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OLED Display earns Industry’s First “Circadian Friendly” Certification

Jul 20, 2023

A TÜV-certified Display for Undisrupted Sleep Circadian Friendly Display

A woman is sleeping with a slight smile on her bed, and an OLED logo is seen in the bottom right of the picture.
Circadian Friendly Certification Logo from TÜV Rheinland
TÜV Rheinland’s “Circadian Friendly” Certification (* Applies to 27" & 65" OLED panels only)

In these modern times, we are bombarded by a multitude of distractions that disrupt our sleep, causing our circadian rhythm, including our sleep habits, to go increasingly haywire. In particular, the light emitted from TVs or smartphones that we use before we fall asleep is known to be the greatest factor that disrupts healthy sleep cycles and circadian rhythms.

LG Display’s OLED TV and monitor panels have recently received TÜV Rheinland’s “Circadian Friendly” certification, which officially acknowledges OLED displays as a human-centric technology that minimizes adverse effects on the viewers’ circadian rhythms.

It was the first time that TÜV Rheinland, a world-renowned German company for safety and quality certification, certified a display panel as “Circadian Friendly”. Let’s examine how OLED displays were able to receive the industry’s first “Circadian Friendly” certification after defining what exactly circadian rhythms are.

What are Circadian Rhythms?

In order to adapt to a 24-hour day and night cycle, we have a biological pattern that optimizes our body by adjusting functions such as hormones, body temperature, and blood pressure. This biological pattern is called the “circadian rhythm”. For example, our bodies secrete cortisol to wake us up in the morning and increase melatonin levels at night to induce sleep.

Graph indicating changes in the body's melatonin and cortisol hormones over time of day
Circadian Rhythm - Daily Cortisol & Melatonin Cycles

The key element for circadian rhythm is light. When external light passes through the retina, it is delivered to the suprachiasmatic nucleus(SCN) for the regulation of circadian rhythm. When we are exposed to artificial light via electronic devices at night, our brains interpret this as natural light, in turn affecting our circadian rhythm. The ensuing suppression of nighttime melatonin may disrupt our sleep quality, causing insomnia, depression, malignant tumors, and a myriad of other diseases.

OLED, Achieving the Highest “Circadian Friendly Level (CFL) 1”

TÜV Rheinland certifies products that minimize their adverse effects on daytime activities and nighttime sleep quality while still providing superior picture quality. The basis of the rating is evaluated by undergoing rigorous testing based on a “Circadian Stimulus” metric designed by the Rensselaer Polytechnic Institute’s Lighting Research Center in the USA.

OLED has been proven to have fulfilled the criteria for the highest rating of CFL 1 (Circadian Friendly Level) in relation to color temperature and visual quality deviation that affect melatonin levels.

Yoon Soo-young, CTO at LG Display receives Circadian Friendly certification from Frank Holzmann at TÜV Rheinland.
Yoon Soo-young, CTO and Executive Vice President at LG Display receives Circadian Friendly certification from Frank Holzmann, Global Business Field Manager at TÜV Rheinland.

TechRadar, the UK-based technology magazine, commented, “While not watching TV before bedtime is the best option, “Circadian Friendly” certified LG Display OLED would be the next best choice in your bedroom.”

“LG Display's self-emissive OLED TVs and monitors are the world's first displays to get the 'Circadian Friendly Level (CFL) 1', certification's highest rating, which means they're less disruptive on your biological clock than others.”

- Watching TV before bed isn’t great, but it’s okay if you have an OLED

OLED for Health and Picture Quality

LG Display's OLED display closely mirrors natural light and is widely recognized for emitting the lowest blue light level in the industry, proven by receiving the industry’s first Eyesafe® certification. The self-lit OLED display’s strengths such as high contrast ratio, color expression, and high luminance have been further validated by its minimal effects on eye health and circadian rhythms. The only display that provides unmatched picture quality and a healthier lifestyle is OLED.

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