, and it is the state that the whole face lighting is synchronous and dark.

The key points are drawn here: SVM is an indicator tested by the lighting industry, not an authoritative indicator in the screen field.

2. SVM test method

The strobe of traditional lighting is caused by the alternation of the lighting of the whole lamp bead, and the instrument measures the SVM value of the whole light. At present, the OLED screen is not bright and dark on the whole side, but based on the concept of a black bar (duty cycle) on the display line.

The difference between the visual angle of the human eye and the test angle of the measuring equipment leads to the different feeling of the actual fluctuation of the screen brightness. When the human eye looks at the screen, the viewing angle is larger, and the mobile phone can see a complete screen in the viewing angle range of 20 cm and 30 degrees from the human eye.

As shown in figure 1, due to the limitation of the measuring angle, the spectrometer can only measure the brightness change of a small area of the screen. Therefore, the reset black stripe in the high brightness range of the screen accounts for a relatively low fluctuation in the real brightness of the human eye, while for the spectrometer test, the reset black stripe area accounts for a large proportion (duty cycle), so the brightness fluctuates greatly.

The test results will vary depending on the Sensor size of the equipment itself, PIN photoelectric conversion rate, ADC sampling speed and sampling area. If the detection area is larger, the influence of reset black stripes will be smaller. In addition, this phenomenon will be magnified in PWM mode.

Let's make another point here: there is no recognized test standard for screen SVM testing, which can not represent the true feeling of human eyes. At present, the values advertised by various companies are taken from their own laboratory data.

3. The practice of Redmi

Under the measured DC dimming mode, the red rice K70 and K70 proline 60Hz SVM:0.18/ 120Hz SVM:0.17 are much less than the screen flash risk standard. In fact, there is no strobe effect on the human eye.

In view of the fact that competitors have been trumpeting this indicator, we announce that the OTA upgrade will be officially launched tomorrow! Keep the SVM value of # k7 within 0.1! End this numbers game!

At the same time, tomorrow @ Calvin_ Wu Cangzhi will lead our display team to hold # Castle Peak Eye Care # Technical Forum with Sun Yat-sen University Eye Center to explore how to do eye care from a more scientific "integration of doctors and workers", rather than non-industry standard parameter competition, let alone regulating metaphysics such as melatonin. I will continue to share with you tomorrow.

Related reading: "Redmi Wang Teng added: competitors' new products have" some user complaints "in terms of" screen display consistency ".

"in response to one plus, Xiaomi Wang Teng popular science screen brightness: competitors reflect" product power first "by forcibly pulling parameters."

Li Jie responded to the "gap" and "dispensing" of one plus 12 mobile phones: it is not a quality or design problem, open a green channel for return and exchange. "

"Xiaomi Lu Weibing evaluation" gap "" dispensing "accident: the quality standard is looser than Redmi, and the width of" gap "meets its internal quality control standard.

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