Samsung Display was currently focusing on securing the screen uniformity of its quantum dot nanorod LED (QNED) display panel, as it wraps up development, market research firm UBI Research said on Friday.
The research firm unveiled core patents filed by Samsung Display it found, which shows the structure of QNED display panels.
According to UBI Research, QNED display panel stacks quantum dot (QD) and color filter __ the color conversion layers __ as well as the nanorod LED on top of the thin-film transistor (TFT). QNED’s TFT shares the same 3T1C, or 3 transistors and 1 capacitors, used in large OLED panels.
The difference between QNED and OLED is that, while OLED has the electrodes, both cathode and anode, and the electrode line located on top of and below the light emitting materials, QNED has the pixel electrodes and electrode lines located on the same plane, the research firm said.
QNED also has an additional reflective electrode to increase efficiency of light output. Pixel electrodes also acts as alignment electrodes for the nanorod LED, UBI Research said.
UBI Research explained further: In a QNED pixel, multiple pixel electrodes are also connected serially. Nanorod LEDs are positioned between these pixel electrodes. These pixel electrodes are also on the pixel walls made out of insulating materials. Each pixel is surrounded by banks to separate regions.
The core technologies in QNED that were noticeable were those for driving and sensing, the research firm said.
Samsung Display’s QNED includes driving techniques for aligning the nanorod LEDs and uniform pixel controls for ones with different number of naonorod LEDs.
The alignment circuit has switching devices for each pixel. These switching devices sends a signal on the alignment status to the pixel. These signals sent by pixels determine how nanorod LEDs are aligned.
On the circuit, there are transistors that approve these signals and sensing transistors that can check the alignment of the nanorod LEDs. These sensing transistors check the number of nanorod LEDs by analyzing the electric currents on the pixels.
Ultimately, after these processes, the panel supplies current to each pixel so that the luminance is uniform across the entire screen, even if the number of nanorod LEDs on each pixel are different. The current sent for each pixel is based on the data analyzed by sensing transistors.
There are also sensing technologies used in the production of QNED panels. During the inkjet process during production, these technologies sense the number of nanorod LEDs in the ink, the viscosity of the solvent, the number of nanorod LEDs sprayed on the substrate and their alignment state.
“The reason Samsung Display is developing QNED as part of its large-size display business, is that it is the only display that can produce the image quality that Samsung Display's biggest customer, Samsung Electronics, can satisfy,” UBI Research noted.
Samsung Electronics' TV business is aiming to use QD to make color gamut better than OLED, and to use a display that can maximize HDR performance with high luminance and excellent gradation characteristics on a bright screen, the research firm added.
“It can be confirmed” by the structures UBI Research analyzed that QNED is the display with the best characteristics, the firm claimed.