Why should it be OLED, for the Flexible Display?
Recently, we are seeing smartphones, PCs, and TVs with curved displays being continuously introduced one after another. Driven by the expertise of LG Display and LG Electronics, ‘LG G Flex’, a 6-inch curved-screen smartphone curved horizontally, was introduced at CES 2014 and was brought to the attention of a large group of audiences.
So, what is the secret behind the flexible or curved design, free from an ordinary shape of a smartphone or TV? The answer is ‘Flexible Display’ technology. Today we will look into ‘OLED Flexible Display’ that came into spotlight, as the most optimal display to implement flexible display technology.
What is Flexible Display?
First and foremost, Flexible Display refers to the form of display that can be bent freely in any way possible. The reason why the display does not crack or break is because a type of plastic substrate that can be bent freely is used, instead of the commonly used stiff glass substrate.
OLED self-emits when an electrical current flows into it, eliminating the need for backlight to provide light. So compared to conventional TFT-LCD, it has an advantage in achieving much thinner and lighter flexible display.
How about Curved OLED TVs? LG Display not only produced the panel for flat OLED TVs for the first time in the world, but also proved to be the leader in the OLED TV industry with the world’s first 55-inch Curved OLED TV released in May of 2013.
Curved OLED TVs refer to the curved form of a TV, which the ends are curved towards the viewer. This opens a whole new era of TV, following the era of CRT with a convex surface bulged out in the middle, and the era of flat screen LCD display.
The New Awe-Inspiring Curved OLED TV for Truly Immersive Experience
Due to its curved design, Curved OLED TVs have several advantages. First of all, the biggest characteristic of the Curved OLED TV is its ability to enhance the viewer’s immersive experience with its curved form. Because the screen ‘wraps around’ the viewer, the viewer gets the feeling of stability and being immersed in the image as if he/she is at the amphitheater.
The curved form of the screen is similar to the ‘Horopter Line’ seen by human eyes. The ‘Horopter Line’ refers to the hypothetical line connecting the dots one sees as being in the same focal distance when our eyes focus on an image.
This means that curved OLED TVs have a screen with a curved trajectory similar to a person’s ‘Horopter Line’ allowing the maintenance of a constant focus, and because of this, the viewer can enjoy more comfortable viewing without tiring their eyes.
Second, the distance of viewer’s gaze between the center of the screen and each end of the screen isn’t steep due to the gradually curved form of the Curved OLED TV. For example when watching a flat screen TV, the viewer’s gaze when sitting in front of the center of the screen would require more distance when watching each ends of the screen, compared to the middle of the screen.
The viewer will not sense a big difference because he/she sees the center and end of the screen at the same time, but in reality, there is a subtle distortion of image and color due to this distance. The larger the screen and the closer the distance from the screen, the distortion becomes more noticeable.
In comparison, for Curved OLEDs, the center of the screen that is closest to the viewer’s eyes is pushed back and the farthest ends of the screen are bent forward, the distance between the viewer’s eyes and every point of the screen can be maintained almost the same!
Because of this, we can enjoy more realistic images without color or image distortion. This difference in the form also affects the expression of 3D images. In case of Curved OLED TVs, the user can enjoy more realistic and comfortable viewing of 3D images since the 3D depth at any point of the screen is the same, as the distance between the user’s eyes to the any point on the screen is also kept the same.
Thirdly, Curved OLEDs compared to flat screen TVs of the same size feels larger and brighter, resulting in the immersive experience similar to that of the movie theater. Though the sizes may be the same, a curved screen offers a larger viewing angle than a flat screen, and therefore, the viewer will feel that the size of a curved TV screen is larger than its actual size. Curved OLED TV also feels brighter because the light coming from the screen is focused on the center of the screen.
Design Innovation in Curved OLED Smartphone
When curved OLED technology is applied, versatility in design is possible for smartphones as well. Curved design can heighten comfort for users like that of a wire telephone, and also enhance immersive experience for game playing or video viewing.
LG Display developed a flexible OLED panel using plastic for the first time in the world last October. Plastic substrate was used instead of glass in 6 inches, biggest in OLED panel market for mobile.
While smartphones have always stuck to the same rectangular shape, this curved OLED smartphone is curved vertically by 700mm, bound to spearhead new design revolution in smartphones. It boasts world’s thinnest glass thickness of 0.44mm, 1/3 of traditional smartphone glass, and also the lightest, with mere 7.2g in weight!
The Future of Flexible Display
We fully expect flexible display to bring lifestyle innovation in not only mobile, but also various areas such as safety imperative built-in displays in vehicles, tablets, PCs, and smart-watches. We also look more forward to LG Display’s innovative moves coming ahead.
In March of 2012, LG Display was the first to develop and produce electronic-ink-based Plastic Electronic Display(EPD), and it has also succeeded in being the first to produce the largest size plastic flexible OLED. By introducing for the first time to the world a 55-inch Curved OLED TV, it is leading the flexible display technology in both small and large sizes.
Currently, transparent•flexible display development with a consortium of 36 companies is underway as a national project, and a separate research is also ongoing with the aim to develop 55-inch and 75-inch transparent flexible displays in 2016 and 2017, respectively. We look very much forward to the next level of lifestyle innovation by this development of innovative flexible display technology.