| 25,000 pixels per inch… Plan to develop 72K within the year
| Creating pixels 1/3 the size of existing ones using vertical stacking technology
| Securing Core Technology for 1㎛ Pitch Pixel Holograms

Domestic researchers have developed ultra-high-resolution pixel technology that increases the viewing angle of holograms. This is expected to accelerate the realization of display panels capable of playing more natural holograms and ultra-high-definition video content.

The Electronics and Telecommunications Research Institute (ETRI) announced on the 23rd that it has developed a new pixel structure technology that can significantly improve image quality with a 30-degree viewing angle by drastically reducing the pixel size and pixel spacing to the micrometer (㎛) level.

Through this, it is expected that it will be possible to develop a panel capable of achieving 72K resolution by applying the world's smallest 1㎛ pixel pitch element.

Spatial light modulation technology using liquid crystals is primarily used for holographic representation. It is a method of creating an image by applying voltage to the liquid crystal to change the phase of light.

In this case, to improve the image quality and viewing angle of the holographic image, the key is to reduce the spacing between the pixels of the elements used in the liquid crystal.

Previously, research was primarily conducted to reduce the size and spacing of pixels within a single plane, but this method has had limitations in enabling the reproduction of natural holographic images.
To solve this problem, ETRI devised a method of stacking pixels vertically instead of designing them flat.

It is a so-called vertical stacked thin-film transistor (VST) structure.

This technology minimizes the required area by vertically stacking pixel components that were previously formed on a single plane, thereby significantly reducing the pixel pitch.

The research team demonstrated that a 1㎛ pixel pitch is possible using existing TFT technology for displays.

It amounts to having succeeded in developing a structure that can drastically reduce pixel pitch without any additional processes.

In addition, through the development of a 1㎛ pixel pitch device, the resolution of current 8K UHD TVs, which has a pixel count of about 100 PPI per inch, has been made to have an ultra-high resolution of over 25,000 PPI.

In other words, it has become possible to achieve ultra-high definition of up to 250 times or more.

The development of this technology has also significantly increased the field of view of holographic images.

While existing holographic display technology has a narrow viewing angle of 2 to 3 degrees, applying ETRI's technology can achieve a wide viewing angle of up to 30 degrees.

In fact, at this Display Week conference, the research team demonstrated a scene in which a swirling shape moves in three dimensions using a 2.2-inch panel with 51 million (16,000 x 3,200) pixels.

This technology is expected to have a wide range of applications, as it can be applied not only to holograms but also to various ultra-high-resolution display fields such as microdisplays (µLED), augmented reality (AR), and virtual reality (VR), as well as to components for ultra-high-speed communication and imaging devices.

If future microfabrication technology is combined with the structural technology developed by the research team, it appears that pixel sizes exceeding the micrometer (㎛) level, reaching the nanometer (nm) level, will be achievable.

ETRI is currently developing panels applying this technology, and within the year, it will develop a 3.1-inch spatial light modulator with 72K resolution and a hologram We also plan to expand the video size to the 20-inch class based on projection technology.

If a spatial light modulator is developed, holographic images can be naturally reproduced without the need for separate optical devices to magnify the image.

We plan to move beyond the current stage of displaying only one color per element and also research the field of color holograms.

“This research result achieved a 1㎛ pixel pitch, which was previously considered an impossible goal to realize in spatial light modulators, and will make a significant contribution to the practical application of holograms,” said Hwang Chi-seon, head of the Realistic Display Research Group at ETRI.

The research team plans to prioritize technology transfer for transistor and liquid crystal technologies to display component-related companies.