Japanese panel maker JDI provided insight into research and development of its OLED division on Display Week. Visitors could see ultra-high resolution 4K OLED files produced by the printing process. In this case, the printing means that the organic luminescent material is applied to the glass substrate in the ink printing process. Below is the control electronics with pixel transistors in LTPS technology (Low temperature PolySilicon).
In order to sharpen the transmitted wavelength ranges and thereby improve the colors, JOLED has provided each subpixel with micro cavities. In this is introduced the organic phosphor, which emits upwards from it (Top Emission). JOLED sets a color space of 130 percent sRGB – very rich colors so. The image content is updated 60 times per second, the color depth is 10 bits.
High-color 4K OLED in a 27-inch display; The organic material was applied to the substrate in an ink jet process.
(Image: Ulrike Kuhlmann / c. Magazine)
High-contrast 10-bit screens
Japan Display showed this technique in three examples: a 21.6-inch 4K 204-dpi display, which will achieve a contrast of 1 million to one. Also, considering its fine 10-bit color resolution, the monitor is recommended for medical assessment. In addition, a 27-inch diagonal (68 cm) monitor was seen, reaching a good 164 dpi at 4K resolution.
The printing technique should be considerably cheaper in the future than the previously used vapor deposition of organic material. That's why almost all panel manufacturers are working on this technology. To date, however, nobody uses the printing process in serial production.
JDI takes its printed 4K OLEDs, not just for flat screens, but also showed with an animated picture cylinder that the organic displays are also flexible: Thanks to the 4K resolution at 204 dpi, the images in the video were incredibly three-dimensional – you could see literally in the barrel.