[Smart Electronics Story] 'Iron Man' Movie Becomes Reality... 'Transparent Display'

‘Agile Electronics Stories’ is a corner that keenly examines small details about electronic and mechanical products and devices. We kindly cover everything from hot new products frequently appearing in advertisements and news, to nostalgic items, and puzzling product and industry terms and news, all with the heart of a beginner.

Displays are evolving into various forms such as foldable, rollable, and stretchable types. Both the space behind the display screen and the visible display itself have been under development for over a decade.

If you imagined a scene like Tony Stark, one of the Marvel heroes, interacting with images or blueprints floating on glass behind his Iron Man suit, then you are thinking of the right display. That screen is called a ‘Transparent Display.’ In this edition of ‘Agile Electronics Stories,’ we have prepared a time to organize the principles and applications of transparent displays.

What is the principle of a transparent display that can be seen from both the front and the opposite side?

Smart Bed Equipped with Transparent Popup Display

[Photo by LG Display]

A transparent display refers to a display that shows various information on a panel that allows light to pass through. It is broadly divided into projection type and transmissive type.

The projection type works on the principle of projecting light from a beam projector onto glass or the eyeball, while the transmissive type controls light passing through (transmitting) liquid crystals to display images. Projection types have mainly been developed for aircraft, vehicles, or glasses-type displays, while transmissive types have mainly evolved into LCD and transparent OLED forms.

Transparent displays appeared a few years ago in LCD form and are already in use in our society. The most important factor in transparent displays is transmittance. For cars and sunglasses, films are attached to glass or lenses, which lowers sunlight transmittance, making it difficult to clearly see the displayed images. Existing transparent LCDs also have limitations because their LCD structure causes light transmittance to drop to 10-20% due to backlight, liquid crystal, and color filters.

Therefore, display companies are developing products with higher transmittance using organic light-emitting diodes (OLEDs) that emit light from each pixel without backlight. Currently, Samsung Display’s transparent display is known to have a transmittance of about 45%, similar to glass, and LG Display is also developing technology to secure transparency reaching 50%, up from the existing 40% range.

Endless applications... Where can it be used?

LG Display recently supplied transparent organic light-emitting diode (OLED) displays for windows to the Beijing and Shenzhen subways in China.
[Image source=Yonhap News]

It’s fascinating, but where can it be used? The application fields of transparent displays are vast enough to be used anywhere displays are involved, such as information delivery, commercial advertising, TVs, and smartphones.

Transparent displays, once installed in department stores and exhibition halls, are now also installed in public places such as aircraft and subways. The most eye-catching example was the transparent OLED displays installed on windows in subway cars in Beijing and Shenzhen, China. Subway passengers can check operation information, flight information, weather forecasts, and more on these transparent OLED windows. This display was the first to be introduced in subway cars and was supplied by the Korean company LG Display.

Companies are integrating augmented reality (AR) technology to deliver more vivid information outdoors. Moreover, combining what display and home appliance companies have revealed and demonstrated, it seems the era of decorating homes like movies with AI dedicated to home appliances and transparent OLED displays is approaching in the near future.

Rendering image of Samsung Electronics transparent smartphone released by Dutch IT media LetsGoDigital

Furthermore, transparent display-equipped smartphones are also highly anticipated. While existing smartphones have been developed focusing on performance, image quality, and cameras, now the evolution of display forms is underway. Samsung Electronics is reportedly developing smartphones applying transparent displays following foldables. They have registered related patents. Additionally, the Dutch IT media LetsGoDigital has released rendering images of Samsung’s transparent display smartphone.

The transparent display market size is also expected to grow steadily. According to the global consulting firm Prescient & Strategic Intelligence, the transparent display market is projected to grow at an average annual rate of 46%, expanding to $4.933 billion (approximately 6 trillion KRW) by 2024.

This content was produced with the assistance of AI translation services.